Influence of thiotepa and doxorubicin instillation at time of transurethral surgical treatment of bladder cancer on tumor recurrence: a prospective, randomized, double-blind, controlled trial.

The influence of the instillation of thiotepa or doxorubicin hydrochloride into the bladder at the end of transurethral surgical treatment on the recurrence of bladder cancer was evaluated. We studied in a randomized, double-blind, controlled fashion 89 patients with transitional cell epithelioma (carcinoma in situ or papillary carcinoma) whose tumors were considered to have been completely removed. Of these patients 28 (the control group) received a placebo (sterile water), 30 received thiotepa and 31 received doxorubicin. By 3 to 4 months postoperatively 71 per cent of the control group, and 30 and 32 per cent, respectively, of the patients treated with thiotepa and doxorubicin had recurrences (p less than 0.01). Additional treatment during the followup interval was ineffective in all groups. Patients studied also were classified according to grade, histological findings, multiplicity of tumors and history of bladder tumor. Treatment was most effective in reducing recurrence in patients with low grade, papillary or multiple tumors and in patients with a history of bladder cancer. No effect was observed in patients with single tumors and only modest effects were found in those with high grade tumors, carcinoma in situ or new tumors. The results support the concept that recurrences may arise from tumor cell implantation at the time of transurethral management of bladder tumors and may be reduced effectively by concomitant intravesical chemotherapy.