Concurrent vinblastine and radiation therapy in bladder cancer

RTOG 97-06: Initial report of a Phase I–II trial of selective bladder conservation using TURBT, twice-daily accelerated irradiation sensitized with cisplatin, and adjuvant MCV combination chemotherapy

To examine combination cisplatin and twice-daily accelerated irradiation (RT) after aggressive transurethral resection of bladder tumor (TURBT) in an attempt to preserve the bladder and to determine the likelihood that patients who complete this regimen could then complete three cycles of methotrexate, cisplatin, vinblastine (MCV) chemotherapy. Between 1998 and 2000, 52 patients with Stage T2-T4aN0M0 disease, from 17 institutions, were entered into the trial. Forty-seven patients were deemed eligible; the planned accrual was 40. Of the 46 patients, 68% were >60 years old, 70% were men, and 96% had a Karnofsky score >/=90. The clinical T stage was T2 in 66%, T3a in 25%, and T3b in 9%. The median follow-up at the time of analysis was 26 months. The protocol required TURBT within 6 weeks of the initiation of induction therapy. Induction treatment involved 13 days of concomitant boost RT, 1.8 Gy to the pelvis in the morning followed by 1.6 Gy to the tumor 4-6 h later. For sensitization, cisplatin (20 mg/m(2)) was given on the first 3 days of each treatment week. Three to four weeks after induction, patients were evaluated cystoscopically for residual disease. Patients whose biopsies and cytologic evaluations showed no disease completed consolidation chemoirradiation. Patients with residual tumor went on to cystectomy. After either consolidation or cystectomy, patients were to complete three cycles of MCV chemotherapy. Of the 47 patients, 45% completed all phases of the protocol treatment with minor, or no, deviations. Five patients refused either the postinduction evaluation or cystectomy and 6 refused adjuvant chemotherapy. The CR rate after induction therapy was 74%. For 2 patients, residual disease after induction was limited to positive cytologic findings, and for 8 patients, biopsy of the primary site revealed persistence. Of the 8 cystectomy patients, 2 had no evidence of disease in the bladder at pathologic review of the surgery specimen. Grade 3 toxicity related to chemotherapy was observed in 11% of patients during both induction and consolidation, and in 41% during adjuvant chemotherapy. A total of 8 patients (36% of those receiving adjuvant chemotherapy) went on to develop Grade 4 neutropenia or thrombocytopenia during additional adjuvant chemotherapy. Grade 3 toxicity due to RT was seen in 4% and 0% of patients during induction and consolidation, respectively. One patient developed Grade 4 hydronephrosis during consolidation. The projected 36-month value for locoregional failure, distant metastasis, overall survival, and bladder-intact survival was 27%, 29%, 61%, and 48%, respectively. After aggressive TURBT, twice-daily accelerated RT initiated in concomitant-boost format is well tolerated and results in a rate of complete response (74%) similar to that in previous bladder-sparing trials. The projected 2-year values for locoregional control, bladder-intact survival, and overall survival were also consistent with previously reported trials of bladder-sparing treatment. With only 45% of patients completing three cycles of MCV, this form of adjuvant chemotherapy appears to be poorly tolerated by most patients.