Background: Recognition of the predisposing factors of bladder cancer is very important and provides possible prevention measures. The aim of this study was to investigate the types, distribution of bladder tumors and their relationship with opium consumption and smoking in patients who referred to Shahid Beheshti Hospital, Babol, Iran. 

Methods: In this case-control study, all patients diagnosed with bladder cancer who underwent surgery during 2001-2012 were enrolled. The subjects of the control group were selected among the patients who underwent ERCP (endoscopic retrograde cholangiopancreatography) for gallstone and had no tumors and genitourinary problems. Data regarding demographic, pathology reports and tumor type, smoking status, history of opium consumption and its duration were collected. Patients and controls were compared using t-test and chi-square test. SPSS software Version 20 was used for analysis. 

Results: In this study, 175 patients with an average age of 63.30±15.29 years and 175 age- matched controls were studied. A significant association was observed between smoking and opium consumption with bladder cancer (P=0.001 for both).