S.O. Vozianov, P.G. Yakovlev, D.A. Klyushin

Effect of adjuvant radiotherapy on cancer specific survival of patients with high grade urinary bladder cancer after bladder sparring surgery

External beam radiotherapy is an important element of the organ sparring treatment of muscle invasive bladder cancer. Multimodal approach to treating selected patients can yield satisfactory long term oncological outcomes, preservation of adequate function of urinary bladder, acceptable quality of life and low rate of salvage cystectomies in case of cancer progression.

Purpose. To determine the effect of conventional adjuvant radiotherapy (ART) delivered with linear accelerator on cancer specific survival (CSS) of patients with high grade bladder cancer (HGBCa) after bladder sparring surgery.

Materials and methods. We retrospectively assessed the treatment outcomes of 325 HGBCa patients after bladder sparring surgery with or without ART on linear accelerator Oncor Impression Plus with total dose 62 Gy (58-70 Gy) and daily fraction of 2 Gy. Kaplan-Meier statistical method was used to compare the survival outcomes between groups of patients.

Results. Radiotherapy after bladder sparring surgery was delivered to 101 (31.1%) patients. Salvage cystectomy in case of cancer progression after combined therapy was performed on 12 (11.9%) patients. Only patients with stage рТ4N0 demonstrated improvements in CSS after ART (р=0,041), with 5-year survival 16% vs. 10%. In patients of other cancer stages the improvement in CSS were not determined. Five-year CSS for HGBCa patients stage I, II, III, IV and N+ after bladder sparring surgery with and without ART was 50% vs. 36%, 20% vs. 33%, 31% vs. 29%, 16% vs. 10%, and 13% vs. 14%.

Conclusion. External beam radiotherapy after bladder sparring surgery in patients with high grade bladder cancer improved cancer specific survival in patients with stage рТ4N0 (р=0,041), 5-year survival was 16% vs. 10% for patients without radiotherapy. In patients of other stages of bladder cancer adjuvant radiotherapy did not demonstrate the benefits for survival.