Low-penetrance alleles predisposing to sporadic colorectal cancers: a French case-controlled genetic association study.

Background: Sporadic colorectal cancers (CRC) are multifactorial diseases resulting from the combined effects of numerous genetic, environmental and behavioral risk factors. Genetic association studies have suggested low-penetrance alleles of extremely varied genes to be involved in susceptibility to CRC in Caucasian populations.

Methods: Through a large genetic association study based on 1023 patients with sporadic CRC and 1121 controls, we tested a panel of these low-penetrance alleles to find out whether they could determine "genotypic profiles" at risk for CRC among individuals of the French population.

The thorough screening of the MUTYH gene in a large French cohort of sporadic colorectal cancers.

The MUTYH gene encodes a key glycosylase of the base-excision repair system that is involved in maintaining genomic DNA stability against oxidative damage. Biallelic germline MUTYH mutations have been proved to greatly predispose to non-familial adenomatous polyposis (FAP) and non-hereditary non-polyposis colorectal cancer (HNPCC) familial recessive forms of colorectal cancer with multiple adenomas. To date, there is still much debate over the impact of monoallelic germline MUTYH mutations on colorectal carcinogenesis.

Combinations of cytochrome P450 gene polymorphisms enhancing the risk for sporadic colorectal cancer related to red meat consumption.

Susceptibility to sporadic colorectal cancers (CRC) is generally thought to be the sum of complex interactions between environmental and genetic factors, all of which contribute independently, producing only a modest effect on the whole phenomenon. However, to date, most research has concealed the notion of interaction and merely focused on dissociate analyses of risk factors to highlight associations with CRC. By contrast, we have chosen a combinative approach here to explore the joint effects of several factors at a time.