Factors associated with testosterone recovery after androgen deprivation therapy in patients with prostate cancer

Purpose We investigated factors affecting testosterone recovery after androgen deprivation therapy (ADT) withdrawal in patients with prostate cancer. Materials and Methods The medical records of patients who underwent radical prostatectomy with ADT were retrospectively reviewed. In all, 221 patients were included in the analysis. Testosterone recovery was defined as supra-castration (SC) (testosterone levels in serum >50 ng/dL) or out of hypogonadism (OH) (>300 ng/dL) after ADT withdrawal. Kaplan-Meier analyses were used to estimate testosterone recovery after ADT cessation. Cox regression analyses were used to determine the factors affecting the recovery of testosterone. Results After ADT, 206 patients (93.2%) recovered to the SC level and 122 patients (55.2%) recovered to the OH level. Patients treated with ADT for ≤18 months recovered to OH in a mean of 6.8 months (74.6%), but patients treated with ADT for >18 months recovered in a mean of 9.7 months (27.5%). In multivariate analyses, age (hazard ratio [HR], 0.915; p<0.001), serum level of sex hormone-binding globulin (SHBG) (HR, 1.015; p=0.002), initial testosterone level (HR, 1.002; p=0.002), and ADT duration (HR, 0.915; p<0.001) were associated with recovery to the OH level after ADT withdrawal, and hypertension (HR, 0.697; p=0.029) and duration of ADT (HR, 0.979; p=0.012) were significantly associated with recovery to SC. Conclusions In patients treated with ADT for ≤18 months, testosterone recovers to the OH level more often and faster after ADT cessation. Age, SHBG level, initial testosterone level, and ADT duration are associated with testosterone recovery.