Cancer Risk Linked to SNPs Not Affected by Lifestyle Factors
Study assesses effects of 12 SNPs linked to breast cancer in relation to 10 environmental factors
WEDNESDAY, June 2 (HealthDay News) -- The risk of breast cancer associated with a dozen low-penetrance genetic susceptibility polymorphisms isn't affected by a number of established environmental risk factors, according to research published online June 2 in The Lancet.
Ruth C. Travis, Ph.D., of the University of Oxford in the United Kingdom, and colleagues analyzed data from 7,610 women who developed breast cancer and 10,196 women without the disease. They assessed the effects of 12 single-nucleotide polymorphisms (SNPs) previously associated with the disease in relation to 10 environmental risk factors, including age at menarche, breast-feeding, use of hormone replacement therapy, body mass index, height, and alcohol consumption.
The researchers found that, after allowance for multiple testing, none of the 120 comparisons showed significant evidence of a gene-environment interaction. Hormone replacement therapy showed little evidence of affecting genotypic relative risks. The researchers also found that carriers of the high-risk allele of one of the SNPs were significantly shorter than non-carriers.
"The function of most of the SNPs is unclear and future investigations might show them to be only markers of the true causal variants. Although our study is fairly large, with prospectively collected exposure data from one cohort, it still lacked power to assess moderate gene-environment interactions for all but the four or so SNPs most strongly related to breast cancer risk or to investigate interactions separately for causally distinct types of breast cancer, such as those with and without estrogen receptors," the authors write.