Abstract 5983: Gene profile analysis of breast cancer lung metastasis, liver metastasis, brain metastasis and primary tumor

Background: The incidence of male breast cancer (MBC) is lower than female breast cancer (FBC), representing 1% of all breast cancer worldwide. The difference with FBC may affect the treatment strategy of MBC, but the necessary precondition is that we should know more about the difference between FBC and MBC. However, Because of its low incidence that the relevant data about MBC is relatively scarce. Here we report some data about gene mutation of MBC, and compared it with FBC. Methods: Blood or tumor Tissue samples of breast cancer were collected and subjected to NGS in a College of American Pathologists (CAP)-certified and Clinical Laboratory Improvement Amendments (CLIA)-accredited lab for gene mutation analysis (3D Medicines Inc.,Shanghai, China). Statistical analysis was performed using GraphPad Prism (version 7.01) and SPSS version 21.0 (SPSS,Inc.). Results: Approximately 182 samples were analyzed, among which, exist 82 samples were from primary tissue, 66 samples were breast cancer liver metastases, 20 were lung metastases and 14 were brain metastases. High genomic heterogeneity was found among primary breast cancer tissue, breast cancer liver metastases, lung metastases, brain metastases, that is at least 20 gene mutations were found in these BC samples, while different gene mutations were showed among primary and different metastases tissues. The top five mutated gene in primary tumor tissue were TP53(80.49%), PIK3CA(53.66%), FGF19(30.49%), ERBB2(26.83%), MYC(23.17%); in liver metastases tissues were TP53(54.55%), FGF19(39.39%), PIK3CA(37.88%), ERBB2(21.21%), CCND1(19.70%); in lung metastases tissues were TP53(70.00%), PIK3CA(55.00%), ERBB2,MCL1(25.00%), CDKN2A/2B(20.00%), CCND1, NF1, CDK12(15.00%), CCND2, MYC, PTEN, GNAS, FGF19, PTK2, FGFR1(10.00%); in brain metastases tissues were TP53(42.86%), PIK3CA(28.57%), ZNF703, PREX2, JAK3, MYC, FGFR1(14.29%). Besides, levels of TMB were also different among primary tissue, liver, lung and brain metastases tissues. Higher TMB level were showed in liver and brain metastases tissue than primary and lung metastases tissues (p