Is the controversy on breast cancer as part of the Lynch-related tumor spectrum still open?

Several studies report an increased risk of breast/pancreatic cancer in MMR (DNA mismatch repair) mutation carriers that has significant consequences on standard cancer screening in such population. The French national network involved in Lynch syndrome molecular characterization registered 15 families with an identified MMR germline mutation and the occurrence of breast/pancreatic adenocarcinoma in mutations carriers. Corresponding tumors were investigated and the MMR function was shown to be intact. This observation tends to exclude breast/pancreatic cancers from Lynch tumor spectrum defined by a complete loss of the MMR function in tumor cells and to support the hypothesis of another causal factor.