LAUSR

BACKGROUND to investigate the feasibility, efficacy, and safety of trimodal therapy (TMT) using a bifractionated split-course hypofractionated radiation therapy for nonmetastatic muscle-invasive bladder (MIBC) cancer in elderly patients. PATIENTS AND METHODS we retrospectively reviewed the characteristics and outcomes of patients over 75 years old with nonmetastatic MIBC suitable or not for radical cystectomy (RC) and treated with transurethral resection of bladder tumor followed by concomitant radiochemotherapy (platinum salt and 5-fluorouracil) at two institutions (Saint Louis Hospital, Paris, France and European Georges Pompidou Hospital, Paris, France) between 1990 and 2021. Radiation therapy consisted of an adapted bifractionated split-course hypofractionated radiation therapy. Acute toxicities were reported according to CTCAE v5.0 and late toxicities were reported according to the RTOG/EORTC late radiation morbidity scoring schema. The primary end point was overall survival. Secondary end points included others survivals outcomes and safety. RESULTS 122 patients were identified, with a median follow-up of 51.1 months (range: 0.5-210.8). 83.5 % of patients completed radiochemotherapy. The overall survival was 61.7 % at 3 years and 51.2 % at 5 years. In multivariate analysis, the completion of radiation therapy and concomitant chemotherapy were significantly associated with better overall survival and specific survival. For patients fit for RC, a complete histologic response was achieved for 77 patients (91.7 %) with radiochemotherapy and the bladder conservation rate was 90.5 %. Acute and late grade 3 or higher toxicities were below 5%. CONCLUSION bifractionated split-course hypofractionated radiation therapy with concomitant chemotherapy regimen appears to be well-tolerated and effective. Trimodal treatment seems to be a curative option for elderly patients unfit for radical surgery compared with palliative care and may contribute to improved survival in these patients.