Introduction Objectives: More than 1,000 new cases and 500 deaths from ovarian cancer are detected annually in Kazakhstan. The aim of this study was to examine the BRCA1/2 mutation rate in a cohort of Kazakhstani women with high-grade serous ovarian carcinoma (HGSOC).

Methods We performed a retrospective review of the Kazakhstan Cancer Registry Database and identified all patients with HGSOC who had undergone genetic testing between 2018–2022. Gynecologic oncologists and genetic counselors initiated genetic testing within the KazIOR health care system. All testing was performed on site through DNA isolation from tumor tissue using the cobas® DNA sample preparation kit (Roche Diagnostics, Basel, Switzerland). Genomic DNA was amplified using the AmpliSeq BRCA1 and BRCA2 panel. The DNA Libraries were pooled, barcoded, and sequenced. Data was analyzed using SPSS 23.0. Study covered byMOH BR11065390

Results 96 patients underwent genetic testing. The median age was 55.3 years (range, 26–83 years). Of the 96 patients, 34 tested positive for a pathogenic mutation in either BRCA1 or BRCA2, yielding a prevalence of 35.4%. Median age did not differ based on mutation status. Patients with BRCA mutations were more likely to recur. Of the 96 patients, 18 of 34 BRCA+ patients (52.9%) recurred, compared with 13 of 62 BRCA- patients (21%, p=0.001). Median overall survival was similar for BRCA+ patients (23.6 months) compared with BRCA- patients (22.1 months).

Conclusion/Implications Pathogenic mutations in BRCA1/2 are more common than expected in women with HGSOC in Kazakhstan. All women diagnosed with HGSOC should undergo genetic testing to guide personalized treatment using PARP inhibitors.