Prevalence and oncologic outcomes of BRCA1/2 mutation and variant of unknown significance in epithelial ovarian carcinoma patients in Korea

Survival outcomes in patients with BRCA mutated, variant of unknown significance, and wild type ovarian cancer treated with PARP inhibitors

OBJECTIVE

Correlation between BRCA1/2 (BRCA) pathogenic variants and the response to poly (ADP-ribose) polymerase inhibitors (PARPi) has been recognized in patients with ovarian cancer. Moreover, data on the clinical implications of variants of unknown significance are lacking. The aim of this study was to evaluate differences in survival outcomes in patients with BRCA variants of unknown significance, mutated, and wild type relapsed ovarian cancer treated with PARPi.

METHODS

Patients with ovarian cancer whose somatic BRCA testing was available and who were receiving PARPi as maintenance treatment at the first recurrence between January 2014 and January 2021 were included in the present study and analyzed. Patients were divided into three groups according to BRCA mutational status (variant of unknown significance, mutated, and wild type). Progression-free survival was assessed in each study group.

RESULTS

Of 67 patients identified, 20 (29.9%), 24 (35.8%), and 23 (34.3%) had BRCA variant of unknown significance, mutated, and wild type, respectively. Patients received PARPi as maintenance treatment at the time of the first relapse after a complete response or partial response to platinum-based chemotherapy without differences in the previous platinum-free interval among the analyzed groups. The median progression-free survival of patients with BRCA mutation was significantly longer than for those with BRCA wild type or variant of unknown significance (not reached vs 4 months vs 7 months, respectively; p<0.001). Additionally, no significant difference was found between patients with BRCA wild type and BRCA variant of unknown significance (p=0.50).

CONCLUSION

Our study suggests that carriers of BRCA variant of unknown significance have survival outcomes comparable to patients with BRCA wild type and shorter progression-free survival than women harboring BRCA pathogenic variants.

The expression and mutation of BRCA1/2 genes in ovarian cancer: a global systematic study

INTRODUCTION

This systematic review was designed to summarize the findings on expression and mutation of BRCA1/2 genes in ovarian cancer (OC) patients, focusing on mutation detection technology and taking clinical decisions for better treatment.

AREAS COVERED

We conducted a systematic review by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses document selection guidelines for the document selection process and the PICOT standard for developing the keywords to search for. A total of 5729 publications were included, and 50 articles were put into the final screening. The results showed that Next-Generation Sequencing was a breakthrough technology in detecting Breast Cancer 1/2 (BRCA1/2) gene mutations because of its efficacy and affordability. Other technologies are also being applied now for mutation detection. The most prominent associations of BRCA1/2 gene mutations were age, heredity, and family history. Furthermore, mutations of BRCA1/2 could improve survival rate and overall survival. There is no sufficient study available to conclude a systematic analysis for the expression of BRCA1/2 gene in OC.

EXPERT OPINION

Research will continue to develop more diagnostic techniques based on the expression and mutation of BCRA1/2 genes for OC in the near future.

Germline mutations in Chinese ovarian cancer with or without breast cancer

BACKGROUND

Ovarian and breast cancers are known to have significant genetic components. Considering the differences in the mutation spectrum across ethnicity, it is important to identify hereditary breast and ovarian cancer (HBOC) genes mutation in Chinese for clinical management.

METHODS

Two cohorts of 451 patients with ovarian cancer only (OV) and 93 patients with both breast and ovarian (BROV) cancers were initially screened for BRCA1, BRCA2, TP53, and PTEN. 109 OV and 43 BROV patients with extensive clinical risk and were being tested negative, were then further characterized by 30-gene panel analysis.

RESULTS

Pathogenic BRCA1/2 variants were identified in 45 OV patients and 33 BROV patients, giving a prevalence of 10% and 35.5%, respectively. After the extended screening, mutations in other HBOC genes were identified in an additional 12.8% (14/109) of the OV cohort and 14% (6/43) in the BROV cohort. The most commonly mutated genes in the OV cohort were MSH2 (4.6%) while in the BROV cohort were MSH2 (4.7%) and PALB2 (4.7%). With this extended multigene testing strategy, pathogenic mutations were detected in 12.8% of OV patients (BRCAs: 10%; additional genes: 12.8%) and 40.9% (BRCAs: 35.5%; additional genes: 14%) of BROV patients.

CONCLUSION

Extended characterization of the contributions of HBOC genes to OV and BROV patients has significant impacts on further management in patients and their families, expanding the screening net for more asymptomatic individuals.

Probability of detecting germline BRCA1/2 pathogenic variants in histological subtypes of ovarian carcinoma. A meta-analysis

BACKGROUND

Histology restricted genetic predisposition testing of ovarian carcinoma patients is a topic of debate as the prevalence of BRCA1/2 pathogenic variants (PVs) in various histological subtypes is ambiguous. Our primary aim was to investigate the proportion of germline BRCA1/2 PVs per histological subtype. Additionally, we evaluated (i) proportion of somatic BRCA1/2 PVs and (ii) proportion of germline PVs in other ovarian carcinoma risk genes.

METHODS

PubMed, EMBASE and Web of Science were systematically searched and we included all studies reporting germline BRCA1/2 PVs per histological subtype. Pooled proportions were calculated using a random-effects meta-analysis model. Subsets of studies were used for secondary analyses.

RESULTS

Twenty-eight studies were identified. The overall estimated proportion of germline BRCA1/2 PVs was 16.8% (95% CI 14.6 to 19.2). Presence differed substantially among patients with varying histological subtypes of OC; proportions being highest in high-grade serous (22.2%, 95% CI 19.6 to 25.0) and lowest in clear cell (3.0%, 95% CI 1.6 to 5.6) and mucinous (2.5%, 95% CI 0.6 to 9.6) carcinomas. Somatic BRCA1/2 PVs were present with total estimated proportion of 6.0% (95% CI 5.0 to 7.3), based on a smaller subset of studies. Germline PVs in BRIP1, RAD51C, RAD51D, PALB2, and ATM were present in approximately 3%, based on a subset of nine studies.

CONCLUSION

Germline BRCA1/2 PVs are most frequently identified in high-grade serous ovarian carcinoma patients, but are also detected in patients having ovarian carcinomas of other histological subtypes. Limiting genetic predisposition testing to high-grade serous ovarian carcinoma patients will likely be insufficient to identify all patients with a germline PV.

PARP Inhibitors in Patients With Newly Diagnosed Advanced Ovarian Cancer: A Meta-Analysis of Randomized Clinical Trials

Background: The efficacy of poly(adenosine diphosphate-ribose) polymerase inhibitors (PARPi) as a maintenance therapy in patients with newly diagnosed advanced ovarian cancer remains unclear. We conducted a meta-analysis to assess the benefits and safety of PARPi maintenance therapy in patients with newly diagnosed advanced ovarian cancer. Methods: We searched the PubMed, EMBASE, and Cochrane databases for randomized controlled trials (RCTs), which assessed the efficacy of PARPi as a maintenance therapy for newly diagnosed advanced ovarian cancer. Progression-free survival (PFS) was the primary endpoint, which was assessed using hazard ratios (HRs) with 95% confidence intervals (95% CI). Progression-free survival was extracted independently, and the pooled results were used to compare the prognoses of patients who received PARPi maintenance therapy and those who received a placebo. Results: Three RCTs, SOLO1, VELIA/GOG-3005, and PRIMA, which included 1,881 patients with newly diagnosed advanced ovarian cancer, were included in the meta-analysis. The overall analysis showed that PARPi maintenance therapy significantly increased PFS (HR, 0.51; 95% CI, 0.33-0.80; P = 0.004) compared to placebo. Subgroup analyses confirmed this result. We also observed an improved PFS in patients with homologous recombination deficiency (HR, 0.50; 95% CI, 0.38-0.66; P < 0.001) and in patients with BRCA mutations (HR, 0.42; 95% CI, 0.31-0.57; P < 0.001). Moreover, there were no significant differences in health-related quality of life between the PARPi and placebo groups. Conclusions: Patients with newly diagnosed advanced ovarian cancer who received PARPi maintenance therapy had a better prognosis than did those who received a placebo. Moreover, no significant changes in health-related quality of life were seen in PARPi-treated individuals.