Case-control study of lifetime alcohol intake and prostate cancer risk.

Purpose: Alcohol consumption may be a modifiable risk factor for prostate cancer, but previous results have been inconsistent and limited by a lack of data on lifetime exposure and specific beverages. Furthermore, the effect of tumor stage and severity of disease on the association between alcohol and prostate cancer risk has not been fully investigated.
Methods: We examined the relation between both current and lifetime alcohol intake and prostate cancer risk in a population-based case-control study in Alberta, Canada with 947 cases with stage T2 and higher prostate cancer diagnosed between 1997 and 2000 and frequency matched to 1,039 controls, identified through random digit dialing. Cases were classified on cancer stage and severity into 619 non-aggressive (Stage II and Gleason score <8) and 328 aggressive cases (Stage III/IV or Gleason score ≥8). In-person interviews were completed on current and lifetime history of alcohol consumption and all other prostate cancer risk factors.
Results: Current alcohol intake did not increase prostate cancer risk but lifetime intake increased risk for both non-aggressive and aggressive cases, with an odds ratio of 1.78 (95 % CI 1.19-2.66) and 2.00 (95 % CI 1.19-3.36), respectively, for the highest intake quartile compared to non-drinkers with evidence for a linear trend. Associations with alcohol intake remained after exclusion of non-drinkers for non-aggressive prostate cancer cases. Only lifetime beer intake was significantly associated with increased risk, however, intakes of liquor and wine by participants were low.
Conclusions: Results support the evidence for an increased risk of prostate cancer from lifetime alcohol consumption.