PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior intravesical interferon alfa and/or BCG At least 2 years since prior immunotherapy for other malignancies or nonmalignancies Chemotherapy: At least 4 weeks since prior intravesical chemotherapy At least 2 years since prior chemotherapy for other malignancies or nonmalignancies No concurrent cytotoxic chemotherapy for other malignancies or nonmalignancies Endocrine therapy: Not specified Radiotherapy: At least 2 years since prior pelvic radiotherapy for other malignancies or nonmalignancies No concurrent pelvic radiotherapy for other malignancies or nonmalignancies Surgery: See Disease Characteristics At least 3 weeks since prior papillary or solid transitional cell carcinoma resection, bladder biopsy, or transurethral resection of the prostate At least 4 weeks since prior surgery Other: At least 2 years since any prior cytotoxic agents for other malignancies or nonmalignancies