Testosterone Recovery Following Androgen Suppression and Prostate Radiotherapy (TRANSPORT): A Pooled Analysis of Five Randomized Trials from the Meta-Analysis of Randomized Trials in Cancer of the Prostate (MARCAP) Consortium.

BACKGROUND AND OBJECTIVE: Time to testosterone recovery (TR) following androgen deprivation therapy (ADT) with gonadotropin-releasing hormone agonists varies widely. We evaluate TR kinetics and the oncological impact of an effective castration period in patients receiving definitive radiotherapy and ADT for prostate cancer. METHODS: We obtained individual patient data from randomized controlled trials of radiotherapy with ADT and prospectively collected serial testosterone data from the MARCAP Consortium. We estimated the times to noncastrate TR (>1.7 nmol/l) and nonhypogonadal TR (>8.0 nmol/l) were estimated for each prescribed ADT duration, and developed corresponding nomograms. The association between effective castration period and metastasis-free survival (MFS) for any given ADT duration was evaluated via multivariable Cox regression. We conducted cubic spline analyses to assess nonlinear associations. KEY FINDINGS AND LIMITATIONS: We included 1444 men from five trials in the analysis, of whom 115 received 4 mo, 880 received 6 mo, 353 received 18 mo, 36 received 28 mo, and 60 received 36 mo of ADT. Times to noncastrate TR and to nonhypogonadal TR varied considerably by ADT duration. Higher baseline testosterone and lower age were associated with a higher likelihood of TR (p < 0.001 for both). Effective castration period was not linearly associated with MFS for any ADT duration on Cox regression. Cubic spline analysis revealed that the optimal effective castration period for an MFS benefit was 10.6 mo for men who received 6 mo of ADT and 18 mo for men who received 18 mo of ADT. CONCLUSIONS AND CLINICAL IMPLICATIONS: Time to TR varies according to the ADT duration, baseline testosterone, and age. The relationship between effective castration period and MFS may be nonlinear, with a longer effective castration period being helpful for men receiving 6 mo of ADT.

A randomised trial of short- vs long-term androgen deprivation with salvage radiotherapy for biochemical failure following radical prostatectomy: URONCOR 06-24.

BACKGROUND: Salvage radiotherapy (SRT) and androgen-deprivation therapy (ADT) are widely used in routine clinical practice to treat patients with prostate cancer who develop biochemical recurrence (BCR) after radical prostatectomy (RP). However, there is no standard-of-care consensus on optimal duration ADT. Investigators propose three distinct risk groups in patients with prostate cancer treated with SRT in order to better define the indications and duration of ADT combined with SRT. STUDY DESIGN: The URONCOR 06-24 trial (ClinicalTrials.gov identifier NCT05781217) is a prospective, multicentre, randomised, open-label, phase III, clinical trial. The aim of the trial is to determine the impact of short-term (6 months) vs long-term (24 months) ADT in combination with SRT on distant metastasis-free survival (MFS) in patients with prostate cancer with BCR after RP (intermediate and high risk). ENDPOINTS: The primary endpoint is 5-year MFS rates in patients with prostate cancer treated with long- vs short-term ADT in combination with SRT. Secondary objectives are biochemical-relapse free interval, pelvic progression-free survival, time to start of systemic treatment, time to castration resistance, cancer-specific survival, overall survival, acute and late toxicity, and quality of life. METHODS AND ANALYSIS: Total of 534 patients will be randomised 1:1 to ADT 6 months or ADT 24 months with a luteinizing hormone-releasing hormone analogue in combination with SRT, stratified by risk group and pathological lymph node status. ETHICS AND DISSEMINATION: The study is conducted under the guiding principles of the World Medical Association Declaration of Helsinki. The results will be disseminated at research conferences and in peer-reviewed journals. TRIAL REGISTRATION NUMBER: EudraCT number 2021-006975-41.

Case report: Exceptional and durable response to Radium-223 and suspension of androgen deprivation therapy in a metastatic castration-resistant prostate cancer patient.

Despite the development of new therapies in the last few years, metastatic prostate cancer (PCa) is still a lethal disease. Radium-223 (Ra-223) is approved for patients with advanced castration-resistant prostate cancer (CRPC) with bone metastases and no visceral disease. However, patients' outcomes are heterogenous, and there is lack of validated predictive biomarkers of response, while biomarkers for early identification of patients who benefit from treatment are limited. This case report describes a remarkable and durable response to Ra-223 in a CRPC patient with bone metastases who had rapidly progressed to many previous therapies; this response is now lasting for 5 years even after having stopped backbone androgen deprivation therapy (ADT). Here, we present the clinical course of this exceptional response, as well as comprehensive genomic and histopathology analyses on sequential biopsies acquired before and after therapy. Additionally, we review current knowledge on predictive and response biomarkers to Ra-223 in metastatic prostate cancer.

Biochemical Recurrence Surrogacy for Clinical Outcomes After Radiotherapy for Adenocarcinoma of the Prostate.

PURPOSE: The surrogacy of biochemical recurrence (BCR) for overall survival (OS) in localized prostate cancer remains controversial. Herein, we evaluate the surrogacy of BCR using different surrogacy analytic methods. MATERIALS AND METHODS: Individual patient data from 11 trials evaluating radiotherapy dose escalation, androgen deprivation therapy (ADT) use, and ADT prolongation were obtained. Surrogate candidacy was assessed using the Prentice criteria (including landmark analyses) and the two-stage meta-analytic approach (estimating Kendall's tau and the R2). Biochemical recurrence-free survival (BCRFS, time from random assignment to BCR or any death) and time to BCR (TTBCR, time from random assignment to BCR or cancer-specific deaths censoring for noncancer-related deaths) were assessed. RESULTS: Overall, 10,741 patients were included. Dose escalation, addition of short-term ADT, and prolongation of ADT duration significantly improved BCR (hazard ratio [HR], 0.71 [95% CI, 0.63 to 0.79]; HR, 0.53 [95% CI, 0.48 to 0.59]; and HR, 0.54 [95% CI, 0.48 to 0.61], respectively). Adding short-term ADT (HR, 0.91 [95% CI, 0.84 to 0.99]) and prolonging ADT (HR, 0.86 [95% CI, 0.78 to 0.94]) significantly improved OS, whereas dose escalation did not (HR, 0.98 [95% CI, 0.87 to 1.11]). BCR at 48 months was associated with inferior OS in all three groups (HR, 2.46 [95% CI, 2.08 to 2.92]; HR, 1.51 [95% CI, 1.35 to 1.70]; and HR, 2.31 [95% CI, 2.04 to 2.61], respectively). However, after adjusting for BCR at 48 months, there was no significant treatment effect on OS (HR, 1.10 [95% CI, 0.96 to 1.27]; HR, 0.96 [95% CI, 0.87 to 1.06] and 1.00 [95% CI, 0.90 to 1.12], respectively). The patient-level correlation (Kendall's tau) for BCRFS and OS ranged between 0.59 and 0.69, and that for TTBCR and OS ranged between 0.23 and 0.41. The R2 values for trial-level correlation of the treatment effect on BCRFS and TTBCR with that on OS were 0.563 and 0.160, respectively. CONCLUSION: BCRFS and TTBCR are prognostic but failed to satisfy all surrogacy criteria. Strength of correlation was greater when noncancer-related deaths were considered events.

Novel Approaches in the Systemic Management of High-Risk Prostate Cancer.

Locally advanced prostate cancer comprises approximately 20% of new prostate cancer diagnoses. For these patients, international guidelines recommend treatment with radiotherapy (RT) to the prostate in combination with long-term (2-3 years) androgen deprivation therapy (ADT), or radical prostatectomy in combination with extended pelvic lymph node dissection (PLND) as another treatment option for selected patients as part of multimodal therapy. Improvements in overall survival with docetaxel or an androgen receptor signaling inhibitor have been achieved in patients with metastatic castration sensitive or castration resistant prostate cancer. However, the role of systemic therapy combinations for high risk and/or unfavorable prostate cancer is unclear. In this context, the aim of this review is to assess the current evidence for systemic treatment combinations as part of primary definitive therapy in patients with high-risk localized prostate cancer.

Sequencing of Androgen-Deprivation Therapy of Short Duration With Radiotherapy for Nonmetastatic Prostate Cancer (SANDSTORM): A Pooled Analysis of 12 Randomized Trials.

PURPOSE: The sequencing of androgen-deprivation therapy (ADT) with radiotherapy (RT) may affect outcomes for prostate cancer in an RT-field size-dependent manner. Herein, we investigate the impact of ADT sequencing for men receiving ADT with prostate-only RT (PORT) or whole-pelvis RT (WPRT). MATERIALS AND METHODS: Individual patient data from 12 randomized trials that included patients receiving neoadjuvant/concurrent or concurrent/adjuvant short-term ADT (4-6 months) with RT for localized disease were obtained from the Meta-Analysis of Randomized trials in Cancer of the Prostate consortium. Inverse probability of treatment weighting (IPTW) was performed with propensity scores derived from age, initial prostate-specific antigen, Gleason score, T stage, RT dose, and mid-trial enrollment year. Metastasis-free survival (primary end point) and overall survival (OS) were assessed by IPTW-adjusted Cox regression models, analyzed independently for men receiving PORT versus WPRT. IPTW-adjusted Fine and Gray competing risk models were built to evaluate distant metastasis (DM) and prostate cancer-specific mortality. RESULTS: Overall, 7,409 patients were included (6,325 neoadjuvant/concurrent and 1,084 concurrent/adjuvant) with a median follow-up of 10.2 years (interquartile range, 7.2-14.9 years). A significant interaction between ADT sequencing and RT field size was observed for all end points (P interaction < .02 for all) except OS. With PORT (n = 4,355), compared with neoadjuvant/concurrent ADT, concurrent/adjuvant ADT was associated with improved metastasis-free survival (10-year benefit 8.0%, hazard ratio [HR], 0.65; 95% CI, 0.54 to 0.79; P < .0001), DM (subdistribution HR, 0.52; 95% CI, 0.33 to 0.82; P = .0046), prostate cancer-specific mortality (subdistribution HR, 0.30; 95% CI, 0.16 to 0.54; P < .0001), and OS (HR, 0.69; 95% CI, 0.57 to 0.83; P = .0001). However, in patients receiving WPRT (n = 3,049), no significant difference in any end point was observed in regard to ADT sequencing except for worse DM (HR, 1.57; 95% CI, 1.20 to 2.05; P = .0009) with concurrent/adjuvant ADT. CONCLUSION: ADT sequencing exhibits a significant impact on clinical outcomes with a significant interaction with field size. Concurrent/adjuvant ADT should be the standard of care where short-term ADT is indicated in combination with PORT.

Management of high-risk and post-operative non-metastatic prostate cancer in Catalonia: an expert Delphi consensus.

BACKGROUND: To reach a consensus on recommendations for the management of high-risk and post-operative non-metastatic prostate cancer by a group of Radiation Oncologists in Catalonia dedicated to prostate cancer. METHODS: A modified Delphi approach was employed to reach consensus on controversial topics in Radiation Oncology on high-risk non-metastatic (eight questions) and post-operative (eight questions) prostate cancer. An agreement of at least 75% was considered as consensus. The survey was electronically sent 6 weeks before an expert meeting where topics were reviewed and discussed. A second-round survey for the controversial questions only was sent and answered by participants after the meeting. RESULTS: After the first round of the survey, 19 experienced Radiation Oncologists attended the meeting and 74% fulfilled the second-round online questionnaire. An agreement of 9 of the 16 questions was accounted for the first round. After the meeting, an additional agreement was reached in 3 questions leading to a final consensus on 12 of the 16 questions. There are still controversial topics like the use of PET for staging of high-risk and post-operative non-metastatic prostate cancer and the optimal dose to the prostate bed in the salvage setting. CONCLUSION: This consensus contributes to establish recommendations and a framework to help in prostate cancer radiation therapy and pharmacological management in daily clinical practice of high-risk and post-operative non-metastatic prostate cancer.

Phase II Study of ENZAlutamide Combined With Hypofractionated Radiation Therapy (ENZART) for Localized Intermediate Risk Prostate Cancer.

Background: Intermediate-risk prostate cancer (PCa) is usually treated by a combination of external beam radiation therapy (EBRT) and a short course of androgen deprivation therapy (ADT). ADT is associated with multiple side effects, including weight gain, loss of libido, and hot flashes. In contrast, anti-androgen monotherapy is generally better tolerated in spite of higher rates of gynecomastia. Objective: This study assessed the effectiveness of enzalutamide monotherapy combined with hypofractionated EBRT (Hypo-EBRT) for treating intermediate risk prostate cancer. Method: This trial was a multicenter, open-label phase II study of 6 months of enzalutamide monotherapy combined with Hypo-EBRT for intermediate-risk prostate cancer. Hypo-EBRT was initiated 8-12 weeks after initiating enzalutamide. The primary endpoint was PSA decline >80% measured at the 25th week of enzalutamide administration. Secondary end-points included assessment of toxicity, changes in anthropomorphic body measurements, sexual hormones, and metabolic changes. Results: Sixty-two patients were included in the study from January 2018 to February 2020. A PSA decline of >80% was observed in all evaluable patients at the end of enzalutamide treatment and 92% achieved PSA values under 0.1 ngr/ml. All patients remain in PSA response (<80% reduction of the initial values) 6 months after the end of enzalutamide treatment. The most frequent adverse events were hypertension, asthenia, and gynecomastia. There were no significant changes in bone density, body mass index (BMI), or patient-reported outcomes (PROs). Conclusion: Enzalutamide monotherapy is very effective along with hEBRT in reducing PSA levels for patients with intermediate-risk prostate cancer. Longer follow-up is needed to confirm the potential use of this combination in future randomized trials.

High-dose Radiotherapy or Androgen Deprivation Therapy (HEAT) as Treatment Intensification for Localized Prostate Cancer: An Individual Patient-data Network Meta-analysis from the MARCAP Consortium.

BACKGROUND: The relative benefits of radiotherapy (RT) dose escalation and the addition of short-term or long-term androgen deprivation therapy (STADT or LTADT) in the treatment of prostate cancer are unknown. OBJECTIVE: To perform a network meta-analysis (NMA) of relevant randomized trials to compare the relative benefits of RT dose escalation ± STADT or LTADT. DESIGN, SETTING, AND PARTICIPANTS: An NMA of individual patient data from 13 multicenter randomized trials was carried out for a total of 11862 patients. Patients received one of the six permutations of low-dose RT (64 to <74 Gy) ± STADT or LTADT, high-dose RT (≥74 Gy), or high-dose RT ± STADT or LTADT. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES: Metastasis-free survival (MFS) was the primary endpoint. Frequentist and Bayesian NMAs were performed to rank the various treatment strategies by MFS and biochemical recurrence-free survival (BCRFS). RESULTS AND LIMITATIONS: Median follow-up was 8.8 yr (interquartile range 5.7-11.5). The greatest relative improvement in outcomes was seen for addition of LTADT, irrespective of RT dose, followed by addition of STADT, irrespective of RT dose. RT dose escalation did not improve MFS either in the absence of ADT (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.80-1.18) or with STADT (HR 0.99, 95% CI 0.8-1.23) or LTADT (HR 0.94, 95% CI 0.65-1.37). According to P-score ranking and rankogram analysis, high-dose RT + LTADT was the optimal treatment strategy for both BCRFS and longer-term outcomes. CONCLUSIONS: Conventionally escalated RT up to 79.2 Gy, alone or in the presence of ADT, does not improve MFS, while addition of STADT or LTADT to RT alone, regardless of RT dose, consistently improves MFS. RT dose escalation does provide a high probability of improving BCRFS and, provided it can be delivered without compromising quality of life, may represent the optimal treatment strategy when used in conjunction with ADT. PATIENT SUMMARY: Using a higher radiotherapy dose when treating prostate cancer does not reduce the chance of developing metastases or death, but it does reduce the chance of having a rise in prostate-specific antigen (PSA) signifying recurrence of cancer. Androgen deprivation therapy improves all outcomes. A safe increase in radiotherapy dose in conjunction with androgen deprivation therapy may be the optimal treatment.

High-dose radiotherapy and risk-adapted androgen deprivation in localised prostate cancer (DART 01/05): 10-year results of a phase 3 randomised, controlled trial.

BACKGROUND: The optimal duration of androgen deprivation combined with high-dose radiotherapy in prostate cancer remains controversial. The DART 01/05 trial was designed to determine whether long-term androgen deprivation is superior to short-term androgen deprivation when combined with high-dose radiotherapy. The 5-year results showed that 2 years of adjuvant androgen deprivation combined with high-dose radiotherapy significantly improved biochemical control, metastasis, and overall survival, especially in patients with high-risk disease. In this report, we present the 10-year final results of the trial. METHODS: This open-label, phase 3, randomised, controlled trial was done in ten hospitals in Spain. The eligibility criteria included patients aged 18 years or older with histologically confirmed T1c to T3, N0, and M0 adenocarcinoma of the prostate, according to the 2002 classification of the American Joint Committee on Cancer, with intermediate-risk and high-risk factors, prostate-specific antigen (PSA) less than 100 ng/mL, and a Karnofsky performance score of at least 70%. Patients were randomly assigned (1:1) to receive 4 months of neoadjuvant and concomitant short-term androgen deprivation (STAD) plus high-dose radiotherapy (minimum dose 76 Gy; median dose 78 Gy) or to receive the same treatment followed by 24 months of adjuvant long-term androgen deprivation (LTAD), via a randomisation scheduled generated by Statistical Analysis Software programme (version 9.1) and an interactive web response system. Patients assigned to the STAD group received 4 months of neoadjuvant and concomitant androgen deprivation (oral flutamide 750 mg per day or oral bicalutamide 50 mg per day) with subcutaneous goserelin (2 months before and 2 months combined with high-dose radiotherapy). Anti-androgen therapy was added during the first 2 months of treatment. Patients assigned to LTAD continued with goserelin every 3 months for another 24 months. The primary endpoint was biochemical disease-free survival at 5 years. For this 10-year study we analysed overall survival, metastasis-free survival, biochemical disease-free survival, and cause-specific survival. Analysis was by intention to treat. This trial is closed and is registered at ClinicalTrials.gov (NCT02175212) and in the EU Clinical Trials Register (EudraCT 2005-000417-36). FINDINGS: Between Nov 7, 2005, and Dec 20, 2010, 355 patients were enrolled. One patient in the STAD group withdrew from the trial, hence 354 participants were randomly assigned to STAD (n=177) or LTAD (n=177). The median follow-up was 119·4 months (IQR 100·6-124·3). The 10-year biochemical disease-free survival for LTAD was 70·2% (95% CI 63·1-77·3) and for STAD was 62·3% (54·9-69·7; hazard ratio [HR] 0·84; 95% CI 0·50-1·43; p=0·52). At 10 years, overall survival was 78·4% (72·1-84·8) for LTAD and 73·3% (66·6-80·0) for STAD (HR 0·84; 95% CI 0·55-1·27; p=0·40), and metastasis-free survival was 76·0% (69·4-82·7) for LTAD and 70·9% (64·0-77·8) for STAD (HR 0·90; 95% CI, 0·37-2·19; p=0·81). For the subgroup of high-risk patients, the 10-year biochemical disease-free survival was 67·2% (57·2-77·2) for LTAD and 53·7% (43·3-64·1) for STAD (HR 0·90; 95% CI 0·49-1·64; p=0·73), the 10-year overall survival was 78·5% (69·6-87·3) for LTAD and 67·0% (57·3-76·7) for STAD (HR 0·58; 95% CI 0·33-1·01; p=0·054), and the 10-year metastasis-free survival was 76·6% (95% CI 67·6-85·6) for LTAD and 65·0% (55·1-74·8) for STAD (HR 0·89; 95% CI 0·33-2·43; p=0·82). Only 11 (3%) of 354 patients died from prostate cancer, all of them in the high-risk subgroup (five in the LTAD group and six in the STAD group). 76 (21%) patients died from other causes (mainly second malignancies in 31 [9%] and cardiovascular disease in 21 [6%]). No treatment-related deaths were observed. INTERPRETATION: After an extended 10-year follow-up, we were unable to support the significant benefit of LTAD reported at 5 years. However, the magnitude of the benefit was clinically relevant in high-risk patients. Intermediate-risk patients treated with high-dose radiotherapy do not benefit from LTAD. A biological characterisation with the inclusion of genomic testing is needed in the decision-making process. FUNDING: Grupo de Investigación en Oncología Radioterápica and Sociedad Española de Oncología Radioterápica, the National Health Investigation Fund, and AstraZeneca.