Guidelines for Colorectal Cancer Screening and the Recent Evidence Behind Them
Nazia Hasan, MD MPH
Faculty peer reviewed
For most residents, screening for colorectal cancer (CRC) may seem as established as that for breast and cervical cancer. In reality, the use of CRC screening has only recently approached that of screening for those other malignancies. We have seen recently changes to the CRC screening guidelines last published by The American College of Gastroenterology in 2000. The updated screening guidelines for colorectal cancer became available in the March 2009 issue of The American Journal of Gastroenterology.
Along with changes in the timing and modalities used for CRC screening, the goal of screening has also been transformed. Screening efforts have shifted focus to favor cancer prevention tests over cancer detection tests. This blog series aims to review the updated guidelines for CRC screening illustrated through cases.
Please also see Case 1 in this series
A 62 year old male with a history of four adenomatous polyps on a prior screening colonoscopy that were removed without complication 2 years ago comes to your office.
How many years after this initial colonoscopy should the patient have a repeat?
- Determine which patients are at an higher than average risk for CRC
- Determine follow up periods for patients with history of adenomatous polyps
The initial factor to consider when tailoring CRC screening for a given individual is their risk status. Affirmative answers to any of the following questions characterize a patient as high risk:
1. Does the patient have a personal history of CRC or an adenomatous polyp?
2. Does the patient have an illness (e.g., IBD) that predisposes him/her to CRC?
3. Does the patient have a family history of CRC or an adenomatous polyp?
The following are recommendations for CRC screening in patients with a history of adenomatous polyps established by the GI Consortium Panel.1
- The timing of the subsequent colonoscopy should depend on the pathology and number of adenomas detected at follow-up colonoscopy
- Patients who have 1 or 2 small (<1 cm) tubular adenomas should have their first follow-up colonoscopy at 5 years.
- Patients who have an advanced adenoma (villous features on pathology or size >1cm) or multiple adenomas (>3) should have their first follow-up colonoscopy in 3 years.
- Patients who have had numerous adenomas, a malignant adenoma (with invasive cancer), a large sessile adenoma, or an incomplete colonoscopy should have a short interval follow-up colonoscopy based on clinical judgment.
The rationale behind these guidelines from the GI Consortium Panel lies in evidence that colonoscopic polypectomy and surveillance reduces subsequent colorectal cancer incidence.2,3 A post-polypectomy surveillance study by Citarda et. al showed a 66% reduction in CRC incidence3. There is also evidence to suggest no improved detection of advanced lesions with surveillance after initial colonoscopy is done at 1 year versus 3 years. 4
Since our patient in Case 2 had four adenomatous polyps on his last exam 2 years ago, a repeat colonoscopy 3 years from the initial is warranted.
Dr. Hasan is a 3rd year internal medicine resident at NYU Medical Center.
Reviewed by Michael Poles MD, Assistant Professor of Medicine, NYU Division of Gastroenterology
1.Winawer S, et al. (2003). Gastrointestinal Consortium Panel. Colorectal cancer screening andsurveillance: clinical guidelines and rationale. Update based on new evidence.Gastroenterology; 124(2): 544-60.
2. Winawer SJ, Zauber AG, Ho MN, O’Brien MJ, Gottlieb LS, Sternberg SS, et al. (1993). Prevention of colorectal cancer by colonoscopic polypectomy. The National Polyp Study Workgroup. N Engl J Med; 329: 1977-1981.
3. Citarda F, Tomaselli G, Capocaccia R, Barcherini S, Crespi M. (2001). Efficacy in standard clinical practice of colonoscopic polypectomy in reducing colorectal cancer incidence. Gut; 48: 812-815.
4. Winawer SJ, Zauber AG, O’Brien MJ, Ho MN, Gottlieb L, Sternberg SS, et al. (1993). Randomized comparison of surveillance intervals after colonoscopic removal of newly diagnosed adenomatous polyps. The National Polyp Study Workgroup. N Engl J Med; 328: 901-906.