Muscle-Invasive Bladder Cancer: Two Regimens, Two Successes in Phase II Trial
Posted: Monday, December 10, 2018
Both arms of a phase II trial evaluating bladder-sparing treatments for patients with muscle-invasive bladder cancer met the 75% threshold of no distant metastases after 3 years: one tested twice-daily radiation plus fluorouracil/cisplatin (FCT) and the other tested once-daily radiation plus gemcitabine (GD). In the Journal of Clinical Oncology, John J. Coen, MD, of 21st Century Oncology, Providence, Rhode Island, and colleagues found “either gemcitabine and once-daily radiation or a cisplatin-based regimen could serve as a base for future trials of systemic therapy.”
A total of 70 patients with cT2-4a muscle-invasive bladder cancer enrolled between 2008 and 2014, and 66 were eligible for analysis. At a median follow-up of 5.1 years among surviving patients, distant metastasis–free survival at 3 years was 78% and 84% in the FCT group and the GD group, respectively. Bladder-intact distant metastasis–free survival at 3 years was 67% and 72%, respectively.
The team chose the 75% threshold as the primary endpoint “because distant metastasis is the primary mode of failure…and generally precedes a bladder cancer–related death,” they described. “The trial was not statistically powered to compare regimens.”
Neither can “definitive comment…be made on the toxicity of once-per-day versus twice-a-day radiation,” because the chemotherapy regimens differed between arms, Dr. Coen and colleagues noted. The daily radiation schedule, however, “is more convenient for patients and better suited to routine clinical practice.” Patients in the GD arm did experience fewer treatment-related grade 3 or 4 toxicities (55% vs. 64%).