Introduction/Background CRS has a prognostic value in patients with AEOC undergoing interval debulking surgery after neoadjuvant chemotherapy (NACT). AEOC patients (pts) harboring mutations in BRCA and other genes involved in homologous recombination (HR) have a better prognosis and response rates to platinum-based chemotherapy. The impact of such genetic abnormalities on CRS is yet to be elucidated.

Methodology We conducted a retrospective study of 45 patients diagnosed with AEOC between April 2018 and June 2023, treated with platinum-based NACT followed by interval debulking surgery. Somatic mutations were detected by BRCA MASTR Plus Dx, Myriad myChoice CDx Plus, Foundation One Medicine or SOPHiA Genetics and germline mutations were detected by Hereditary OncokitDx. Pathologic tumor response was evaluated using CRS (CRS1=no/minimal response; CRS2=appreciable response; CRS3=complete/near-complete response) by experienced pathologists.

Results Mutations were found in BRCA1/2 (N=11, 24,4%), ATM (N=1) and BRIP1 (N=2). Among BRCA-mutated pts, 4 (36,4%) achieved considerable response (CRS3), compared to 6 (17,6%) in BRCA wild type (WT) pts. This difference was not statistically significant (p=0.32). Moreover, among the 15 pts with known HR, 3 (33,3%) of HR Deficient (HRD) accomplish considerable response compared to 1 (16,7%) of the pts with HR proficient. This difference was also not statistically significant (p=0.58).

Conclusion In our cohort, BRCA1/2-mutated pts and HRD showed a trend towards a better response to NACT as opposed to BRCA-WT and HR proficient pts, according to CRS, although statistical significance is not reached due to the limited number of patients. Further research is guaranteed.

Disclosures EV: Receipt of honoraria or consultation fees: Pfizer and received grants for travel/accomodation: GSK.

JP: Receipt of honoraria or consultation fees: LEO Pharma, Takeda, Ipsen.

EG: Receipt of honoraria or consultation fees: AstraZeneca-MSD, Clovis Oncology, GSK-Tesaro, PharmaMar; Participation in a company sponsored speaker’s bureau: AstraZeneca-MSD, PharmaMar, Roche, GSK-Tesaro, Clovis; Travel/accommodation/expenses from Roche, GSK-Tesaro and Baxter

BP: Participation in a company sponsored speaker’s bureau: Roche, AstraZeneca

CS: Participation in a company sponsored speaker’s bureau: AstraZeneca, Novartis; Travel/accomodation: Pfizer, Lilly, Novartis,Astrazeneca

MG: Receipt of honoraria or consultation fees: Gilead, Astra Zeneca; Participation in a company sponsored speaker’s bureau: Roche, Astra Zeneca, Pfizer, Lilly

MF: Participation in a company sponsored speaker’s bureau: Pfizer, Novartis, Eisai, Daiichi/Astra Zeneca, Lilly

NM: Receipt of grants/research supports: Pfizer; Receipt of honoraria or consultation fees: EISAI, ROCHE, NOVARTIS, ASTRA ZENECA, daiichi sankyo, PFISER, LILLY

EL: Receipt of honoraria or consultation fees: AstraZeneca, Seagen

AC: Receipt of grants/research supports: GSK, Pfizer; Receipt of honoraria or consultation fees: GSK, AZ, Daiichi Sankyo; Participation in a company sponsored speaker’s bureau: GSK, MSD, AZ, Eisai, Accord.