(O-28) CHRONOLOGY OF ENDOGENOUS TESTOSTERONE RECOVERY AFTER DISCONTINUATION OF ANDROGEN DEPRIVATION THERAPY - RESULTS FROM A PROSPECTIVE ANALYSIS

Abstract

I - Testosterone recovery after different androgen deprivation therapy regimens for prostate cancer varies widely (7-96%) in the literature, with data coming mainly from retrospective studies. O - Evaluate testosterone recovery after ADT cessation prospectively. M - This secondary analysis of a neoadjuvant ADT study for high-risk prostate cancer patients collected total testosterone (TT) levels at baseline and up to 12 months post-ADT cessation. Three recovery outcomes were assessed: return to non-castrate (TT > 50 ng/dL), normal (TT ≥ 300 ng/dL), and baseline (BTB - TT ≥ baseline). A time-to-event analysis and multivariate analysis were conducted. R - 1-year follow-up data from 53 patients (60 with at least 1 follow-up data. Mean age was 64.6 (± 5.89), 28% had diabetes (DM), and 61% had hypertension (HTN). Mean TT levels were 450 ng/dL (± 170) at baseline, 112.7 ± 96.9 at 3 months, 208.5 ± 197 at 6 months, 341.8 ± 172 at 9 months, and 381.1 ± 166 at 12 months. Figure 1 shows the cumulative incidence of each outcome over time. The median time to achieve T > 50 was 5 months, for T > 300 it was 9.1 months, and for BTB it was 13.1 months. At 1 year post-ADT discontinuation, 98.1% had returned to TT > 50, 79.5% had TT > 300, and 33.9% had returned to baseline level. In a multivariate analysis including DM, HTN, age, and baseline T, only baseline T was associated with a higher chance of recovery to normality (baseline T > 450-88.5% vs. 46.9%, HR: 3.06, p < 0.05). C - In this prospective analysis, after discontinuing 3-month neoadjuvant ADT, most achieved normal T levels (80%) after 1 year, but less than half recovered to baseline levels. Cumulative Incidence of each outcome Janssen-Cilag Farmacêutica Ltda.