Genetic polymorphisms in the DNA repair enzyme ERCC2 and breast tumour risk in a Chinese population.

DNA repair systems enable our cells to respond to carcinogens and mutagens. The ERCC2 gene encodes a DNA repair protein that has multiple regulatory cellular functions including nucleotide excision repair, basal transcription, cell cycle control, and apoptosis. The ERCC2 polymorphism Lys751Gln may alter the capacity for DNA repair, which could affect the risk of certain cancers. We examined whether the Lys751Gln polymorphism was associated with the risk of breast cancer in Chinese women by analysing the genotype frequencies in 486 patients with breast cancer and 479 cancer-free control subjects. At least one variant allele (Lys/Gln or Gln/Gln) was associated with a 44% decreased risk of breast cancer. Patients with breast cancer with the 751Lys/Gln or 751Gln/Gln genotypes were less likely to be hormone receptor positive. In conclusion, our results demonstrated that ERCC2 polymorphisms might be potential risk markers for breast cancer in the Chinese population.