Associations between dietary heterocyclic amines and polycyclic aromatic hydrocarbons and colon cancer risk

Meat intake, red meat in particular, is a recognized risk factor for colon cancer. Heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), produced when meats are cooked at high temperatures, are believed to be important colon carcinogens, and have been associated with increased risks of colon cancer in some, but not all, epidemiologic studies. We sought to further clarify this relationship in a Kentucky SEER Cancer Registry-based incident case-control study. Dietary data were collected from 1,296 participants (524 cases, and 772 population controls) using the validated Arizona Meat Preparation Questionnaire. This 50-item self-administered instrument measures intakes of 2-Amino-3,8-dimethylimidazo[4,5-f] quinoxaline (MeIQx), 1-Methyl-6-phenyl-1H-imidazo[4,5-b]pyridin-2-amine (PhIP), 2-amino-3,4-8-trimethyl-imidazo[4,5-f] quinoxaline (DiMeIQx), and Benzo(á) pyrene (BaP) based on participants' responses to frequency of meat consumption and its relative doneness. Using a two-sided t-test, we found that MeIQx (p = 0.011) and DiMeIQx (p = 0.029) were statistically different between the cases and controls whereas PhIP (p = 0.493) and Benzo(á) pyrene (p = 0.464) were not statistically significant. Multivariate regression analysis of the relative risk (odds ratio) for HCAs and PAHs is forthcoming. These data add evidence supporting that meat intake, MeIQx and DiMeIQx in particular, may promote colon carcinogenesis.