Abstract
OBJECTIVES: To evaluate the role of smoking as a risk factor for higher stages and grades of bladder cancer, for although smoking is considered to be one of the most important risk factors for bladder cancer, its relationship to grade and stage is not clear. PATIENTS AND METHODS: In all, 300 patients diagnosed with bladder cancer were studied to compare the grade and stage and bladder cancer between non-smokers, low-dose, moderate-dose and high-dose smokers. RESULTS: The smokers and non-smokers had no significant difference in tumour grade or stage (P = 0.702 for grade and 0.166 for stage) but the high-dose group had significantly higher grades and stages than the other groups (P = 0.026, odds ratio 4.8, 95% confidence interval 1.2-19.1 for grade, and 0.037, 10.91 and 1.16-102.6, respectively, for stage). CONCLUSION: Smoking has a potential dose-dependent effect on the grade and stage of bladder cancer, with high-dose smokers having more aggressive disease. The equality in the aggressiveness of the cancer between smokers in general and non-smokers might be a result of the hazardous effect of passive smoking in countries where smoking is a common habit.