Grilled meat consumption and PhIP-DNA adducts in prostate carcinogenesis

2-Amino-l-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is the major heterocyclic amine generated from cooking meats at high temperatures, and dietary exposures have been shown to induce prostate cancer in rats. PhIP derives its carcinogenic potential through the formation of PhIP-DNA adducts. The purpose of this study was to examine whether self-reported consumption and preparation doneness of grilled meats were associated with PhIP-DNA adduct levels in prostate epithelial cells. The study population consisted of 268 African-American and Caucasian men who underwent radical prostatectomy for prostate cancer. PhIP-DNA adducts in tumor and adjacent nontumor cells were measured using immunohistochemical methods, and dietary meat intake information was based on food frequency questionnaires. Data were analyzed using multivariate linear regression models. After adjusting for age at prostatectomy and race, grilled meat consumption (P = 0.002) was significantly associated with higher adduct levels in tumor cells, but this association seemed to be primarily due to consumption of grilled red meats (P = 0.001) as opposed to grilled white meat consumption (P = 0.15). Among the specific food items, grilled hamburger consumption had the most significant association with adduct level in tumor cells (P = 0.002). Similar trends in positive associations with grilled meat consumption and adduct levels were observed in nontumor cells, but none of these associations reached statistical significance. Our results suggest that dietary interventions targeted at lower consumption of grilled red meats may reduce prostate cancer risk via the PhIP prostate carcinogenic pathway.