Chemoresection in Ta-T1 bladder cancer. Members of the EORTC Genito-Urinary Group

The authors present the results of two parallel phase II trials, instituted by the EORTC Genito-Urinary Group in 1986, whose aims were to assess the tolerability and ablative capacity of mitomycin C (study 30864) and epirubicin (study 30869) in patients with multiple primary or recurrent Ta-T1 bladder cancer.

A well-defined tumour (marker lesion) was left in the bladder after transurethral resection (TUR). All patients received 8 weekly instillations, after which cystoscopy with bladder biopsies +/- TUR was performed. Responses were rated as follows: (1) complete-no visible or microscopic bladder cancer; (2) no change-persistence of the marker lesion; (3) progression-increased marker lesion size, new tumour(s) or presence of muscle-invasive disease at any site.

Ninety-six evaluable patients were treated with mitomycin and 36 with epirubicin. The overall bladder response in the former group was complete in 50%, no change in 30% and progression in 20% of patients, while the marker lesion response was complete in 57%, no change in 39% and progression in 4%. In the epirubicin group, 56% of the patients achieved a complete overall response, while there was no change in 22% and progression in 22%. The marker lesion response in this group was complete in 67%, no change in 31% and progression in 3%. Only 2 cases of progression were due to the presence of muscle-invasive disease. Both of these were in the mitomycin group; 1 was at the marker lesion site, and 1 was at a remote site.

The present studies confirm the feasibility and safety of the marker lesion model for the objective evaluation of the antitumoural activity of intravesically administered drugs.