My research focuses on clinical and translational epidemiology of cancer. One aspect of my work is to integrate large-scale observational studies with biomarker-based randomized clinical trials to identify novel nutritional and gut microbiota-targeted strategies for cancer prevention and treatment. Another part of my work involves integration of electronic health record (EHR) data with molecular profiling for developing cost-effective risk assessment tools for precision cancer screening and surveillance. I was awarded the NextGen Star by the American Association for Cancer Research. My current research is supported by the National Cancer Institute and American Cancer Society. The ultimate goal of my research is to translate epidemiologic advances into the clinic for improved cancer prevention and treatment.
1. Diet/Lifestyle, Gut Microbiome, and Cancer Prevention and Treatment
Over the past few years, I have studied the role of diet and lifestyle factors, in conjunction with host immune factors and the gut microbiota, in colorectal cancer development and survivorship. Much of my work has been based on three large prospective cohort studies, the Nurses’ Health Study I and II, and the Health Professionals Follow-up Study, in which diet, lifestyle and colorectal cancer diagnosis and mortality have been assessed over decades with blood, stool, and tumor tissue specimens collected in a subset of participants. Building on the findings from observational studies, I am leading two biomarker-based clinical trials of omega-3 fatty acid treatment in colon cancer patients (supported by the American Cancer Society) and individuals with a history of colorectal adenoma resection (supported by the National Cancer Institute) at Massachusetts General Hospital to investigate causality and explore the potential for future clinical translation. I am also chairing the Microbiome Epidemiology Working Group (MEWG) at Harvard Chan School, and serving as a co-investigator of the Microbiome among Nurses Study (MICRO-N), which aims to establish the world’s largest prospective collection of microbiome specimens from 25,000 individuals.
2. Integration of EHR and Molecular Data for Precision Cancer Screening and Surveillance
While substantial advances have been made in epidemiology to identify environmental and genetic risk factors, this knowledge has not yet been effectively translated into the clinic for better patient care. A particular example is the age-based or “one-size-fits-all” colonoscopy screening approach that does not take into account the individual variation in colorectal cancer risk. Similar issue occurs to colonoscopy surveillance after polypectomy, where histopathologic features of polyps that are being used in clinical guidelines demonstrate poor sensitivity in predicting subsequent risk of colorectal neoplasia. As result, lower-risk patients can undergo unnecessary excess testing, whereas higher-risk patients may receive delayed or no testing. To address these gaps, I am building a longitudinal cohort of patients who had undergone repeated colonoscopy exams in the Partners HealthCare. Detailed clinical and epidemiologic data are being extracted from the EHR systems supplemented by use of validated natural language processing algorithms; and then linked to the state cancer registry for cancer incidence and to the Partners Biobank for genomic information. Tissue specimens will be collected from the pathology departments for tumor profiling. This integrated cohort will allow us to identify novel biomarkers for early detection, validate prediction models in the real clinical setting, and develop and evaluate clinically applicable risk assessment tools for precision screening and surveillance.