Sex differences in bladder cancer pathology and survival: analysis of a population-based cancer registry

Sex differences in bladder cancer pathology and epidemiology have been the focus of recent research. We investigated the epidemiological characteristics and compared bladder cancer pathology and survival between men and women in Japan. A total of 13,184 patients with primary bladder cancer diagnosed from 1954 to 2010 were identified in a large-scale cancer registry database in Kanagawa Prefecture. Using this database, we compared the odds ratios (ORs) for nonurothelial carcinoma (non-UC) using a multiple logistic regression model adjusted for age and diagnosis periods. We also compared hazard ratios (HRs) for overall death and cancer-specific death using a Cox proportional hazards model adjusted for non-UC, age, and diagnosis period. The proportion of non-UC was significantly higher in female compared with male patients (OR=2.14, 95% confidence interval [CI]: 1.81-2.52). Furthermore, survival was significantly poorer in female patients than in male patients after adjusting for UC or non-UC (HR for overall death=1.15, 95% CI: 1.06-1.23; HR for cancer-specific death=1.39, 95% CI: 1.28-1.52). Sex differences exist in the epidemiological characteristics of bladder cancer in Japan, with female patients having less favorable pathology and poorer survival compared with male patients.