Clinical characteristics and treatment outcomes in metastatic prostate cancer: a retrospective cohort analysis.

Abstract

Introduction & Objectives: The therapeutic landscape for metastatic prostate cancer (mPCa) has evolved substantially, with the use of androgen receptor pathway inhibitors (ARPIs), Androgen Deprivation Therapy, chemotherapy, and radiotherapy (RT). While ARPIs and RT are now considered standard of care for mPCa, real-world data regarding treatment duration and local symptom control remain limited. The aim of this study is to evaluate the treatment outcomes of patients with mPCa treated with ARPIs. Method(s): A retrospective analysis was conducted to identify all the patients treated with ARPI for mPCA at our institution from 2020 to 2024. Findings from CT, bone scan, and PSMA were analysed, and biopsy results were reviewed. Data included demographics, Gleason grade, metastatic profile, surgical history, and local symptom burden (haematuria and LUTS) were obtained from medical record. Outcomes were assessed descriptively, including ARPI duration, recurrence-free survival (RFS) following RT, and local symptom control. Result(s): 119 patients were identified. The mean PCa diagnosis age was 67.7 years. 53.8% (n = 64) had synchronous metastases and 46.2% (n = 55) had metachronous metastases (23.5% [n = 28] post radical prostatectomy; 16.8% [n = 20] post definitive RT, and 5.9% [n = 7] did not receive RP or definitive RT), with a median interval of 8.0 years. 41% (n = 49) of patients had high risk PCa with a Gleason score >=8 with 55% (n = 65) with high volume tumour according to the CHAARTED criteria. Metastatic distribution sites are detailed in Table 1. The mean duration of ARPI therapy was 1.2 years. Treatment discontinuation was most commonly due to disease progression (n = 42, 35%) and toxicity or intolerance (n = 18, 25%). The median RFS in the ARPI group was 12 months. Sixteen patients also underwent salvage RT to the primary, with a median RFS of 134 months. Thirty-six patients received chemotherapy, of which 20 were treated upfront (median RFS 28 months) and 16 post-ARPI (median RFS 2 months). 9.2% (n = 11) of patients developed haematuria post treatment for metastatic disease, 31.1% (n = 37) developed LUTS, and 8.4% (n = 10) had both haematuria and LUTS. The median times to onset were 2.2 years for haematuria and 1.4 years for LUTS. Of these patients, 13.8% (n = 8) had salvage RT. 30% (n = 61) experienced no local complications. Among patients with synchronous metastases (n = 64), 10.9% (n = 7) had TURP post metastasis diagnosis, with a median interval of 25 days. Conclusion(s): Most patients with mPCa presented with high-risk disease and significant tumour burden. ARPI therapy was used but limited by short duration and toxicity, while salvage RT was associated with delayed progression in selected cases.