The standard treatment in the United States for patients with muscle infiltrating tumors is radical cystectomy with or without radiation treatment. The results of such treatment have been generally unsatisfactory, with 40% or more patients developing systemic disease with a 5-year survival rate of less than 50%. Combination chemotherapy employing both cisplatin and methotrexate can produce a 30% to 50% clinical complete response rate (negative biopsy, negative urinary cytology) of the primary tumor. Although the optimal combination of chemotherapeutic agents has not yet been determined, it is unlikely that combination chemotherapy alone, even in completely responding patients, will be adequate to rid the bladder of a primary invasive transitional cell carcinoma. Additional therapy by either surgery or external beam radiotherapy seems warranted owing to the high likelihood that there will be residual microscopic tumor in the bladder. Concomitant systemic chemotherapy and external beam radiotherapy produces complete remissions in 65% to 90% of patients. Follow-up of from 3 to 5 years following full chemoradiotherapy will be necessary to be certain that the bladder has been sterilized of cancer. Combined cisplatin and external beam radiation (using a boost technique that spares the section of the bladder uninvolved with tumor) does not seem to enhance local soft-tissue toxicity (relative to the radiotherapy alone) with the exception of the neurotoxicity seen with intra-arterial cisplatin. Debulking TURB tumor appears to improve the local success rate for patients being considered for bladder preservation with the use of the combination of systemic chemotherapy and/or radiotherapy. Not all patients respond to concomitant chemotherapy and radiation therapy. Our current approach is that the selection process must be carried on at several points during the treatment. Only patients who respond completely to the initial courses of chemotherapy and radiation should be carried to a full radiation dose. In the absence of a complete response following upfront chemotherapy and 4000 cGy in combination with additional cisplatin courses, cystectomy at that point is the recommended treatment.(ABSTRACT TRUNCATED AT 400 WORDS)