Impact of non-BRCA genes in the indication of risk-reducing surgery in hereditary breast and ovarian cancer syndrome (HBOC)

Hereditary breast and ovarian cancer syndrome (HBOC) is associated with other genes beyond BRCA. The performance of prophylactic bilateral mastectomy (PBM) and risk-reducing salpingo-oophorectomy (RRSO) are primary prevention measures that can be recommended depending on the type of pathogenic/likely pathogenic (P/LP) variant detected or family history. Descriptive, retrospective, and observational audit. Be-tween the years 2015 to May 2023, a total of 288 families were studied by a multigene panel using NGS. Statistical analysis was performed using IBM SPSS Statistics 22. Non-BRCA P/LP variants were detected in 38 families (84.2% females and 15.8% males); 18 in ATM (44.7 %), 7 in CHEK2 (18.4%), 5 in TP53 (13.2%), 2 in PTEN (5.3%), 2 in PALB2 (5.3%), 1 in RAD51C (2.6%), 1 in BRIP1 (2.6%), 1 in CDH1 (2.6%) and 1 in RAD51D (2.6%). Risk-reducing surgery was recommended in 18 patients (PBM in 18 [46.2 %] and RRSO in 5 [13.2%]). Given the results of our study, we support the recommendations of the guidelines on the use of multigene panels in the study of HBOC. Knowing P/LP variants beyond BRCA1 and 2 has an impact on the follow-up and primary and secondary prevention of affected families.