The association of smoking and prevalent adenomatous polyp characteristics

We assessed the relationship of cigarette smoking to the location, size, and histology of prevalent adenomatous colorectal polyps detected among 1429 participants, all adenoma patients, in a randomized trial testing the effects of a high (13.5 g/day) versus low (2 g/day) wheat bran fiber intervention on adenoma recurrence. Participants had a complete qualifying colonoscopy with at least one histologically confirmed adenomatous polyp 3 mm or larger. Location, size and histology of the baseline adenoma(s) were recorded. Cigarette smoking was evaluated at baseline through a self-administered questionnaire. Among the study participants, 66% had a history of ever smoking and 14% were current smokers. Compared to never smokers, those in the upper tertile of pack-years of smoking had a lower, non-significant risk of having one or more of their adenomas in the proximal colon (OR = 0.79; 95% CI = 0.53-1.16) and a lower risk of having one or more of their adenomas of villous histology (OR = 0.63; 95% CI = 0.43-0.94). Individuals in the upper tertile of pack-years of smoking were more likely to have a large (>1 cm) adenoma (OR = 1.27; 95% CI = 0.91-1.76) but no dose-response was observed. These results suggest that among adenoma patients, those who are exposed to cigarette smoking are more likely to have distal adenomas versus adenomas found only in the proximal colon. Exposure to cigarette smoke is a predictor of non-villous as opposed to villous adenomas and is not associated with adenoma size. These data describe correlations of adenoma characteristics among adenoma patients; they do not refer to the probability of adenoma presence