Bladder-Sparing Treatment Regimens for Muscle-Invasive Bladder Cancer
In a phase II trial (NRG/RTOG 0712) reported in the Journal of Clinical Oncology, Coen et al found that bladder-sparing treatment with twice-daily radiation plus fluorouracil/cisplatin (FCT) or once-daily radiation plus gemcitabine (GD) produced similar distant metastasis-free survival in patients with muscle-invasive bladder cancer. The GD regimen was associated with less toxicity.
Study Details
In the study, 66 eligible patients with cT2–4a muscle-invasive bladder cancer enrolled between December 2008 and April 2014 were randomly assigned to receive FCT (n = 33) or GD (n = 33). Patients underwent transurethral resection and induction chemoradiation to 40 Gy. Patients with a complete response received consolidation chemoradiation to 64 Gy, and all others underwent cystectomy. Patients received adjuvant therapy consisting of gemcitabine/cisplatin chemotherapy.
The primary endpoint was freedom from distant metastasis at 3 years, with the main assessment being whether either group had a rate greater than a benchmark figure of 75%.
Survival and Toxicity
Median follow-up was 5.1 years among surviving patients. Distant metastasis–free survival at 3 years was 78% in the FCT group and 84% in the GD group. Bladder-intact distant metastasis–free survival at 3 years was 67% and 72%, respectively. Postinduction complete response was observed in 88% and 78% of patients.
A prompt cystectomy was performed in 3 of 4 patients without complete response in the FCT group and in 5 of 7 in the GD group. Of the 10 vs 8 patients with documented treatment failure, 5 vs 3 had distant metastasis, 3 vs 2 died, and 2 vs 3 underwent cystectomy as the first failure event.
Treatment-related grade 3 or 4 toxicities occurred in 64% of the FCT group vs 55% of the GD group, including hematologic (55% vs 42%), gastrointestinal (6% vs 9%), and genitourinary (6% vs 6%) adverse events. Grade 4 adverse events, all hematologic, occurred in 21% vs 6% of patients.
The investigators concluded, “Both regimens demonstrated [3-year distant metastasis–free survival] greater than 75%. There were fewer toxicities observed in the GD arm. Either gemcitabine and once daily radiation or a cisplatin-based regimen could serve as a base for future trials of systemic therapy.”
John J. Coen, MD, of 21st Century Oncology, Providence, Rhode Island, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by grants from the National Cancer Institute. See the study authors’ full disclosures at jco.ascopubs.org.
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