Review: Single nucleotide polymorphisms associated with the oncogenesis of colorectal cancer

Colorectal cancer (CRC) is provoked by interactions between genetic and environmental factors. We herein review the incidence and the mechanisms of action of the reported single nucleotide polymorphisms (SNPs) in the oncogenesis of CRC. More than 15 reports have studied the SNPs at 8q24, which are associated with the incidence of CRC as well as prostate cancer. We have also reported a SNP at the 10p14 locus, and the risks of other loci for CRC oncogenesis. With regard to the underlying mechanism for CRC, 8q24 is a locus of the long-enhancer site for MYC, which could determine the efficacy of MYC transcription. We suggest that 8q24 SNPs might be associated with the progression of CRC cases mediated by MYC expression. In this report, we summarize the published studies of the genetic background SNPs in the oncogenesis of CRC. The level of risk (most studies indicated less than a twofold increase) for CRC was lower than anticipated. Therefore, it is necessary to identify bona fide SNPs that precisely predict the risk for CRC. Alternatively, it is important to consider other factors, such as environmental or lifestyle-related factors, for the future prevention of CRC.