Current Achievement and Challenges of Food, Cooking Methods and Cancer Control: A Pooled Multivariable-Adjusted Analysis for the Association Between Meat Mutagens Intake and Colorectal Adenoma and Cancer

Abstract

Background: Heterocyclic amines (HCAs), a group of dietary carcinogens, have been hypothesized to increase risk of colorectal adenoma (CRA) cancer (CRC). However, previous findings have been inconsistences. Aim: The aim was to pool analysis of multivariable-adjusted relative risks from published articles for the association between HCAs intake and the risk of CRD and CRC. Methods: We used all available 34 published articles to access the multivariable-adjusted relative risk (hazard ratio or odds ratio) and their 95% confidence interval (95% CI) to estimate ln(RR) and se(ln(RR)). The HCAs 2-amino-3,8-dimethylimidazo[4,5,-f]quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,4,8-trimethylimidazo[4,5,-f]quinoxaline (DiMeIQx), and meat-derived mutagenicity (MDM) were examined. The random pooled RR, 95% CI was analyzed in using ln(RR) and se(ln(RR)) for separated prospective cohort studies and case-control studies by STATA-10. Results: Prospective cohort studies have examined for 5,684 CRC occurred among 528,111 registered participants; and for 2,484 CRA occurred among 136,902 registered participants. Case-control studies have examined for 12,753 CRC and 17,152 matched controls; and for 10,821 CRA and 45,099 matched controls. PhIP was majority contributed by cooked chicken (54%–74%). MeIQx was mainly contributed by red meat (83%–92%). For prospective cohort studies on CRC, fifth versus first-quintile, the random pooled RR, (95% CI) was 1.11, (1.00, 1.23), P = 0.052 for MDM; 1.00, (0.91, 1.09), P = 0.958 for PhIP; 1.12, (1.03, 1.22), P = 0.009 for MeIQx; 1.03, (0.87, 1.22), P = 0.763 for DiMeIQx. For CRA, third versus first-quintile, the random pooled RR, (95% CI) was 1.13, (0.92, 1.39), P = 0.237 for MDM; 1.11, (0.96, 1.29), P = 0.169 for PhIP; 1.14, (1.00, 1.30), P = 0.048 for MeIQx; 1.00, (0.87, 1.15), P = 0.999 for DiMeIQx. For case-control studies, the null association was observed for PhIP, DiMeIQx and CRC. A positive association was significantly seen for MeIQx, MDM and both CRC and CRA. Conclusion: Because intake of MeIQx significantly increased the risk of both CRC and CRA in both prospective cohort and case-control studies, the findings support to the hypothesis of the role of underlying mechanisms of red meat induced CRC.