Synchronous chemotherapy combined with radiotherapy significantly improves locoregional control of muscle-invasive bladder cancer (MIBC) compared with radiotherapy alone, according to British researchers.
In an unblinded phase 3 study of 360 patients with MIBC, 182 patients treated with radiotherapy and synchronous chemotherapy using fluorouracil and mitomycin C had a 67% rate of locoregional disease-free survival at two years compared with a 54% rate for the 178 patients treated with radiotherapy alone, investigators reported in The New England Journal of Medicine (2012;366:1477-1488).
After a median follow-up of about 70 months, the chemoradiotherapy group had a significant 32% decreased likelihood of locoregional disease recurrence and a significant 43% decreased likelihood of invasive locoregional recurrence.
Muscle-invasive bladder cancer developed in 20 patients (11%) in the chemoradiotherapy group and 34 (19.1%) in the radiotherapy-only arm. Non-muscle invasive bladder cancer developed in 26 patients (14.3%) in the chemoradiotherapy group and 30 (16.9%) in the radiotherapy-only group.
The chemoradiotherapy group and the radiotherapy-only group had five-year overall survival rates of 48% and 35%, respectively, but the difference was not statistically significant. A total of 166 deaths from bladder cancer occurred: 74 in the chemoradiotherapy group and 92 in the radiotherapy-only group.
The researchers observed no significant increase in adverse events with the use of chemotherapy.
“Although further clinical trials to refine and improve chemoradiotherapy schedules are warranted,” the investigators, led by Nicholas D. James, MB, BS, PhD, of the University of Birmingham, concluded, “our study shows that the addition of chemotherapy to radiotherapy improved local control, particularly freedom from invasive recurrence, as compared with radiotherapy alone, and resulted in good long-term bladder function and low rates of salvage cystectomy, all of which are of major importance in this elderly, relatively frail group of patients.”
The authors noted that it may be time to re-evaluate the relative roles of bladder preservation and surgery in the treatment of muscle-invasive bladder cancer, especially in patients at high risk for surgical complications.