Introduction: Despite treatment intensification (TI) with novel hormonal agents (NHA) or chemotherapy being the standard of care in treatment of metastatic prostate cancer (mPCA), the uptake remains low outside of trial settings. We aim to report the prescription patterns and treatment outcomes of de novo mPCA in a tertiary institution. Methods: This is a retrospective cohort study using real-world data from a prospectively maintained prostate cancer registry. We selected patients newly diagnosed with mPCA from January 2016 to December 2020. Patient characteristics, tumour and treatment patterns, time to castration-resistant prostate cancer (CRPC) and overall survival (OS) were analysed. Results: 585 patients with metastatic prostate cancer were identified, with a mean age of 73. Altogether, 36.6% received TI with chemotherapy or NHA. Prescription of NHA increased from 10.5% (2016) to 50.4% (2020), but that of chemotherapy declined. Factors associated with TI prescription were identified: patient factors (Charlson Comorbidity Index 0-2 (OR 4.456, 95% CI: 2.417-8.215, p<0.001), ECOG 0-1 (OR 1.834, 95% CI: 1.297-2.594, p=0.001), and age £65 (OR 2.506, 95% CI: 1.666-3.771, p < 0.001)), disease factors (PSA >400 (OR 1.986, 95% CI: 1.385-2.846, p < 0.001), CHAARTED high volume disease (OR 1.667, 95% CI: 1.181-2.351, p=0.004), and development of systemic complications (OR 2.190, 95% CI: 1.410-3.403, p < 0.001), and physician factors (primary physician being uro-oncologist (OR 8.953, 95% CI: 4.730-15.612, p<0.001) and medical oncologist (OR 18.112, 95% CI: 9.929-33.040, p<0.001). Patients with TI had longer mean time to CRPC (45.0 vs 32.5 months, HR: 0.567, 95% CI: 0.441-0.730, p < 0.001) and OS (55.3 vs 46.8 months, HR: 0.612, 95% CI: 0.447-0.837, p=0.001). More significant benefits were found in the high-volume disease subgroup than in the overall study population. Conclusions: This study demonstrated the trend of treatment prescription of mPCA and factors contributing to the use of TI. TI improved mean time to CRPC and OS. SOURCE OF Funding: Nil
