Abstract
Female breast cancer is the most common and the fifth deadliest cancer worldwide. It is influenced by a combination of genetic, hormonal, and environmental factors. The excision repair cross-complementation group 3 gene (ERCC3) has recently been identified as a breast cancer susceptibility gene in various cohorts of different geographical and ethnic origin. To explore the role of ERCC3 mutations in breast cancer development and pathological diagnosis, genetic analysis was conducted in 291 patients and 291 controls from mainland China. Bioinformatic analysis and immunohistochemistry (IHC) were performed. A novel ERCC3 mutation p.Y116X was identified in a breast cancer family, while no frequency bias for the genotype and allele of rs754010782 and rs371627165 was observed (all P > 0.05). Bioinformatic analysis revealed that ERCC3 expression was negatively associated with estrogen receptor (ER), progesterone receptor (PR), nontriple-negative status, and nodal status of breast cancers. ERCC3 amplifications and deep deletions primarily occurred in breast invasive cancer not otherwise specified (NOS) and metaplastic breast cancer, respectively. The decreased ERCC3 expression in tumor tissues of patient with p.Y116X mutation was found by IHC. The ERCC3 mutation p.Y116X may increase breast cancer risk in the Han-Chinese population. ERCC3 exhibits potential as a biomarker for the pathological diagnosis of breast cancer.