Alcohol consumption and rectal tumor mutations and epigenetic changes.

PURPOSE: An association between alcohol and rectal cancer has been reported in the epidemiological literature. In this study we further explore the association by examining specific tumor markers with alcohol consumption as well as types of alcoholic beverages consumed.
METHODS: We assessed alcohol consumption with CpG Island Methylator Phenotype, TP53, and KRAS2 mutations in incident rectal cancer cases and compared them with population-based controls. We evaluated type, long-term, and recent alcohol consumption.
RESULTS: We observed a trend toward increasing risk of CpG Island Methylator Phenotype positive tumors and long-term alcohol consumption. In contrast, after adjusting for total alcohol intake, recent high beer consumption significantly increased the odds of having a TP53 mutation compared with those who did not drink beer (odds ratio, 1.97; 95% CI 1.24, 3.12). We observed a nonstatistically significant reduced risk of a TP53 mutation among those who drank wine (in particular, red wine) vs nonconsumers of wine. The association between TP53 mutations and recent beer consumption was strongest for transversion mutations.
CONCLUSIONS: These data suggest that both alcohol and specific constituents of alcoholic beverages contribute to rectal cancer risk among unique disease pathways.