Abstract P4-06-16: Frequency of pathogenic mutation in patients at high risk for hereditary breast cancer

Abstract

Background: Next-generation sequencing technology allows the simultaneous sequencing of multiple target genes. We developed a gene panel containing 64 genes which were associated with various hereditary cancers. This study was performed to evaluate the frequency of pathogenic mutations associated with hereditary cancer among Korean patients at high risk hereditary breast cancer using multi-gene sequencing panel. Methods: A total of 252 breast cancer patients with high-risk hereditary cancer were included. Among them, 179 patients (71.0%) had multiple primary cancers including breast cancer, 27 patients (10.7%) were diagnosed with bilateral breast cancer at age 40 or younger. Thirty-five patients (13.9%) had breast cancer family history of more than 2 relatives. With the 64-gene panel, sequence variants were detected by next-generation sequencing technology. Results: Sixty seven patients (26.8%) were found to have 77 germline pathogenic mutations, 12 in BRCA1, 13 in BRCA2, 9 in CDH1, 3 in FH, 5 in MSH2, 2 in MSH6, 4 in NAT1, 6 in PTCH1, 3 in RAD51, 7 in RET, 4 in SPINK1, 3 in TP53 and one each in ALK, BRIP1, CHEK2, MLH2, MUTYH, and PTEN. In 20 patients (4.0%), 2 (n=9) or 3 (n=1) pathogenic mutations were detected. In 227 patients with BRCA1/2 negative, CDH1 (n=7), RET (n=7), PTCH1 (n=5), and MSH2 (n=5) were the most prevalent pathogenic mutations. Conclusions: The 64 gene panel detected germline pathogenic mutations in 26.8% of Korean breast cancer patients with feature of hereditary cancer. Mutations of BRCA1, BRCA2, CDH1, RET, and PTCH1 were the most prevalent variants.Mutation carriers were considered as high risk to develop malignancy and recommended to receive genetic counseling and intensive cancer screening. Citation Format: Shin H-C, Yoo T-K, Lee H-B, Moon H-G, Noh D-Y, Han W. Frequency of pathogenic mutation in patients at high risk for hereditary breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-06-16.