Abstract
BACKGROUND: Prostate adenocarcinoma (PCa) imposes a significant global health burden. Radiotherapy is a primary local treatment for non-surgically managed patients; however, reliable tools to predict which individuals will derive a survival benefit are lacking. This study aimed to develop a risk stratification model to evaluate survival benefits of radiotherapy in non-surgically treated PCa patients and identify subgroups likely to benefit from radiotherapy. METHODS: Data from 100,155 non-surgically treated PCa patients [2004-2015] were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. All-subsets regression and multivariate Cox regression were used to construct nomograms for overall survival (OS) and cancer-specific survival (CSS), quantifying survival risk and stratifying patients into low- and high-risk groups. Subgroup analyses based on risk stratification were conducted to assess the value of radiotherapy. RESULTS: In the whole cohort, radiotherapy significantly improved 5-year OS (84.2% vs. 76.6%, P<0.001) and CSS (84.2% vs. 76.6%, P<0.001). After risk stratification, high-risk patients receiving radiotherapy exhibited 10.1% and 10.2% improvements in 5-year OS and CSS, respectively (both P<0.05). In contrast, low-risk patients demonstrated no CSS benefit (P>0.05) and reduced OS [hazard ratio (HR): 1.07, 95% confidence interval (CI): 1.02-1.13, P=0.01] following radiotherapy. In non-metastatic stage patients, the nomograms retained good discrimination and the pattern of radiotherapy benefit was consistent with the main analysis. CONCLUSIONS: The developed nomograms effectively identify patients likely to benefit from radiotherapy. High-risk patients experience significant OS and CSS benefits, while radiotherapy is not recommended for low-risk patients.