Association between alcohol consumption and cancer of the sigmoid colon: observations from a Japanese cohort study.

A 17-year follow up of 265,118 Japanese adults aged 40 years and above revealed a close association between cancer of the sigmoid colon (n = 91) and alcohol consumption: relative risk (RR) for drinkers versus non drinkers was 4.38 (90% CI 1.75-10.97) in men and 1.92 (1.13-3.26) in women. In men, attributable risk was 74% and RRs in non, infrequent, occasional, and daily drinkers were 1.00, 2.03, 3.83, and 5.42, respectively. RRs of daily consumption versus non-consumption in men for cancers of mouth, pharynx, oesophagus, stomach, proximal colon, sigmoid colon, and rectum were 2.27, 2.44, 2.29, 0.92, 0.98, 5.42, and 1.39, respectively. A combined effect of alcohol and smoking was evident for cancers of the upper digestive tract but almost absent for those of the lower digestive tract.