Germline Mutations in Cancer Susceptibility Genes in a Large Series of Unselected Breast Cancer Patients

Clin Cancer Res. 2017 Oct 15;23(20):6113-6119. doi: 10.1158/1078-0432.CCR-16-3227. Epub 2017 Jul 19.

Abstract

Purpose: The prevalence of mutations in cancer susceptibility genes such as BRCA1 and BRCA2 and other cancer susceptibility genes and their clinical relevance are largely unknown among a large series of unselected breast cancer patients in the Chinese population.Experimental Design: A total of 8,085 consecutive unselected Chinese breast cancer patients were enrolled. Germline mutations in 46 cancer susceptibility genes were detected using a 62-gene panel.Results: Pathogenic mutations were identified in 9.2% of patients among the 8,085 unselected breast cancer patients. Of these, 5.3% of patients carried a BRCA1 or BRCA2 mutation (1.8% in BRCA1 and 3.5% in BRCA2), 2.9% carried other breast cancer susceptibility genes (BOCG) and 1.0% carried another cancer susceptibility genes. Triple-negative breast cancers had the highest prevalence of BRCA1/2 mutations (11.2%) and other BOCG mutations (3.8%) among the four molecular subgroups, whereas ER-/PR-HER2+ breast cancers had the lowest mutations in BRCA1/2 (1.8%) and BOCG (1.6%). In addition, BRCA1 mutation carriers had a significant worse disease-free survival [unadjusted hazard ratio (HR) 1.60; 95% confidence interval (CI) 1.10-2.34; P = 0.014] and disease-specific survival (unadjusted HR 1.96; 95% CI, 1.03-3.65; P = 0.040) than did non-carriers, whereas no significant difference in survival was found between BRCA2 mutation carriers and non-carriers.Conclusions: 9.2% of breast cancer patients carry a pathogenic mutation in cancer susceptibility genes in this large unselected series. Triple-negative breast cancers have the highest prevalence of mutations in BRCA1 /2 and other breast cancer susceptibility genes among the four molecular subgroups, whereas ER-/PR-HER2+ breast cancers had the lowest mutations in these genes. Clin Cancer Res; 23(20); 6113-9. ©2017 AACR.

MeSH terms

  • Adult
  • BRCA1 Protein / genetics
  • BRCA2 Protein / genetics
  • Biomarkers, Tumor
  • Breast Neoplasms / diagnosis
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / mortality
  • Computational Biology / methods
  • DNA Mutational Analysis
  • Databases, Genetic
  • Female
  • Follow-Up Studies
  • Genetic Association Studies*
  • Genetic Predisposition to Disease*
  • Germ-Line Mutation*
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Middle Aged
  • Neoplasm Grading
  • Neoplasm Metastasis
  • Neoplasm Staging
  • Prevalence
  • Young Adult

Substances

  • BRCA1 Protein
  • BRCA2 Protein
  • Biomarkers, Tumor