Background: Alcohol consumption is associated with a higher risk of colorectal cancer, but to the authors' knowledge its influence on survival after a diagnosis of colorectal cancer is unclear. The authors investigated associations between prediagnosis and postdiagnosis alcohol intake with mortality among survivors of colorectal cancer.

Methods: The authors identified 2458 men and women who were diagnosed with invasive, nonmetastatic colorectal cancer between 1992 (enrollment into the Cancer Prevention Study II Nutrition Cohort) and 2011. Alcohol consumption was self-reported at baseline and updated in 1997, 1999, 2003, and 2007. Postdiagnosis alcohol data were available for 1599 participants.

Results: Of the 2458 participants diagnosed with colorectal cancer, 1156 died during follow-up through 2012. Prediagnosis and postdiagnosis alcohol consumption were not found to be associated with all-cause mortality, except for an association between prediagnosis consumption of <2 drinks per day and a slightly lower risk of all-cause mortality (relative risk [RR], 0.86; 95% confidence interval [95% CI], 0.74-1.00) compared with never drinking. Alcohol use was generally not associated with colorectal cancer-specific mortality, although there was some suggestion of increased colorectal cancer-specific mortality with postdiagnosis drinking (RR, 1.27 [95% CI, 0.87-1.86] for current drinking of <2 drinks/day and RR, 1.44 [95% CI, 0.80-2.60] for current drinking of ≥2 drinks/day).

Conclusions: The results of the current study do not support an association between alcohol consumption and all-cause mortality among individuals with nonmetastatic colorectal cancer. The association between postdiagnosis drinking and colorectal cancer-specific mortality should be examined in larger studies of individuals diagnosed with nonmetastatic colorectal cancer. Cancer 2017;123:2006-2013. © 2017 American Cancer Society.