BackgroundOvarian cancer is the leading cause of death worldwide among gynecologic malignancies. The recent approval of inhibitors of poly (ADP-ribose) polymerase (iPARP) in the treatment of ovarian cancer in the presence of a BRCA1/2 mutation has sparked the analysis of women with such diagnosis, which can further benefit from the detection of carriers in the family. Germline sequence and large rearrangements for BRCA1/2 were tested in 398 consecutive epithelial ovarian cancer (EOC) patients.The aim of this study was to identify the frequency and spectrum of germline BRCA1/2 pathogenic alterations in a cohort of patients with ovarian serous carcinoma, with a view to adequately selecting patients for prevention through family counseling and correlating this frequency with platinum sensitivity as a guidance to identify patients eligible for iPARP in our population.ResultsA total of 96 patients carried a pathogenic germline mutation, accounting for an overall 24.1% mutation incidence. Among mutation carriers, BRCA1 showed 62.5% incidence, BRCA2 rendered 36.5%, and one patient exhibited a mutation in both genes. Three pathogenic mutations were recurrent mutations detected five, three, and four times and represented 12.5% of the mutated samples. Worth highlighting, a 50% mutation incidence was detected when breast and ovarian cancer coexisted in the same patient. Novel mutations amounted to 9.4% of the total mutations, as compared to 4.7% in breast cancer. Forty out of 60 BRCA1 mutations were beyond the ovarian cancer cluster region (OCCR), in stark contrast with 22 out of 36 BRCA2 mutations being inside the OCCR. Taken together, germline BRCA1/2 mutations in EOC patients showed a distinct mutational spectrum compared to our previously published data on breast cancer patients.ConclusionsIn sum, our study provides novel data on ovarian BRCA1/2 mutation prevalence worldwide, enhances adequate patient selection for family counseling and prevention, and sheds light on the benefits of iPARP treatment.Electronic supplementary materialThe online version of this article (10.1186/s40246-018-0171-5) contains supplementary material, which is available to authorized users.

Aim: FLABRA (NCT02984423) evaluated prevalence of BRCA mutations, genetic counseling and management approaches in patients with ovarian cancer in Latin America. Patients & methods: Patients with ovarian cancer from six Latin American countries were enrolled. Tumor samples were tested for BRCA mutations. In cases with BRCA mutations ( BRCA mut), blood samples were analyzed to determine germline versus somatic mutations. Medical records were reviewed for counseling approach and treatment plan. Results: From 472 patients enrolled, 406 samples yielded conclusive results: 282 were BRCA wild-type ( BRCA wt), 115 were  BRCA mut and nine were variants of uncertain significance. In total, 110/115 were tested for germline mutations (77 germline and 33 somatic). Conclusion: Tumor testing to identify mutations in BRCA1/2 in ovarian cancer can help optimize treatment choices, meaning fewer patients require germline testing and genetic counseling, a scant resource in Latin America. Clinical trial registration: NCT02984423 (https://ClinicalTrials.gov)

e17050 Background: The majority of OC cases are sporadic, but it is estimated that in 17%, germline mutations in BRCA1 or BRCA2 genes can be identified. BRCA mutated OC has distinct clinical characteristics, increased sensitivity to platinum and non-platinum agents, and to DNA damage repair (DDR) targeting agents like PARP inhibitors. Additionally, somatic BRCA mutations could be identified in tumor tissue. The prevalence of germline BRCA mutations (gBRCAm) and somatic mutations (sBRCAm) has been not been characterized in Latin-american population, which is a paradigm of poly-ethnicity, where prevalence of germline, but especially somatic BRCA mutations in OC, has not been studied. Furthermore, tumor testing as first step may be a new option in BRCA testing algorithm that could avoid the necessity for double testing (gBRCA, then sBRCA testing), in case of gBRCAm negative result. Methods: FLABRA is a cross-sectional, multi-center, study designed to determine the prevalence of sBRCAm in newly diagnosed OC patients versus gBRCAm, and to describe different treatment approaches at front line in LA, as well as current OC genetic counselling. We enrolled 400 consecutive patients from 40 institutions in Argentina, Brazil, Colombia, Mexico, Peru and Panama, diagnosed with OC. Tumor blocks were tested for sBRCA (Myriad Tumor BRACAnalysis CDx™). In sBRCA positive patients, blood samples were analyzed to confirm if the mutation was germline or somatic in origin. In gBRCAm, genetic counseling was advised. Medical records were reviewed for data relevant to medical history, surgery results, treatment approach and genetic counseling. Results: We present the preliminary results with 291 patients already tested. For this first subset of patients, 85/291 (29%) had BRCA mutations identified in their tumors. Preliminary results confirm that starting with tumor testing enlarges the population eligible for PARP inhibitors, by identifying additional patients with somatic mutations only detectable in the tumor. Although preliminary, our data confirms the possibility of identifying additional patients with sBRCA mutations by testing in tumor, with a more cost-effective approach, avoiding a second round of gBRCA testing in patients with BRCA negative results in tumor. Conclusions: In this preliminary analysis we found that somatic BRCA mutations account for a significant proportion from total BRCA mutations within LA population studied.