Study to Determine the Prevalence of Homologous Recombination Deficiency Among Women With Newly Diagnosed, High-grade, Serous or Endometrioid Ovarian, Primary Peritoneal, and/or Fallopian Tube Cancer

To maximise the accessibility and benefit of PARP inhibitors to eligible patients, it is essential to know the prevalence of HRD in women with advanced high-grade serous or endometrioid ovarian cancer. Presently, the prevalence data for HRD are available from selected geographies only and range from 31% to 50%. Furthermore, the risk factors associated with HRD and clinical characteristics of patients with HRD need exploration for region-specific differences. In the present study, we will estimate the region- and country-specific prevalence of HRD in women with stage III or IV high-grade serous or endometrioid ovarian, primary peritoneal, and/or fallopian tube cancer and associated risk factors with clinical characteristics in Asia-Pacific countries, Latin America, Africa, Russia, Australia, and Middle East countries. The findings of the study will help the oncologists in optimal patient selection and clinical decision-making for the first-line maintenance of patients with HGSOC

Sex

Female

Minimum age

18 Years

Inclusion Criteria:

* Patients ≥18 years of age or adults according to age of majority as defined by the local regulations;
* Willing and able to provide written informed consent for participation in the study;
* Patients with histologically confirmed new diagnosis (within past 120 days of enrolment) of high-grade (stage III or IV of FIGO classification 2014) serous or endometrioid ovarian, primary peritoneal, and/or fallopian tube cancer;
* Patients having availability of histopathology report and FFPE archival tumour tissue block(s) collected within past 120 days of enrolment.

Exclusion Criteria:

* Patients with mucinous, clear-cell, undifferentiated carcinoma or malignant Brenner's tumour;
* Patients diagnosed with any severe acute or chronic medical or psychiatric conditions that may increase the risk associated with study participation or may interfere with the interpretation of the study results, and those in the judgment of the investigator are not appropriate for enrolment in this study

• DERIVEDShash E, Vardar MA, Taskiran C, Boujassoum S, Riromar J, Aboutaleb A, Sadek F, Samy E, Bahaj W. Homologous recombination deficiency in newly diagnosed advanced ovarian cancer across nine Middle East countries: prevalence, real-world testing pathways, and treatment implications. BMC Cancer. 2026 Feb 4;26(1):296. doi: 10.1186/s12885-025-15537-3. PMID 41639797
• DERIVEDLiou WS, Chao A, Sheu BC, Yeh LS, Wu CH. Prevalence of homologous recombination deficiency in ovarian, primary peritoneal, and/or fallopian tube cancer: results from HALO-Taiwan subset. J Gynecol Oncol. 2026 May;37(3):e55. doi: 10.3802/jgo.2026.37.e55. Epub 2025 Dec 29. PMID 41575336
• DERIVEDKhokhlova S, Alnaqqash MA, Bahaj W, Bujassoum S, Lee J, Mokhtar M, Tyulyandina A, Vargas Malaga CL, Wu CH. Prevalence of homologous recombination deficiency among women with newly diagnosed ovarian, primary peritoneal, and/or fallopian tube cancer: the international HALO study. Int J Gynecol Cancer. 2025 Jul;35(7):101645. doi: 10.1016/j.ijgc.2025.101645. Epub 2025 Jan 17. PMID 40064569