Dukes B2-C colorectal cancer patients who had no evidence of disease at the end of their front line treatment (surgery and adjuvant radio-chemotherapy, if indicated) are eligible for the trial and randomized to two different surveillance programs. These programs differ greatly in the frequency of diagnostic imaging. They have similar schedules of physical examinations and carcinoembryonic antigen (CEA) assessments. Patients will receive baseline and yearly health-related quality of life (HR-QoL) questionnaires. Primary outcomes are overall survival and QoL.