Spectrum of mutations in breast cancer is luminal subtype-predominant and related to prognosis.

MAP3K1 is a MAPK family serine-threonine kinase that is frequently mutated in human cancer. The association between mutations in the gene and the clinicopathological characteristics and prognosis of patients with breast cancer remain unclear in the Chinese population. Thus, the aim of the present retrospective study was to investigate the possible role and function of in breast cancer. Data obtained from 412 consecutive patients with breast cancer were selected from Guangdong Provincial People's Hospital (GDPH) for analysis in the present study. Mutations were assessed using next-generation sequencing. The association between mutations and clinicopathological features were analyzed and further compared with the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) cohort and data from The Cancer Genome Atlas (TCGA). In the GDPH cohort, a total of 45 mutations were identified in 8.5% (n=35) of the 412 patients, compared with 9.7% (n=244) in METABRIC and 7.9% (n=88) in TCGA. The majority of the mutations identified in the in three cohorts were truncating mutations, followed by mis-sense mutations. Mutations in were predominant in patients with the luminal A and B breast cancer subtypes in METABRIC datasets (P<0.001), although no significant differences were observed in the GDPH cohort (P=0.227). In the METABRIC cohort, patients with mutations experienced a improved overall survival (OS) rate than patients without mutations (P=0.006). In patient with hormone receptor (HR) breast cancer, a more significantly higher OS rate was observed in patients with mutations (P<0.001). MAP3K1 expression was associated with OS in the HR subgroup. Moreover, the methylation levels were reduced in primary breast cancer tissue, compared with normal tissue. Thus, the present findings identified mutations in Chinese patients with breast cancer, and compared mutations between the cohorts from Western and Eastern countries.