Marker tumour responses to the sequential combination of intravesical therapy with mitomycin-C and BCG-RIVM in multiple superficial bladder tumours. Report from the European Organisation for Research and Treatment on Cancer-Genitourinary Group (EORTC 30897).

OBJECTIVES: To study the ablative activity of intravesical mitomycin C followed by intravesical bacillus Calmette-Guérin (BCG) on a papillary marker tumour and to determine the incidence of side effects.
METHODS: Thirty-five patients with multiple pTa or pT1 bladder tumours were treated with 4 instillations of mitomycin C at weekly intervals followed by 6 instillations at weekly intervals of BCG-RIVM. All visible tumours were resected before starting intravesical instillations except one marker tumour. Response was determined 2 weeks after the last instillation.
RESULTS: The incidence of adverse effects was similar to previously reported toxicity of either mitomycin C or BCG alone. Complete response, histologically proven, was observed in 16 of 35 patients and in 3 patients without histological confirmation. One patient showed progression.
CONCLUSION: The sequential combination of mitomycin C and BCG is an efficacious treatment. The measurement of response to a marker tumour is a safe and efficient method to test new drugs or combinations of drugs.