Germline and somatic mutations in 25 hereditary breast and ovarian cancer related genes and platinum-based chemotherapy response among Chinese patients with epithelial ovarian cancer.

Abstract

e18088 Background: Insight on the germline and somatic mutation in BRCA1/2 was predictable on the sensitivity on platinum-based therapy. The therapeutic impact of mutations in other hereditary breast and ovarian cancer related genes is uncertain. Methods: We sought to investigate the germline and somatic deleterious mutations through all exons in 25 hereditary breast and ovarian cancer related genes in paired blood and frozen tumor samples from 235 Chinese women diagnosed with epithelial ovarian carcinomas. Results: Forty-seven subjects (24.6%) had a germline deleterious mutation, and 126 subjects (66%) had a somatic deleterious mutation. Thirty-four (17.8%) had both a germline and somatic mutation. Of the 203 germline and somatic deleterious mutations, 114 (56.2%) occurred in TP53, 41 (20.2%) in BRCA1, 11 (5.4%) in BRCA2 and 37 (23.6%) in 13 other genes: ATM, BARD1, BRIP1, CDH1, CHEK2, MLH1, MRE11A, MSH2, NF1, PALB2, PTEN, RAD51C and, STK11. In 235 patients, 215 (91.5%) and 20 (8.5%) cases were sensitive and resistant to the platinum-based chemotherapy. In the whole population, homologous recombination repair (HRR) mutations, non- homologous recombination repair(non-HRR) mutations, mismatch repair (MMR) mutations had no impact on the platinum-based chemotherapy response. No significant difference in platinum response were found in HRR, non-HRR and MRR mutation(P = 0.788). In 235 patients, ones with ATM (10), CHEK2(9), NF1(5), PALB2(8), PTEN (8) mutations were available for platinum response information; Among them, there were three patients with either ATM, CHEK2 or PALB2 mutation presented platinum resistance. Conclusions: Multi-gene panel testing of germline and somatic HBOC related gene mutations was feasible to characterize a comprehensive molecular profile of ovarian cancer and showed non-BRCA gene stratification potential value in predicting patient’s response for platinum-based chemotherapy.