Diagnosis and management of colorectal cancer.

Colorectal cancer is an important disease with high mortality. Clinical features are usually nonspecific and vary with the location of the tumor. Diagnosis depends on colonic investigations initiated by a high index of clinical suspicion. Rectal examination, sigmoidoscopy, air-contrast barium enema, and colonoscopy are the crucial diagnostic tools. Clinical judgment dictates the extent of work-up in individual symptomatic patients. Screening of asymptomatic middle-aged and elderly persons is widely advised but less widely practiced. More evidence is needed to clarify the value of screening, especially by occult blood testing. CEA testing is unsuitable for screening and of only limited value for monitoring patients with known colorectal cancer. Surgical resection is the mainstay of treatment. Radiotherapy is useful for palliation of rectal cancer and may delay postoperative tumor recurrence. Chemotherapy for disseminated disease generally gives disappointing results, since only a minority of tumors respond and survival benefit is marginal. Periodic colonic surveillance is important after tumor resection, primarily to detect premalignant new growths.