226O - Prevalence of germline BRCA1 and BRCA2 mutations and variants among ovarian, primary peritoneal and fallopian tube cancer patients: A multicentre Indian study

Abstract

BackgroundThe worldwide reported prevalence of germline pathogenic BRCA1 and BRCA2 mutations in ovarian cancer patients is 17 % (3-27 %) and that of variants of uncertain significance (VUS) is about 10 %. 1, 2There is deficient data on the prevalence of BRCA mutations in Indian patients. We aimed to estimate the prevalence of germline BRCA mutations among Indian patients with ovarian, primary peritoneal or fallopian tube cancer. MethodsThis was a cross-sectional, multicenter, prospective, observational study conducted at 9 sites from different geographical regions across India which enrolled patients with new or previous diagnosis of ovarian, primary peritoneal, or fallopian tube cancer. Patients underwent blood testing using NGS based platform for germline BRCA. The calculated sample size for this study was 228, assuming 5 % precision around an estimated point prevalence of 15.8 % with a dropout rate of 10 %. ResultsA total of 239 patients were enrolled, of whom 16 were newly diagnosed, treatment naïve, and 223 had a previous diagnosis of ovarian cancer and had received between 1- 9 prior lines of therapy. Germline pathogenic or likely pathogenic BRCA1/BRCA2 mutations were seen in 61 (25.5%, 95% CI 20.12, 31.54) and VUS were seen in 10 (4.2%, 95% CI 2.02 – 7.54) patients, respectively. Among 159 patients with serous histology tumours, 48 (30.2%) had pathogenic/likely pathogenic germline BRCA1/BRCA2 mutations while 16 of 74 (16.2 %) patients with non-serous histology tumours had this finding. Of the 61 patients in this study with germline pathogenic/likely pathogenic BRCA1/BRCA2 mutation, 41 (67.1 %) did not have a family history of breast and/or ovarian cancer. ConclusionsApproximately one-fourth of unselected ovarian cancer patients from India had germline BRCA1/BRCA2 mutations of whom, nearly two-thirds did not have a family history of breast and/or ovarian cancers. Legal entity responsible for the studyAstraZeneca Pharma India Limited. FundingAstraZeneca Pharma India Limited. DisclosureS. Gupta: Honoraria (institution), Advisory / Consultancy, Speaker Bureau / Expert testimony: AstraZeneca. S. Rajappa: Advisory / Consultancy, Speaker Bureau / Expert testimony: AstraZeneca. S.H. Advani: Advisory / Consultancy: AstraZeneca. A. Agarwal: Speaker Bureau / Expert testimony: AstraZeneca. S. Aggarwal: Advisory / Consultancy: AstraZeneca. C. Goswami: Advisory / Consultancy, Speaker Bureau / Expert testimony: AstraZeneca. S. Dattatreya Palanki: Advisory / Consultancy, Speaker Bureau / Expert testimony: AstraZeneca. D. Arya: Advisory / Consultancy, Speaker Bureau / Expert testimony: AstraZeneca. R. Kodagali: Full / Part-time employment: AstraZeneca. All other authors have declared no conflicts of interest.