New colonoscopy schedule mirrors prior advice
Three main recommendations for colonoscopy surveillance do not depart from information presented in the 2006 version of the guidelines, but two of the three are supported by stronger evidence than previously.
Persons at average risk for colorectal cancer should begin to undergo screening at age 50 years. Surveillance refers to the schedule for retesting patients for recurring polyps after their initial screening.
According to “Guidelines for Colonoscopy Surveillance After Screening and Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer,” recently issued by the US Multi-society Task Force (MSTF) on Colorectal Cancer and published by the journal Gastroenterology (2012;143:844-857), the following colonoscopy schedule is advised for patients with a high-quality initial exam:
- If the initial exam finds no polyps or finds only hyperplastic polyps smaller than 10 mm in the rectum or sigmoid colon, the next colonoscopy can be done in 10 years. This remains unchanged from the MSTF's stand in the 2006 version of the guidelines.
- If the initial exam finds low-risk adenomas, defined as 1 to 2 tubular adenomas smaller than 10 mm, the next colonoscopy should take place in 5 to 10 years. Although this recommendation represents no change in position from 2006, the evidence supporting it is now stronger.
- If the initial exam finds benign but high-risk neoplastic polyps, the next colonoscopy should be done in 3 years. High-risk neoplastic polyps include: adenoma of 10 mm or larger, or with villous histology, high-grade dysplasia; three or more adenomas; and sessile serrated lesions that are dysplastic and/or 10 mm or larger. Again, although this represents no change from the 2006 recommendation for the next colonoscopy examination, the evidence supporting the recommendation is now stronger.
The guidelines also offer advice on what a press release from the American Gastroenterological Association refers to as “murky areas” related to colorectal cancer screening:
- If the patient's bowel isn't properly prepared for colonoscopy, in most cases the exam should be repeated within 1 year. Splitting the bowel-preparation dose yields better results.
- Fecal testing between colonoscopies isn't necessary within 5 years of colonoscopy.
- There is insufficient evidence to recommend any change in screening intervals for persons taking aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs), which may reduce the risk of polyps.
- Regarding performing a colonoscopy earlier than guidelines recommend if a patient develops new symptoms: The likelihood of finding significant pathology after a complete and adequate colonoscopy is uncertain, but likely to be low. However, a repeat colonoscopy might be valuable if it will answer an important clinical question.
- There's no reason to alter the surveillance interval based on a person's race, ethnicity, or gender if he or she has had a high-quality colonoscopy.
- The decision to continue colonoscopy in the elderly should be individualized based on an assessment of benefit, risk, and other medical conditions.