Objectives Background Homologous recombination deficiency (HRD) is common in women with newly diagnosed high-grade serous ovarian and other morphologically related cancers. Exploiting the prevalence of HRD positive status can help optimize the use of targeted therapies in these patients and improve survival. Due to limited statistics, the study is aimed to determine global as well as country-specific (Egypt, Lebanon, Malaysia, Russia, Singapore, Taiwan, Saudi Arabia, Turkey, and United Arab Emirates) data on the prevalence of HRD positive patients using locally developed tests and commercial kits.

Methods Method Study design and population: This cross-sectional, non-interventional, multicentre observational study will enroll a minimum of 405 women (≥ 18 years) with high-grade serous or endometrioid ovarian, primary peritoneal, and/or fallopian tube cancer having histopathology report and formalin-fixed paraffin-embedded (FFPE) tumour tissue block(s). FFPE tissue blocks will be used for HRD status and BRCA mutation testing. Objective: Primary endpoints include prevalence of patients with positive HRD status. Secondary endpoints include 1) Region- and country-specific prevalence of the patients with a) positive HRD status, b) positive tBRCA1m/tBRCA2m; 2) risk factors associated with these patients. Exploratory endpoints include clinical characteristics of overall patient population and by geographical regions. Statistical analysis: Analyses will be performed using full analysis set (FAS). Logistic regression analysis will be used to identify the potential risk factors.

Results Trail in progress.

Conclusions Importance The study will generate reliable evidence on prevalence of HRD positive patients and help health care professionals to understand the clinical and genetic characteristic of the disease in various countries guiding optimal treatment.