My research focuses on clinical and nutritional epidemiology of cancer. Specifically, my work integrates large-scale observational studies with biomarker-based randomized clinical trials to identify novel nutritional and gut microbiota-targeted strategies for 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.
Another area of my research focuses on sessile serrated adenoma/polyp (SSA/P), a newly recognized precursor lesion for colorectal cancer. Because SSA/P remained unrecognized in pathology and gastroenterology practice until 2003-2005, very little is known about its etiology and natural history, and, as a consequence, the current clinical guidelines for the disease management are very poorly developed and largely non-evidence-based. To address this significant knowledge gap, I am leveraging various data sources, including the Harvard cohort studies, the Partners Research Patient Data Registry (RPDR), and the nationwide histopathology database in Sweden, to investigate the risk factors and molecular biomarkers of SSA/P as well as the influence of SSA/P on subsequent risk of colorectal cancer incidence and mortality. The goal of my research is to provide scientific evidence to improve the current clinical guidelines of SSA/P management, including tailored screening and surveillance colonoscopy, for better prevention of colorectal cancer.
I am also 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, and a member of the Cancer Epidemiology and Gastrointestinal Malignancies Programs at Dana-Farber / Harvard Cancer Center.