Abstract 198: Molecular genetic characterization of primary breast cancer via clinical next-generation sequencing

Abstract

Abstract Targeting appropriate driver genes is crucial in cancer precision medicine. To find oncogenic drivers, targeted next-generation sequencing is becoming widely used in the clinical field. Using targeted next-generation sequencing, we aimed to detect targetable genetic alterations and characterize mutational profiles of breast cancer. We analyzed breast cancer biopsy specimens using customized 50-gene panel. In total, 196 patients of primary operable breast cancer patients were selected from single institution in South Korea. Among the 196 patients, 22 kinds of genes were significantly mutated or amplified. They comprised 161 nonsynonymous missense mutations, 54 frameshift mutations, 29 missense mutations and 5 small indels; 64 gene amplifications and 2 deletions. The most frequently mutated gene was PIK3CA (n=81/196; 41.3%), followed by TP53 (n=62; 31.6%), AKT1 (n=21; 10.7%), GATA3 (n=17; 8.7%) and PTEN (n=14; 7.1%). The most frequently amplified gene was ERBB2 (n=25/196; 12.8%), followed by FGFR1 (n=11; 5.6%), MYC (n=9; 4.6%), FGFR2 (n=3; 1.5%) and FGFR3 (n=3; 1.5%). Targeted next-generation sequencing can be readily performed in daily clinical practice. The most commonly found targetable genetic alterations were mutations of PI3K/AKT/mTOR pathway genes and FGFR family gene amplifications. Despite the limited number of available targeted agents, our study shows the feasible application of precision medicine in breast cancer. Citation Format: Jung Ho Park, Seung Yeon Ko, Sang Hwa Kim, Ho Young Kim, Sung Hoon Ko, Lee Su Kim. Molecular genetic characterization of primary breast cancer via clinical next-generation sequencing [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 198.