Intravesical thiotepa versus mitomycin C in patients with Ta, T1 and TIS transitional cell carcinoma of the bladder: A phase III prospective randomized study

A prospective randomized clinical trial was conducted by the National Bladder Cancer Group to compare thiotepa and mitomycin C in ablating residual Ta, T1 and TIS transitional cell carcinoma of the bladder. Eight weekly instillations were given followed by cystoscopy 4 weeks after the treatment was stopped. The over-all complete response rate based on cystoscopy and either biopsy or cytology was 26 per cent for thiotepa versus 39 per cent for mitomycin C (p equals 0.08). The greatest efficacy was seen in the Ta group with mitomycin C demonstrating superiority over thiotepa. Patients with negative cystoscopy and biopsy but who had positive cytology were considered to be partial responders. When partial and complete responders were combined the over-all response rate was 53 per cent for thiotepa and 63 per cent for mitomycin C (p equals 0.23). Patients with TIS appeared to respond equally to thiotepa and mitomycin C. Toxicity included urinary frequency in 22 of the 73 patients in the thiotepa arm and 31 of the 76 patients receiving mitomycin C. A rash was observed in 2 of the thiotepa group versus 14 of the mitomycin C group. Bone marrow depression occurred in 15 patients receiving thiotepa and in 12 receiving mitomycin C.