Asociación Española
de Gastroenterología
Oncología Digestiva

Sabela Carballal Ramil
Coordinador

El grupo de trabajo de oncología de la Asociación Española de Gastroenterología (AEG) incluye a todos los socios y socias de AEG que comparten su interés por el conocimiento del cáncer gastrointestinal, incluyendo las formas hereditarias y de alto riesgo asociadas a estos tumores. La filosofía del grupo es promover la investigación colaborativa, impulsar las actividades formativas y fomentar la docencia relacionada con esta área de la especialidad de Aparato Digestivo.


Identification of Lynch Syndrome Carriers among Patients with Small Bowel Adenocarcinoma
2021 Ariadna Sánchez Hospital Clinic Barcelona 176
Revista
Cancers

Abstract

Background: 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.