Prognostic factors in superficial bladder tumors. A study of the European Organization for Research on Treatment of Cancer: Genitourinary Tract Cancer Cooperative Group.

A randomized clinical trial was performed on 308 patients with stage T1 carcinoma of the bladder to compare the efficacy of transurethral resection alone or followed by bladder instillations of thiotepa or VM-26 (teniposide) for 1 year. With the recurrence rate as the primary end point of interest the data from this trial were used to assess the prognostic importance of the following factors at entry into the study: number of tumors, prior recurrence rate, tumor size, grade, age, treatment group assigned and, finally, the interval between transurethral resection at entry into the study and the start of intravesical treatment. Using multivariate statistical techniques we found that the number of tumors at presentation was the most important prognostic factor followed by, in order of importance, the recurrence rate at entry and the size of the largest tumor. Of particular note was the discovery that patients with less than 1 recurrence per year at entry had a prognosis similar to patients with primary tumors, while those with a higher recurrence rate did uniformly poorly. These results show that patients with stage T1 carcinoma of the bladder form a heterogeneous group and that more aggressive therapy should be considered for patients with a poor prognosis.