Flame-broiled food, NAT2 acetylator phenotype, and breast cancer risk among women with benign breast disease

Purpose. The objective of this study was to examine the association between flame-broiled food consumption, a source of heterocyclic amine exposure, and the development of breast cancer among cohort of women with benign breast disease (BBD). The variation of the association by acetylation phenotype, as determined by the genotypes of selected N-acetyltransferase 2 (NAT2) enzymes, was also examined. Methods. Among participants in an ongoing cohort study, 1187 women reported having a breast biopsy for BBD and completed a food frequency questionnaire. NAT2 G857A, NAT2 T341C, and NAT2 G590A genotypes were determined using DNA extracted from blood specimens collected in 1989. Incident cases of breast cancer were identified through linkage of the cohort participants with the Washington County Cancer Registry and the Maryland State Cancer Registry. Follow-up for the BBD cohort began at study entry in 1989 and ended on April 28, 2003. Results. Of the women in this study, 77 subsequently developed breast cancer. Results showed that, among rapid acetylators, flame-broiled food intake was associated with a statistically significant increase in the risk of breast cancer (odds ratio (OR) 2.62; 95% confidence interval (CI) 1.06, 6.46). No association was observed between flame-broiled food intake and breast cancer among slow acetylators (OR 0.75; 95% CI 0.39, 1.43). Conclusions. These findings suggest that flame-broiled food may be a modifiable risk factor for the progression of BBD to invasive breast cancer among women who have genotypes consistent with rapid acetylation.