ALCOHOL AND SMOKING IN RELATION TO THE PREVALENCE OF ADENOMATOUS COLORECTAL POLYPS DETECTED AT SIGMOIDOSCOPY

Cigarette smoking has been associated with adenomatous polyps of the l arge bowel but not with increased risk of colorectal cancer. Giovannuc ci et al recently proposed a hypothesis to explain this inconsistency. A key testable aspect of the hypothesis is that smoking in the distan t past increases the risk of large polyps. Questions also remain about the association between colorectal polyps and consumption of alcohol. To address these issues, we examined data from 488 cases with adenoma tous polyps and 488 controls. Subjects were members of a prepaid healt h plan in Los Angeles who had a sigmoidoscopy in 1991-1993. As expecte d, the adjusted odds of polyps in current smokers compared with never- smokers was increased [odds ratio = 2.43; 95% confidence interval (CI) = 1.56-3.79]. For those who had smoked in the distant Fast (for examp le, 30 or more pack-years before 20 years ago), the adjusted odds of a n adenoma greater than or equal to 1 cm, relative to nonsmokers, was 0 .88 (95% CI = 0.23-3.42), The adjusted odds of polyps in those consumi ng greater than or equal to 46 gm per day of alcohol compared with non drinkers was 1.50 (95% CI = 0.72-3.13). Although imprecise, these data do not support the hypothesis that past smoking increases the risk of large polyps, but our results indicate a weak association between alc ohol use and risk of adenomatous polyps.