Introduction/Background*To investigate the association between the presence of BRCA1/2 mutations and the chemotherapy response score (CRS) in patients with advanced stage high-grade serous ovarian cancer (HGSOC) undergoing neoadjuvant chemotherapy (NACT) and interval debulking surgery (IDS).

Methodology We retrospectively collected patients with unresectable HGSOC, who were assessed for BRCA1/2 mutational status and underwent 3 or 4 cycles of NACT, in our Institution from 2016 to 2020. All patients received germline test on peripheral blood sampling or somatic test at diagnostic biopsy. In all patients, the omental specimen obtained at IDS was evaluated according to Bohm’s CRS System.

Result(s)*Of 184 patients analyzed, 69 were BRCA1/2 mutation carriers (37.5%) and 115 were wild type (62.5%). In the wild type patients group, 80 patients had a CRS 1/2 (69.6%) and 35 patients had a CRS 3 (30.4%). In the BRCA1/2 mutation carriers group, 38 patients had a CRS 1/2 (55.1%) and 31 had a CRS 3 (44.9%), (p=0.034).

Conclusion*BRCA1/2 mutational status is significantly associated with a different response rate to chemotherapy, as assessed according to Bohm’s CRS System. Whereas in BRCA1/2 mutation carriers there does not appear to be a greater predisposition to achieve a CRS 3 than a CRS 1/2, wild type patients appear to be more likely to have a CRS 1/2.