Bladder cancer survival: Women better off in the long run

Mortality among patients with bladder cancer is usually reported to be higher for women than men, but how the risk differs and why remain largely unexplained. We also described gender-specific differences in survival for patients with bladder cancer and estimated to what extent they can be explained by differences in T-stage distribution at the first diagnosis.

The present study comprised all 15,129 new cases of histologically verified invasive and non-invasive urothelial carcinoma of the urinary bladder diagnosed between 1997 and 2011 as registered in the Cancer Registry of Norway. Gender-specific excess mortality risk rates and risk ratios were calculated based on a flexible parametric relative survival model adjusting for T-stage and age, allowing the effect of gender to vary over time. We also present gender-specific relative survival curves for different T-stage patterns adjusted for age.

Risk rates were significantly higher for women than men up to 2 years after bladder cancer diagnosis, particularly for muscle-invasive cancers. Thereafter, risk rates appeared to be higher in men. Adverse T-Stage distribution in women explained half of the unfavourable survival difference in female patients 2 years after diagnosis.

The common view of worse bladder cancer prognosis in women than in men needs to be revised. Norwegian women have a less favourable prognosis solely within the first 2 years after diagnosis, particularly when diagnosed with a muscle-invasive tumour; parts of this discrepancy can be attributed to more severe initial diagnoses in women.