A Dardenne, R Cohen, C Evrevin, C Duros, N Basset, P Cervera, J H Lefevre, T Germain, C Lepillier, N Chabbert-Buffet, T André, X Dray, Y Parc
Despite structured, multiorgan surveillance, patients with Lynch syndrome exhibit high cancer incidence and broad tumor distribution. Although current protocols enable early detection for several organs, a substantial proportion of cancers occur outside existing recommendations. These findings support follow-up in dedicated coordination centers and may inform the selective expansion of surveillance strategies to additional high-risk organs.
BACKGROUND: Lynch syndrome confers a high lifetime risk of multiorgan cancers. Although colorectal surveillance is well established, prospective data on cancer incidence and adherence to structured multiorgan follow-up and surveillance recommendations remain limited.
MATERIALS AND METHODS: We retrospectively analyzed prospectively collected data from 517 individuals carrying a pathogenic or likely pathogenic variant in a mismatch repair gene at a single specialized French center. All patients underwent structured surveillance, including regular colonoscopy and organ-specific follow-up according to national guidelines. Cancer incidence rates, tumor distribution, and modes of detection (asymptomatic versus symptomatic) were assessed over the follow-up.
RESULTS: Over 4827 person-years, 201 cancers were diagnosed (annual cancer incidence 4.16%, 95% confidence interval 3.59-4.74). Colorectal cancer was most frequent (41.8%), followed by urinary tract (11.9%) and skin cancers. Among guideline-surveilled organs (n = 132), most were detected asymptomatically, particularly lower gastrointestinal (GI) (84.5%) and urinary tract (85%) cancers, whereas >50% of upper GI cancers were diagnosed symptomatically. Gynecologic cancers were rare, likely reflecting prophylactic surgery. Notably, 69 cancers (34%) arose outside guideline-recommended surveillance organs, primarily skin, breast, prostate, and pancreas. Cancer-specific mortality was lower among the cancers detected under surveillance, although this difference did not reach statistical significance.
CONCLUSIONS: Despite structured, multiorgan surveillance, patients with Lynch syndrome exhibit high cancer incidence and broad tumor distribution. Although current protocols enable early detection for several organs, a substantial proportion of cancers occur outside existing recommendations. These findings support follow-up in dedicated coordination centers and may inform the selective expansion of surveillance strategies to additional high-risk organs.