Clinical characteristics of bladder cancer in patients previously treated with radiation for prostate cancer.

OBJECTIVE: To determine if bladder cancer diagnosed after prostatic radiation therapy (RT) differs in behaviour from bladder cancer diagnosed after prostate cancer not treated with RT, as such bladder cancer is thought to be more aggressive than de novo bladder cancer, and epidemiological studies show a higher rate of bladder cancer in patients after irradiation. PATIENTS AND METHODS: We reviewed our records to identify patients who had a diagnosis of bladder cancer with a previous diagnosis of prostate cancer. Patient age, date of diagnosis of prostate cancer, date of diagnosis of bladder cancer, symptoms, clinical stage, initial pathology, definitive therapy, definitive pathological stage, and disease status were recorded.
RESULTS: In all, 100 patients were identified who had a diagnosis of bladder cancer after a diagnosis of prostate cancer between January 1992 and August 2003; 58 had had RT for prostate cancer. The mean time between a diagnosis of bladder cancer and prostate cancer was 62 months in the RT group and 34 months in the unirradiated group (P = 0.002) At diagnosis of bladder cancer, 56 (97%) of the patients who received RT had high-grade urothelial carcinoma, vs 27 (64%) of those not irradiated (P < 0.001). Thirty (52%) of the patients with RT had muscle-invasive bladder cancer, vs 17 (40%) of those not irradiated (P = 0.3). The survival rate was similar for both groups.
CONCLUSIONS: Bladder cancer is diagnosed later, and is of higher grade, in patients who are irradiated for prostate cancer than in those treated with other methods. Patients with prostate cancer who are treated with RT should be monitored closely for the presence of bladder cancer.