BRCA-associated ovarian cancer in the russian patient population. Analysis of the non-interventional study Ovatar

Abstract

Purpose: To evaluate the proportion of BRCA1 / 2 mutations in patients with serous and endometrioid cancer of the ovary, fallopian tube, and peritoneum in Russia, to evaluate the percentage of germinal and somatic mutations, to identify the spectrum of mutations in BRCA1 / 2 genes, to evaluate clinical and morphological features of the BRCA-associated ovarian cancer (OC).Patients and methods: The study enrolled patients of 18 years and older with newly diagnosed serous and endometrioid cancer of the ovary, fallopian tube, and peritoneum. Biological material (blood, tumor tissue) was collected, followed by molecular genetic analysis. The method of mutations detecting in the blood were: allele-specific PCR, high-resolution melting (HRM), Sanger sequencing method. Advanced genetic testing included the use of generation sequencing (NGS) and multiplex amplification of ligated probes (MLPA). The collection of clinical data, family history, clinical and morphological characteristics of the tumor was performed.Results: 500 patients were included in the study, the evaluation of BRCA1 / 2 mutations was performed in 496 patients (99,2 %). The frequency of BRCA1 / 2 mutations in the Russian patient population was 28,4 % (n = 141 / 496). The incidence of germinal mutations was 23,5 % (n = 117 / 141), and somatic — 4,8 % (n = 24 / 141). Frequent mutations in the Russian population were identified in 50 % of cases. When analyzing the ethnicity of patients in the Russian Federation BRCA-associated OC was most common in Russian (83,6 %, n = 118 / 141), Ukrainian (4,2 %, n = 6 / 141) and Tatar (3,5 %, n = 5 / 141) women. A family history of cancer was detected in 44 % of patients (n = 62 / 141) with BRCA1 / 2 mutations.Conclusions: Due to the high frequency of germinal and somatic BRCA1 / 2 mutations in the Russian patients it is recommended to conduct the advanced testing methods not only in blood samples but also in tumor tissue.