Real-world progression in the survival of de novo Metastatic prostate cancer over the past decade

Abstract

Background: The impact of evolving treatment strategies for metastatic prostate cancer (mPCa) on real-world survival is not well understood. We analyzed changes in mPCa survival over the past decade and discussed the potential driving factors behind these changes.

Methods: Our study involved 43,228 mPCa patients (2004-2020) from the SEER database, divided into 4 diagnostic periods. We used a multivariate Cox proportional hazards model to evaluate diagnostic periods' influence on overall mortality (OM) and prostate cancer-specific mortality (PSM), and calculated relative median survival improvements between adjacent periods. Subgroup analyses based on age and distant metastasis sites were conducted.

Results: Patients diagnosed in 2016 to 2020 experienced significantly reduced mortality risk compared to those in 2004 to 2007 (HR 0.64 for OM, HR 0.62 for CSM, both P < 0.001). The study period witnessed an absolute improvement in median overall survival (OS) and prostate cancer-specific survival (PCSS), 17 months (54.8%) and 25 months (67.6%) respectively. The most rapid relative survival improvement occurred post-2016, with a 29.7% increase in median OS and a 37.8% increase in PCSS compared to 2012 to 2015. There was a significant reduction in mortality risk throughout the study period in both age groups (age <75 and ≥75), but absolute survival gains were smaller in the older group (24 months [68.6%] vs. 8 months [32%] for OS, 36 months [90.0%] vs. 11 months [33.3%] for PCSS), with lower relative survival improvements after 2016 (37.2% vs. 17.9% for OS, 49% vs. 22.2% for PCSS). All metastasis site subgroups (except M1a) exhibited a significant reduction in mortality risk (all P < 0.001). Absolute survival improvements were 58 months (134.9%) for M1a, 16 months (50.0%) for M1b, and 17 months (54.8%) for M1c.

Conclusion: The survival of mPCa have significantly improved over the past decade, although the progress is slower in elderly patients. Investigating the underlying reasons for survival differences among various patient profiles can further refine mPCa treatment strategies.

Keywords: De novo metastatic prostate cancer; SEER; Survival progression.