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Journal of the National Cancer Institute

JNCI Journal of the National Cancer Institute - RSS feed of current issue

It is 45 years since a pleural effusion from a patient with metastatic breast cancer led to the generation of the MCF-7 breast cancer cell line. MCF-7 is the most studied human breast cancer cell line in the world, and results from this cell line have had a fundamental impact upon breast cancer research and patient outcomes. But of the authors for the nearly 25000 scientific publications that used this cell line, how many know the unique story of its isolation and development? In this commentary we will review the past, present, and future of research using MCF-7 breast cancer cells.


Background:

Many men with elevated prostate-specific antigen (PSA) levels in serum do not have aggressive prostate cancer and undergo unnecessary biopsy. Retrospective studies using cryopreserved serum suggest that four kallikrein markers can predict biopsy outcome.

Methods:

Free, intact and total PSA, and kallikrein-related peptidase 2 were measured in cryopreserved blood from 6129 men with elevated PSA (≥3.0ng/mL) participating in the prospective, randomized trial Prostate Testing for Cancer and Treatment. Marker levels from 4765 men providing anticoagulated plasma were incorporated into statistical models to predict any-grade and high-grade (Gleason score ≥7) prostate cancer at 10-core biopsy. The models were corrected for optimism by 10-fold cross validation and independently validated using markers measured in serum from 1364 men. All statistical tests were two-sided.

Results:

The four kallikreins enhanced prostate cancer detection compared with PSA and age alone. Area under the curve (AUC) for the four kallikreins was 0.719 (95% confidence interval [CI] = 0.704 to 0.734) vs 0.634 (95% CI = 0.617 to 0.651, P < .001) for PSA and age alone for any-grade cancer, and 0.820 (95% CI = 0.802 to 0.838) vs 0.738 (95% CI = 0.716 to 0.761) for high-grade cancer. Using a 6% risk of high-grade cancer as an illustrative cutoff, for 1000 biopsied men with PSA levels of 3.0ng/mL or higher, the model would reduce the need for biopsy in 428 men, detect 119 high-grade cancers, and delay diagnosis of 14 of 133 high-grade cancers. Models exhibited excellent discrimination on independent validation among men with only serum samples available for analysis.

Conclusions:

A statistical model based on kallikrein markers was validated in a large prospective study and reduces unnecessary biopsies while delaying diagnosis of high-grade cancers in few men.


Rapidly improving understanding of molecular oncology, emerging novel therapeutics, and increasingly available and affordable next-generation sequencing have created an opportunity for delivering genomically informed personalized cancer therapy. However, to implement genomically informed therapy requires that a clinician interpret the patient’s molecular profile, including molecular characterization of the tumor and the patient’s germline DNA. In this Commentary, we review existing data and tools for precision oncology and present a framework for reviewing the available biomedical literature on therapeutic implications of genomic alterations. Genomic alterations, including mutations, insertions/deletions, fusions, and copy number changes, need to be curated in terms of the likelihood that they alter the function of a "cancer gene" at the level of a specific variant in order to discriminate so-called "drivers" from "passengers." Alterations that are targetable either directly or indirectly with approved or investigational therapies are potentially "actionable." At this time, evidence linking predictive biomarkers to therapies is strong for only a few genomic markers in the context of specific cancer types. For these genomic alterations in other diseases and for other genomic alterations, the clinical data are either absent or insufficient to support routine clinical implementation of biomarker-based therapy. However, there is great interest in optimally matching patients to early-phase clinical trials. Thus, we need accessible, comprehensive, and frequently updated knowledge bases that describe genomic changes and their clinical implications, as well as continued education of clinicians and patients.


Background:

Prevention and treatment of advanced prostate cancer (PCa) by a nontoxic agent can improve outcome, while maintaining quality of life. 4-methylumbelliferone (4-MU) is a dietary supplement that inhibits hyaluronic acid (HA) synthesis. We evaluated the chemopreventive and therapeutic efficacy and mechanism of action of 4-MU.

Methods:

TRAMP mice (7–28 per group) were gavaged with 4-MU (450mg/kg/day) in a stage-specific treatment design (8–28, 12–28, 22–28 weeks). Efficacy of 4-MU (200–450mg/kg/day) was also evaluated in the PC3-ML/Luc+ intracardiac injection and DU145 subcutaneous models. PCa cells and tissues were analyzed for HA and Phosphoinositide 3-kinase (PI-3K)/Akt signaling and apoptosis effectors. HA add-back and myristoylated Akt (mAkt) overexpression studies evaluated the mechanism of action of 4-MU. Data were analyzed with one-way analysis of variance and unpaired t test or Tukey’s multiple comparison test. All statistical tests were two-sided.

Results:

While vehicle-treated transgenic adenocarcinoma of the prostate (TRAMP) mice developed prostate tumors and metastases at 28 weeks, both were abrogated in treatment groups, without serum/organ toxicity or weight loss; no tumors developed at one year, even after stopping the treatment at 28 weeks. 4-MU did not alter the transgene or neuroendocrine marker expression but downregulated HA levels. However, 4-MU decreased microvessel density and proliferative index (P < .0001,). 4-MU completely prevented/inhibited skeletal metastasis in the PC3-ML/Luc+ model and DU145-tumor growth (85–90% inhibition, P = .002). 4-MU also statistically significantly downregulated HA receptors, PI-3K/CD44 complex and activity, Akt signaling, and β-catenin levels/activation, but upregulated GSK-3 function, E-cadherin, and apoptosis effectors (P < .001); HA addition or mAkt overexpression rescued these effects.

Conclusion:

4-MU is an effective nontoxic, oral chemopreventive, and therapeutic agent that targets PCa development, growth, and metastasis by abrogating HA signaling.


Background:

The NCIC CTG LY.12 study showed that gemcitabine, dexamethasone, and cisplatin (GDP) were noninferior to dexamethasone, cytarabine, and cisplatin (DHAP) in patients with relapsed or refractory aggressive histology lymphoma prior to autologous stem cell transplantation. We conducted an economic evaluation from the perspective of the Canadian public healthcare system based on trial data.

Methods:

The primary outcome was an incremental cost utility analysis comparing costs and benefits associated with GDP vs DHAP. Resource utilization data were collected from 519 Canadian patients in the trial. Costs were presented in 2012 Canadian dollars and disaggregated to highlight the major cost drivers of care. Benefit was measured as quality-adjusted life-years (QALYs) based on utilities translated from prospectively collected quality-of-life data. All statistical tests were two-sided.

Results:

The mean overall costs of treatment per patient in the GDP and DHAP arms were $19 961 (95% confidence interval (CI) = $17 286 to $24 565) and $34 425 (95% CI = $31 901 to $39 520), respectively, with an incremental difference in direct medical costs of $14 464 per patient in favor of GDP (P < .001). The predominant cost driver for both treatment arms was related to hospitalizations. The mean discounted quality-adjusted overall survival with GDP was 0.161 QALYs and 0.152 QALYs for DHAP (difference = 0.01 QALYs, P = .146). In probabilistic sensitivity analysis, GDP was associated with both cost savings and improved quality-adjusted outcomes compared with DHAP in 92.6% of cost-pair simulations.

Conclusions:

GDP was associated with both lower costs and similar quality-adjusted outcomes compared with DHAP in patients with relapsed or refractory lymphoma. Considering both costs and outcomes, GDP was the dominant therapy.


Background:

Previous reports suggested that female breast cancer is associated with earlier ages at onset among Asian than Western populations. However, most studies utilized cross-sectional analyses that may be confounded by calendar-period and/or birth cohort effects. We, therefore, considered a longitudinal (forward-looking) approach adjusted for calendar-period changes and conditioned upon birth cohort.

Methods:

Invasive female breast cancer data (1988–2009) were obtained from cancer registries in China, Hong Kong, South Korea, Taiwan, Singapore, and the United States. Age-period-cohort models were used to extrapolate longitudinal age-specific incidence rates for the 1920, 1944, and 1970 birth cohorts.

Results:

Cross-sectional age-specific incidence rates rose continuously until age 80 years among US white women, but plateaued or decreased after age 50 years among Asian women. In contrast, longitudinal age-specific rates were proportional (similar) among all Asian countries and the United States with incidence rates rising continuously until age 80 years. The extrapolated estimates for the most recent cohorts in some Asian countries actually showed later ages at onset than in the United States. Additionally, over successive birth cohorts, the incidence rate ratios (IRRs) for the longitudinal curves converged (narrowed) between Asian and US white women.

Conclusions:

Similar longitudinal age-specific incidence rates along with converging IRRs indicate that the age effects for invasive breast cancer are more similar among Asian and Western populations than might be expected from a solely cross-sectional analysis. Indeed, the Asian breast cancer rates in recent generations are even surpassing the historically high rates in the United States, highlighting an urgent need for efficient prevention and treatment strategies among Asian populations.


Background:

Pretreatment cognitive impairment in cancer patients is well established but unexplained. Similar cognitive compromise has been observed in post-traumatic stress disorder (PTSD) patients, and PTSD symptoms are a frequent concomitant of cancer diagnosis. We tested the hypothesis that pretreatment cognitive impairment is attributable to cancer-related post-traumatic stress.

Methods:

Women aged 65 years or younger who were diagnosed with breast cancer (case patients) or had undergone negative routine breast imaging (control patients) at one of six participating breast centers underwent traditional and computerized neuropsychological testing, clinician-administered diagnostic assessment of stress disorders, and self-report assessments of cognitive function and depression. To minimize confounding, case patients were evaluated prior to any local or systemic treatment. Cognitive indices of case patients, control patients, and normative samples were compared. The patients’ risk of overall cognitive impairment was determined. Linear regression and a mediation model were used to test the study hypothesis. All statistical tests were two-sided.

Results:

The 166 case patients and 60 well-matched control patients showed near-identical deviations from population norms. Case patients scored worse than control patients on two of 20 cognitive indices (Go/Nogo commission errors, Go/Nogo omission errors). Self-reported cognitive problems were associated with Go/Nogo omission errors and more pronounced in case patients. Only PTSD symptoms (Beta = 0.27, P = .004) and age (Beta = 0.22, P = .04) statistically significantly predicted Go/Nogo errors. The effect of having cancer on Go/Nogo errors was mediated by PTSD symptoms. Case patients did not have an increased risk of overall cognitive impairment.

Conclusion:

Prior to any treatment, breast cancer patients may show limited cognitive impairment that is apparently largely caused by cancer-related post-traumatic stress.



The etiologic contribution of germline genetic variation to sporadic osteosarcoma is not well understood. Osteosarcoma is a sentinel cancer of Li-Fraumeni syndrome (LFS), in which approximately 70% of families meeting the classic criteria have germline TP53 mutations. We sequenced TP53 exons in 765 osteosarcoma cases. Data were analyzed with 2 tests, logistic regression, and Cox proportional hazards regression models. We observed a high frequency of young osteosarcoma cases (age <30 years) carrying a known LFS- or likely LFS-associated mutation (3.8%) or rare exonic variant (5.7%) with an overall frequency of 9.5%, compared with none in case patients age 30 years and older (P < .001). This high TP53 mutation prevalence in young osteosarcoma cases is statistically significantly greater than the previously reported prevalence of 3% (P = .0024). We identified a novel association between a TP53 rare variant and metastasis at diagnosis of osteosarcoma (rs1800372, odds ratio = 4.27, 95% confidence interval = 1.2 to 15.5, P = .026). Genetic susceptibility to young onset osteosarcoma is distinct from older adult onset osteosarcoma, with a high frequency of LFS-associated and rare exonic TP53 variants.


Background:

Statins have been associated with moderate reductions in mortality among colorectal cancer (CRC) patients, but these studies lacked adjustment for some potentially relevant factors associated with statin use. We aimed to provide more detailed results on this association from a population-based patient cohort study.

Methods:

Use of statins and other risk or protective factors were assessed in standardized interviews with 2697 patients from southern Germany with a diagnosis of incident CRC between 2003 and 2009 (Darmkrebs: Chancen der Verhütung durch Screening [DACHS] study). Follow-up included assessment of therapy details, recurrence, vital status, and cause of death. Information about molecular pathological subtypes of CRC was available for 1209 patients. Cox proportional hazard regression models were used to estimate adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs). All statistical tests were two-sided.

Results:

Patients were age 68 years on average, 412 used statins (15%), and 769 died during follow-up (29%). After a median follow-up time of 3.4 years, use of statins was not associated with overall (HR = 1.10, 95% CI = 0.85 to 1.41), CRC-specific (HR = 1.11, 95% CI = 0.82 to 1.50), or recurrence-free survival (HR = 0.90, 95% CI = 0.63 to 1.27). Analyses in relevant subgroups also showed no association of statin use with overall and CRC-specific survival, and no associations were observed after stratifying for major pathological subtypes. Among stage I and II patients, statin use was associated with better recurrence-free but not with better CRC-specific survival.

Conclusions:

Statin use was not associated with reduced mortality among CRC patients. Effects reported in previous studies might reflect incomplete control for stage at diagnosis and other factors associated with the use of statins.


Supplemental security income (SSI) and social security disability insurance (DI) are federal programs that provide disability benefits. We report on SSI/DI enrollment in a random sample of adult, long-term survivors of childhood cancer (n = 698) vs a comparison group without cancer (n = 210) from the Childhood Cancer Survivor Study who completed a health insurance survey. A total of 13.5% and 10.0% of survivors had ever been enrolled on SSI or DI, respectively, compared with 2.6% and 5.4% of the comparison group. Cranial radiation doses of 25 Gy or more were associated with a higher risk of current SSI (relative risk [RR] = 3.93, 95% confidence interval [CI] = 2.05 to 7.56) and DI (RR = 3.65, 95% CI = 1.65 to 8.06) enrollment. Survivors with severe/life-threatening conditions were more often enrolled on SSI (RR = 3.77, 95% CI = 2.04 to 6.96) and DI (RR = 2.73, 95% CI = 1.45 to 5.14) compared with those with mild/moderate or no health conditions. Further research is needed on disability-related financial challenges after childhood cancer.


Lung cancer is the leading cause of cancer death worldwide. Low-dose computed tomography screening (LDCT) was recently shown to anticipate the time of diagnosis, thus reducing lung cancer mortality. However, concerns persist about the feasibility and costs of large-scale LDCT programs. Such concerns may be addressed by clearly defining the target "high-risk" population that needs to be screened by LDCT. We recently identified a serum microRNA signature (the miR-Test) that could identify the optimal target population. Here, we performed a large-scale validation study of the miR-Test in high-risk individuals (n = 1115) enrolled in the Continuous Observation of Smoking Subjects (COSMOS) lung cancer screening program. The overall accuracy, sensitivity, and specificity of the miR-Test are 74.9% (95% confidence interval [CI] = 72.2% to 77.6%), 77.8% (95% CI = 64.2% to 91.4%), and 74.8% (95% CI = 72.1% to 77.5%), respectively; the area under the curve is 0.85 (95% CI = 0.78 to 0.92). These results argue that the miR-Test might represent a useful tool for lung cancer screening in high-risk individuals.


Background:

For women with hormone receptor–positive, operable breast cancer, surgical oophorectomy plus tamoxifen is an effective adjuvant therapy. We conducted a phase III randomized clinical trial to test the hypothesis that oophorectomy surgery performed during the luteal phase of the menstrual cycle was associated with better outcomes.

Methods:

Seven hundred forty premenopausal women entered a clinical trial in which those women estimated not to be in the luteal phase of their menstrual cycle for the next one to six days (n = 509) were randomly assigned to receive treatment with surgical oophorectomy either delayed to be during a five-day window in the history-estimated midluteal phase of the menstrual cycles, or in the next one to six days. Women who were estimated to be in the luteal phase of the menstrual cycle for the next one to six days (n = 231) were excluded from random assignment and received immediate surgical treatments. All patients began tamoxifen within 6 days of surgery and continued this for 5 years. Kaplan-Meier methods, the log-rank test, and multivariable Cox regression models were used to assess differences in five-year disease-free survival (DFS) between the groups. All statistical tests were two-sided.

Results:

The randomized midluteal phase surgery group had a five-year DFS of 64%, compared with 71% for the immediate surgery random assignment group (hazard ratio [HR] = 1.24, 95% confidence interval [CI] = 0.91 to 1.68, P = .18). Multivariable Cox regression models, which included important prognostic variables, gave similar results (aHR = 1.28, 95% CI = 0.94 to 1.76, P = .12). For overall survival, the univariate hazard ratio was 1.33 (95% CI = 0.94 to 1.89, P = .11) and the multivariable aHR was 1.43 (95% CI = 1.00 to 2.06, P = .05). Better DFS for follicular phase surgery, which was unanticipated, proved consistent across multiple exploratory analyses.

Conclusions:

The hypothesized benefit of adjuvant luteal phase oophorectomy was not shown in this large trial.


Background:

Racial disparities in cancer survival outcomes have been primarily attributed to underlying biologic mechanisms and the quality of cancer care received. Because prior literature shows little difference exists in the socioeconomic status of non-Hispanic whites and Asian Americans, any difference in cancer survival is less likely to be attributable to inequalities of care. We sought to examine differences in cancer-specific survival between whites and Asian Americans.

Methods:

The Surveillance, Epidemiology, and End Results Program was used to identify patients with lung (n = 130 852 [16.9%]), breast (n = 313 977 [40.4%]), prostate (n = 166 529 [21.4%]), or colorectal (n = 165 140 [21.3%]) cancer (the three leading causes of cancer-related mortality within each sex) diagnosed between 1991 and 2007. Fine and Gray’s competing risks regression compared the cancer-specific mortality (CSM) of eight Asian American groups (Chinese, Filipino, Hawaiian/Pacific Islander, Japanese, Korean, other Asian, South Asian [Indian/Pakistani], and Vietnamese) to non-Hispanic white patients. All P values were two-sided.

Results:

In competing risks regression, the receipt of definitive treatment was an independent predictor of CSM (hazard ratio [HR] = 0.37, 95% confidence interval [CI] = 0.35 to 0.40; HR = 0.55, 95% CI = 0.53 to 0.58; HR = 0.61, 95% CI = 0.60 to 0.62; and HR = 0.27, 95% CI = 0.25 to 0.29) for prostate, breast, lung, and colorectal cancers respectively, all P < .001). In adjusted analyses, most Asian subgroups (except Hawaiians and Koreans) had lower CSM relative to white patients, with hazard ratios ranging from 0.54 (95% CI = 0.38 to 0.78) to 0.88 (95% CI = 0.84 to 0.93) for Japanese patients with prostate and Chinese patients with lung cancer, respectively.

Conclusions:

Despite adjustment for potential confounders, including the receipt of definitive treatment and tumor characteristics, most Asian subgroups had better CSM than non-Hispanic white patients. These findings suggest that underlying genetic/biological differences, along with potential cultural variations, may impact survival in Asian American cancer patients.


Background:

Population-based estimates of absolute risk of lung cancer recurrence, and of mortality rates after recurrence, can inform clinical management.

Methods:

We evaluated prognostic factors for recurrences and survival in 2098 lung cancer case patients from the general population of Lombardy, Italy, from 2002 to 2005. We conducted survival analyses and estimated absolute risks separately for stage IA to IIIA surgically treated and stage IIIB to IV non–surgically treated patients.

Results:

Absolute risk of metastases exceeded that of local recurrence in every stage and cell type, highlighting the systemic threat of lung cancer. In stage I, the probability of dying within the first year after diagnosis was 2.7%, but it was 48.3% within first year after recurrence; in stage IV, the probabilities were 57.3% and 80.6%, respectively. Over half the patients died within one year of first metastasis. Although in stages IA to IB about one-third of patients had a recurrence, stage IIA patients had a recurrence risk (61.2%) similar to stage IIB (57.9%) and IIIA (62.8%) patients. Risk of brain metastases in stage IA to IIIA surgically treated non–small cell lung cancer patients increased with increasing tumor grade. Absolute risk of recurrence was virtually identical in adenocarcinoma and squamous cell carcinoma patients.

Conclusions:

This population-based study provides clinically useful estimates of risks of lung cancer recurrence and mortality that are applicable to the general population. These data highlight the need for more effective adjuvant treatments overall and within specific subgroups. The estimated risks of various endpoints are useful for designing clinical trials, whose power depends on absolute numbers of events.


The consistent reports of mutations at Asp538 and Tyr537 in helix 12 of the ligand-binding domain (LBD) of estrogen receptors (ERs) from antihormone-resistant breast cancer metastases constitute an important advance. The mutant amino acids interact with an anchor amino acid, Asp351, to close the LBD, thereby creating a ligand-free constitutively activated ER. Amino acids Asp 538, Tyr 537, and Asp 351 are known to play a role in either the turnover of ER, the antiestrogenic activity of the ER complex, or the estrogen-like actions of selective ER modulators. A unifying mechanism of action for these amino acids to enhance ER gene activation and growth response is presented. There is a range of mutations described in metastases vs low to zero in primary disease, so the new knowledge is of clinical relevance, thereby confirming an additional mechanism of acquired resistance to antihormone therapy through cell population selection pressure and enrichment during treatment. Circulating tumor cells containing ER mutations can be cultured ex vivo, and tumor tissues can be grown as patient-derived xenografts to add a new dimension for testing drug susceptibility for future drug discovery.


Background:

Pharmacological activation of cannabinoid receptors elicits antitumoral responses in different cancer models. However, the biological role of these receptors in tumor physio-pathology is still unknown.

Methods:

We analyzed CB2 cannabinoid receptor protein expression in two series of 166 and 483 breast tumor samples operated in the University Hospitals of Kiel, Tübingen, and Freiburg between 1997 and 2010 and CB2 mRNA expression in previously published DNA microarray datasets. The role of CB2 in oncogenesis was studied by generating a mouse line that expresses the human V-Erb-B2 Avian Erythroblastic Leukemia Viral Oncogene Homolog 2 (HER2) rat ortholog (neu) and lacks CB2 and by a variety of biochemical and cell biology approaches in human breast cancer cells in culture and in vivo, upon modulation of CB2 expression by si/shRNAs and overexpression plasmids. CB2-HER2 molecular interaction was studied by colocalization, coimmunoprecipitation, and proximity ligation assays. Statistical tests were two-sided.

Results:

We show an association between elevated CB2 expression in HER2+ breast tumors and poor patient prognosis (decreased overall survival, hazard ratio [HR] = 0.29, 95% confidence interval [CI] = 0.09 to 0.71, P = .009) and higher probability to suffer local recurrence (HR = 0.09, 95% CI = 0.049 to 0.54, P = .003) and to develop distant metastases (HR = 0.33, 95% CI = 0.13 to 0.75, P = .009). We also demonstrate that genetic inactivation of CB2 impairs tumor generation and progression in MMTV-neu mice. Moreover, we show that HER2 upregulates CB2 expression by activating the transcription factor ELK1 via the ERK cascade and that an increased CB2 expression activates the HER2 pro-oncogenic signaling at the level of the tyrosine kinase c-SRC. Finally, we show HER2 and CB2 form heteromers in cancer cells.

Conclusions:

Our findings reveal an unprecedented role of CB2 as a pivotal regulator of HER2 pro-oncogenic signaling in breast cancer, and they suggest that CB2 may be a biomarker with prognostic value in these tumors.


Background:

Current screening guidelines for colorectal cancer (CRC) do not consider thyroid dysfunction as a risk factor for disease development. We sought to determine the risk of developing CRC in patients with thyroid dysfunction, with and without thyroid hormone replacement (THR).

Methods:

We conducted a nested case-control study using a large population-based medical records database from the United Kingdom. Study case patients were defined as those with any medical code of CRC. Subjects with familial colorectal cancer syndromes or inflammatory bowel disease (IBD) were excluded. For every case patient, four eligible control patients matched on age, sex, practice site, and duration of follow-up before index date were selected using incidence density sampling. Exposure was THR therapy before index date. We further divided the THR unexposed group into patients with hypothyroidism (TSH > 4mg/dl), patients with hyperthyroidism (TSH < 0.4mg/dl), and subjects without documented thyroid abnormality. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for CRC were estimated using conditional logistic regression. All statistical tests were two-sided.

Results:

We identified 20990 CRC patients and 82054 control patients. The adjusted odds ratio for CRC associated with THR was 0.88 (95% CI = 0.79 to 0.99, P = .03) and 0.68 (95% CI = 0.55 to 0.83, P < .001) for treatment initiated five to 10 years and more than 10 years before index date, respectively. This protective association increased with cumulative duration of therapy. In contrast, hyperthyroidism (adjusted OR = 1.21, 95% CI = 1.08 to 1.36, P = .001) or untreated hypothyroidism (adjusted OR = 1.16, 95% CI = 1.08 to 1.24, P < .001) were associated with increased risk of CRC.

Conclusion:

Long-term THR is associated with a decreased risk of CRC. Hyperthyroidism and untreated hypothyroidism are associated with modestly elevated risk of CRC.


Background:

Short telomeres in peripheral blood leukocytes are associated with older age and age-related diseases. We tested the hypotheses that short telomeres are associated with both increased cancer mortality and all-cause mortality.

Methods:

Individuals (n = 64637) were recruited from 1991 onwards from two Danish prospective cohort studies: the Copenhagen City Heart Study and the Copenhagen General Population Study. All had telomere length measured by quantitative polymerase chain reaction and the genotypes rs1317082 (TERC), rs7726159 (TERT), and rs2487999 (OBFC1) determined. The sum of telomere-shortening alleles from these three genotypes was calculated. We conducted Cox regression analyses and instrumental variable analyses using the allele sum as an instrument. All statistical tests were two-sided.

Results:

Among 7607 individuals who died during follow-up (0–22 years, median = 7 years), 2420 had cancer and 2633 had cardiovascular disease as causes of death. Decreasing telomere length deciles were associated with increasing all-cause mortality (P trend = 2*10–15). The multivariable-adjusted hazard ratio of all-cause mortality was 1.40 (95% confidence interval [CI] = 1.25 to 1.57) for individuals in the shortest vs the longest decile. Results were similar for cancer mortality and cardiovascular mortality. Telomere length decreased 69 base pairs (95% CI = 61 to 76) per allele for the allele sum, and the per-allele hazard ratio for cancer mortality was 0.95 (95% CI = 0.91 to 0.99). Allele sum was not associated with cardiovascular, other, or all-cause mortality.

Conclusion:

Short telomeres in peripheral blood leukocytes were associated with high mortality in association analyses. In contrast, genetically determined short telomeres were associated with low cancer mortality but not with all-cause mortality.



Background:

Several treatment strategies target the human epidermal growth factor receptor 2 (HER2) in breast carcinomas, including monoclonal antibodies directed against HER2’s extracellular domain (ECD) and small molecule inhibitors of its tyrosine kinase activity. Yet, novel therapies are needed that prevent HER2 dimerization with other HER family members, because current treatments are only partially effective.

Methods:

To test the hypothesis that HER2 activation requires a protein sequence in the HER2-ECD that mediates HER2 homo- and heterodimerization, we introduced a series of deletion mutations in the third subdomain of HER2-ECD. These deletion mutants were retrovirally expressed in breast cancer (BC) cells that naturally overexpress HER2 and in noncancerous, HER2-negative breast epithelial cells. One-factor analysis of variance or Student’s t test were used to analyze differences. All statistical tests were two-sided.

Results:

The smallest deletion in the ECD domain of HER2, which removed only 16 amino acids (HER2-ECD451–466), completely disrupted the oncogenic potential of HER2. In contrast to wild-type HER2, the mutant-inhibited anchorage-independent growth (mean number of colonies: mutant, 70, 95% confidence interval [CI] = 55 to 85; wild-type, 400, 95% CI = 320 to 480, P < .001) increased sensitivity to paclitaxel treatment in both transformed and nontransformed cells. Overexpression of HER2451–466 efficiently inhibited activation of HER1, HER2, and HER3 in all cell lines tested.

Conclusions:

These findings reveal that an essential "activating" sequence exists in the extracellular domain of HER2. Disruption of this sequence disables the HER2 dimerization loop, blocks subsequent activation of HER2-driven oncogenic signaling, and generates a dominant-negative form of HER2. Reagents specifically against this molecular activation switch may represent a novel targeted approach for the management of HER2-overexpressing carcinomas.




Background:

The American Cancer Society (ACS), Centers for Disease Control and Prevention (CDC), National Cancer Institute (NCI), and North American Association of Central Cancer Registries (NAACCR) collaborate annually to produce updated, national cancer statistics. This Annual Report includes a focus on breast cancer incidence by subtype using new, national-level data.

Methods:

Population-based cancer trends and breast cancer incidence by molecular subtype were calculated. Breast cancer subtypes were classified using tumor biomarkers for hormone receptor (HR) and human growth factor-neu receptor (HER2) expression.

Results:

Overall cancer incidence decreased for men by 1.8% annually from 2007 to 2011. Rates for women were stable from 1998 to 2011. Within these trends there was racial/ethnic variation, and some sites have increasing rates. Among children, incidence rates continued to increase by 0.8% per year over the past decade while, like adults, mortality declined. HR+/HER2- breast cancers, the subtype with the best prognosis, were the most common for all races/ethnicities with highest rates among non-Hispanic white women, local stage cases, and low poverty areas (92.7, 63.51, and 98.69 per 100000 non-Hispanic white women, respectively). HR+/HER2- breast cancer incidence rates were strongly, positively correlated with mammography use, particularly for non-Hispanic white women (Pearson 0.57, two-sided P < .001). Triple-negative breast cancers, the subtype with the worst prognosis, were highest among non-Hispanic black women (27.2 per 100000 non-Hispanic black women), which is reflected in high rates in southeastern states.

Conclusions:

Progress continues in reducing the burden of cancer in the United States. There are unique racial/ethnic-specific incidence patterns for breast cancer subtypes; likely because of both biologic and social risk factors, including variation in mammography use. Breast cancer subtype analysis confirms the capacity of cancer registries to adjust national collection standards to produce clinically relevant data based on evolving medical knowledge.


Rapid advancements in massively parallel sequencing methods have enabled the analysis of breast cancer genomes at an unprecedented resolution, which have revealed the remarkable heterogeneity of the disease. As a result, we now accept that despite originating in the breast, estrogen receptor (ER)–positive and ER-negative breast cancers are completely different diseases at the molecular level. It has become apparent that there are very few highly recurrently mutated genes such as TP53, PIK3CA, and GATA3, that no two breast cancers display an identical repertoire of somatic genetic alterations at base-pair resolution and that there might not be a single highly recurrently mutated gene that defines each of the "intrinsic" subtypes of breast cancer (ie, basal-like, HER2-enriched, luminal A, and luminal B). Breast cancer heterogeneity, however, extends beyond the diversity between tumors. There is burgeoning evidence to demonstrate that at least some primary breast cancers are composed of multiple, genetically diverse clones at diagnosis and that metastatic lesions may differ in their repertoire of somatic genetic alterations when compared with their respective primary tumors. Several biological phenomena may shape the reported intratumor genetic heterogeneity observed in breast cancers, including the different mutational processes and multiple types of genomic instability. Harnessing the emerging concepts of the diversity of breast cancer genomes and the phenomenon of intratumor genetic heterogeneity will be essential for the development of optimal methods for diagnosis, disease monitoring, and the matching of patients to the drugs that would benefit them the most.


Background:

Bromodomain PHD finger transcription factor (BPTF) plays an important role in chromatin remodeling, but its functional role in tumor progression is incompletely understood. Here we explore the oncogenic effects of BPTF in melanoma.

Methods:

The consequences of differential expression of BPTF were explored using shRNA-mediated knockdown in several melanoma cell lines. Immunoblotting was used to assess the expression of various proteins regulated by BPTF. The functional role of BPTF in melanoma progression was investigated using assays of colony formation, invasion, cell cycle, sensitivity to selective BRAF inhibitors, and in xenograft models of melanoma progression (n = 12 mice per group). The biomarker role of BPTF in melanoma progression was assessed using fluorescence in situ hybridization and immunohistochemical analyses. All statistical tests were two-sided.

Results:

shRNA-mediated BPTF silencing suppressed the proliferative capacity (by 65.5%) and metastatic potential (by 66.4%) of melanoma cells. Elevated BPTF copy number (mean ≥ 3) was observed in 28 of 77 (36.4%) melanomas. BPTF overexpression predicted poor survival in a cohort of 311 melanoma patients (distant metastasis-free survival P = .03, and disease-specific survival P = .008), and promoted resistance to BRAF inhibitors in melanoma cell lines. Metastatic melanoma tumors progressing on BRAF inhibitors contained low BPTF-expressing, apoptotic tumor cell subclones, indicating the continued presence of drug-responsive subclones within tumors demonstrating overall resistance to anti-BRAF agents.

Conclusions:

These studies demonstrate multiple protumorigenic functions for BPTF and identify it as a novel target for anticancer therapy. They also suggest the combination of BPTF targeting with BRAF inhibitors as a novel therapeutic strategy for melanomas with mutant BRAF.


Background:

Lung cancer is the leading cause of cancer-related mortality worldwide. Detection of promoter hypermethylation of tumor suppressor genes in exfoliated cells from the lung provides an assessment of field cancerization that in turn predicts lung cancer. The identification of genetic determinants for this validated cancer biomarker should provide novel insights into mechanisms underlying epigenetic reprogramming during lung carcinogenesis.

Methods:

A genome-wide association study using generalized estimating equations and logistic regression models was conducted in two geographically independent smoker cohorts to identify loci affecting the propensity for cancer-related gene methylation that was assessed by a 12-gene panel interrogated in sputum. All statistical tests were two-sided.

Results:

Two single nucleotide polymorphisms (SNPs) at 15q12 (rs73371737 and rs7179575) that drove gene methylation were discovered and replicated with rs73371737 reaching genome-wide significance (P = 3.3x10–8). A haplotype carrying risk alleles from the two 15q12 SNPs conferred 57% increased risk for gene methylation (P = 2.5x10–9). Rs73371737 reduced GABRB3 expression in lung cells and increased risk for smoking-induced chronic mucous hypersecretion. Furthermore, subjects with variant homozygote of rs73371737 had a two-fold increase in risk for lung cancer (P = .0043). Pathway analysis identified DNA double-strand break repair by homologous recombination (DSBR-HR) as a major pathway affecting susceptibility for gene methylation that was validated by measuring chromatid breaks in lymphocytes challenged by bleomycin.

Conclusions:

A functional 15q12 variant was identified as a risk factor for gene methylation and lung cancer. The associations could be mediated by GABAergic signaling that drives the smoking-induced mucous cell metaplasia. Our findings also substantiate DSBR-HR as a critical pathway driving epigenetic gene silencing.



Background:

Lack of robust predictive biomarkers, other than MGMT promoter methylation, makes temozolomide responsiveness in newly diagnosed glioblastoma (GBM) patients difficult to predict. However, we identified patients with long-term survival (≥35 months) within a group of newly diagnosed GBM patients treated with standard or metronomic adjuvant temozolomide schedules. We thus investigated possible molecular profiles associated with longer survival following temozolomide treatment.

Methods:

We investigated the association of molecular features with progression-free (PFS) and overall survival (OS). Human-derived GBM cancer stem cells (CSCs) were used to investigate in vitro molecular mechanisms associated with temozolomide responsiveness. Surgically removed recurrences allowed investigation of molecular changes occurring during therapy in vivo. Statistical analyses included one- and two-way analysis of variance, Student’s t test, Cox proportional hazards, and the Kaplan-Meier method. All statistical tests were two-sided.

Results:

No association was found between survival and gene classifiers associated with different molecular GBM subtypes in the standard-treated group, while in metronomic-treated patients robust association was found between EGFR amplification/overexpression and PFS and OS (OS, EGFR-high vs low: hazard ratiodeath = 0.22, 95% confidence interval = 0.09 to 0.55, P = .001). The result for OS remained statistically significant after Bonferroni correction (P interaction < .0005). Long-term survival following metronomic temozolomide was independent from MGMT and EGFRvIII status and was more pronounced in EGFR-overexpressing GBM patients with PTEN loss. In vitro findings confirmed a selective dose- and time-dependent decrease in survival of temozolomide-treated EGFR+ human-derived glioblastoma CSCs, which occurred through inhibition of NF-B transcriptional activity. In addition, reduction in EGFR-amplified cells, along with a statistically significant decrease in NF-B/p65 expression, were observed in specimens from recurrent metronomic-treated EGFR-overexpressing GBM patients.

Conclusions:

EGFR-amplified/overexpressing glioblastomas strongly benefit from metronomic temozolomide–based therapies.


We evaluated whether a 76-locus polygenic risk score (PRS) and Breast Imaging Reporting and Data System (BI-RADS) breast density were independent risk factors within three studies (1643 case patients, 2397 control patients) using logistic regression models. We incorporated the PRS odds ratio (OR) into the Breast Cancer Surveillance Consortium (BCSC) risk-prediction model while accounting for its attributable risk and compared five-year absolute risk predictions between models using area under the curve (AUC) statistics. All statistical tests were two-sided. BI-RADS density and PRS were independent risk factors across all three studies (P interaction = .23). Relative to those with scattered fibroglandular densities and average PRS (2nd quartile), women with extreme density and highest quartile PRS had 2.7-fold (95% confidence interval [CI] = 1.74 to 4.12) increased risk, while those with low density and PRS had reduced risk (OR = 0.30, 95% CI = 0.18 to 0.51). PRS added independent information (P < .001) to the BCSC model and improved discriminatory accuracy from AUC = 0.66 to AUC = 0.69. Although the BCSC-PRS model was well calibrated in case-control data, independent cohort data are needed to test calibration in the general population.


Internet marketing may accelerate the use of care based on genomic or tumor-derived data. However, online marketing may be detrimental if it endorses products of unproven benefit. We conducted an analysis of Internet websites to identify personalized cancer medicine (PCM) products and claims. A Delphi Panel categorized PCM as standard or nonstandard based on evidence of clinical utility. Fifty-five websites, sponsored by commercial entities, academic institutions, physicians, research institutes, and organizations, that marketed PCM included somatic (58%) and germline (20%) analysis, interpretive services (15%), and physicians/institutions offering personalized care (44%). Of 32 sites offering somatic analysis, 56% included specific test information (range 1–152 tests). All statistical tests were two-sided, and comparisons of website content were conducted using McNemar’s test. More websites contained information about the benefits than limitations of PCM (85% vs 27%, P < .001). Websites specifying somatic analysis were statistically significantly more likely to market one or more nonstandard tests as compared with standard tests (88% vs 44%, P = .04).


Background:

It is unclear how the extent of surgical lymph node clearance influences prognosis after surgery for esophageal cancer.

Methods:

This nationwide, population-based cohort study included 1044 esophageal cancer patients who had undergone esophagectomy between 1987 and 2010 in Sweden, with follow-up until 2012. The independent role of lymph node removal in relation to survival was analyzed using Cox proportional hazards regression, providing hazard ratios (HRs) with 95% confidence intervals (CIs), adjusted for age, sex, comorbidity, tumor (T) stage, neo-adjuvant treatment, surgeon volume, and calendar period. Statistical tests were two-sided, except tests for trend.

Results:

Analyzed as a linear variable, a higher number of lymph nodes removed did not influence the overall five-year mortality (adjusted HR = 1.00, 95% CI = 0.99 to 1.01). Patients in the third (7–15 nodes) and fourth (16–114 nodes) quartiles of removed nodes did not demonstrate any decreased overall five-year mortality compared with those in the lowest two quartiles (<7 nodes) (HR = 1.13, 95% CI = 0.95 to 1.35 and HR = 1.17, 95% CI = 0.94 to 1.46, respectively). In early T stages (Tis-T1) the hazard ratios indicated a worse survival with more lymphadenectomy using the median as cutoff (HR = 1.53, 95% CI = 1.13 to 2.06). Increased lymph node removal did not decrease mortality in any specific T stage. A greater number of metastatic nodes and a higher positive-to-negative node ratio were associated with strongly increased mortality. All results were similar when disease-specific mortality was analyzed.

Conclusion:

This population-based study indicates that more extensive lymph node clearance during surgery for esophageal cancer may not improve survival. These results challenge current clinical guidelines, and further research is needed to change clinical practice.




Background:

Chemotherapy triggers endoplasmic reticulum (ER) stress, which in turn regulates levels of the active (LAP) and the natural dominant-negative (LIP) forms of the transcription factor C/EBP-β. LAP upregulates and LIP downregulates the multidrug resistance (MDR) protein P-glycoprotein (Pgp), but it is not known how critical is their role in establishing MDR.

Methods:

Cell viability was quantitated by crystal violet staining and measuring absorbance at 540nm. Expression of various proteins was determined by immunoblotting. mRNA levels were determined by quantitative reverse transcriptase polymerase chain reaction (RT-PCR). LIP and LAP were overexpressed using expression plasmids followed by selection with blasticidin. Tumor cells expressing doxycycline-inducible LIP were orthotopically implanted in mice (n = 15 mice per group), and tumor size was measured daily by caliper. Tumor sections were stained with hematoxylin and eosin and immunostained for Pgp, proliferation, and ER stress markers.

Results:

MDR cells do not express basal, chemotherapy-triggered, or ER stress–triggered LIP and fail to activate the CHOP-caspase-3 death-triggering axis upon ER stress or chemotherapy challenge. Overexpression of LIP reversed the MDR phenotype in vitro and in tumors implanted in mice. LIP was undetectable in MDR cells, probably due to its ubiquitination, which was 3.56-fold higher, resulting in lysosomal and proteasomal degradation of LIP.

Conclusions:

Spontaneous and drug-selected MDR cells lack LIP, which is eliminated by ubiquitin-mediated degradation. Loss of LIP drives MDR not only by increasing Pgp expression but also by a two-fold attenuation of ER stress–triggered cell death.


Despite recent increased attention to healthcare performance and the burden of disease from cancer, measures of quality of cancer care are not readily available. In 2013, the California HealthCare Foundation convened an expert workgroup to explore the potential for leveraging data in the California Cancer Registry (CCR), one of the world’s largest population-based cancer registries, for measuring and improving the quality of cancer care. The workgroup assessed current registry operations, the value to be gained by linking CCR data with health insurance claims or encounter data and clinical data contained in health system electronic health records, and potential barriers to these linkages. The workgroup concluded that: 1) The CCR mandate should be expanded to include use of its data for quality of cancer care measurement and public reporting; and 2) a system should be developed to support linkage of registry data with both claims data and provider electronic health record data.


Disruption of the Krebs cycle is a hallmark of cancer. IDH1 and IDH2 mutations are found in many neoplasms, and germline alterations in SDH genes and FH predispose to pheochromocytoma/paraganglioma and other cancers. We describe a paraganglioma family carrying a germline mutation in MDH2, which encodes a Krebs cycle enzyme. Whole-exome sequencing was applied to tumor DNA obtained from a man age 55 years diagnosed with multiple malignant paragangliomas. Data were analyzed with the two-sided Student’s t and Mann-Whitney U tests with Bonferroni correction for multiple comparisons. Between six- and 14-fold lower levels of MDH2 expression were observed in MDH2-mutated tumors compared with control patients. Knockdown (KD) of MDH2 in HeLa cells by shRNA triggered the accumulation of both malate (mean ± SD: wild-type [WT] = 1±0.18; KD = 2.24±0.17, P = .043) and fumarate (WT = 1±0.06; KD = 2.6±0.25, P = .033), which was reversed by transient introduction of WT MDH2 cDNA. Segregation of the mutation with disease and absence of MDH2 in mutated tumors revealed MDH2 as a novel pheochromocytoma/paraganglioma susceptibility gene.



Exercise has been shown to improve postischemia perfusion of normal tissues; we investigated whether these effects extend to solid tumors. Estrogen receptor–negative (ER-, 4T1) and ER+ (E0771) tumor cells were implanted orthotopically into syngeneic mice (BALB/c, N = 11–12 per group) randomly assigned to exercise or sedentary control. Tumor growth, perfusion, hypoxia, and components of the angiogenic and apoptotic cascades were assessed by MRI, immunohistochemistry, western blotting, and quantitative polymerase chain reaction and analyzed with one-way and repeated measures analysis of variance and linear regression. All statistical tests were two-sided. Exercise statistically significantly reduced tumor growth and was associated with a 1.4-fold increase in apoptosis (sedentary vs exercise: 1544 cells/mm2, 95% CI = 1223 to 1865 vs 2168 cells/mm2, 95% CI = 1620 to 2717; P = .048), increased microvessel density (P = .004), vessel maturity (P = .006) and perfusion, and reduced intratumoral hypoxia (P = .012), compared with sedentary controls. We also tested whether exercise could improve chemotherapy (cyclophosphamide) efficacy. Exercise plus chemotherapy prolonged growth delay compared with chemotherapy alone (P < .001) in the orthotopic 4T1 model (n = 17 per group). Exercise is a potential novel adjuvant treatment of breast cancer.


Background:

Previous studies have reported a breast cancer (BC) risk reduction of approximately 50% after risk-reducing salpingo-oophorectomy (RRSO) in BRCA1/2 mutation carriers, but may have been subject to several types of bias. The purpose of this nationwide cohort study was to assess potential bias in the estimated BC risk reduction after RRSO.

Methods:

We selected BRCA1/2 mutation carriers from an ongoing nationwide cohort study on Hereditary Breast and Ovarian Cancer in the Netherlands (HEBON). First, we replicated the analytical methods as previously applied in four major studies on BC risk after RRSO. Cox proportional hazards models were used to calculate hazard ratios and conditional logistic regression to calculate odds ratios. Secondly, we analyzed the data in a revised design in order to further minimize bias using an extended Cox model with RRSO as a time-dependent variable to calculate the hazard ratio. The most important differences between our approach and those of previous studies were the requirement of no history of cancer at the date of DNA diagnosis and the inclusion of person-time preceding RRSO.

Results:

Applying the four previously described analytical methods and the data of 551 to 934 BRCA1/2 mutation carriers with a median follow-up of 2.7 to 4.6 years, the odds ratio was 0.61 (95% confidence interval [CI] = 0.35 to 1.08), and the hazard ratios were 0.36 (95% CI = 0.25 to 0.53), 0.62 (95% CI = 0.39 to 0.99), and 0.49 (95% CI = 0.33 to 0.71), being similar to earlier findings. For the revised analysis, we included 822 BRCA1/2 mutation carriers. After a median follow-up period of 3.2 years, we obtained a hazard ratio of 1.09 (95% CI = 0.67 to 1.77).

Conclusion:

In previous studies, BC risk reduction after RRSO in BRCA1/2 mutation carriers may have been overestimated because of bias. Using a design that maximally eliminated bias, we found no evidence for a protective effect.



Background:

There is strong evidence that breast cancer risk is influenced by environmental factors. Blood lipid and lipoprotein levels are also influenced by environmental factors and are associated with some breast cancer risk factors. We examined whether serial measures of serum lipids and lipoproteins were associated with breast cancer risk.

Methods:

We carried out a nested case-control study within a randomized long-term dietary intervention trial with 4690 women with extensive mammographic density followed for an average of 10 years for breast cancer incidence. We measured lipids in an average of 4.2 blood samples for 279 invasive breast cancer case subjects and 558 matched control subjects. We calculated subaverages of lipids for each subject based on menopausal status and use of hormone replacement therapy (HRT) at blood collection and analyzed their association with breast cancer using generalized estimating equations. All statistical tests were two-sided.

Results:

High-density lipoprotein-cholesterol (HDL-C) (P = .05) and apoA1 (P = .02) levels were positively associated with breast cancer risk (75th vs 25th percentile: HDL-C, 23% higher; apoA1, 28% higher) and non-HDL-C (P = .03) and apoB (P = .01) levels were negatively associated (75th vs 25th percentile: non-HDL-C, 19% lower; apoB, 22% lower). These associations were observed only when lipids were measured when HRT was not used. Total cholesterol and triglyceride levels were not statistically significantly associated with breast cancer risk.

Conclusions:

These results demonstrate that serum lipids are associated with breast cancer risk in women with extensive mammographic density. The possibility that interventions for heart disease prevention, which aim to reduce non-HDL-C or raise HDL-C, may have effects on breast cancer risk merits examination.



Deleterious BRCA2 genetic variants markedly increase risk of developing breast cancer. A rare truncating BRCA2 genetic variant, rs11571833 (K3326X), has been associated with a 2.5-fold risk of lung squamous cell carcinoma but only a modest 26% increase in breast cancer risk. We analyzed the association between BRCA2 SNP rs11571833 and upper aerodigestive tract (UADT) cancer risk with multivariable unconditional logistic regression adjusted by sex and combinations of study and country for 5942 UADT squamous cell carcinoma case patients and 8086 control patients from nine different studies. All statistical tests were two-sided. rs11571833 was associated with UADT cancers (odds ratio = 2.53, 95% confidence interval = 1.89 to 3.38, P = 3x10-10) and was present in European, Latin American, and Indian populations but extremely rare in Japanese populations. The association appeared more apparent in smokers (current or former) compared with never smokers (P het = .026). A robust association between a truncating BRCA2 variant and UADT cancer risk suggests that treatment strategies orientated towards BRCA2 mutations may warrant further investigation in UADT tumors.



Background:

Data for multiple common susceptibility alleles for breast cancer may be combined to identify women at different levels of breast cancer risk. Such stratification could guide preventive and screening strategies. However, empirical evidence for genetic risk stratification is lacking.

Methods:

We investigated the value of using 77 breast cancer-associated single nucleotide polymorphisms (SNPs) for risk stratification, in a study of 33 673 breast cancer cases and 33 381 control women of European origin. We tested all possible pair-wise multiplicative interactions and constructed a 77-SNP polygenic risk score (PRS) for breast cancer overall and by estrogen receptor (ER) status. Absolute risks of breast cancer by PRS were derived from relative risk estimates and UK incidence and mortality rates.

Results:

There was no strong evidence for departure from a multiplicative model for any SNP pair. Women in the highest 1% of the PRS had a three-fold increased risk of developing breast cancer compared with women in the middle quintile (odds ratio [OR] = 3.36, 95% confidence interval [CI] = 2.95 to 3.83). The ORs for ER-positive and ER-negative disease were 3.73 (95% CI = 3.24 to 4.30) and 2.80 (95% CI = 2.26 to 3.46), respectively. Lifetime risk of breast cancer for women in the lowest and highest quintiles of the PRS were 5.2% and 16.6% for a woman without family history, and 8.6% and 24.4% for a woman with a first-degree family history of breast cancer.

Conclusions:

The PRS stratifies breast cancer risk in women both with and without a family history of breast cancer. The observed level of risk discrimination could inform targeted screening and prevention strategies. Further discrimination may be achievable through combining the PRS with lifestyle/environmental factors, although these were not considered in this report.






Background:

Recent meta-analyses show strong evidence of associations among genetic variants in CHRNA5 on chromosome 15q25, smoking quantity, and lung cancer. This meta-analysis tests whether the CHRNA5 variant rs16969968 predicts age of smoking cessation and age of lung cancer diagnosis.

Methods:

Meta-analyses examined associations between rs16969968, age of quitting smoking, and age of lung cancer diagnosis in 24 studies of European ancestry (n = 29 072). In each dataset, we used Cox regression models to evaluate the association between rs16969968 and the two primary phenotypes (age of smoking cessation among ever smokers and age of lung cancer diagnosis among lung cancer case patients) and the secondary phenotype of smoking duration. Heterogeneity across studies was assessed with the Cochran Q test. All statistical tests were two-sided.

Results:

The rs16969968 allele (A) was associated with a lower likelihood of smoking cessation (hazard ratio [HR] = 0.95, 95% confidence interval [CI] = 0.91 to 0.98, P = .0042), and the AA genotype was associated with a four-year delay in median age of quitting compared with the GG genotype. Among smokers with lung cancer diagnoses, the rs16969968 genotype (AA) was associated with a four-year earlier median age of diagnosis compared with the low-risk genotype (GG) (HR = 1.08, 95% CI = 1.04 to 1.12, P = 1.1*10–5).

Conclusion:

These data support the clinical significance of the CHRNA5 variant rs16969968. It predicts delayed smoking cessation and an earlier age of lung cancer diagnosis in this meta-analysis. Given the existing evidence that this CHRNA5 variant predicts favorable response to cessation pharmacotherapy, these findings underscore the potential clinical and public health importance of rs16969968 in CHRNA5 in relation to smoking cessation success and lung cancer risk.


Background:

Survival after a diagnosis of breast cancer varies considerably between patients, and some of this variation may be because of germline genetic variation. We aimed to identify genetic markers associated with breast cancer–specific survival.

Methods:

We conducted a large meta-analysis of studies in populations of European ancestry, including 37954 patients with 2900 deaths from breast cancer. Each study had been genotyped for between 200000 and 900000 single nucleotide polymorphisms (SNPs) across the genome; genotypes for nine million common variants were imputed using a common reference panel from the 1000 Genomes Project. We also carried out subtype-specific analyses based on 6881 estrogen receptor (ER)–negative patients (920 events) and 23059 ER-positive patients (1333 events). All statistical tests were two-sided.

Results:

We identified one new locus (rs2059614 at 11q24.2) associated with survival in ER-negative breast cancer cases (hazard ratio [HR] = 1.95, 95% confidence interval [CI] = 1.55 to 2.47, P = 1.91 x 10–8). Genotyping a subset of 2113 case patients, of which 300 were ER negative, provided supporting evidence for the quality of the imputation. The association in this set of case patients was stronger for the observed genotypes than for the imputed genotypes. A second locus (rs148760487 at 2q24.2) was associated at genome-wide statistical significance in initial analyses; the association was similar in ER-positive and ER-negative case patients. Here the results of genotyping suggested that the finding was less robust.

Conclusions:

This is currently the largest study investigating genetic variation associated with breast cancer survival. Our results have potential clinical implications, as they confirm that germline genotype can provide prognostic information in addition to standard tumor prognostic factors.





Current dogma suggests that tumor-reactive IFN-–producing (TH1-type) T-cells are beneficial to patient outcome; however, the clinical consequence of these responses with respect to long-term prognosis in colorectal cancer (CRC) is not understood. Here, we compared the utility of preoperative, peripheral blood–derived IFN-+ T-cell responses specific to carcinoembryonic antigen (CEA), 5T4, or control antigens (n = 64) with tumor staging and clinical details (n = 87) in predicting five-year outcome of CRC patients who underwent resection with curative intent. Although disease recurrence was more likely in patients with stage III tumors, the presence of preoperative, CEA-specific IFN-–producing T-cells identified patients at a statistically significantly greater risk of tumor recurrence following surgical resection, irrespective of tumor stage (odds ratio = 5.00, 95% confidence interval = 1.96 to 12.77, two-sided P <.001). Responses to other antigens, including 5T4, did not reflect outcome. Whilst these results initially appear surprising, they could improve prognostication and help redirect adjuvant treatments.


Background:

Prior cancer is a common exclusion criterion in lung cancer trials. This practice reflects concerns that prior cancer may affect trial conduct or outcomes. However, the impact of prior cancer on survival in lung cancer is not known.

Methods:

We identified patients older than age 65 years with stage IV lung cancer diagnosed between 1992 and 2009 in the Surveillance, Epidemiology, and End Results–Medicare linked registry. Prior cancer was characterized by type, stage, and timing. All-cause and lung cancer–specific survival were compared between patients with and without prior cancer using propensity score–adjusted Cox regression.

Results:

Overall, 102 929 patients with stage IV lung cancer were identified, of whom 14.7% had a history of prior cancer. More than two-thirds (76.0%) of prior cancers were localized or regional stage; most were diagnosed five or fewer years prior to the lung cancer diagnosis. In propensity score–adjusted analysis, patients with prior cancer had better all-cause (hazard ratio [HR] = 0.93, 95% confidence interval [CI] = 0.91 to 0.94) and lung cancer–specific (HR = 0.81, 95% CI = 0.79 to 0.82) survival. In a simulated clinical trial–eligible population (age <75 years, no comorbidity, treated with chemotherapy), similar trends were noted. In subset analyses according to stage, type, and timing of prior cancer, no group of patients with prior cancer had inferior survival compared with patients without prior cancer.

Conclusion:

Among patients with stage IV lung cancer, prior cancer does not convey an adverse effect on clinical outcomes, regardless of prior cancer stage, type, or timing. Broader inclusion in clinical trials of advanced lung cancer patients with a history of prior cancer should be considered.


There is growing interest in the application of molecular profiling, including sequencing, genotyping, and/or mRNA expression profiling, to the analysis of patient tumors with the objective of applying these data to inform therapeutic choices for patients with advanced cancers. Multiple clinical trials that are attempting to validate this personalized or precision medicine approach are in various stages of development and execution. Although preliminary data from some of these efforts have fueled excitement about the value and utility of these studies, their execution has also provoked many questions about the best way to approach complicating factors such as tumor heterogeneity and the choice of which genetic mutations to target. This commentary highlights some of the challenges confronting the clinical application of molecular tumor profiling and the various trial designs being utilized to address these challenges. Randomized trials that rigorously test patient response to molecularly targeted agents assigned based on the presence of a defined set of mutations in putative cancer-driving pathways are required to address some of the current challenges and to identify patients likely to benefit from this approach.


Background:

ACRIN 6668/RTOG 0235 evaluated the prognostic value of positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) uptake before and after definitive, concurrent, platinum-based chemoradiotherapy for locally advanced non–small cell lung cancer (NSCLC). In this secondary analysis, we evaluate volumetric pretreatment PET measures as predictors of clinical outcomes.

Methods:

Patients with stage III NSCLC underwent FDG-PET prior to treatment. A commercially available gradient-based segmentation tool was used to contour all visible hypermetabolic lesions on each scan. For each patient, the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total glycolytic activity (TGA) for all contoured lesions were recorded. Cox proportional hazards regression models were used to evaluate clinical variables and PET metrics as predictors of overall survival (OS) and locoregional control (LRC). Time-dependent covariables were added to the models when necessary to address nonproportional hazards. All statistical tests were two-sided.

Results:

Complete data were available for 214 patients in the OS analysis and 189 subjects in the LRC analysis. In multivariable analysis incorporating clinical and imaging data available prior to treatment, MTV was an independent predictor of OS (HR = 1.04 per 10cm3 increase, 95% CI = 1.03 to 1.06, P < .001). High MTV was also associated with increased risk of locoregional failure at baseline (HR = 1.16 per 10cm3 increase, 95% CI = 1.08 to 1.23, P < .001) and at six months (HR = 1.05 per 10cm3 increase, 95% CI = 1.02 to 1.07, P < .001) but not at 12 months or later time points.

Conclusion:

Pretreatment MTV is a predictor of clinical outcomes for NSCLC patients treated with chemoradiotherapy. Quantitative PET measures may serve as stratification factors in clinical trials for this patient population and may help guide novel trial designs.


Background:

Colorectal cancer is the second leading cause of cancer death in the United States. Approximately 3% of colorectal cancers are associated with Lynch Syndrome. Controversy exists regarding the optimal screening strategy for Lynch Syndrome.

Methods:

Using an individual level microsimulation of a population affected by Lynch syndrome over several years, effectiveness and cost-effectiveness of 21 screening strategies were compared. Modeling assumptions were based upon published literature, and sensitivity analyses were performed for key assumptions. In a two-step process, the number of Lynch syndrome diagnoses (Step 1) and life-years gained as a result of foreknowledge of Lynch syndrome in otherwise healthy carriers (Step 2) were measured.

Results:

The optimal strategy was sequential screening for probands starting with a predictive model, then immunohistochemistry for mismatch repair protein expression (IHC), followed by germline mutation testing (incremental cost-effectiveness ratio [ICER] of $35 143 per life-year gained). The strategies of IHC + BRAF, germline testing and universal germline testing of colon cancer probands had ICERs of $144 117 and $996 878, respectively.

Conclusions:

This analysis suggests that the initial step in screening for Lynch Syndrome should be the use of predictive models in probands. Universal tumor testing and general population screening strategies are not cost-effective. When family history is unavailable, alternate strategies are appropriate. Documentation of family history and screening for Lynch Syndrome using a predictive model may be considered a quality-of-care measure for patients with colorectal cancer.


Background:

Chronic inflammation is involved in the development of colorectal cancer (CRC) and microsatellite instability (MSI), a distinct phenotype of CRC. Experimental evidence indicates an anti-inflammatory and antineoplastic effect of marine -3 polyunsaturated fatty acids (PUFAs). However, epidemiologic data remain inconclusive.

Methods:

We investigated whether the association between marine -3 PUFAs and CRC varies by MSI-defined subtypes of tumors in the Nurses’ Health Study and Health Professionals Follow-up Study. We documented and classified 1125 CRC cases into either MSI-high tumors, in which 30% or more of the 10 microsatellite markers demonstrated instability, or microsatellite-stable (MSS) tumors. Cox proportional hazards model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of MSS tumors and MSI-high tumors in relation to marine -3 PUFA intake. All statistical tests were two-sided.

Results:

Marine -3 PUFA intake was not associated with overall incidence of CRC. However, a statistically significant difference was detected by MSI status (P heterogeneity = .02): High marine -3 PUFA intake was associated with a lower risk for MSI-high tumors (comparing ≥0.30g/d with <0.10g/d: multivariable HR = 0.54, 95% CI = 0.35 to 0.83, P linearity = .03) but not MSS tumors (HR = 0.97, 95% CI = 0.78 to 1.20, P linearity = .28). This differential association appeared to be independent of CpG island methylator phenotype and BRAF mutation status.

Conclusions:

High marine -3 PUFA intake is associated with lower risk for MSI-high CRC but not MSS tumors, suggesting a potential role of -3 PUFAs in protection against CRC through DNA mismatch repair. Further research is needed to confirm our findings and elucidate potential underlying mechanisms.


Background:

Hodgkin lymphoma (HL) survivors are at increased risk for developing valvular heart disease (VHD). We evaluated the determinants of the risk and the radiation dose-response.

Methods:

A case-control study was nested in a cohort of 1852 five-year HL survivors diagnosed at ages 15 to 41 years and treated between 1965 and 1995. Case patients had VHD of at least moderate severity as their first cardiovascular diagnosis following HL treatment. Control patients were matched to case patients for age, gender, and HL diagnosis date. Treatment and follow-up data were abstracted from medical records. Radiation doses to heart valves were estimated by reconstruction of individual treatments on representative computed tomography datasets. All statistical tests were two-sided.

Results:

Eighty-nine case patients with VHD were identified (66 severe or life-threatening) and 200 control patients. Aortic (n = 63) and mitral valves (n = 42) were most frequently affected. Risks increased more than linearly with radiation dose. For doses to the affected valve(s) of less than or equal to 30, 31–35, 36–40, and more than 40 Gy, VHD rates increased by factors of 1.4, 3.1, 5.4, and 11.8, respectively (P trend < .001). Approximate 30-year cumulative risks were 3.0%, 6.4%, 9.3%, and 12.4% for the same dose categories. VHD rate increased with splenectomy by a factor of 2.3 (P = .02).

Conclusions:

Radiation dose to the heart valves can increase the risk for clinically significant VHD, especially at doses above 30 Gy. However, for patients with mediastinal involvement treated today with 20 or 30 Gy, the 30-year risk will be increased by only about 1.4%. These findings may be useful for patients and doctors both before treatment and during follow-up.


Background:

Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) are widely prescribed to reduce cholesterol levels. Studies have suggested that statins are associated with reduced risk for liver cancer, but much of the evidence is from regions of the world with high liver cancer incidence rates. The current study examined the statins–liver cancer relationship in a low-rate region and examined the effects of preexisting liver disease and diabetes on that association.

Methods:

A nested case-control study was conducted within the United Kingdom’s Clinical Practice Research Datalink (CPRD). Persons diagnosed with primary liver cancer between 1988 and 2011 were matched to controls at a four-to-one ratio. Matches stratified on liver disease and on diabetes were also completed. Odds ratios (ORs) and 95% confidence intervals (CIs) for associations of statins with liver cancer were estimated using conditional logistic regression.

Results:

In total, 1195 persons with primary liver cancer were matched to 4640 control patients. Statin use was associated with a statistically significantly reduced risk for liver cancer (ORadj = 0.55, 95% CI = 0.45 to 0.69), especially among current users (ORadj = 0.53, 95% CI = 0.42 to 0.66). The reduced risk was statistically significant in the presence (ORadj = 0.32, 95% CI = 0.17 to 0.57) and absence of liver disease (ORadj = 0.65, 95% CI = 0.52 to 0.81) and in the presence (ORadj = 0.30, 95% CI = 0.21 to 0.42) and absence of diabetes (ORadj = 0.66, 95% CI = 0.51 to 0.85).

Conclusions:

In the current study in a low-rate area, statin use was associated with a statistically significantly reduced risk for liver cancer overall. Risk was particularly reduced among persons with liver disease and persons with diabetes, suggesting that statin use may be especially beneficial in persons at elevated risk for liver cancer.


Background:

Neopterin may be relevant for colorectal cancer (CRC) development, as a biomarker of cellular immune activity exerting pleiotropic effects on cellular ageing, oxidative stress, and inflammation. So far, the association between prediagnostic neopterin and colon and rectal cancer risk has not been evaluated in human populations.

Methods:

A nested case-control study was conducted within the European Prospective Investigation into Cancer and Nutrition cohort using data on plasma concentrations of total neopterin (T-N, sum of neopterin and 7,8-dihydroneopterin) in 830 incident CRC case patients (561 colon and 269 rectal) matched within risk sets to 830 control participants. A subsequent replication study used data from the Hordaland Health Study, where 173 CRC case patients have been diagnosed among 6594 healthy participants over 12 years of follow-up.

Results:

After multivariable adjustment for a priori chosen CRC risk factors, a "U-shaped" association of T-N with CRC was revealed. Compared with the second quintile of the T-N distribution, the relative risks for the first, third, fourth, and fifth quintiles were 2.37 (95% CI = 1.66 to 3.39), 1.24 (95% CI = 0.87 to 1.77), 1.55 (95% CI = 1.08 to 2.22), and 2.31 (95% CI = 1.63 to 3.27), respectively. Replication of these associations within the Hordaland Health Study yielded similar results. No differences have been observed when the associations were explored by colon and rectal cancer site (two-sided P difference = .87) and after excluding case patients diagnosed within the first four follow-up years.

Conclusions:

These novel findings provide evidence of the role of both suppressed and activated cell-mediated immunity as reflected by prediagnostic T-N concentrations in the development of CRC.


Validation of early detection cancer biomarkers has proven to be disappointing when initial promising claims have often not been reproducible in diagnostic samples or did not extend to prediagnostic samples. The previously reported lack of rigorous internal validity (systematic differences between compared groups) and external validity (lack of generalizability beyond compared groups) may be effectively addressed by utilizing blood specimens and data collected within well-conducted cohort studies. Cohort studies with prediagnostic specimens (eg, blood specimens collected prior to development of clinical symptoms) and clinical data have recently been used to assess the validity of some early detection biomarkers. With this background, the Division of Cancer Control and Population Sciences (DCCPS) and the Division of Cancer Prevention (DCP) of the National Cancer Institute (NCI) held a joint workshop in August 2013. The goal was to advance early detection cancer research by considering how the infrastructure of cohort studies that already exist or are being developed might be leveraged to include appropriate blood specimens, including prediagnostic specimens, ideally collected at periodic intervals, along with clinical data about symptom status and cancer diagnosis. Three overarching recommendations emerged from the discussions: 1) facilitate sharing of existing specimens and data, 2) encourage collaboration among scientists developing biomarkers and those conducting observational cohort studies or managing healthcare systems with cohorts followed over time, and 3) conduct pilot projects that identify and address key logistic and feasibility issues regarding how appropriate specimens and clinical data might be collected at reasonable effort and cost within existing or future cohorts.


The aim of cancer screening is to detect asymptomatic cancers whose treatment will result in extension of life, relative to length of life absent screening. Unfortunately, cancer screening also results in overdiagnosis, the detection of cancers that, in the absence of screening, would not present symptomatically during one’s lifetime. Thus, their detection and subsequent treatment is unnecessary and detrimental. This definition of overdiagnosis, while succinct, does not capture the ways it can occur, and our interactions with patients, advocates, researchers, clinicians, and journalists have led us to believe that the concept of overdiagnosis is difficult to explain and, for some, difficult to accept. We propose a dichotomy, the "tumor-patient" classification, to aid in understanding overdiagnosis. The tumor category includes asymptomatic malignant disease that would regress spontaneously if left alone, as well as asymptomatic malignant disease that stagnates or progresses too slowly to be life threatening in even the longest of lifetimes. The patient category includes asymptomatic malignant disease that would progress quickly enough to be life threatening during a lifetime of typical length, but lacks clinical relevance because death due to another cause intercedes prior to what would have been the date of symptomatic diagnosis had screening not occurred. Cancer screening of most organs is likely to result in overdiagnosis of both types. However, the ratio of tumor- to patient-driven overdiagnosis almost certainly varies, and may vary drastically, by organ, screening modality, patient characteristics, and other factors.


Background:

Matrix metalloproteinase (MMP) 14 may mediate tumor progression through vascular and immune-modulatory effects.

Methods:

Orthotopic murine breast tumors (4T1 and E0771 with high and low MMP14 expression, respectively; n = 5–10 per group) were treated with an anti-MMP14 inhibitory antibody (DX-2400), IgG control, fractionated radiation therapy, or their combination. We assessed primary tumor growth, transforming growth factor β (TGFβ) and inducible nitric oxide synthase (iNOS) expression, macrophage phenotype, and vascular parameters. A linear mixed model with repeated observations, with Mann-Whitney or analysis of variance with Bonferroni post hoc adjustment, was used to determine statistical significance. All statistical tests were two-sided.

Results:

DX-2400 inhibited tumor growth compared with IgG control treatment, increased macrophage numbers, and shifted the macrophage phenotype towards antitumor M1-like. These effects were associated with a reduction in active TGFβ and SMAD2/3 signaling. DX-2400 also transiently increased iNOS expression and tumor perfusion, reduced tissue hypoxia (median % area: control, 20.2%, interquartile range (IQR) = 6.4%-38.9%; DX-2400: 1.2%, IQR = 0.2%-3.2%, P = .044), and synergistically enhanced radiation therapy (days to grow to 800mm3: control, 12 days, IQR = 9–13 days; DX-2400 plus radiation, 29 days, IQR = 26–30 days, P < .001) in the 4T1 model. The selective iNOS inhibitor, 1400W, abolished the effects of DX-2400 on vessel perfusion and radiotherapy. On the other hand, DX-2400 was not capable of inducing iNOS expression or synergizing with radiation in E0771 tumors.

Conclusion:

MMP14 blockade decreased immunosuppressive TGFβ, polarized macrophages to an antitumor phenotype, increased iNOS, and improved tumor perfusion, resulting in reduced primary tumor growth and enhanced response to radiation therapy, especially in high MMP14-expressing tumors.


Background:

Survivors of Hodgkin’s lymphoma (HL) treated as adults are at risk for late effects of therapy. However, the burden of late morbidity and mortality among adults treated for HL remains incompletely characterized.

Methods:

Vital status and, for deceased, cause of death were determined for 746 adults treated on a first-line trial at a single center from 1975 to 2000. Survivors completed a detailed survey describing their physical and mental health. A severity score (grades 1–4, ranging from mild to life-threatening or disabling) was assigned to self-reported conditions.

Results:

At a median follow-up of 22 years, 227 of patients (30.4%) had died, 107 (47.1%) from HL, 120 (52.9%) from other causes, including second primary malignancies (SPMs) (n = 52) and cardiovascular disease (n = 27). Across the duration of follow-up, all-cause and SPM-specific risk of death remained higher than predicted by normative data. Among survivors, late morbidity survey data are available for 238 patients (45.9%). Ninety-four-point-one percent of respondents reported at least one morbidity, and 47.5% reported at least one grade 3 or 4 morbidity; 20.2% reported two or more grade 3 morbidities. Commonly reported morbidities included cardiovascular (54.6%), endocrine (68.5%), pulmonary disease (21.4%), and nonfatal second malignancy (23.1%). Anxiety, depression, and fear of recurrence were frequently reported.

Conclusions:

Among a large cohort of patients treated for HL with extensive follow-up, risk of late mortality from causes other than HL and prevalence of late medical morbidity are high. Guidelines for prevention, screening, and management of late effects in adult survivors of HL are needed.





























Background:

Nearly 900 000 people in the United States are living with diagnosed human immunodeficiency virus (HIV) infection and therefore increased cancer risk. The total number of cancers occurring among HIV-infected people and the excess number above expected background cases are unknown.

Methods:

We derived cancer incidence rates for the United States HIV-infected and general populations from Poisson models applied to linked HIV and cancer registry data and from Surveillance, Epidemiology, and End Results program data, respectively. We applied these rates to estimates of people living with diagnosed HIV at mid-year 2010 to estimate total and expected cancer counts, respectively. We subtracted expected from total cancers to estimate excess cancers.

Results:

An estimated 7760 (95% confidence interval [CI] = 7330 to 8320) cancers occurred in 2010 among HIV-infected people, of which 3920 cancers (95% CI = 3480 to 4470) or 50% (95% CI = 48 to 54%) were in excess of expected. The most common excess cancers were non-Hodgkin’s lymphoma (NHL; n = 1440 excess cancers, occurring in 88% excess), Kaposi’s sarcoma (KS, n = 910, 100% excess), anal cancer (n = 740, 97% excess), and lung cancer (n = 440, 52% excess). The proportion of excess cancers that were AIDS defining (ie, KS, NHL, cervical cancer) declined with age and time since AIDS diagnosis (both P < .001). For anal cancer, 83% of excess cases occurred among men who have sex with men, and 71% among those living five or more years since AIDS onset. Among injection drug users, 22% of excess cancers were lung cancer, and 16% were liver cancer.

Conclusions:

The excess cancer burden in the US HIV population is substantial, and patterns across groups highlight opportunities for cancer control initiatives targeted to HIV-infected people.


Background:

Resistance to microtubule-stabilizing agents is a major hurdle for successful cancer therapy. We investigated combined treatment of microtubule-stabilizing agents (MSAs) with inhibitors of angiogenesis to overcome MSA resistance.

Methods:

Treatment regimens of clinically relevant MSAs (patupilone and paclitaxel) and antiangiogenic agents (everolimus and bevacizumab) were investigated in genetically defined MSA-resistant lung (A549EpoB40) and colon adenocarcinoma (SW480) tumor xenografts in nude mice (CD1-Foxn1<nu>, ICRnu; 5–14 per group). Tumor growth delays were calculated by Kaplan-Meier analysis with Holm-Sidak tests. All statistical tests were two-sided.

Results:

Inhibition of mTOR-kinase by everolimus only minimally reduced the proliferative activity of β tubulin–mutated lung adenocarcinoma cells alone and in combination with the MSA patupilone, but everolimus inhibited expression and secretion of vascular endothelial growth factor (VEGF) from these cells. mTOR-kinase inhibition strongly sensitized tumor xenografts derived from these otherwise MSA-resistant tumor cells to patupilone. Tumors treated with the combined modality of everolimus and patupilone had statistically significantly reduced tumor volume and stronger tumor growth delay (16.2±1.01 days) than control- (7.7±0.3 days, P = .004), patupilone- (10±0.97 days, P = .009), and everolimus-treated (10.6±1.4 days, P = .014) tumors. A combined treatment modality with bevacizumab also resensitized this MSA-refractory tumor model to patupilone. Treatment combination also strongly reduced microvessel density, corroborating the relevance of VEGF targeting for the known antivasculature-directed potency of MSA alone in MSA-sensitive tumor models. Resensitization to MSAs was also probed in P glycoprotein–overexpressing SW480-derived tumor xenografts. Different bevacizumab regimens also sensitized this otherwise-resistant tumor model to clinically relevant MSA paclitaxel.

Conclusions:

A treatment combination of MSAs with antiangiogenic agents is potent to overcome tumor cell–linked MSA resistance and should be considered as strategy for MSA-refractory tumor entities.


Background:

The functions of long noncoding RNAs (lncRNAs) have been identified in several cancers, but the roles of lncRNAs in colorectal cancer (CRC) are less well understood. The transcription factor MYC is known to regulate lncRNAs and has been implicated in cancer cell proliferation and tumorigenesis.

Methods:

CRC cells and tissues were profiled to identify lncRNAs differentially expressed in CRC, from which we further selected MYC-regulated lncRNAs. We used luciferase promoter assay, ChIP, RNA pull-down assay, deletion mapping assay, LC-MS/MS and RNA immunoprecipitation to determine the mechanisms of MYC regulation of lncRNAs. Moreover, soft agar assay and in vivo xenograft experiments (four athymic nude mice per group) provided evidence of MYC-regulated lncRNAs in cancer cell transformation and tumorigenesis. The Kaplan-Meier method was used for survival analyses. All statistical tests were two-sided.

Results:

We identified lncRNAs differentially expressed in CRC (P < .05, greater than two-fold) and verified four lncRNAs upregulated and two downregulated in CRC cells and tissues. We further identified MYC-regulated lncRNAs, named MYCLos. The MYC-regulated MYCLos may function in cell proliferation and cell cycle by regulating MYC target genes such as CDKN1A (p21) and CDKN2B (p15), suggesting new regulatory mechanisms of MYC-repressed target genes through lncRNAs. RNA binding proteins including HuR and hnRNPK are involved in the function of MYCLos by interacting with MYCLo-1 and MYCLo-2, respectively. Knockdown experiments also showed that MYCLo-2, differentially expressed not only in CRC but also in prostate cancer, has a role in cancer transformation and tumorigenesis.

Conclusions:

Our results provide novel regulatory mechanisms in MYC function through lncRNAs and new potential lncRNA targets of CRC.