[Significance of genome-wide association study in cancer]

The single-nucleotide polymorphism (SNP)-based genome-wide association study (GWAS) is now widely performed because of the development of new SNP genotyping technologies from 2007 onward. The GWAS provides a powerful approach to identify regions of the genome that harbor genetic variants conferring risk for disease without prior knowledge of location or function. During the past few years, the GWAS has identified numerous robust associations between specific chromosomal loci and different types of cancer. For nearly all regions identified in the GWAS, the per allele effect sizes estimated are < 1.5 and the mechanism of SNP in carcinogenesis was not clear. Consequently, GWAS findings underscore the complex nature of cancer. The combined effects may be sufficiently great to be useful for risk prediction, targeted screening, and prevention, particularly as more loci are identified. Some loci, such as 8q24, were identified as a cancer susceptibility region for many unrelated cancers, and therefore an investigation of those loci may disclose new mechanisms of carcinogenesis or unknown genes including noncoding RNA. Furthermore, the development of new strategies for GWAS analysis is expected.