Follow-up of patients after primary colorectal cancer resection.

Improved survival rates for patients with colorectal cancer may depend on early detection of metachronous colon lesions and early detection of distant disease. Frequent serial CEA determinations and history and physical examination are the two most useful techniques for diagnosing early recurrent disease. Colonoscopy rarely detects early recurrent disease but is useful in finding metachronous colon lesions. Other radiographic and hematologic examinations have an extremely low yield and should be used to localize and stage disease discovered by other means. Simplified follow-up can be expected to minimize early detection of recurrent and metachronous lesions yet offers minimal patient risk and expense.