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Andrew T. Chan, MD, MPH - Chief / Director

Dr. Andrew T. Chan is Chief of the Clinical and Translational Epidemiology Unit (CTEU) at Massachusetts General Hospital (MGH), Director of Cancer Epidemiology at the MGH Cancer Center, Daniel K. Podolsky Professor of Medicine at Harvard Medical School (HMS), and Professor of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health. He also co-leads the Cancer Epidemiology Program at the Dana-Farber Harvard Cancer Center. His research broadly aims to advance epidemiological investigation for the translation of discoveries into effective clinical interventions. His current focus is on chronic digestive diseases, including gastrointestinal cancer (colorectal, esophageal, gastric), inflammatory bowel disease, diverticulitis, and gastrointestinal bleeding. His group utilizes molecular approaches encompassing genetic, metabolomic, proteomic, and biochemical platforms applied to populations ranging from large cohort studies to small biomarker-driven clinical trials. He also has an active program studying the oral and gut microbiome as a determinant and mediator of chronic disease.


Dr. Chan earned his MD from Harvard Medical School and a MPH from Harvard T.H. Chan School of Public Health. He completed his internal medicine residency, chief residency, and gastroenterology fellowship at MGH. He is the Stuart and Suzanne Steele MGH Research Scholar. He is an Elected Fellow of the American Society of Clinical Investigation. His work is supported by grants from the National Cancer Institute, the National Institute for Diabetes, Digestive and Kidney Diseases, the National Institutes of Aging, Stand Up to Cancer, Cancer Research UK, the Crohn’s and Colitis Foundation, and the Damon Runyon Cancer Research Foundation. He is chair of the GI Oncology section of the American Gastroenterological Association Council and the Molecular Epidemiology Group of the American Association for Cancer Research. 

Dana Farber/Harvard Cancer Center (DF/HCC)


Biomarker trial of aspirin in colorectal neoplasia (ASPIRED and ASPIRED-XT)

We recently completed ASPIRED, an NCI-funded, randomized, clinical trial of aspirin among patients with a history of colorectal adenoma in relation to several cancer-specific biomarkers. We constructed a “living biobank” in which we developed organoid models from colon tissue collected from study participants. We are now conducting multi-omic profiling of biospecimens from the study, including plasma markers, stool, and organoid models. We are also beginning a second phase of the study in which we will recruit older adults into an expansion trial. In collaboration with leading stem cell biologists, we will use this trial population to examine the effect of aspirin on colon stem cells in different age groups.

Role of aspirin on age-related outcomes (ASPREE-XT)

We are co-leading the off-trial, observational 5-year follow-up study of the ASPirin in Reducing Events in the Elderly (ASPREE) randomized controlled trial (RCT) of low dose aspirin conducted among 19,114 initially healthy individuals ³65 years. This ASPREE-XT study will leverage deep phenotyping of ASPREE participants with genetic profiling, lifestyle and diet questionnaires, biochemical measures, and in person annual face-to-face visits (ASPREE-XT). 


Epidemiology of the oral and gut microbiome

We have initiated or completed several prospective collections of the oral and gut microbiome to examine key questions regarding the association of the microbiome in relation to risk of several chronic diseases, including colorectal cancer, diverticulitis, and age-associated conditions such as dementia and disability. We collaborate closely with leading immunologists, computational biologists, microbiologists, and biostatisticians in this field.

Molecular imaging of gastrointestinal neoplasia

We are leading a clinical trial to translate novel near infrared activatable agents that selectively target tumor-specific cathepsin proteases. We are using these agents with fluorescent imaging devices to enhance the early detection of gastrointestinal neoplasia.


Early detection and interception of gastric cancer

We are leading the Stand Up to Cancer Gastric Cancer Interception Team, an international, multidisciplinary, multi-institutional collaborative to identify novel modalities of early detection and interception of both intestinal-type gastric cancer and diffuse-type gastric cancer.  Our team leverages complementary expertise with a robust bench-to-bedside pipeline to maximize improvement of early detection tools with potential for wide-spread clinical incorporation in a clinically relevant timeline. 


Role of Marine ω-3 Polyunsaturated Fatty Acid Intake and colorectal cancer survival

With collaborators in Leeds, UK, we are leveraging a recently launched, randomized placebo-controlled phase III randomized trial of daily eicosapentaenoic acid (EPA), a naturally-occurring marine omega-3 polyunsaturated fatty acid treatment on survival among patients undergoing liver resection surgery for colorectal cancer livers metastases (EPA for Metastasis Trial 2). Using tissue specimens collected from the post-treatment liver resection, and blood, urine, and stool samples we will interrogate immune and microbiome pathways in relation to survival.

Epidemiology of colorectal adenoma and cancer

We are leading several studies in the prevention of colorectal adenoma and cancer using chemopreventative drugs and lifestyle interventions. We are also focused on genetic and biochemical markers that may be used to stratify risk of colorectal cancer for individuals, as well as predict responsiveness to various interventions.

Epidemiology of gastrointestinal bleeding

We focus on lifestyle risk factors for gastrointestinal bleeding, including intake of medications such as aspirin and NSAIDs, in relation to genetic and biochemical risk factors.

Epidemiology of inflammatory bowel disease

We are examining lifestyle and dietary factors and risk of incident Crohn’s disease and ulcerative colitis. Based on this work, we will ultimately examine how these factors interact with known genetic risk loci and circulating metabolomic profiles for Crohn’s and ulcerative colitis.

Epidemiology of diverticulitis

We are studying the association of diet, lifestyle, and the gut microbiome with risk of incident diverticulitis using large, population-based cohorts.


Genomic landscape of interval cancers

We are using state-of-the art genome sequencing techniques to identify molecular markers of colorectal cancers which evade traditional endoscopic detection. We will examine the role of these markers in predicting the risk of adenomatous polyps that arise within a short interval.

Genetic epidemiology of colorectal cancer

We are members of a national consortium of epidemiological studies of colorectal cancer which is examining the role of germline genetic risk and colorectal cancer according to somatic mutational profiles. The primary focus is to investigate the interaction between known environmental risk factors for colorectal cancer and genetic risk loci, as well as the interaction between germline genetic risk factors and colorectal cancers defined by molecular subtypes.


Epidemiology of COVID-19

We established the COronavirus Pandemic Epidemiology (COPE) Consortium with the support of the Massachusetts Consortium on Pathogen Readiness (MassCPR). This international collaboration of researchers has implemented the COVID Symptom Study (CSS) mobile phone application which asks individuals to log how they are feeling, even when they are well, to capture individuals that experience possible symptoms related to COVID-19 and testing results in real-time. The CSS has enrolled more than 4.5 million individuals in the United States, United Kingdom, and Sweden. We are using this data to define risk factors contributing to incidence of COVID-19 among the general population and those at high risk, including those with cancer, frontline healthcare workers, and racial and ethnic minority communities.

Key Publications

Chan AT, Ogino S, Fuchs CS. Aspirin and the risk of colorectal cancer in relation to the expression of COX-2. N Engl J Med 2007; 356:2131-2142. PMC- Published before April 2007.

Liao X, Lochhead P, Nishihara R, Morikawa T, Kuchiba A, Yamauchi M, Imamura Y, Qian Z, Baba Y, Shima K, Meyerhardt JA, Giovannucci E, Fuchs CS,† Chan AT,† Ogino S † (co-senior authors). Aspirin use, PIK3CA mutation, and colorectal cancer survival. N Engl J Med 2012; 367:1596-606.  PMCID: PMC3532946

Nishihara R, Lochhead P, Kuchiba A, Jung S, Yamauchi M, Liao X, Imamura Y, Qian ZR, Morikawa T, Wang M, Spiegelman D, Cho E, Giovannucci E, Fuchs CS, Chan AT,† Ogino S † († co-senior authors).  Aspirin use and risk of colorectal cancer according to BRAF mutation status. JAMA 2013;309:2563-71. PMCID: PMC3743040

Nishihara R, Wu K, Lochhead P, Morikawa T, Liao X, Qian ZR, Inamura K, Kim SA, Kuchiba A, Yamauchi M, Imamura Y, Willett WC, Rosner BR, Fuchs CS, Giovannucci E, Ogino S, Chan AT.   Long-term colorectal-cancer incidence and mortality after lower endoscopy.  N Engl J Med 2013; 369(12):1095-105.  PMCID: PMC38401604

Fink SP, Yamauchi M, Nishihara R, Jung S, Kuchiba A, Wu K, Cho E, Giovannucci E, Fuchs CS, Ogino S, Markowitz SD, Chan AT. Aspirin and the risk of colorectal cancer in relation to the expression of 15-hydroxyprostaglandin dehydrogenase (HPGD).  Sci Transl Med 2014;6:233re2.  PMCID: PMC4030641

Nan H, … (49 co-authors)…, Peters U, Hsu L, Chan AT. Association of aspirin and NSAID use with risk of colorectal cancer according to genetic variants. JAMA. 2015 Mar 17.  PMCID: PMC4382867

Song M, Nishihara R, Cao Y, Chun E, Qian ZR, Mima K, Inamura K, Masugi Y, Nowak JA, Nosho K, Wu K, Wang M, Giovannucci E, Garrett WS, Fuchs CS, Ogino S, Chan AT. Marine ω-3 Polyunsaturated Fatty Acid Intake and Risk of Colorectal Cancer Characterized by Tumor-Infiltrating T Cells. JAMA Oncol. 2016 Sep 1;2(9):1197-206.  PMCID: PMC5016204

Cao Y, Nishihara R, Wu K, Wang M, Ogino S, Willett WC, Spiegelman D, Fuchs CS, Giovannucci EL, Chan AT. Population-wide impact of long-term use of aspirin and the risk for cancer. JAMA Oncol 2016 Mar 3. PMCID: PMC4900902

Simon TG, Ma Y, Ludvigsson JF, Chong DQ, Giovannucci EL, Fuchs CS, Meyerhardt JA, Corey KE, Chung RT, Zhang X, Chan AT.  Association between aspirin use and risk of hepatocellular carcinoma. JAMA Oncol. 2018 Oct 4. PMCID: PMC6440745

Mehta RS, Abu-Ali G, Drew DA, Lloyd-Price J, Subramanian A, Lochhead P, Joshi AD, Ivey KL, Khalili H, Brown GT, DuLong C, Song M, Nguyen LH, Mallick H, Rimm EB, Izard J, Huttenhower C,† Chan AT †  (†co-senior authors). Stability of the human fecal microbiome in a cohort of adult men. Nature Microbiol. 2018. PMCID: PMC6016839

Nguyen LH, Ma W, Wang DD, Cao Y, Mallick H, Gerbaba TK, Lloyd-Price J, Abu-Ali G, Hall AB, Sikavi D, Drew DA, Mehta RS, Arze C, Joshi AD, Yan Y, Branck T, DuLong C, Ivey KL, Ogino S, Rimm EB, Song M, Garrett WS, Izard J, Huttenhower C, Chan AT. Gastroenterology. Association between sulfur-metabolizing bacterial communities in stool and risk of distal colorectal cancer. 2020;158(5):1313-1325. PMCID: PMC7384232

McNeil JJ, Gibbs P, Orchard SG, Lockery JE, Bernstein WB, Cao Y, Ford L, Haydon A, Kirpach B, Macrae F, McLean C, Millar J, Murray AM, Nelson MR, Polekhina G, Reid CM, Richmond E, Rodríguez LM, Shah RC, Tie J, Umar A, van Londen GJ, Ronaldson K, Wolfe R, Woods RL, Zalcberg J, Chan AT; ASPREE Investigator Group. Effect of aspirin on cancer incidence and mortality in older adults. J Natl Cancer Inst. 2020;djaa114. doi:10.1093/jnci/djaa114. PMC Journal

Drew DA….(30 co-authors)….Chan AT. Effect of low-dose and standard-dose aspirin on PGE2 biosynthesis among individuals with colorectal adenomas: a randomized clinical trial. Cancer Prev Res (Phila). 2020 Jul 27. NIHMS 1614248

Drew DA, Nguyen LH, Steves CJ, Menni C, Freydin M, Varsavsky T, Sudre CH, Cardoso MJ, Ourselin S, Wolf J, Spector TD, Chan AT; COPE Consortium. Rapid implementation of mobile technology for real-time epidemiology of COVID-19. Science. 2020;368(6497):1362-1367. doi:10.1126/science.abc0473.  PMCID: PMC7200009

Nguyen LH, Drew DA, Graham MS, Joshi AD, Guo CG, Ma W, Mehta RS, Warner ET, Sikavi DR, Lo CH, Kwon S, Song M, Mucci LA, Stampfer MJ, Willett WC, Eliassen AH, Hart JE, Chavarro JE, Rich-Edwards JW, Davies R, Capdevila J, Lee KA, Lochlainn MN, Varsavsky T, Sudre CH, Cardoso MJ, Wolf J, Spector TD, Ourselin S, Steves CJ, Chan AT; COronavirus Pandemic Epidemiology Consortium. Risk of COVID-19 among front-line health-care workers and the general community: a prospective cohort study. Lancet Public Health. 2020;5(9):e475-e483. doi:10.1016/S2468-2667(20)30164-X

Group Members

David Drew, PhD, Director of Biobanking

Takuma Higurashi, MD, Postdoctoral Fellow

Connor Geraghty, PhD, Postdoctoral Fellow

Yiqing Wang, PhD, Postdoctoral Fellow

Keming Yang, PhD, Postdoctoral Fellow

Marina Magiceva-Gupta, Clinical Research Project Manager

Betsy Prezioso, Clinical Research Coordinator

Trenton Reinicke, Clinical Research Coordinator

Rebecca Rojas, Research Technician

Janavi Sethurathnam, Clinical Research Coordinator

Jacqueline Woo, Clinical Research Coordinator

Alex Caraballo, Research Technician

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