Hypofractionated Radiation Therapy (Hypo-RT) for the Treatment of Localized Bladder Cancer

BACKGROUND: Various radiotherapeutic regimens are used in the treatment of bladder cancer. OBJECTIVE: We aimed to evaluate early toxicity and outcomes associated with hypofractionated radiation therapy (Hypo-RT), 55Gy in 20 fractions. MATERIAL AND METHODS: We identified 40 patients who received definitive Hypo-RT for localized bladder cancer. Most patients were men (62.5%), elderly (median age 82), had high Charlson Comorbidity Index score (median 7, range 4-9) and were nonsurgical candidates (80%). Sixty-eight percent had a macroscopically complete transurethral resection of bladder tumor (TURBT) and 33 patients (82.5%) received concurrent chemotherapy. Acute (<=3mo) and late (>3mo) toxicities were assessed according to CTCAE v4.0. Survival outcomes were estimated using the Kaplan-Meier method. Median follow up after Hypo-RT was 32 months (95% CI: 28-49 months). RESULTS: Overall rates of acute grade 2 genitourinary (GU) and gastrointestinal (GI) toxicities were 40% each, most commonly urinary frequency and diarrhea. Two cases of acute grade 3 GU/GI toxicity occurred. Late grade 2+ toxicity occurred in 3 patients (7.5%): 2 grade 2 GU and 1 grade 3 GI. Seventy-seven percent achieved a complete response (CR). Six patients (20%) developed disease recurrence at a median time of 9.1 months. The estimated 2-year DFS and 2-year DSS rate were 59% (95% CI, 45-78%) and 78% (95% CI, 65-93%), respectively. Receipt of concurrent chemotherapy (p = 0.003) and achieving a CR (p = 0.018) were univariably associated with improved DSS. Tis component was associated with worse DSS (p = 0.015). CONCLUSION: Hypo-RT had a favorable toxicity profile and encouraging cancer control outcomes in this mostly elderly and frail patient cohort.