Prognosis of muscle-invasive bladder cancer: difference between primary and progressive tumours and implications for therapy.

OBJECTIVE: To evaluate the difference in prognosis between progressive and primary muscle-invasive bladder cancer.
MATERIALS AND METHODS: From 1986 to 2000, 74 patients with progressive muscle-invasive bladder cancer were identified. Eighty-nine patients with primary muscle-invasive bladder cancer were frequency matched for stage to these patients with progressive disease. Baseline data including patient and tumour characteristics were collected at the time of diagnosis of the muscle-invasive tumour. Duration of survival was defined as time from muscle-invasive bladder cancer diagnosis until disease-specific death. Kaplan-Meier curves were drawn to determine the difference in prognosis between the two study groups. To adjust for potential residual confounding due to differences in treatment, 4 subgroups (T2/3, T4, N+ and M+) were constructed according to the TNM classification. In order to see whether age and gender had any effect on outcome, the four stage groups, age and gender were entered in a Cox's proportional hazard regression model.
RESULTS: The 3-year bladder cancer-specific survival was 67% in the primary group and 37% in the progressive group (log rank p=0.0015). Kaplan-Meier curves comparing the different stage groups showed a better prognosis for the patients with primary, i.e. pT2/3 or N+, tumours at baseline. Cox regression analysis demonstrated that age and gender had no influence on bladder cancer-specific survival.
CONCLUSIONS: Patients with muscle-invasive bladder cancer and a history of superficial bladder cancer have a worse prognosis than patients with primary muscle-invasive bladder cancer.