Purpose: Although the use of radical transurethral resection followed by concurrent radiochemotherapy leads to a similar survival rate to that achieved after cystectomy, the number of long-term survivors is low in both cases. An improvement may be obtained by adding a new drug, such as gemcitabine, which is active in bladder cancer and acts as a radiosensitizer. However, because gemcitabine may be very toxic when associated with radiotherapy, we designed this dose-finding study in an attempt to find the dose that can be safely added to radiotherapy and concurrent cisplatin in patients treated with transurethral resection for infiltrating bladder cancer.
Patients and methods: After undergoing macroscopically complete transurethral resections for transitional carcinoma of the bladder, patients staged pT2 or higher and without distant metastases concurrently received 54 Gy of fractionated radiotherapy over 6 weeks with cisplatin (100 mg/m(2) q.3 w), starting on Day 1 of radiotherapy. Concomitant gemcitabine was administered on Days 1, 8, and 15 q.3 w for 2 cycles at a dose of 200 mg/m(2), escalated to 500 mg/m(2), with a 100 mg/m(2) increase at each dose level. The maximum tolerated dose was defined as the dose of gemcitabine associated with dose-limiting toxic effects (febrile neutropenia, Grade 4 thrombocytopenia, Grade 3 or 4 enteric toxicity, or Grade 4 nonhematologic toxicity) in 33% of the patients treated at that dose level. Six to 8 weeks after completing the therapy, the patients underwent cystoscopic reevaluation with multiple biopsies of the initial tumor site.
Results: Of our consecutive series of 16 patients, 5 received a gemcitabine dose of 200 mg/m(2)/week, 3 a dose of 300 mg/m(2)/week, 3 a dose of 400 mg/m(2)/week, and 5 a dose of 500 mg/m(2)/week for 6 weeks. No dose-limiting toxicity was observed at doses of up to 400 mg/m(2)/week. At the dose 500 mg/m(2)/week, 1 patient experienced an intestinal perforation that recovered after surgery, and another suddenly died after developing Grade 3 untreated diarrhea in the last treatment week. All of the 15 evaluable patients were microscopically disease free at the cystoscopic reevaluation; furthermore, the posttreatment computed tomography scans did not reveal any distant metastases.
Conclusions: After transurethral resection for the conservative treatment of infiltrating bladder cancer, gemcitabine doses of up to 400 mg/m(2)/week seem to be safe in combination with cisplatin and radiotherapy in organ-sparing management. On the basis of the promising results of this Phase I study, we are currently conducting a Phase II trial to verify the possible improvement in local control resulting from the addition of gemcitabine.