Clinical outcome and proportion of hereditary cancer genes gPV in TNBC: the HEaRTBeat study.

We aimed to study the proportion of germline pathogenic variants (gPV) in hereditary cancer genes and the clinical-pathological characteristics, local and systemic treatments, pathological complete response (pCR) rate to neoadjuvant therapy, invasive breast cancer-free survival (IBCFS), and overall survival (OS) in triple-negative breast cancer (TNBC) patients, consecutively tested between 2017 and 2024 at Modena and Reggio Emilia University Hospital, Italy. A total of 387 early-stage patients were included in the study. Eighty-seven patients (22%) showed gPV in hereditary predisposing genes, mostly BRCA1/2 (11%), PALB2 (5%), RAD51C/D (2%), MUTYH (2%), ATM (1%), and others (1%). The proliferation index was high in all, whereas the most frequent stage was stage I/II, except in MUTYH gPV carriers. More mastectomies, also contralateral, were performed in gPV than in non-carriers. Finally, 64% gPV achieved pCR compared to 39% non-carriers (p < 0.001), although no differences were observed between the two groups in IBCFS or OS.