Colorectal Tumor Development and Lynch Syndrome

Because mutations responsible for Lynch syndrome can cause colorectal adenomas to pass rapidly through the polyp–cancer sequence, interval cancers are common in patients with Lynch syndrome. As such, current U.S. screening guidelines recommend that adults with Lynch syndrome undergo colonoscopy every 2 years until age 40 and then annually thereafter (JW Gastroenterol Jul 9 2010).

To determine the polyp dwell time (the duration of the adenoma–carcinoma sequence from normal mucosa to cancer) in patients with Lynch syndrome, investigators retrospectively studied 54 individuals from 29 pedigrees with known pathogenic mutations in either MSH2 or MLH1. None of the patients had colorectal cancer or other cancers associated with Lynch syndrome prior…