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Objective: To test the hypothesis that ever smokers would suffer more recurrences and worse overall and disease-free survival than never smokers following colon cancer resection.
Summary Background Data: Smoking is associated with an increased risk of developing colon polyps, specifically aggressive polyps, as well as an increased risk of colon cancer. Large database studies have shown an increased risk of colon cancer mortality among smokers, but it is not clear whether this risk is related to differences in the biology/aggressiveness of the disease or differences in clinical response to treatment.
Methods: The medical records of 2540 patients with resected stage I-III colon cancers treated at a single institution were reviewed. Demographics, tumor and surgical variables, and follow-up information were recorded. Univariate and multivariate analyses were performed to examine predictors of overall and disease-free survival as well as time to recurrence of colon cancer.
Results: Tumor variables and chemotherapy administration were similar among smokers and nonsmokers. Overall survival was significantly higher for never smokers compared to ever smokers (5 year OS 79.8% nonsmokers versus 72.3% ever smokers, p<0.0001; HR 1.51, 95% CI 1.30 -1.74). Disease free survival was significantly higher for nonsmokers compared to smokers. Time to cancer recurrence was also significantly influenced by smoking status. Smoking status remained a poor prognostic factor in multivariate models for overall and disease-free survival as well as time to recurrence.
Conclusions: This study confirms that ever smokers have worse colon cancer outcomes than never smokers. Surgeons should refer all smokers with colon polyps or cancers for smoking cessation programs.
Multivariate Predictors of Disease-Free and Overall Survival

Disease-Free Survival
Factor	Hazard Ratio	95% CI	p value
Any smoking	1.460	1.269-1.679	<0.0001
Stage I	1.00 (referent)
Stage II	1.303	1.090-1.557	0.0036
Stage III	2.212	1.776-2.754	<0.0001
Chemotherapy	0.703	0.573-0.863	0.0007
Diabetes	1.181	0.987-1.421	0.0796
Age	1.046	1.038-1.054	<0.0001
Overall Survival
Factor	Hazard Ratio	95% CI	p value
Any smoking	1.506	1.301-1.742	<0.0001
Stage I	1.00 (referent)
Stage II	1.257	1.047-1.509	0.0142
Stage III	2.221	1.772-2.783	<0.0001
Chemotherapy	0.585	0.470-0.728	<0.0001
Diabetes	1.206	0.994-1.464	0.0578
Age	1.058	1.048-1.065	<0.0001