Prognostic impact of definitive local therapy of the primary tumor in men with metastatic prostate cancer at diagnosis: A population-based, propensity score analysis

Abstract

Background: This study investigated whether definitive local therapy [radical prostatectomy (RP) or brachytherapy (BT)] of the primary tumor improves survival in men with metastatic prostate cancer (PrCA) at diagnosis.

Methods: Data on newly diagnosed metastatic PrCA cases (stage IV, N=7858) were obtained from the Surveillance Epidemiology and End Results (SEER) program. Conventional multivariable survival analysis and propensity score analysis were used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (95% CI) comparing men who underwent definitive local therapy of the primary tumor to those who did not.

Results: After adjusting for sociodemographic and tumor attributes, having RP after diagnosis with metastatic PrCA was associated with 73% (HR=0.27, 95% CI: 0.20-0.38) lower risk of all-cause mortality and 72% (HR=0.28, 95% CI: 0.20-0.39) reduced risk of death from PrCA. Having BT also was associated with 57% (HR=0.43, 95% CI: 0.31-0.59) and 54% (HR=0.46, 95% CI: 0.33-0.64) lower risk of all-cause and PrCA-specific mortality. Similar results were observed in propensity score-adjusted analysis as well as when stratified by age and extent of tumor metastasis.

Conclusions: These findings suggest that definitive local therapy improves survival in men with metastatic PrCA at diagnosis. Future work should consider comorbidities, diet, physical activity and smoking status.

Keywords: Definitive therapy; Metastasis; Prostate cancer; SEER data; Stage IV prostate cancer; Survival.