MARKER TUMOR RESPONSE TO THE SEQUENTIAL COMBINATION OF INTRAVESICAL THERAPY WITH MITOMYCIN-C AND BCG-RIVM IN MULTIPLE SUPERFICIAL BLADDER-TUMORS - REPORT FROM THE EUROPEAN ORGANIZATION 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-Guerin (BCG) on a papillar y marker tumour and to determine the incidence of side effects. Method s: Thirty-five patients with multiple pTa or pT1 bladder tumours were treated with 4 instillations of mitomycin C at weekly intervals follow ed by 6 instillations at weekly intervals of BCG-RIVM. All visible tum ours were resected before starting intravesical instillations except o ne marker tumour. Response was determined 2 weeks after the last insti llation. Results: The incidence of adverse effects was similar to prev iously 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 p rogression. Conclusion: The sequential combination of mitomycin C and BCG is an efficacious treatment. The measurement of response to a mark er tumour is a safe and efficient method to test new drugs or combinat ions of drugs.