Clinical outcomes of adapted hypofractionated radiotherapy for bladder cancer in elderly patients

Objective: To investigate the feasibility, efficacy, and safety of trimodal therapy (TMT) using a bifractionated split-course hypofractionated radiotherapy (RT) for non-metastatic muscle-invasive bladder cancer (MIBC) in elderly patients.

Patients and methods: We retrospectively reviewed the characteristics and outcomes of patients aged >75 years with non-metastatic MIBC suitable or not for radical cystectomy (RC) and treated with transurethral resection of bladder tumour followed by concomitant radio-chemotherapy (platinum salt and 5-fluorouracil) at two institutions (Saint Louis Hospital, Paris, France and European Georges Pompidou Hospital, Paris, France) between 1990 and 2021. RT consisted of an adapted bifractionated split-course hypofractionated RT. Acute toxicities were reported according to Common Terminology Criteria for Adverse Events version 5.0 and late toxicities were reported according to the Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer late radiation morbidity scoring schema. The primary end-point was overall survival (OS). Secondary end-points included other survivals outcomes and safety.

Results: A total of 122 patients were identified, with a median (range) follow-up of 51.1 (0.5-210.8) months. In all, 83.5% of patients completed radio-chemotherapy. The OS rate was 61.7% at 3 years and 51.2% at 5 years. In multivariate analysis, the completion of RT and concomitant chemotherapy were significantly associated with better OS and cancer-specific survival. For patients fit for RC, a complete histological response was achieved for 77 patients (91.7%) with radio-chemotherapy and the bladder conservation rate was 90.5%. Acute and late Grade ≥3 toxicities were <5%.

Conclusion: Bifractionated split-course hypofractionated RT 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.