A descriptive retrospective study of bladder cancer at a hospital in Iran (1973-2003).

Background: Bladder cancer is the ninth most common cancer worldwide, and it is the fourth most common cancer in males in Iran. The objective of this study was to collect, analyze, and discuss epidemiologic features of bladder cancer using data from our University hospital.
Methods: A review of medical records of 603 patients with histologically confirmed primary malignant bladder tumors who were then referred and treated at the Radiation-Oncology Department during a time period 1973-2003 was performed. The topography and the histology of cases were coded and classified according to the International Classification of Diseases for Oncology (ICD -O) and a frequency distribution of bladder tumors by age at diagnosis, gender, histology types, was calculated. For age and cancer, mean, standard deviation, and 95% confidence intervals were presented. T test and Chi-squared test with p<0.05 were used depending on the variable analyzed, using the SPSS statistical package.
Results: Of the total, 85.2% were males and 15.0% were females (P<0.0001). The mean age of diagnosis was not significantly different between the sexes and the frequency of bladder cancer increased with age in both cases. Overall, two thirds of cases were between 50-74 years of age. For those aged 49 years and below the male to female ratio were 3.6 while after this age the ratio rose to 6.1. The most common histological diagnosis in both sexes among patients was transitional cell carcinoma.
Conclusion: The frequency distribution and histologic types of tumors were comparable with reported from other studies.