Quality of life and testosterone recovery after androgen deprivation therapy in high-risk prostate cancer patients: long-term data from a phase III trial.

Purpose: The aim was to compare quality of life (QoL) of patients with testosterone recovery (TR) to patients without TR after the completion of either 18- or 36-month androgen deprivation therapy (ADT) for prostate cancer.

Methods: From a Phase III trial, we selected all 630 randomised patients with testosterone measured at baseline (during screening, before randomisation) and follow-up and who completed baseline, 6-month and, at least, one further QoL questionnaire in follow-up (EORTC 30 - PR25). We estimated means and standard deviation of items and scales for each group at each time point. We analyzed items and scales scores with general linear model with repeated measures to evaluate changes between patients with or without TR to a normal level. p-values were adjusted for multiple comparisons with Benjamini-Hochberg's false discovery rate procedure (p_adj). A p_adj < 0.05 was considered significant and mean differences of 10 points or more considered clinically relevant.

Results: 494 patients retained for analysis (median follow-up 16.2 years). A significantly higher number of patients (177/314 vs 79/180, p = 0.008) recovered a normal testosterone level in a significantly shorter time [median (IQR): 3.06 (2.55-3.65) vs 5.00 years (4.5-5.96), p < 0.001] in the 18- vs the 36-month cohort. Patients with TR had a significantly better QoL: 37/55 items and 14/21 scales (p_adj<0.05) in the 18-month and 25/55 items and 13/21 scales in the 36-month cohort. Moreover, 9 items and one scale reached clinical relevance in the 18-month cohort and 7 items and one scale in the 36-month cohort.

Conclusions: TR is associated with significant regaining in QoL. A faster and significantly higher TR is seen in the shorter ADT schedule.