Effect Modification of Meat Intake by Genetic Polymorphismson Colorectal Neoplasia Susceptibility

Colorectal cancer incidences differ considerably between Western and non-Western countries. In recentyears, a dramatic increase in colorectal cancer incidence has been reported in several Asian countries.Immigration studies have suggested that environmental rather than genetic factors are primarily responsiblefor the international variability and secular trends of colorectal cancer incidence rates. Therefore, not only themain effect of a gene but also the inflkuence of gene-environment interactions on cancer risk are important fromthe public health perspective. This review encompasses the literature on gene-diet interactions, particularlyfocusing on meat intake and its association with the risk of colorectal carcinoma or adenomas. It is generallyaccepted that genotypes which are associated with the higher enzyme activity for metabolic activation or loweractivity for detoxification would affect individual’s susceptibility to meat carcinogens. The most intensivelystudied genes were those involved in xenobiotic metabolism, including N-acetyltransferase (NAT), cytochromeP450 (CYP) families, glutathione S-transferase (GST), and sulfotransferase (SULT). However, the associationswere not consistent across studies. The role of genetic polymorphisms and their role in effect modificationof environmental carcinogens should be assessed in well-designed large-scale epidmiological studies withcomprehensive information for risk factors for better understanding the etiologic role of dietary factors and indeveloping personalized cancer prevention strategy in the genome-wide association study era.