I am a board-certified gastroenterologist with a special interest in the screening for and surveillance and management of polyps, colon cancer, and gastrointestinal diseases. I have been on staff at Memorial Sloan Kettering since 1968 and now hold the hospital’s Paul Sherlock Chair in Medicine. I am also a Professor of Medicine at Weill Cornell Medical College.
Over my career I have made significant contributions to the prevention and diagnosis of colorectal cancer. Under my leadership the National Polyp Study determined that removing polyps prevents colorectal cancer. I introduced colonoscopy for screening as chair of the US Multisociety Task Force guidelines committee. I headed the World Health Organization Collaborating Center for the Prevention of Colorectal Cancer, which established guidelines for the prevention of colorectal cancer. I am past President of the American College of Gastroenterology, and am Co-Chair of the International Digestive Cancer Alliance, which has initiated a worldwide campaign to increase awareness and prevention of digestive cancers. I am also co-chair of the New York City Department of Health colorectal cancer screening campaign.