Abstract
Persons at 50% risk of Lynch Syndrome were screened with colonoscopy at six or twelve month intervals. On initial exam, eight of fifty-five patients had adenomas. Follow-up was available in 27 patients (mean 35.5 months). Estimated time to finding new adenomas was 58 months for patients clear on first colonoscopy and 16 months for patients who had adenomas on first exam (p <0.01). One adenocarcinoma has been found, arising in a tubulovillous adenoma. The short-term risk of colorectal cancer in Lynch syndrome relatives without adenomas is low, as is the risk in those who had all adenomas removed.