Genes and environment in the etiology of colorectal cancer

Environmental factors, including diet, are important in the etiology of colorectal cancer. Genetic pathways of hereditary and sporadic bowel cancer are being elucidated. Highly penetrant mutations in certain genes, such as mismatch repair genes, play a major role in development of hereditary colorectal cancer, while interactions between low penetrance polymorphisms in carcinogen-metabolizing enzymes and environmental factors may identify susceptible subgroups and shed light on the etiology of sporadic colorectal cancers. In this review we summarize the current state of Knowledge regarding the rob of gene-environment interactions in development of colorectal cancer and discuss areas of particular promise, as well the limitations of these studies.