Cessation of long-term adjuvant androgen deprivation therapy after radical prostatectomy: Is it feasible?

Background: Adjuvant androgen deprivation therapy is a common treatment option for prostate cancer after radical prostatectomy, especially in Asia. However, no study has investigated the oncological outcome after cessation of long-term adjuvant androgen deprivation therapy with favorable prostate-specific antigen control. Methods: Among 855 patients undergoing radical prostatectomy at our institution between 2000 and 2012, we identified 56 men with pT2-4N0-1M0 prostate cancer who had received long-term (> 2 years) adjuvant androgen deprivation therapy after radical prostatectomy and subsequently stopped it under a condition of continued prostate-specific antigen values < 0.1 ng/mL. The oncological outcome was evaluated using biochemical recurrence, defined as two consecutive prostate-specific antigen values ≥0.2 ng/mL, as the primary endpoint. Cox proportional hazards model was used for multivariate analysis. Age at androgen deprivation therapy cessation was dichotomized as < 68 years and ≥68 years, based on the most discriminatory cutoff. Results: Median duration of adjuvant androgen deprivation therapy was 70 months. Overall, 13 of 56 (23%) patients developed biochemical recurrence with a median follow-up period of 41 months after androgen deprivation therapy cessation. Multivariate analysis identified age at androgen deprivation therapy cessation < 68 years and pN1 as independent predictors of biochemical recurrence. Predisposition of younger age to poorer survival may be related to more frequent testosterone recovery in younger men (73 vs 33%, P = 0.0299). One patient had evidence of clinical metastasis and no one died of prostate cancer. Conclusions: Androgen deprivation therapy cessation would be feasible in most men who received long-term adjuvant androgen deprivation therapy after radical prostatectomy with favorable prostate-specific antigen control. Risk factors of biochemical recurrence after androgen deprivation therapy cessation included younger age at androgen deprivation therapy cessation and pN1.