Hypofractionated radiotherapy in elderly patients (≥75 years) affected by localized prostate cancer: a multicenter retrospective analysis from the IPOPROMISE study

Background: Prostate Cancer (PCa) is the second leading cause of cancer death in the elderly (≥75 years). There is currently little data on hypofractionated radiotherapy in older patients affected by localized PCa. We present the long-term results of hypofractionated radiotherapy in elderly patients with localized PCa from the IPOPROMISE database. Materials and Methods: retrospective analysis of 719 PCa elderly (≥75 years) patients treated with daily volumetric image-guided hypofractionated radiotherapy between 2007 and 2020. For survival endpoints, we used Kaplan-Meier survival curves and univariate and multivariable Cox’s proportional hazards regression models. Results: Median age at PCa diagnosis was 78.4 years (interquartile [IQR], 76.8–80.3 years), 74% of patients had a modified Charlson co-morbidity index (elderly-PCa-CCI, (e-PCCI)) of 0. Based on NCCN risk grouping, 399 patients (55.5%) were affected by unfavorable to very high-risk disease. Median follow-up was 4.2 years (IQR 2.4–6.4 years). 31/719 (4.3%) patients died from any cause. At 5 years, overall survival (OS), cancer-specific survival (CSS), and metastasis-free survival were 95.6% (95% CI 93.4–97.1%), 99.2% (95%CI 97.9–99.7%), and 97.3% (95% CI 95.1–98.5%), respectively. In multivariate analysis, baseline PSA, and Gleason score were associated with MFS. On univariate analysis, e-PCCI ≥ 2 was associated with OS (p = 0.02). The 5-year freedom from late grade ≥2 gastrointestinal (GI) and genitourinary (GU) toxicity were 95.1% (95% CI 93.0–96.5%) and 96.7% (95% CI 93.7–97.1%), respectively. Conclusions: Our results represent a valuable add-on to the current literature, confirming the prominent role of radiotherapy in the cure of elderly fit patients affected by localized disease.