The Panel performed a complete literature review from 1999 through June 2005 and met twice to assemble its recommendations.The Colorectal Cancer Surveillance Panel presents ASCO’s 2005 practice guideline update for follow up after primary therapy of stage II or III colorectal cancer.

Computed tomography. Patients who are at higher risk of recurrence, and who could be candidates for curative-intent surgery, should undergo annual computed tomography (CT) of the chest and abdomen for 3 years after primary therapy for colon and rectal cancer. Chest x-ray. Annual chest x-rays are not recommended. Recommending routine chest CT settled previous disagreements among Panel members about the use of routine chest x-ray.Colonoscopy. All patients with colon and rectal cancer should have a colonoscopy for the pre- or perioperative documentation of a cancer- and polyp-free colon. Flexible proctosigmoidoscopy (rectal cancer). For patients who have not received pelvic radiation, flexible sigmoidoscopy of the rectum every 6 months for 5 years is recommended.

Coordinating physician visits should occur every 3 to 6 months for the first 3 years, every 6 months during years 4 and 5, and subsequently at the discretion of the physician. Physician visits should focus on the initial risk assessment followed by the implementation of a surveillance strategy and periodic counseling based on estimated risk and feasibility of surgical interventions such as hepatic resection.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2794573/