Evaluation of Cancer Prevention Strategies in Japan*

Background: It remains unclear whether alcohol drinking is causally associated with colorectal cancer. On the basis of a systematic review of epidemiological evidence, we evaluated this association among the Japanese population, who may be more susceptible to alcohol-related diseases than Western populations. Methods:Original datawereobtained fromsearchesofMEDLINEusingPubMed,complemented with manual searches. The evaluation of associations was based on the strength of evidence and the magnitude of association, together with biological plausibility as previously evaluated by the International Agency for Research on Cancer. Results:Weidentified5cohort studiesand13case–control studies.Amoderateorstrongpositive association was observed between alcohol drinking and colon cancer risk in all large-scale cohort studies, with some showing a dose–response relation, and among several case–control studies. The risk of colon or colorectal cancer was increased even among moderate drinkers consuming <46 g of alcohol per day, levels at which nomaterial increase in the risk was observed in a pooled analysis ofWestern studies. A positive associationwith rectal cancerwas also reported, but it was less consistent, and themagnitude of the association was generally weaker compared with colo