Inverse relationship between moderate alcohol intake and rectal cancer: analysis of the North Carolina Colon Cancer Study.

Abstract

The relationship between alcohol intake and rectal cancer is uncertain. We sought to evaluate whether alcohol consumption is associated with distal colorectal cancer and rectal cancer specifically. Data on alcohol intake were examined from the North Carolina Colon Cancer Study, a population-based case-control study of distal colorectal cancer. This study encompassed 33 counties in the central and eastern part of North Carolina. Cases had adenocarcinoma of the rectum, rectosigmoid, and sigmoid colon. Controls were frequency-matched on age, race, and sex. Demographic and dietary intake data were collected with use of a validated questionnaire. Logistic regression was used to estimate odds ratios for the relationship between alcohol consumption and distal colorectal cancer. Included in the study were 1033 cases and 1011 controls. The odds ratio for rectal cancer comparing any vs no alcohol intake was 0.73 (95% CI 0.60, 0.90), adjusted for age, sex, race, smoking status, obesity, education, red meat intake, use of nonsteroidal anti-inflammatory medications, and family history of colorectal cancer. The odds ratio for moderate alcohol (≤14 g/day) was 0.66 (95% CI 0.53, 0.82), whereas the odds ratio for heavy alcohol (>14 g/day) was 0.93 (95% CI 0.70, 1.23). Moderate beer and wine intakes were also inversely associated with distal colorectal cancer: odds ratios 0.76 (95% CI 0.60, 0.96) and 0.69 (95% CI 0.56, 0.86). This was a retrospective, observational study. Residual confounding is possible. In this study, moderate alcohol intake (especially wine) was inversely associated with distal colorectal cancer.