In Lynch syndrome, when should colonoscopy begin and what interval is recommended for ongoing surveillance?

• A. Start around age 50, with colonoscopy every 5 years.
• B. Start around age 20-25, and repeat every 1-2 years lifelong.
• C. Start at age 30, every 3-5 years lifelong.
• D. Start at age 40, annually.

Answer: (B)

Lynch syndrome demands earlier and more frequent colonoscopic surveillance because the risk of colorectal cancer is high and the pathway from polyp to cancer progresses quickly in mismatch repair–deficient individuals. Therefore, screening begins well before the general population and is done at short intervals.

Start around age 20–25, or 2–5 years before the youngest colorectal cancer diagnosed in the family, whichever happens first. After surveillance starts, perform colonoscopies every 1–2 years for life. This ongoing, tight schedule is essential to detect and remove precancerous lesions early and to catch cancers at a stage when treatment is most effective.