Gastroenterologists spend much of their working lives focused on cancer prevention through an array of approaches, including screening and surveillance colonoscopy, endoscopic surveillance of Barrett’s esophagus, investigating pancreatic cysts noted incidentally, and investigating symptoms that patients are concerned may be the harbingers of malignancy. Helicobacter pylori eradication should also be considered an important element of cancer prevention, because it has the potential of decreasing gastric cancer by about 50%.