Rationale for evaluating breast cancers of Lynch syndrome patients for mismatch repair gene expression

ConclusionsSporadic dMMR breast cancers are extremely rare (Davies et al. in Cancer Res 77:4755 –4762, 2017). It seems reasonable to conclude that identifying a dMMR breast cancer in a patient with known LS strongly suggests that her LS is breast cancer-predisposing. LS patients with dMMR breast cancers might therefore be considered for above-average breast cancer screening for the developme nt of additional breast cancers. Also, the FDA recently granted approval of checkpoint inhibitor therapy for all metastatic dMMR solid malignancies (Lemery et al. in N Engl J Med 377:1409–1412, 2017). MMR expression assays in metastatic breast cancers of LS patients would represent a more focused approach to identifying patients with breast cancers who are potentially eligible for checkpoint inhibitor therapy than would be universal MMR testing of all metastatic breast cancers.

Source: Breast Cancer Research and Treatment - October 17, 2019 Category: Cancer & Oncology Source Type: research