Homologous recombination deficiency in high-grade serous ovarian carcinoma: clinical pathological characteristics, impact of neoadjuvant chemotherapy, and prognostic implications

OBJECTIVE: To investigate the clinicopathological and prognostic significance of homologous recombination deficiency (HRD) in high-grade serous ovarian carcinoma (HGSC) and evaluate the impact of neoadjuvant chemotherapy (NACT) on HRD detection. METHODS: HRD Complete Panel. HRD positivity was defined as a pathogenic/likely pathogenic BRCA1/2 mutation and/or genomic scar score (GSS) ≥45. Correlations with clinicopathological variables, histological subtypes (classic vs. solid, endometrial-like, and transitional [SET] patterns), and survival were analyzed. RESULTS: HRD positivity was detected in 76 (60.3%) cases, with BRCA1/2 mutations in 26.2%. HRD-positive tumors showed larger size (p=0.034) and more SET patterns (p=0.001). Notably, among BRCA1/2 wild-type patients, the NACT group showed significantly lower HRD positivity (22.2% vs. 56.1%; p=0.003) and decreased median GSS (19.5 vs. 55.2; p