Background: Individuals with a family history of colorectal cancer may be more susceptible to adverse effects of alcohol consumption.
Objective: We investigated whether the association between alcohol consumption and colon cancer risk differed by family history of colorectal cancer.
Design: We conducted prospective studies in women and men in the Nurses' Health Study and Health Professionals Follow-Up Study, respectively. Alcohol consumption was first assessed in 1980 in women and in 1986 in men.
Results: During a follow-up of 26 y among 87,861 women and 20 y among 47,290 men, we documented 1801 cases of colon cancer (1094 women and 707 men). Higher alcohol consumption was associated with an elevated risk of colon cancer, although the association was significant only for the highest intake category of ≥30 g/d, with no significant linear trend. The association between alcohol consumption and colon cancer risk differed by family history of colorectal cancer; in comparison with nondrinkers, the pooled multivariate RRs for alcohol consumption of ≥30 g/d were 1.23 (95% CI: 0.96, 1.57; NS) among those with no family history and 2.02 (95% CI: 1.30, 3.13) among those with a family history of colorectal cancer (P value test for difference = 0.05). In comparison with nondrinkers with no family history, the RR for colon cancer was 2.80 (95% CI: 2.00, 3.91) for individuals who consumed ≥30 g/d and who had a family history of colorectal cancer.
Conclusion: Reducing alcohol consumption may decrease the incidence of colon cancer, especially among those with a family history of colorectal cancer.