Characterization of 9p24 risk locus and colorectal adenoma and cancer: gene-environment interaction and meta-analysis.

Background: A potential susceptibility locus for colorectal cancer on chromosome 9p24 (rs719725) was initially identified through a genome-wide association study, though replication attempts have been inconclusive.

Methods: We genotyped this locus and explored interactions with known risk factors as potential sources of heterogeneity, which may explain the previously inconsistent replication. We included Caucasians with colorectal adenoma or colorectal cancer and controls from 4 studies (total 3,891 cases, 4,490 controls): the Women's Health Initiative (WHI); the Diet, Activity and Lifestyle Study (DALS); a Minnesota population-based case-control study (MinnCCS); and the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO).