Real-world Treatment Sequencing in Patients with Metastatic Castration-resistant Prostate Cancer: Results from the Prospective, International, Observational Prostate Cancer Registry

Abstract

BackgroundProstate cancer has a multifaceted treatment pattern. Evidence is lacking for optimal treatment sequences for metastatic castration-resistant prostate cancer (mCRPC). ObjectiveTo increase the understanding of real-world treatment pathways and outcomes in patients with mCRPC. Design, setting, and participantsA prospective, noninterventional, real-world analysis of 3003 patients with mCRPC in the Prostate Cancer Registry (PCR; NCT02236637) from June 14, 2013 to July 9, 2018 was conducted. InterventionPatients received first- and second-line hormonal treatment and chemotherapy as follows: abiraterone acetate plus prednisone (abiraterone)-docetaxel (ABI-DOCE), abiraterone-enzalutamide (ABI-ENZA), abiraterone–radium-223 (ABI-RAD), docetaxel-abiraterone (DOCE-ABI), docetaxel-cabazitaxel (DOCE-CABA), docetaxel-enzalutamide (DOCE-ENZA), and enzalutamide-docetaxel (ENZA-DOCE). Outcome measurements and statistical analysisBaseline patient characteristics, quality of life, mCRPC treatments, and efficacy outcomes (progression and survival) were presented descriptively. Results and limitationsData from 727 patients were eligible for the analysis (ABI-DOCE n = 178, ABI-ENZA n = 99, ABI-RAD n = 27, DOCE-ABI n = 191, DOCE-CABA n = 74, DOCE-ENZA n = 116, and ENZA-DOCE n = 42). Demographics and disease characteristics among patients between different sequences varied greatly. Most patients who started on abiraterone or enzalutamide stopped therapy because of disease progression. No randomisation to allow treatment/sequence comparisons limited this observational study. ConclusionsThe real-world PCR data complement clinical trial data, reflecting more highly selected patient populations than seen in routine clinical practice. Baseline characteristics play a role in mCRPC first-line treatment selection, but other factors, such as treatment availability, have an impact. Efficacy observations are limited and should be interpreted with caution. Patient summaryBaseline characteristics appear to have a role in the first-line treatment selection of metastatic castration-resistant prostate cancer in the real-world setting. First-line abiraterone acetate plus prednisone seems to be the preferred treatment option for older patients and those with lower Gleason scores, first-line docetaxel for younger patients and those with more advanced disease, and first-line enzalutamide for patients with fewer metastases and more favourable performance status. The benefit to patients from these observations remains unknown.