Body Mass Index Is Associated with Gene Methylation in Estrogen Receptor–Positive Breast Tumors
Brionna Y. Hair, Melissa A. Troester, Sharon N. Edmiston, Eloise A. Parrish, Whitney R. Robinson, Michael C. Wu, Andrew F. Olshan, Theresa Swift-Scanlan, and Kathleen Conway
Cancer Epidemiol Biomarkers Prev; Published OnlineFirst January 12, 2015;
doi:10.1158/1055-9965.EPI-14-1017
Lay Abstract
Obesity is an established risk factor for breast cancer in postmenopausal women. Though it is not clear how obesity influences breast cancer risk, several hypotheses have been posited, including exposure to estrogens, insulin resistance, and increased inflammation. In this study, we sought to determine how obesity (body mass index ≥ 30 kg/m2) might influence cancer-relevant cellular-level processes in breast tissue. Specifically, we examined the relationship between obesity and gene methylation, a mechanism that influences whether a gene is expressed. We found that among estrogen receptor-positive breast tumors, obesity is associated with increased methylation of genes with known relevance to cancer, including genes that function in immune response, cell growth, and DNA repair. Our findings suggest that obesity is associated with altered gene methylation in breast tissue, and these changes could potentially influence the expression of genes that act in cancer initiation or progression. |
