Polymorphisms in Nucleotide Excision Repair Genes Modify Breast Cancer Risk in Smokers

Robert C. Millikan, DVM, Ph.D.
University of North Carolina School of Public Health
P30ES10126

Breast cancer occurs at different rates in different racial groups. NIEHS-supported researchers at the University of North Carolina determined that African-American women smokers with specific combinations of polymorphisms in nucleotide excision repair genes are more susceptible to breast cancer than white women who smoke.

Nucleotide excision repair is the primary means by which smoking-induced DNA damage is repaired. Smoking is a recognized risk factor for lung, head and neck and other cancers, but the relationship between smoking and breast cancer is unclear. There are several known polymorphisms in genes involved in nucleotide excision repair. These investigators conducted a genetic epidemiologic study aimed at determining whether genetic polymorphisms alter the association between smoking and breast cancer.

They found that in general, smoking was a stronger risk factor for breast cancer in African-American women than white women. The risks increased even more for African-American women with particular patterns of polymorphisms when combined with different smoking characteristics such as amount of smoking, duration, and age at smoking initiation.

The investigators claim that this is the first study to examine nucleotide excision repair polymorphisms as susceptibility factors for breast cancer in combination with smoking. Further studies with larger numbers of participants are needed to confirm these results.

Citation: Mechanic LE, Millikan RC, Player J, de Cotret AR, Winkel S, Worley K, Heard K, Heard K, Tse CK, Keku T. Polymorphisms in nucleotide excision repair genes, smoking and breast cancer in African Americans and whites: a population-based case-control study. Carcinogenesis. 2006 Jul;27(7):1377-85.