Objective: The aim of this investigation was to study differences between male and female patients with stage T1 urinary bladder cancer (UBC) regarding intravesical instillation therapy, second resection and survival.
Materials and methods: This study included all patients with non-metastatic primary T1 UBC reported to the Swedish National Register of Urinary Bladder Cancer (SNRUBC) from 1997 to 2014, excluding those treated with primary cystectomy. Differences between groups were evaluated using chi-squared tests and logistic regression, and survival was investigated using Kaplan-Meier and log-rank tests and Cox proportional hazards analysis.
Results: In all, 7681 patients with T1 UBC (77% male, 23% female) were included. Females were older than males at the time of diagnosis (median age at presentation 76 and 74 years, respectively; p < .001). A larger proportion of males than females underwent intravesical instillation therapy (39% vs 33%, p < .001). Relative survival was lower in women aged ≥75 years and women with G3 tumours compared to men. However, women aged ≥75 years who had T1G3 tumours and underwent second resection followed by intravesical instillation therapy showed a relative survival equal to that observed in men.
Conclusions: This population-based study demonstrates that women of all ages with T1 UBC undergo intravesical instillation therapy less frequently than men, and that relative survival is poorer in women aged ≥75 years than in men of the same age when intravesical instillation therapy and second resection are not used. However, these disparities may disappear with treatment according to guidelines.
Keywords: Bladder cancer; female; gender; intravesical instillation therapy; male; population-based; survival.