Monotherapy of androgen deprivation therapy versus radical prostatectomy among veterans with localized prostate cancer: comparative effectiveness analysis of retrospective cohorts

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

1</sup>Tulane University, School of Public Health and Tropical Medicine, ²Southeast Louisiana Veterans Health Care System, Tulane University, ³School of Medicine and Tulane Cancer Center, New Orleans, LA, USA

Background: This retrospective cohort study aimed to examine the comparative effectiveness of monotherapy of primary androgen deprivation therapy or radical prostatectomy.
Methods: Male patients with localized prostate cancer (T1-T2, N0, M0) were identified in the Veterans Affairs Veterans Integrated Service Network 16 data warehouse (January 2003 to June 2006), with one-year baseline and at least three-year follow-up data (until June 2009). Patients were required to be 18–75 years old and without other recorded cancer history. The initiation of primary androgen deprivation therapy or monotherapy of radical prostatectomy within six months after the first diagnosis of prostate cancer was used as the index date. Primary androgen deprivation therapy patients were matched to the radical prostatectomy patients via propensity score, which was predicted from a logistic regression of treatment selection (primary androgen deprivation therapy versus radical prostatectomy) on age, race, marital status, insurance type, cancer stage, Charlson comorbidity index, and alcohol and tobacco use. The overall survival from initiation of index treatment was then analyzed using the Kaplan–Meier and Cox proportional hazards model.
Results: The two cohorts were well matched at baseline (all P > 0.05). During a median follow-up of 4.3 years, the cumulative incidence of death was 13 (10.57%) among 123 primary androgen deprivation therapy patients and four (3.25%) among 123 radical prostatectomy patients (P < 0.05). The overall three-year survival rate was 92.68% for primary androgen deprivation therapy and 98.37% for radical prostatectomy (P < 0.05). Patients who received primary androgen deprivation therapy had almost three times as high a mortality risk as those using radical prostatectomy (hazards ratio 3.388, 95% confidence interval 1.094–10.492, P = 0.034).
Conclusion: After propensity score matching, overall three-year survival rate following radical prostatectomy among patients with localized prostate cancer was significantly higher than that after primary androgen deprivation therapy.

Keywords: prostate cancer, primary androgen deprivation therapy, radical prostatectomy, survival rate