Overview of treatment of superficial bladder cancer

Seventy per cent to 80 per cent of patients with bladder cancer will have their initial tumor confined to the mucosa (Stage Ta or Tcis, carcinoma in situ) or lamina propria (Stage T1), and at least 50 per cent of them will have a true recurrence or new recurrence despite resection of their initial tumor. If the tumor is of low grade and confined to the mucosa, intravesical chemotherapy might be considered either as treatment if the neoplasm is too extensive to resect completely or if multiple prior endoscopic resections have failed, or, alternatively, as prophylaxis against a subsequent tumor after complete endoscopic removal of the existing neoplasm. Thiotepa, until recently the most commonly used agent, completely eradicates all obvious tumor in approximately 30 per cent of patients, and it is effective in preventing subsequent tumor. Myelosuppression occurs in up to 20 per cent of patients receiving this agent, so careful monitoring of the white blood cell and platelet counts is mandatory. Mitomycin has low risk of myelosuppression and is effective in both the treatment and prophylaxis of superficial bladder cancer; the complete response rate is the same whether patients had an initial low-grade papillary or high-grade tumor (carcinoma in situ). Doxorubicin hydrochloride and bacillus Calmette-Guérin (BCG) are other agents that have been used for intravesical therapy. Chemical cystitis, the primary side effect of doxorubicin, has caused discontinuation of treatment in 15 per cent to 20 per cent of patients. The efficacy of doxorubicin varies among those reporting its use. BCG has been shown to be effective in both treatment and prophylaxis, with response rates similar to those reported for mitomycin; however, a comparative trial has not been performed. There is a need to standardize the potency of each BCG vial and to determine fully the necessity of concomitant intradermal administration.