What is the recommended colon cancer surveillance for PMS2 mutation carriers?

• A. Colonoscopy every 1-2 years starting around age 20-25, with consideration of longer intervals in some cases but generally continued surveillance due to elevated risk.
• B. Annual colonoscopy starting at age 60.
• C. No colonoscopy beyond average risk.
• D. Flexible sigmoidoscopy every 5 years.

Answer: (A)

The key idea is that hereditary colorectal cancer risk guides how aggressively to surveil for cancer. For PMS2 mutation carriers, there is an increased risk of colorectal cancer compared with the general population, though this risk is lower than for some other MMR gene mutations. Because the goal is to catch cancers early and prevent progression, surveillance is continued with colonoscopy rather than less thorough tests, and the starting age is in early adulthood with fairly frequent intervals.

Starting around when young adulthood begins (approximately 20-25 years) and repeating every 1-2 years aligns with the principle of early, proactive detection. In some cases, intervals may be longer if there is a lower estimated risk or reassuring findings, but overall surveillance remains ongoing due to the elevated risk relative to average risk. This approach is more effective than waiting until age 60, using no colonoscopy, or relying on flexible sigmoidoscopy alone, which would miss cancers in parts of the colon.