Modifiable risk factors for colorectal neoplasms and hyperplastic polyps.

PURPOSE Obesity, smoking and alcohol are modifiable putative risk factors for colorectal neoplasms (CRN) and hyperplastic polyps (HP). The aim of this study was to evaluate the strength of association between these modifiable risk factors and colorectal polyps. METHODS These risk factors were assessed by using a questionnaire completed by the patient prior to colonoscopy. Eight hundred-seventy consecutive patients satisfying inclusion criteria who had undergone a complete colonoscopy were divided into 4 groups: CRN (n=194), HP (n=132), CRN and HP (n=42) and control (neither CRN nor HP; n=586). Multiple logistic regression was performed. RESULTS The ORs [95%CI] of both CRN and HP for incremental body mass index expressed in 2 categories (>or=22, >or=25) were 2.12 [1.00, 4.50] and 1.41 [0.53, 3.77], respectively. The ORs [95%CI] of CRN and HP for heavy smoking of over 20 pack-years were 1.66 [1.05, 2.64] and 1.67 [1.01, 2.77], respectively. The ORs of CRN and HP for habitual alcohol drinking (median ethanol intake 32 g/day and interquartile range 18-40 g/day) were 1.31 [0.86, 1.98] and 1.91 [1.06, 3.47], respectively. CRN and HP were correlated with each other (p=0.0043, chi-square test). Aging was a significant risk factor for all three groups of colorectal polyps. CONCLUSION These findings are especially important since smoking and alcohol consumption are modifiable risk factors. Heavy smokers should be encouraged to quit to reduce their risk of CRN and HP. Habitual drinkers should be warned of the risk of HP. HP can be a marker of coincidence of CRN.