Association of PSA kinetics after testosterone recovery with subsequent recurrence: secondary analysis of a phase III randomized controlled trial.

PURPOSE: After cessation of androgen deprivation therapy (ADT), testosterone gradually recovers to supracastrate levels (> 50 ng/dL). After this, rises in prostate-specific antigen (PSA) are often seen. However, it remains unknown whether early PSA kinetics after testosterone recovery are associated with subsequent biochemical recurrence (BCR). METHODS: We performed a secondary analysis of a phase III randomized controlled trial in which newly diagnosed localized prostate cancer patients were randomly allocated to ADT for 6 months starting 4 months prior to or simultaneously with prostate RT. We calculated the PSA doubling time (PSADT) based on PSA values up to 18 months after supracastrate testosterone recovery. Competing risk regression was used to evaluate the association of PSADT with relative incidence of BCR, considering deaths as competing events. RESULTS: Overall, 313 patients were eligible. Median PSADT was 8 months. Cumulative incidence of BCR at 10 years from supracastrate testosterone recovery was 19% and 11% in patients with PSADT < 8 months and ≥ 8 months (p = 0.03). Compared to patients with PSADT of < 4 months, patients with higher PSADT (sHR for PSADT 4 to < 8 months: 0.36 [95% CI 0.16-0.82]; 8 to < 12 months: 0.26 [0.08-0.91]; ≥ 12 months: 0.20 [0.07-0.56]) had lower risk of relative incidence of BCR. CONCLUSIONS: Early PSA kinetics, within 18 months of recovery of testosterone to a supracastrate level, can predict for subsequent BCR. Taking account of early changes in PSA after testosterone recovery may allow for recognition of potential failures earlier in the disease course and thereby permit superior personalization of treatment.

Androgen deprivation therapy duration is significantly associated with Testosterone recovery in Japanese patients with prostate cancer.

OBJECTIVE: Due to the fear generated by COVID-19 in Spring 2020, many patients postponed their scheduled outpatient visits. To differentiate those patients with prostate cancer (PCa) whose androgen deprivation therapy (ADT) injection treatment can be postponed, we investigated the characteristics of testosterone (T) recovery in Japanese patients after they received combined ADT and radiation therapy (RT). METHODS: We included 81 patients with PCa treated with ADT and RT at Keio University Hospital from January 2013 to December 2018. T-recovery was defined as the time interval between the last ADT injection and 3-6 months after T-normalization. The Kaplan-Meier method was used to estimate time to T-recovery. Cox proportional hazards models identified T-recovery predictors. RESULTS: The 50% cumulative incidence of T-recovery was 7.0 months for the 6-short-term group (defined as patients having ≤6 months of ADT therapy) versus 13.0 months for the 6-long-term group (>6 months of therapy) (p < 0.001). The incidence was 7.0 months for the 12 short-term-ADT (ST) group versus 18.0 months for the 12 long-term-ADT (LT) group (p < 0.001). Multivariate analysis revealed that a shorter duration of ADT was associated with a shorter time to T-recovery (hazard ratio, 0.253; 95% CI, 0.138-0.465; p < 0.001). No other factors were significant predictors of T-recovery. CONCLUSION: Androgen deprivation therapy duration is significantly associated with T-recovery in Japanese patients with PCa. If a patient undergoes ADT for more than 6 or 12 months, it is possible to postpone their outpatient visits for 13 and 18 months, respectively.

Testosterone Recovery after Neoadjuvant Gonadotropin-Releasing Hormone Antagonist versus Agonist on Permanent Iodine-125 Seed Brachytherapy in Prostate Cancer Patients: A Propensity Score Analysis.

Optimal neoadjuvant hormone therapy (NHT) for reducing prostate cancer (PC) patients' prostate volume pre-brachytherapy is controversial. We evaluated the differential impact of neoadjuvant gonadotropin-releasing hormone (GnRH) antagonist versus agonist on post-brachytherapy testosterone recovery in 112 patients treated pre-brachytherapy with NHT (GnRH antagonist, n=32; GnRH agonists, n=80) (Jan. 2007-June 2019). We assessed the effects of patient characteristics and a GnRH analogue on testosterone recovery with logistic regression and a propensity score analysis (PSA). There was no significant difference in the rate of testosterone recovery to normal levels (> 300 ng/dL) between the GnRH antagonist and agonists (p=0.07). The GnRH agonists induced a significantly more rapid testosterone recovery rate at 3 months post-brachytherapy versus the GnRH antagonist (p<0.0001); there was no difference in testosterone recovery at 12 months between the GnRH antagonist/agonists (p=0.8). In the multivariate analysis, no actor was associated with testosterone recovery. In the PSA, older age and higher body mass index (BMI) were significantly associated with longer testosterone recovery. Post-brachytherapy testosterone recovery was quicker with the neoadjuvant GnRH agonists than the antagonist, and the testosterone recovery rate was significantly associated with older age and higher BMI. Long-term follow-ups are needed to determine any differential effects of GnRH analogues on the quality of life of brachytherapy-treated PC patients.

Testosterone Recovery Profiles After Cessation of Androgen Deprivation Therapy for Prostate Cancer.

INTRODUCTION: Androgen deprivation therapy (ADT) is frequently used in the treatment of prostate cancer worldwide. Variable testosterone (T) recovery profiles after ADT cessation have been cited. AIM: To evaluate T recovery after cessation of ADT. METHODS: We reviewed our institutional prospectively maintained database of patients with prostate cancer who received ADT. Serum early morning total T (TT) levels, collected at baseline and periodically after ADT cessation, were analyzed. Patient age, baseline T level, duration of ADT, and presence of diabetes and sleep apnea were selected as potential predictors of T recovery. 3 metrics of T recovery after 24 months of ADT cessation were analyzed: return to non-castrate level (TT > 50 ng/dL), return to normal (T > 300 ng/dL), and return back to baseline level (BTB). Multivariable time-to-event analysis (Cox proportional hazards), χ2 test, logistic regression model, and Kaplan-Meier curve were performed to define impact of the above predictors on time and chance of T recovery. MAIN OUTCOME MEASURES: Time and chance of T recovery to non-castrate level (TT > 50 ng/dL), return to normal (T > 300 ng/dL), and return BTB. RESULTS: 307 men with a mean age of 65 ± 8 years were included. Mean duration of ADT was 17 ± 25 months, and median follow-up was 31 ± 35 months. Mean TT values were 379 ng/dL at baseline and 321 ng/dL at >24 months. At 24 months after cessation of ADT, 8% of men remained at castrate level, 76% returned to TT >300 ng/dL, and 51% had returned BTB. Lower baseline T levels (TT < 400 ng/dL) and ADT duration >6 months were associated with a lower likelihood of recovery to normal TT at 24 months. Age >65 years and receiving ADT for >6 months were significantly associated with a slower T recovery. CLINICAL IMPLICATIONS: T recovery after ADT is not certain and may take longer than expected. Considering the range of side effects of low T, we believe that these findings must be discussed with patients before initiating such therapies. STRENGTHS & LIMITATIONS: Our strengths consisted of a relatively large database, long follow-up, and clinically meaningful endpoints. Limitations included the retrospective design of the study. CONCLUSION: T recovery rates after ADT cessation vary according to patient age, ADT duration, and baseline T levels. Approximately one-quarter of patients failed to normalize their TT level, and one-tenth of men remained at castrate levels 24 months after ADT cessation. Nascimento B, Miranda EP, Jenkins LC, et al. Testosterone Recovery Profiles After Cessation of Androgen Deprivation Therapy for Prostate Cancer. J Sex Med 2019;16:872-879.

Duration of androgen deprivation therapy and nadir of testosterone at 20 ng/dL predict testosterone recovery to supracastrate level in prostate cancer patients who received external beam radiotherapy.

OBJECTIVES: To determine the predictors of testosterone recovery after termination of androgen deprivation therapy in high/intermediate-risk prostate cancer patients receiving external beam radiation therapy with neoadjuvant and adjuvant androgen deprivation therapy. METHODS: A total of 82 patients who underwent external beam radiation therapy with androgen deprivation therapy for prostate cancer were retrospectively analyzed. Serum testosterone levels after androgen deprivation therapy terminations were studied. Cox proportional hazard models and the Kaplan-Meier method were used for statistical analysis. RESULTS: Median age, baseline testosterone, nadir testosterone and duration of androgen deprivation therapy were 73 years, 456 ng/dL, 16 ng/dL and 26 months, respectively. Androgen deprivation therapy duration of 33 months (hazard ratio 0.13; P = 0.0018), nadir testosterone of 20 ng/dL (hazard ratio 0.35; P = 0.0112) and testosterone >50 ng/dL at 6 months after androgen deprivation therapy termination (hazard ratio 0.21; P = 0.0075) were significantly associated with testosterone recovery to normal levels (200 ng/dL) on multivariate analysis. Androgen deprivation therapy duration of 33 months (hazard ratio 0.31; P = 0.0023) and nadir testosterone of 20 ng/dL (hazard ratio 0.38; P = 0.0012) were significantly associated with testosterone recovery to the supracastrate level (50 ng/dL) on multivariate analysis. After dividing patients into three risk groups, the rate of testosterone recovery to the normal level after 2 years of androgen deprivation therapy termination was 100% in the low-risk group versus 20.8% in the high-risk group (P < 0.0001); the rate of testosterone recovery to the supracastrate level was 100% in the low-risk group versus 51.5% in the high-risk group (P < 0.0001). CONCLUSIONS: Duration of androgen deprivation therapy and achievement of nadir testosterone 20 ng/dL both predict testosterone recovery to the supracastrate level in prostate cancer patients undergoing external beam radiation therapy with androgen deprivation therapy.

External Beam Radiotherapy Affects Serum Testosterone in Patients With Localized Prostate Cancer.

BACKGROUND: Previous studies have examined testosterone levels after external beam radiation (EBRT) monotherapy, but since 2002 only sparse contemporary data have been reported. AIM: To examine testosterone kinetics in a large series of contemporary patients after EBRT. METHODS: The study was conducted in 425 patients who underwent definitive EBRT for localized prostate cancer from 2002 through 2014. Patients were enrolled in several phase II and III trials. Exclusion criteria were neoadjuvant or adjuvant androgen-deprivation therapy or missing data. Testosterone was recorded at baseline and then according to each study protocol (not mandatory in all protocols). Statistical analyses consisted of means and proportions, Kaplan-Meier plots, and logistic and Cox regression analyses. OUTCOMES: Testosterone kinetics after EBRT monotherapy and their influence on biochemical recurrence. RESULTS: Median follow-up of 248 assessable patients was 72 months. One hundred eighty-six patients (75.0%) showed a decrease in testosterone. Median time to first decrease was 6.4 months. Median percentage of decrease to the nadir was 30% and 112 (45.2%) developed biochemical hypogonadism (serum testosterone < 8 nmol/L). Of all patients with testosterone decrease, 117 (62.9%) recovered to at least 90% of baseline levels. Advanced age, increased body mass index, higher baseline testosterone level, and lower nadir level were associated with a lower chance of testosterone recovery. Subgroup analyses of 166 patients treated with intensity-modulated radiotherapy confirmed the results recorded for the entire cohort. In survival analyses, neither testosterone decrease nor recovery was predictive for biochemical recurrence. CLINICAL IMPLICATIONS: EBRT monotherapy influences testosterone kinetics, and although most patients will recover, approximately 45% will have biochemical hypogonadism. STRENGTHS AND LIMITATIONS: We report on the largest contemporary series of patients treated with EBRT monotherapy in whom testosterone kinetics were ascertained. Limitations are that testosterone follow-up was not uniform and the study lacked information on health-related quality-of-life data. CONCLUSION: Our findings indicate that up to 75% of patients will have a profound testosterone decrease, with up to a 40% increase in rates of biochemical hypogonadism, although the latter events will leave biochemical recurrence unaffected. Pompe RS, Karakrewicz PI, Zaffuto E, et al. External Beam Radiotherapy Affects Serum Testosterone in Patients With Localized Prostate Cancer. J Sex Med 2017;14:876-882.

Testosterone recovery after androgen deprivation therapy in localised prostate cancer: Long-term data from two randomised trials.

BACKGROUND AND PURPOSE: To determine the rate and time of testosterone (T) recovery in patients (pts) with localised prostate cancer treated with radiotherapy plus 0-, 6-, 18- or 36-month of androgen deprivation therapy (ADT). MATERIALS AND METHODS: In 1230 pts with prostate cancer randomised into two phase III trials, serum T was measured at baseline, then regularly. T recovery rate was compared between normal vs. abnormal baseline T and with ADT duration with Chi-square test or Fisher's exact test. A multivariable logistic regression model to predict the probability of recovering normal T was performed. RESULTS: Overall, 87.4 % (167/191), 75.9 % (293/386), 54.8 % (181/330) and 43.2 % (80/185) of pts, recovered normal T on the 0-, 6-, 18- or 36-month schedule, respectively (p < 0.001). In patients recovering normal T, the median time to T recovery increased with ADT duration ranging from 0.31, 1.64, 3.06 to 5.0 years for the 0-, 6-, 18- or 36-month schedules, respectively (p < 0.001) and was significantly faster for those with a normal T at baseline (p < 0.001). On multivariable analysis, older age and longer ADT duration are associated with a lower T recovery. CONCLUSIONS: Testosterone recovery rate after ADT depends on several factors including hormonal duration, normal baseline T, age and medical comorbidities. A longer ADT duration is the most important variable affecting T recovery. The data from this report might be a valuable tool to help physicians and patients in evaluating risks and benefits of ADT.

Identification of Factors Contributing to Testosterone Recovery After Hormone Therapy Combined With External Radiation Therapy.

BACKGROUND/AIM: When hormone therapy (HT) is combined with radiotherapy, understanding the recovery of testosterone levels after the end of HT becomes crucial for considering subsequent therapy. The aim of this study was to determine the factors influencing the time to recovery of testosterone levels after discontinuation of HT and the likelihood of recovery. PATIENTS AND METHODS: The study included a total of 108 patients with prostate cancer who were treated with GnRH agonist in combination with radiotherapy and followed up for at least 12 months after discontinuation of the GnRH agonist. The presence of recovery of testosterone levels and the time to recovery were investigated. Univariate and multivariate analyses were performed on several factors contributing to testosterone recovery, including age at initiation of HT, and the duration of HT. RESULTS: Testosterone levels recovered in 61 cases (56.5%). The median time to recovery was 14.8 months. There was a significant difference in the recovery of testosterone levels between patients aged ≥71 years and those aged <71 years at the start of HT (p=0.002), and between those who had been on HT for ≥34 months and those for <34 months (p=0.031). In both univariate and multivariate analyses, age at initiation of HT and duration of HT contributed to the recovery of testosterone levels. CONCLUSION: The rate of recovery of testosterone levels after long-term (median 34.3 months) HT was lower in patients who were older than 71 years at the start of HT.

Testosterone Recovery for Relugolix Versus Leuprolide in Men with Advanced Prostate Cancer: Results from the Phase 3 HERO Study.

BACKGROUND: In the HERO study, relugolix demonstrated sustained testosterone suppression superior to that of leuprolide acetate (97% vs 89%; difference 7.9% [95% confidence interval, 4.1-12%; p < 0.001]). OBJECTIVE: To analyze testosterone recovery in a prespecified subset of men from the HERO study not indicated to continue androgen deprivation therapy. DESIGN, SETTING, AND PARTICIPANTS: Men (N = 934) were randomized (2:1) to receive relugolix 120 mg orally daily or leuprolide acetate injections every 12 wk for 48 wk. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Testosterone recovery was assessed in 184 men who completed 48 wk of treatment. During the 90-d recovery period, assessments included time to testosterone recovery (>280 ng/dl; ≥80% of baseline testosterone), serum levels of prostate-specific antigen and pituitary hormones, and adverse events. RESULTS AND LIMITATIONS: The cumulative incidence rate of testosterone recovery to >280 ng/dl at 90 d following drug discontinuation was significantly higher in the relugolix cohort (n = 137) than in the leuprolide acetate cohort (n = 47; 54% vs 3.2%; nominal p = 0.002). The median time to testosterone recovery was faster following relugolix treatment than with leuprolide acetate treatment (86.0 d vs 112.0 d). Compared with leuprolide acetate, more men treated with relugolix achieved ≥80% of baseline testosterone levels (39% vs 2.1%). Men ≤65 yr and those with baseline testosterone greater than the median had a higher incident rate of testosterone recovery. Adverse events were generally similar between treatment groups. One limitation is the short testosterone recovery follow-up period. CONCLUSIONS: Oral relugolix had faster and more complete recovery of testosterone to normal levels after treatment discontinuation than leuprolide acetate in a subset of men from the HERO study. The clinical implications of a faster testosterone recovery with relugolix may be significant for men being treated with androgen deprivation therapy and influence treatment decisions. PATIENT SUMMARY: The male hormone testosterone is reduced during androgen deprivation therapy for prostate cancer. Reduced testosterone levels cause side effects, impacting patient quality of life. When treatment is stopped, the side effects lessen over time as the levels of testosterone come back to pretreatment range (testosterone recovery). In this study, we found that the time to testosterone recovery was faster with relugolix than with leuprolide acetate.

Implications of Delayed Testosterone Recovery in Patients with Prostate Cancer.

To assess the clinical impact of delayed testosterone recovery (TR) following the discontinuation of medical androgen deprivation therapy (ADT), a retrospective, longitudinal analysis was conducted in adult males with prostate cancer using the Optum® de-identified Electronic Health Record data set and Optum® Enriched Oncology Data (2010-2021). Of 3875 patients who initiated and discontinued ADT, 1553 received one or more testosterone-level tests within the 12 mo following discontinuation and were included in this study. These 1553 patients were categorized into two cohorts: 25% as TR (testosterone levels >280 ng/dl at any test within 12 mo following ADT discontinuation) and 75% as non-TR. At baseline, non-TR patients were older, had lower testosterone levels, and were more likely to have diabetes, hyperlipidemia, and hypertension, but less likely to have sexual dysfunction. After adjustment for baseline characteristics, the TR cohort had a lower risk of new-onset diabetes (hazard ratio [HR] 0.47; 95% confidence interval [CI] 0.27-0.79), trended toward a lower risk of new-onset depression (HR 0.58; 95% CI 0.33-1.02), and had a higher likelihood of seeking treatment for sexual dysfunction (HR 1.33; 95% CI 0.99-1.78) versus the non-TR cohort. These findings support monitoring testosterone levels after ADT discontinuation to manage potential long-term comorbidities in patients with prostate cancer. Patient summary: This real-world analysis of males with prostate cancer who were treated with medical androgen deprivation therapy (ADT) found that most patients did not have their testosterone level checked in the 12 mo after stopping ADT. Of those who did, 75% did not achieve normal testosterone levels (>280 ng/dl), and these patients were more likely to experience new-onset diabetes than those who achieved normal testosterone levels. These results suggest that to ensure effective clinical decision-making, physicians should check patients' testosterone levels after stopping ADT.

Adjuvant leuprolide with or without docetaxel in patients with high-risk prostate cancer after radical prostatectomy (TAX-3501): important lessons for future trials.

BACKGROUND: The current trial evaluated 2 common therapies for patients with advanced prostate cancer, docetaxel and hormonal therapy (HT), in the surgical adjuvant setting. METHODS: TAX-3501 was a randomized, phase 3, adjuvant study post-radical prostatectomy (RP) in high-risk patients with prostate cancer (n=228) comparing 18 months of HT with (CHT) without docetaxel chemotherapy either immediately (I) or deferred (D). High-risk disease was defined as a 5-year freedom-from-disease-progression rate of ≤ 60% as predicted by a post-RP nomogram. Progression-free survival (PFS), including prostate-specific antigen disease recurrence, was the primary endpoint. The authors also assessed the accuracy of the nomogram and analyzed testosterone recovery in 108 patients treated with HT who had at least 1 posttreatment testosterone value. RESULTS: Between December 2005 and September 2007, 228 patients were randomized between the treatment cohorts. TAX-3501 was terminated prematurely because of enrollment challenges, leaving it underpowered to detect differences in PFS. After a median follow-up of 3.4 years (interquartile range, 2.3-3.8 years), 39 of 228 patients (17%) demonstrated PSA disease progression, and metastatic disease progression occurred in 1 patient. The median time to baseline testosterone recovery after the completion of treatment was prolonged at 487 days (95% confidence interval, 457-546 days). The nomogram's predicted versus observed freedom from disease progression was significantly different for the combination D(HT) and D(CHT) group (P<.00001). CONCLUSIONS: TAX-3501 illustrated several difficulties involved in conducting postoperative adjuvant systemic trials in men with high-risk prostate cancer: the lack of consensus regarding patient selection and treatment, the need for long follow-up time, nonvalidated intermediate endpoints, evolving standard approaches, and the need for long-term research support. Except for selected patients at very high-risk of disease recurrence and death, surgical adjuvant trials in patients with prostate cancer may not be feasible.

Differences in sex hormone recovery profile after cessation of 12-week gonadotropin-releasing hormone antagonist versus agonist therapy.

BACKGROUND: Pharmacobiological behavior differs between gonadotropin-releasing hormone (GnRH) antagonists and GnRH agonists. However, reliable evidence clarifying the difference between them is limited. OBJECTIVES: We aimed to elucidate the difference in recovery profile between GnRH antagonist (degarelix) and GnRH agonist (leuprorelin acetate or goserelin acetate) as short-term (12 weeks) neoadjuvant androgen deprivation therapy (ADT) prior to 125I-transperineal prostate brachytherapy (TPPB) for localized prostate cancer. MATERIALS AND METHODS: This study was initially designed as a single-center, prospective, open-label, randomized controlled trial. The primary endpoint was a serum testosterone level above the castration range (>50 ng/dl) after the cessation of 12-week neoadjuvant ADT (GnRH antagonist or GnRH agonists). All patients underwent 12 weeks of neoadjuvant ADT. The recovery profiles of hormones, prostate-specific antigen, total prostate volume (TPV), bone mineral density, and quality of life scores were investigated. RESULTS: Testosterone recovery duration after the last injection was significantly longer in the GnRH antagonist arm than in the GnRH agonist arm (median, 27.3 vs. 4.8 weeks, p < 0.001). The serum levels of luteinizing hormone and follicle-stimulating hormone in the GnRH antagonist arm also remained significantly lower than those in the GnRH agonist arm between 16 and 24 weeks (p < 0.01). Meanwhile, reduction in TPV at the time of TPPB was comparable between both arms (p = 0.128). There were also no significant between-arm differences in the International Prostate Symptom Score and the International Index of Erectile Function scores. DISCUSSION AND CONCLUSION: The recovery patterns of hormonal profiles after short-term (12 weeks) neoadjuvant ADT differ between GnRH antagonists and GnRH agonists. The choice between these drugs matters and may have a clinical impact depending on the primary objective of ADT.

Prognostic value of testosterone castration levels following androgen deprivation and high-dose radiotherapy in localized prostate cancer: Results from a phase III trial.

BACKGROUND/OBJECTIVE: The optimal prognostic value of testosterone following androgen deprivation therapy (ADT) is controversial. We studied the effect of serum testosterone levels on clinical outcome in localized prostate cancer (PCa) treated with ADT and high-dose radiotherapy (HRT). PATIENTS AND METHODS: The DART01/05 trial randomized 355 men with intermediate and high-risk PCa to 4 months of ADT plus HRT (STADT, N = 178) or the same treatment followed by 24 months of ADT (LTADT, N = 177). This study included patients treated with LTADT who had at least 3 determinations of testosterone during ADT (N = 154). Patients were stratified into 3 subgroups by testosterone level: minimum <20 ng/dL; median 20-49 ng/dL; and maximum ≥50 ng/dL. Kaplan-Meyer and Cox regression analysis were used for overall survival (OS) and Fine & Gray regression model for metastasis free survival (MFS), biochemical disease-free survival (bDFS) and time to TT recovery. RESULTS: There were no statistically significant differences in 10-year bDFS, MFS, or OS between the <20 ng/mL and 20-49 ng/dL subgroups. Multivariate analysis showed that a median testosterone ≥50 ng/dL was significantly associated with a decrease in bDFS (HR: 6.58, 95%CI 1.28-33.76, p = 0.03). Time to testosterone recovery after ADT did not correlate with bDFS, MFS, or OS and was not significantly associated with any of the testosterone subgroups. CONCLUSIONS: Our results do not support the concept that additional serum testosterone suppression below 20 ng/dL is associated with better outcomes than 20-49 ng/dL. Time to testosterone recovery after ADT and HRT did not impact clinical failure.

The Relationship between Hot Flashes and Testosterone Recovery after 12 Months of Androgen Suppression for Men with Localised Prostate Cancer in the ASCENDE-RT Trial.

AIMS: This study describes the proportion of men who experienced hot flashes (flashes), and the testosterone level at onset, peak frequency and cessation of flashes after 12 months of androgen deprivation therapy (ADT) in men undergoing curative-intent external beam radiation therapy (± brachytherapy boost). We also aimed to characterise testosterone recovery in this population. MATERIALS AND METHODS: This was a pre-specified secondary analysis of the ASCENDE-RT clinical trial. Three hundred and ninety-eight men were randomised. All received 12 months of ADT. The presence and frequency of flashes were patient reported. Cessation of flashes was defined as the first date a patient reported resolution of this symptom. Testosterone recovery was defined as any single serum testosterone above the threshold of 5, 7.5 or 10 nmol/l. RESULTS: The median age and follow-up were 68 years and 6.1 years. Flashes were reported in 93% of men. Flashes began and reached peak frequency at a median time of 4.0 months from the first luteinizing hormone-releasing hormone injection when testosterone levels had fallen to castrate. The median time to cessation of flashes was 7.6 months after the cessation of ADT (last injection + 3 months), when the median testosterone had risen to 5.7 nmol/l. A resolution of flashes was reported in 99% of patients. Baseline testosterone was available in 338 patients (85%). The median baseline testosterone was 13.2 nmol/l. The median (95% confidence interval) time of testosterone recovery to thresholds of 5 nmol/l, 7.5 nmol/l and 10 nmol/l were 9 (9-10) months, 13 (10-15) months and 18 (17-19) months from the cessation of ADT. At the time of censor, 96, 94 and 91% of patients had recovered testosterone to thresholds of 5, 7.5 and 10 nmol/l. CONCLUSION: Flashes occur at castrate levels of testosterone, with cessation of hot flashes antedating full recovery of testosterone in most patients. Rates of testosterone recovery after 12 months of ADT exceed 90%, although it can be delayed.