Intake of Meat Mutagens and Risk of Prostate Cancer in a Cohort of U.S. Health Professionals.

BACKGROUND Evidence relating heterocyclic aromatic amines (HCA), associated with high-temperature cooking methods, to prostate cancer risk is inconsistent. METHODS In a large U.S. cohort study, intakes of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx) and a meat-derived mutagenicity (MDM) index were assessed using a cooking method questionnaire administered in 1996. Until 2010, 2,770 prostate cancer cases were observed among 26,030 participants. RESULTS Intake of PhIP from red meat was statistically significantly associated with total prostate cancer risk (top vs. bottom quintile HR, 1.18; 95% confidence intervals; CI, 1.03-1.35), but not other HCAs (MeIQx, 1.12; 0.98-1.27, PhIP from white meat, 1.08; 0.95-1.22, DiMeIQx, 1.09; 0.97-1.21) or MDM (1.13; 1.00-1.28). For high-grade (Gleason sum 7 with pattern 4+3 and Gleason sum 8-10, n = 483 cases) and advanced cancers (n = 281), we only observed positive associations for PhIP from red meat (top vs. bottom quintile: high grade: HR, 1.44; 95% CI, 1.04-1.98, Ptrend = 0.03; advanced: HR, 1.50; 95% CI, 0.99-2.26; Ptrend = 0.12), but associations for advanced cancers did not reach statistical significance. Observed associations remained similar after adjustment for total, unprocessed, or processed red meat intake. CONCLUSION Observed positive associations between PhIP intake from red meat and prostate cancer, particularly high-grade and possibly also advanced prostate cancer, need to be confirmed in other studies. IMPACT Results do not provide strong evidence that HCAs increase risk of prostate cancers.