The prognostic significance of additional localized treatment to primary lesion in patients undergoing hormone therapy for metastatic hormone-sensitive prostate cancer: A systematic review and meta-analysis

Background: We aimed to compare the prognostic values of ‘localized treatment to the primary lesion (LT) plus hormone therapy (HT)’ versus ‘HT alone’ in metastatic hormone-sensitive prostate cancer (mHSPC). Methods: We conducted a systematic search through the databases of PubMed®, Web of Science®, and Cochrane library® in April 2023 based on the PRISMA (Preferred Reporting Items for Systemic Reviews and Meta-Analyses) statement. A pooled meta-analysis was performed to assess the prognostic differences between LT + HT and HT alone according to randomized and non-randomized controlled studies (RCTs and NRCTs, respectively). Results: The search identified three RCTs and eight NRCTs. In RCTs, LT did not show prognostic benefits regarding biochemical-failure free rate nor overall survival (OS), although in patients with low tumor burdens, the LT + HT group showed better OS (HR: 0.68, 95% CI: 0.54–0.86). In the NRCTs, the LT+HT group showed superior progression-free survival (hazard ratio (HR): 0.42, 95% confidence interval (CI): 0.21–0.87), cancer-specific survival (HR: 0.39, 95% CI: 0.20–0.76), and OS (HR: 0.63, 95% CI: 0.57–0.69) to the HT alone group. In addition, better OS was observed in the LT +HT group regardless of the type of treatment modality for LT; radical prostatectomy (HR: 0.52, 95% CI: 0.39–0.69), radiotherapy (HR: 0.63, 95% CI: 0.56–0.71) in NRCTs. Conclusions: LT to the primary lesion in metastatic hormone-sensitive prostate cancer may provide prognostic benefits and especially in patients with low tumor burden.