Androgen-deprivation therapy versus radical prostatectomy as monotherapy among clinically localized prostate cancer patients

Jinan Liu,¹ Lizheng Shi,^2,3 Oliver Sartor,³ Richard Culbertson<sup>2,3

1</sup>HealthCore, Wilmington, DE, USA; ²School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA; ³School of Medicine, Tulane University, New Orleans, LA, USA

Background: The most recent randomized controlled trial in a predominantly prostate-specific antigen-detected prostate cancer (PC) population found a nonsignificant reduction in mortality from radical prostatectomy (RP) compared to conservative management. The optimal treatment for clinically localized prostate cancer is anything but clear. The PC-specific mortality and all-cause mortality were compared between primary androgen-deprivation treatment (PADT) and RP, both as monotherapy, among clinically localized PC patients.
Methods: A retrospective cohort study among PC patients in Surveillance, Epidemiology and End Results-Medicare data with a median follow up of 2.87 years in the PADT cohort and 2.95 years in the RP cohort. Propensity score-matching was employed to adjust for the observed selection bias. PC-specific mortality and all-cause mortality were modeled using the Fine and Gray competing risk model and Cox proportional hazards model, respectively. The independent variables in these models included age, race, Gleason score risk groups, T-score, prostate-specific antigen, Charlson comorbidity, and index year of treatment initiation.
Results: After propensity score-matching, there were 1624 in the PADT cohort and 1624 in the RP cohort. All baseline values were comparable (all P-values >0.35). There were a total of 266 deaths (16.38%) and 60 (3.69%) PC-specific deaths among PADT recipients, while there were 56 (3.45%) deaths and four (0.25%) PC-specific deaths among RP recipients. According to the Kaplan–Meier estimation, the 8-year survival rate was 43.39% in the PADT cohort and 79.62% in the RP cohort. PADT was associated with increased risk of overall mortality (hazard ratio = 2.98, 95% confidence interval 2.35–3.79; P < 0.001) and increased risk of PC-specific mortality (hazard ratio = 12.47, 95% confidence interval 4.48–34.70; P < 0.001).
Conclusion: With adjustment for the observed selection bias, PADT was associated with increased all-cause mortality and PC-specific mortality when compared to RP.

Keywords: prostate cancer, primary androgen-deprivation treatment, radical prostatectomy, survival