Sánchez, AriadnaHernandez, GorettiIglesias Coma, MarMoreira, Leticia2022-08-032022-08-032021Sánchez A, Bujanda L, Cuatrecasas M, Bofill A, Alvarez-Urturi C, Hernandez G et al. Identification of Lynch syndrome carriers among patients with small bowel adenocarcinoma. Cancers (Basel). 2021 Dec 20;13(24):6378. DOI: 10.3390/cancers132463782072-6694http://hdl.handle.net/10230/53916Background: Small bowel adenocarcinoma (SBA) is a rare disease which can be associated with Lynch syndrome (LS). LS tumors are characterized by the presence of microsatellite instability (MSI) and/or the loss of mismatch repair (MMR) protein expression. In SBA, the frequency of MMR deficient (MMRd) tumors varies from 5% to 35%. This study aims to describe the prevalence of LS carriers among patients with MMRd small bowel adenocarcinomas. Methods: A multicenter retrospective study with identification and MMR testing of all consecutive SBA between 2004 and 2020 in a multicenter Spanish study. Demographical data, tumor characteristics, follow-up and survival information were collected. Germline testing was driven by identification of MMRd tumors. Results: A total of 94 individuals diagnosed with SBA were recruited. We observed 20 (21.3%) MMRd tumors. In 9/15 (60%) patients with MMRd tumors, a pathogenic variant was identified (three MLH1, four MSH2, one MSH6 and one PMS2). Accordingly, the prevalence of LS among all SBA cases was 10.1%. Conclusions: More than one-fifth of SBA display MMRd and in more than a half is due to LS. Our data supports the implementation of universal MMR tumor testing among SBA for the identification of LS families.application/pdfeng© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).info:eu-repo/semantics/articlehttp://dx.doi.org/10.3390/cancers13246378Lynch syndromeHereditary cancerSmall bowel adenocarcinomainfo:eu-repo/semantics/openAccess