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Cancer Disparities

CanCORS: Understanding the reasons for cancer care disparities

Jane Weeks, MD, MSc, ScM (DFCI), co-leader of the DF/HCC Outcomes Research Program, was convinced she knew why elderly patients with colorectal cancer were much less likely to receive adjuvant chemotherapy than were their younger counterparts. “These patients never get a chance to talk with medical oncologists,” she hypothesized, “because surgeons think they’re too old and don’t refer them.” But a recent study of the Cancer Care Outcomes Research and Surveillance (CanCORS) Consortium, funded by the National Cancer Institute, proved otherwise.

“Without this study, I would have designed a fix to the system that was a waste of time,” says Weeks, giving a grateful nod to the rigorous research that proved her wrong. “I would have tried to intervene in the referral process and had no impact because that process is working just fine.”  

Finding and fixing what’s broken in the cancer care system is no simple matter. But the CanCORS Consortium, comprising eight teams of investigators nationwide, is exploring the reasons for differences in care and outcomes − and getting some surprising answers. Under this new research model, the Consortium is conducting prospective observational studies of 10,000 patients with newly diagnosed lung or colorectal cancer who have been recruited from diverse populations and health care delivery systems. By 2007, investigators had collected and shared data from three primary sources − physician surveys, patient surveys, and medical records − to ask a series of high-priority research questions.

DF/HCC researchers are at the center of this effort: while Weeks and John Ayanian, MD, MPP (HMS/BWH) are principal investigators of two of the seven data collection and research sites, David Harrington, PhD (DFCI) directs the statistical coordinating center. “CanCORS has been a focus of intense work over the last five years, giving us a nidus for collaboration that has been very positive for the outcomes program,” says Weeks.

Explaining the steep age-gradient

One key question in the study was why adjuvant chemotherapy was used much less often for patients over 75 with colorectal cancer, despite evidence that it reduces recurrences and improves overall survival for all age groups. Contrary to Weeks’ hunch, virtually all patients, regardless of age, did have the opportunity to consult with a medical oncologist, though some patients chose not to. The real problem was that medical oncologists were “not keen on giving therapy to older patients,” says Weeks. Combing thousands of medical records, investigators found that in two-thirds of the elderly patients who did not receive chemotherapy, the oncologist had deemed treatment unnecessary;  factors such as post-operative complications explained only a small fraction of the steep age-gradient. (One positive finding to emerge from the data, says Weeks, was that there were no differences in treatment by race.)  

Reluctance to treat elderly patients stems, in part, from uncertainty about the effects of chemotherapy on these patients, as Nancy Keating, MD, MPH (HMS) found in an analysis of the physician survey. Although a small number of trials in elderly patients have shown that they tolerate chemotherapy well and derive as much benefit as do younger patients, says Weeks, “Clinical trials are so focused on younger patients that we don’t have the same quality of evidence about how to treat the typical colon cancer patient” – who is over 65 – suggesting the need for new randomized trials in this age group. Data from the CanCORS study also suggest that oncologists need to be better educated about the risk-benefit ratio of treatment before making decisions for patients.

Although the CanCORS Consortium is in its last year, Weeks and Ayanian are now writing a proposal to continue studying the 10,000 patients over a longer term. “We’ve tracked this group of people about whom we know an amazing amount of information,” says Weeks. “It would be crazy not to follow up and see what happens.”

—Lonnie Christiansen