Folate and Folic Acid Supplement Use and Breast Cancer Risk in BRCA1/2 Mutation Carriers

The relationship between folate (a B vitamin important in DNA synthesis and methylation reactions) and cancer risk among BRCA1/2 mutation carriers with a genetic predisposition for developing breast cancer is unclear. Therefore this study investigated the association between plasma folate and folic acid supplement use, along with other B vitamins, and breast cancer risk in BRCA1/2 mutation carriers. Women with high plasma folate concentrations had significantly increased risks for breast cancer, compared with women with low plasma folate concentrations. However, women who never used folic acid-containing supplements had significantly increased risks for breast cancer. Similarly, never use of vitamin B6- or vitamin B12-containing supplements tended to be associated with increased breast cancer risk. These findings support a â Uâ -shaped association of folate and breast cancer risk and suggests that moderate B vitamin supplement use may be protective for BRCA1/2-associated breast cancer, however BRCA1/2 mutation carriers should be cautious of over-supplementation.M.Sc