People with symptoms or signs that suggest the presence of colorectal cancer or polyps fall outside the domain of screening and should be offered an appropriate diagnostic evaluation. Screening programs should begin by classifying the individual patient’s level of risk based on personal, family, and medical history, which will determine the appropriate approach to screening in that person. Men and women at average risk should be offered screening for colorectal cancer and adenomatous polyps beginning at age 45* years. If the result of a screening test is abnormal physicians should recommend a complete structural examination of the colon and rectum by colonoscopy (or flexible sigmoidoscopy and double contrast barium enema if colonoscopy is not available).
Recommendations for Screening People at Average Risk
Men and women at average risk should be offered screening with one of the following options beginning at age 45* years.
Fecal Occult Blood Testing: Offer yearly screening with the fecal occult blood test (FOBT). Two samples from each of three consecutive stools should be examined without re-hydration. Patients with positive test on any specimen should be followed up with colonoscopy.
Sigmoidoscopy: Offer flexible sigmoidoscopy every 5 years.
Combined FOBT and Flexible Sigmoidoscopy: Offer screening with FOBT every year combined with flexible sigmoidoscopy every 5 years. When both tests are performed, the FOBT should be done first.
Colonoscopy: Offer colonoscopy every 10 years.
Double-Contrast Barium Enema: Offer double-contrast barium enema (DCBE) every 5 years.
*In 2018, secondary to new data on the increased risks of colon cancer in those under 50, the American Society of Colon and Rectal Surgery changed recommendations to consider starting screening at age 45.
Recommendations for Screening People at Increased Risk
People with a family history of colorectal cancer or adenomatous polyps: People with a first-degree relative (parent, sibling or child) with colon cancer or adenomatous polyps diagnosed at age <60 years or 2 first degree relatives diagnosed at any age should be advised to have screening colonoscopy starting at age 40 years or ten years younger than the earliest diagnosis in their family, whichever comes first, and repeated every 5 years. People with a first-degree relative with colon cancer or adenomatous polyp diagnosed at age greater than or equal to 60 years or 2 second degree relatives with colorectal cancer should be advised to be screened as average risk persons, but beginning at age 40 years. People with 1 second-degree relative (grandparent, aunt or uncle) or third-degree relative (great-grandparent or cousin) with colorectal cancer should be advised to be screened as average risk persons.
Familial Adenomatous Polyposis (FAP): People who have a genetic diagnosis of familial adenomatous polyposis (FAP), or are at risk of having FAP but genetic testing has not been performed or is not feasible, should have annual sigmoidoscopy, beginning at age 10 to 12 years, to determine if they are expressing the genetic abnormality. Genetic testing should be considered in patients with FAP who have relatives at risk. Genetic counseling should guide genetic testing and considerations of colectomy.
Hereditary Nonpolyposis Colorectal Cancer (HNPCC): People with a genetic or clinical diagnosis of hereditary nonpolyposis colorectal cancer (HNPCC), or who are at increased risk for HNPCC should have colonoscopy every 1-2 years beginning at age 20 to 25 years, or 10 years earlier than the youngest age of colon cancer diagnosis in the family, whichever comes first. Genetic testing for HNPCC should be offered to first-degree relatives of persons with a known inherited mismatch repair (MMR) gene mutation. It should also be offered when the family mutation is not already known, but one of the first three of the modified Bethesda Criteria, is met.
Surveillance of People at Increased Risk
People with a History of Adenomatous Polyps: Patients who have had one or more adenomatous polyps removed at colonoscopy should be managed according to the findings on that colonoscopy; numerous adenomas, a malignant adenoma (with invasive cancer) or a large sessile adenoma should have a short interval follow-up colonoscopy based on clinical judgment. Patients who have advanced or multiple adenomas (>cm) tubular adenomas should have their first follow-up colonoscopy at 5 years. The timing of the subsequent colonoscopy should depend on the pathology and number of adenomas detected at follow-up colonoscopy.
People with a History of Colorectal Cancer: Patients with a colon cancer or rectal that has been resected with curative intent should have a colonoscopy around the time of initial diagnosis to rule out synchronous neoplasms. If the colon is obstructed preoperatively, colonoscopy can be performed approximately 6 months after surgery. If this or a complete preoperative examination is normal, subsequent colonoscopy should be offered after 3 years, and then, if normal, every 5 years.
People with Inflammatory Bowel Disease: In patients with long-standing, extensive inflammatory bowel disease (either ulcerative colitis or Crohn’s colitis), surveillance colonoscopy with systematic biopsies (see below) should be considered. This applies to both ulcerative colitis and Crohn’s colitis because the cancer risk is similar in both diseases.
Newer screening tests, or others yet to be developed, may with time replace the options we have included in this report. Nevertheless, we believe that screening should take place with the tests available now and not wait until something better comes along. In this way, needless suffering and loss of life can be avoided for this, the second leading cause of cancer death, and screening will become even more successful as future technologies enter clinical practice.
*Winawer S, Fletcher R, Rex D, Bond J, Burt R, et al. Colorectal Cancer Screening and Surveillance: Clinical Guidelines and Rationale-Update Based on New Evidence. Gastroenterology 2003;124:544-560.