Patients undergo baseline colonoscopy before or within 6 months of initial curative resection and then surveillance colonoscopy at 1, 3, and 5 years (+/- 6 months) after resection. The number, size, location, histology, and method of removal of polyps are documented at the time of colonoscopy. Patients also undergo microsatellite instability (MSI) status testing and complete family history questionnaires at baseline.