Comparison of Survival Between Hypofractionated and Conventional Radiotherapy in Clinically Localized Prostate Cancer: A Single-Center Retrospective Cohort

Background: Prostate cancer (pCa) is the most frequently diagnosed visceral cancer among men. The main role of radical prostatectomy and external-beam radiation therapy (EBRT) in the management of patients with localized pCa has been established. Objectives: This study aims at comparing the clinical outcomes of hypofractionated versus conventional EBRT in the definitive management of patients with localized pCa. Methods: From 2013 to 2019, a consecutive series of patients with localized pCa was treated with conventional (74 Gy at 2 Gy fractions) or hypofractionated (70.2 Gy at 2.7 Gy fractions) radiotherapy schedules, using 3-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT), respectively. The impact of the fractionation schedule on biochemical or clinical relapse-free survival (bc-RFS) and overall survival (OS) was assessed. Results: The median follow-up was 42 months (range: 8 - 81 months). Among 170 patients, 81 were treated with conventional and 89 with the hypofractionated schedule. The patient characteristics between groups were comparable. The mean bc-RFS of patients in conventional and hypofractionated groups was 34.9 and 35.4 months, respectively (confidence interval (CI) 95%: 34.5 - 35.7, P = 0.25). Accordingly, the mean OS of patients in conventional and hypofractionated groups was 34.6 and 38.6 months, respectively (CI 95%: 37.3 - 38.6, P = 0.04). The sub-analysis showed that the OS benefit of hypofractionated schedule was limited to intermediate- and high-risk groups with a trend toward significance (CI 95%: 0.02 - 1.46, P = 0.054). Conclusions: Hypofractionation had OS benefit over the conventional schedule for definitive radiotherapy of localized pCa. This benefit was limited to patients with intermediate- and high-risk pCa.