Improving the efficacy of BCG immunotherapy by dose reduction.

Several clinical trials have shown intravesical bacillus Calmette-Guérin (BCG) to be effective in the prophylaxis of papillary tumour recurrences and in the therapy of bladder carcinoma in situ (CIS), as well as in delaying progression to muscle invasion. Nevertheless, the optimal regimen of BCG therapy for superficial bladder cancer has still to be defined. In a previous phase II trial, a low-dose regimen (BCG Pasteur strain, 75 mg) was able to achieve clinically significant response rates with a decrease in side-effects compared with other reported studies using standard-dose BCG. However, a phase III randomized trial--low dose versus standard dose (BCG Pasteur strain, 75 vs. 150 mg)--was considered necessary to clarify definitively the relationships between dose, efficacy and toxicity. The results of the interim analysis of 183 patients (performed in 1993) have shown response rates to be better in patients submitted to a low-dose BCG regimen (p = 0.0009) and a significant decrease in most of the common side-effects (cystitis, fever, haematuria; p < 0.05). Breaking down the results by stage, no differences in response rates were found in patients with stage TaM (70 vs. 62% in low-dose and standard-dose regimens, respectively, p = 0.5). In T1M and CIS stages, 82 and 0 (p = 0.07), and 64 and 0% (p = 0.0003) of patients were free of tumour following low-dose and standard-dose therapy, respectively. An additional 6-week course in patients who failed the induction course retrieved additional responses in both groups. No differences in progression rates were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Mitomycin C in multiple superficial bladder tumors: short-term therapy, long-term results.

At the Institute of Urology, University of Padova, 125 patients with multifocal superficial bladder cancer underwent treatment with intravesical Mitomycin C (MMC; 1 weekly instillation of 40 mg for 8 consecutive weeks) between January 1982 and December 1988. Eighty-four patients had multifocal papillary tumors (stages Ta-T1) and 41 patients had carcinoma in situ of the bladder. At 6 and 36 months the tumor free percentage in the group with papillary tumors was 69 and 36%, respectively; for carcinoma in situ the complete response percentage at the same intervals was 80 and 36%. Thirty-one patients previously unsuccessfully treated with adriamycin did not show any difference compared to untreated ones. The authors emphasize the efficacy and low toxicity of intravesical MMC in multiple superficial bladder cancer. The possibility of long-term relapse suggests maintenance therapy.