Jung YS, et al. - This work is meant to assess the effect of passive smoking on the risk of colorectal neoplasia (CRN) in never, former, and current smokers. Researchers recognize passive smoking as an independent risk factor for CRN in never and former smokers. They recommend giving priority for colonoscopy to never and former smokers who are highly exposed to passive smoke, as well as current smokers.

Methods

• Researchers performed a cross-sectional study on asymptomatic examinees who underwent colonoscopy as part of a health check-up.

Results

• There were 136,707 participants; 33,052 (24.2%) were never passive smokers, and 103,655 (75.8%) were ever passive smokers.
• The study population had mean age of 41.0 years.
• In this study, the proportion of never, former, and current smokers was 56.9%, 21.4%, and 24.8%, respectively, and the proportion of overall CRN and advanced CRN (ACRN) was 15.4% and 1.7%, respectively.
• There appeared an association of ever passive smoke exposure with an increased risk of overall CRN in never smokers (adjusted odds ratio [AOR] 1.08; 95% confidence interval [CI] 1.02-1.13) and former smokers (AOR 1.08; 95% CI 1.00-1.17) but not in current smokers (AOR 1.02; 95% CI 0.94-1.11).
• In addition, it markedly increased the risk of ACRN among never smokers (AOR 1.17; 95% CI 1.01-1.35) and tended to increase the risk of ACRN among former smokers (AOR 1.26; 95% CI 0.99-1.61).
• Furthermore, with increasing frequency and duration of passive smoking in never and former smokers, the risk of CRN increased.