Complete androgen blockade vs. medical castration alone as adjuvant androgen deprivation therapy for prostate cancer patients following radical prostatectomy: a retrospective cohort study

BACKGROUND: Till date, the optimal treatment strategy for delivering adjuvant androgen deprivation therapy (ADT) in localized and locally advanced prostate cancer (PCa), as a lower stage in PCa progression compared with metastatic PCa, is still unclear. This study compares the efficacy of castration alone with complete androgen blockade (CAB) as adjuvant ADT in patients with localized and locally advanced PCa undergoing radical prostatectomy (RP). METHODS: Patients diagnosed with PCa, without lymph node or distant metastasis, who received RP in West China Hospital between January 2009 and April 2019, were enrolled in this study. We performed survival, multivariable Cox proportional hazard regression, and subgroup analyses. RESULTS: A total of 262 patients were enrolled, including 107 patients who received castration alone and 155 patients who received CAB. The survival analysis revealed that there was no significant difference between the two groups (hazard ratios [HR] = 1.07, 95% confidence intervals [95% CI] = 0.60–1.90, P = 0.8195). Moreover, the multivariable Cox model provided similarly negative results before and after adjustment for potential covariant. Similarly, there was no significant difference in the clinical recurrence between the two groups in both non-adjusted and adjusted models. Furthermore, our subgroup analysis showed that CAB achieved better biochemical recurrence (BCR) outcomes than medical castration alone as adjuvant ADT for locally advanced PCa (P for interaction = 0.0247, HR = 0.37, 95% CI = 0.14–1.00, P = 0.0497). CONCLUSION: Combined androgen blockade achieved better BCR outcomes compared with medical castration alone as adjuvant ADT for locally advanced PCa without lymph node metastasis.