Muscle-invasive bladder cancer treated with external beam radiotherapy: pretreatment prognostic factors and the predictive value of cystoscopic re-evaluation during treatment.

PURPOSE

To determine the relationship between tumour and patient characteristics and local control and survival for patients with T2 and T3 bladder cancer treated with radical external beam radiotherapy and to evaluate the predictive value of cystoscopic response evaluation during radiation on final outcome.

MATERIALS AND METHODS

Records from 379 patients with non-metastasized T2 or T3 transitional cell carcinoma of the bladder were reviewed. All patient received external beam radiotherapy at The Netherlands Cancer Institute during the period from 1977 to 1990. The total dose varied from 50 to 75 Gy with a mean of 60.5 Gy and a median of 60.4 Gy. The median follow-up was 22 months for all patients and 82 months for the 30 patients still alive at last follow-up. A stepwise procedure using proportional hazard regression was used to identify prognostic factors with respect to local recurrence and survival.

RESULTS

One hundred thirty-six patients experienced a local recurrence and 120 of these occurred before regional or distance metastases. The actuarial results at 5 years were 40.3% local control (SE 4.0%), 24.9% disease-free rate (SE 3.0%) and 22.2% overall survival (SE 2.2%). In the univariate analysis age, performance status, result of intravenous pyelography (IVP) and T-stage were found to be related to overall survival and multifocality was related to local control. Multivariate analysis revealed that only age and T-stage were related to survival and only multifocality was related to local control. In patients with solitary tumours who were identified as having the most favourable outcome. local control was 50% at 5 years. Local control in 89 patients who had a cystoscopic evaluation during treatment was identical regardless of whether a complete, partial or no response was observed. Furthermore, local control was identical in patients selected on the basis of a favourable response and in unselected patients.

CONCLUSIONS

Although we identified some significant prognostic factors, their predictive value is not strong enough to allow accurate estimation of treatment effect and disease outcome. Cystoscopic response evaluation during treatment was found not to provide reliable information to direct further treatment. Prospective studies to identify ways to select patients for bladder conservation using definitive radiotherapy are urgently needed.