(060) Chronology of Endogenous Testosterone Recovery Following Androgen Deprivation Therapy Cessation – Results From a Prospective Analysis

Abstract

Abstract Introduction Testosterone (T) recovery after androgen deprivation therapy (ADT) is reported in the literature from 7 to 96%, with data mainly from retrospective studies using variable definitions for this event. Age, Diabetes and ADT duration may affect the timing and completeness of recovery Objective Prospectively evaluate the chronology of T recovery following ADT cessation Methods This is a secondary analysis of a prospective oncological study designed to evaluate the impact of neoadjuvant use of ADT in combination with abiraterone acetate and prednisone with or without apalutamide in patients with high-risk prostate cancer. Both regimens were administered for 3 months before radical prostatectomy (RP). Early morning Total T (TT) levels were collected (immunoassay) at baseline and periodically (3, 6 and 12 months) after ADT cessation. 3 outcomes for T recovery were evaluated: return to non-castrate level (TT >50 ng/dL), to normal T (TT ≥ 300 ng/dL) and back to baseline level (BTB –TT≥ baseline level). We performed a time-to-event analysis and reported the cumulative incidence of each outcome. Multivariable analysis was conducted to investigate predictors of recovery Results In this preliminary report, from 64 initially enrolled patients, 1 year follow-up T data from 50 pts were available. Mean age was 64.6 ± 5.89 years, 28% had type 2 diabetes (DM) and 61% hypertension (HTN). Mean TT levels were 450 ± 170ng/dl at baseline, 112. 7± 96.9 at 3m, 208.5 ±197 at 6m, 337.7 ± 170 at 9m and 378.2 ± 166 at 12 m. Figure 1 shows the cumulative incidence of each outcome according to time. Median time to achieve T>50 was 5 m, to achieve T>300 was 9.1m and BTB 13.13 m. At 1 year, 98% had returned back from castrate-level, 76% had TT normalized and 42% had return BTB. In a multivariable analysis including DM, HTN, age and baseline T, only baseline T was associated with a greater chance of recovery, with 88.5% of those with baseline T > 450 ng/dl achieving normal T at 1y vs 46.9% for patients with baseline T < 450 ng/dl (HR: 3.56, p< 0.001) Conclusions In this prospective analysis of a population exposed to neoadjuvant short-term ADT, T recovery rates after 1 year showed that the vast majority (98%) had returned back from castrate level (median time 5m), about 2/3 recovered back to normal levels (median time 9,1m) and less than half returned to BTB level. Baseline TT was the only predictor of T recovery Disclosure Yes, this is sponsored by industry/sponsor: Source of Funding: Janssen-Cilag Farmacêutica Ltda Clarification Industry funding only - investigator initiated and executed study