Associations Between Female Sex and Treatment Patterns and Outcomes for Muscle-invasive Bladder Cancer

Bladder Cancer
17/07/2020

Urology. 2020 Jul 13:S0090-4295(20)30823-2. doi: 10.1016/j.urology.2020.06.058. Online ahead of print.

ABSTRACT

OBJECTIVE: To investigate the association of female sex with the selected treatment for patients with nonmetastatic muscle-invasive bladder cancer. Sex is a known independent predictor of death from bladder cancer. A potential explanation for this survival disparity is difference in treatment pattern and stage presentation among males and females.

MATERIALS AND METHODS: Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare data set, we identified 6,809 patients initially diagnosed with nonmetastatic muscle-invasive bladder cancer between 2004-2014. We fit multivariable logistic regression and Cox models to assess the relationship of sex with treatment modality and survival adjusting for differences in patient characteristics.

RESULTS: Of the 6,809 patients with nonmetastatic muscle invasive bladder cancer, 2,528 (37%) received a radical cystectomy while 4,281(63%) received an alternative bladder sparing intervention. Women were significantly more likely to receive a cystectomy (OR 1.39; 95% CI 1.20-1.61), present at an older age with less comorbidities compared to men (p <0.001). Women were also found to have worse bladder cancer-specific survival (CSS) than men (HR 1.18; 95% CI 1.05-1.32), no difference in overall survival (OS) (female HR 0.93; 0.86-1.01) and lower mortality from other causes (HR 0.78; 95% CI 0.70-0.86). There were no differences in OS and CSS by sex in patients with stage pT4a.

CONCLUSIONS: Female sex predicted more aggressive treatment with radical cystectomy yet worse cancer-specific survival than males. This sex disparity in CSS reduced the known OS advantage observed in women.