Effect of Smoking on Bladder Cancer as a Single Risk Factor

Chang, Ching Han; Song, Jae Mann

Abstract

PURPOSE: Bladder cancer can be induced by many chemicals, of which smoking was confirmed by Burch et al to be one well known risk factor. In our study, we evaluate the effect of smoking on bladder cancer as a single risk factor.
MATERIALS AND METHODS
A total of 156 patients were enrolled in this study from March 1999 to April 2003. A survey soliciting smoking pattern, and duration and dose of smoking was mailed to each patient. We classified all patients into current smokers, ex-smokers and never-smokers on the basis of their smoking history. ANOVA and Chi-square tests were performed to evaluate the differences of stage, grade, tumor size and recurrence rate. The Kaplan-Meier technique was used to plot recurrence free survival and the log-rank test was used to compare the survival curves.
RESULTS
There was no significant difference among current smokers, ex-smokers and never-smokers in terms of stage, grade and tumor size. However there was an obvious difference of recurrence rate among these groups. No significant difference of recurrence-free survival rate between ex-smokers and current smokers was noted, while never-smokers showed a better recurrence-survival rate than ex-smokers and current smokers.
CONCLUSIONS
These data suggest that stage, grade, tumor size and tumor character can not represent the effect of smoking on bladder cancer progression. More accurate and prospectively determined assessment of smoking status by molecular investigation and indirect smoking would be required.