Impact of disease volume on survival efficacy of triplet therapy for metastatic hormone-sensitive prostate cancer: a systematic review, meta-analysis, and network meta-analysis

BACKGROUND

Triplet therapy, androgen receptor signaling inhibitors (ARSIs) plus docetaxel plus androgen-deprivation therapy (ADT), is a novel guideline-recommended treatment for metastatic hormone-sensitive prostate cancer (mHSPC). However, the optimal selection of the patient most likely to benefit from triplet therapy remains unclear.

METHODS

We performed a systematic review, meta-analysis, and network meta-analysis to assess the oncologic benefit of triplet therapy in mHSPC patients stratified by disease volume and compare them with doublet treatment regimens. Three databases and meeting abstracts were queried in March 2023 for randomized controlled trials (RCTs) evaluating patients treated with systemic therapy for mHSPC stratified by disease volume. Primary interests of measure were overall survival (OS). We followed the PRISMA guideline and AMSTAR2 checklist.

RESULTS

Overall, eight RCTs were included for meta-analyses and network meta-analyses (NMAs). Triplet therapy outperformed docetaxel plus ADT in terms of OS in both patients with high-(pooled HR: 0.73, 95%CI 0.64-0.84) and low-volume mHSPC (pooled HR: 0.71, 95%CI 0.52-0.97). There was no statistically significant difference between patients with low- vs. high-volume in terms of OS benefit from adding ARSI to docetaxel plus ADT (p = 0.9). Analysis of treatment rankings showed that darolutamide plus docetaxel plus ADT (90%) had the highest likelihood of improved OS in patients with high-volume disease, while enzalutamide plus ADT (84%) had the highest in with low-volume disease.

CONCLUSIONS

Triplet therapy improves OS in mHSPC patients compared to docetaxel-based doublet therapy, irrespective of disease volume. However, based on treatment ranking, triplet therapy should preferably be considered for patients with high-volume mHSPC while those with low-volume are likely to be adequately treated with ARSI + ADT.

Treatment of metastatic hormone-sensitive prostate cancer: from doublet therapy to triplet therapy

For metastatic prostate cancer, androgen deprivation therapy (ADT) is the key strategy to control the disease. However, after 18-24 months of treatment, most patients will progress from metastatic hormone-sensitive prostate cancer (mHSPC) to metastatic castration-resistant prostate cancer (mCRPC) even with ADT. Once patients enter into mCRPC, they face with significant declines in quality of life and a dramatically reduced survival period. Thus, doublet therapy, which combines ADT with new hormone therapy (NHT) or ADT with docetaxel chemotherapy, substitutes ADT alone and has become the "gold standard" for the treatment of mHSPC. In recent years, triplet therapy, which combines ADT with NHT and docetaxel chemotherapy, has also achieved impressive effects in mHSPC. This article provides a comprehensive review of the recent applications of the triplet therapy in the field of mHSPC.

Current Systemic Therapy in Men with Metastatic Castration-Sensitive Prostate Cancer

PURPOSE OF REVIEW

This review aims to explore the evolving landscape of treatments available for metastatic castration-sensitive prostate cancer (mCSPC) patients.

RECENT FINDINGS

In less than a decade, evidence was chronologically provided that (1) systemic treatment intensification with docetaxel improves outcomes, including survival, in men with mCSPC, (2) then that these outcomes are also improved when a second-generation androgen receptor pathway inhibitor (ARPI) is combined with androgen deprivation therapy (ADT), and (3) using a "triplet systemic therapy," which consists in the combination of ADT, an ARPI and docetaxel, further improves outcomes, including survival. Radiotherapy to the prostate combined with ADT alone is now recommended in men with low-volume mCSPC. Combining prostate radiotherapy and intensified systemic treatment including abiraterone may be synergistic as suggested in the PEACE-1 trial. Also, the role of metastases-directed local therapies (mostly stereotactic radiotherapy) is currently being assessed in phase 3 trials. Finally, the integration of biomarkers (e.g. BRCA2 gene alterations, PTEN loss, PSMA expression) for decision making is not currently established, though trials are also currently underway. Importantly, most evidence currently available was obtained in men with de novo metastases, while for those with metastatic relapse after definitive local treatment, the role of treatment intensification is less well established. Treatment intensification is nowadays the standard of care for patients with de novo mCSPC as it leads to outcomes improvement, including survival, and the standard of care is evolving almost on a yearly basis.

Metastatic Hormone-Sensitive Prostate Cancer in the Era of Doublet and Triplet Therapy

OPINION STATEMENT

Treatment for metastatic hormone-sensitive prostate cancer has undergone significant evolution in recent years, leading to substantial improvements in overall survival. Men are living longer than ever before with a median survival now which is almost 6 years. The timing and extent of metastatic disease combined with individual patient factors helps treatment recommendation of doublet therapy including androgen deprivation (ADT) plus either chemotherapy or androgen receptor signaling inhibition (ARSI) or triplet therapy with ADT+ARSI+chemotherapy. New treatments must continue to be developed to enhance survival with goals of cure. Better biomarkers that allow for more effective treatments will enhance disease control, quality of life, and survival.

Docetaxel Provides Oncological Benefits in the Era of New-Generation Androgen Receptor Inhibitors - or Is Three a Crowd?

In recent years, several systemic therapies have been introduced for metastatic hormone-sensitive prostate cancer, including androgen deprivation therapy (ADT) combined with docetaxel (Doc) and/or new-generation androgen receptor signaling inhibitors (ARSI). Trials evaluating ADT + ARSI have consistently demonstrated an overall survival (OS) benefit for doublet therapy over ADT alone. Similarly, the STOPCaP meta-analysis showed an OS benefit in favor of ADT + Doc versus ADT alone. ARSI, Doc, and ADT have different antitumor mechanisms, thus potentiating the effect of combination therapy. Two randomized trials showed that the addition of ARSI to ADT + Doc improves OS, especially for synchronous high-volume disease. However, the real question about triplet therapy remains unanswered: whether combining Doc with ARSI improves outcomes compared to ADT + ARSI. As there are no head-to-head comparisons, this narrative review aims to summarize the current evidence regarding triplet therapy versus doublet therapy including ADT+ ARSI.

[Palliative urologic surgery for metastatic prostate cancer: what needs to be considered in the future?]

Androgen deprivation in combination with novel hormonal agents, docetaxel or the combination of abiraterone/prednisone plus docetaxel or darolutamide plus docetaxel represent the standard therapeutic approach in metastatic hormone-sensitive prostate cancer (mHSPC). Patients with low-risk prostate cancer also benefit from additional radiation therapy or radical prostatectomy in terms of progression-free and overall survival. Despite favourable response rates, basically all patients will develop castration-resistant prostate cancer (CRPC) within 2.5 to 4 years. Systemic chemotherapy, second-line hormonal treatment or systemic application of radionuclides such as Radium-223 or 177Lu-PSMA represent salvage management options. As the new medical treatment options have led to an improved oncological outcome with significantly prolonged survival times, about 50% to 65% of patients will develop symptoms due to local progression of prostate cancer. The management of such symptomatic local progression will become more important in upcoming years, which means that all uro-oncologists need to be aware of the various surgical management options. If complications of the lower urogenital tract occur, for example repetitive gross haematuria with or without bladder clotting and with the necessity for red blood cell transfusions, subvesical obstruction, acute urinary retention or rectourethral or rectovesical fistulas, these may be managed by palliative surgery such as palliative TURP, radical cystectomy, radical cystoprostatectomy with urinary diversion, and pelvic exenteration. Symptomatic or asymptomatic obstruction of the upper urinary tract can be managed by endoluminal or percutaneous urinary diversion, ureteral reimplantation, ileal ureter replacement, or implantation of a Detour system. However, an individualised and risk-adapted treatment strategy needs to be developed for each single patient to achieve an optimal therapeutic outcome with improvement of both symptoms and quality of life. In specific clinical situations, best supportive care may be an adequate option.

Novel androgen receptor inhibitors for metastatic hormone-sensitive prostate cancer: Current application and future perspectives

Androgen receptor (AR) signaling is essential in prostate cancer treatment. For many years, androgen deprivation therapy (ADT) has been primarily applied to manage advanced prostate cancer. However, most individuals with metastatic hormone-sensitive prostate cancer (mHSPC) administered ADT alone are at risk of developing metastatic castration-resistant prostate cancer (mCRPC) in less than two years. New approaches employing novel AR inhibitors (ARi) as intensified upfront systemic treatment in mHSPC have recently demonstrated substantial benefits in delaying disease progression and prolonging overall survival. Administration of novel ARi has become the new standard of care in mHSPC. The new landscape simultaneously makes treatment choice more challenging. This review provides comprehensive data on molecular structure, pharmaceutical properties, and efficacy and safety profiles reported by pivotal clinical trials. We also discuss future directions with ongoing Phase III trials of novel ARi in mHSPC. Considering these biological and clinical insights, this review aimed to provide a comprehensive understanding of differences in the development and applications of novel ARi for mHSPC, which may be helpful in designing strategies for first-line treatment choices.

Improved Outcomes with Enzalutamide in Biochemically Recurrent Prostate Cancer

BACKGROUND

Patients with prostate cancer who have high-risk biochemical recurrence have an increased risk of progression. The efficacy and safety of enzalutamide plus androgen-deprivation therapy and enzalutamide monotherapy, as compared with androgen-deprivation therapy alone, are unknown.

METHODS

In this phase 3 trial, we enrolled patients with prostate cancer who had high-risk biochemical recurrence with a prostate-specific antigen doubling time of 9 months or less. Patients were randomly assigned, in a 1:1:1 ratio, to receive enzalutamide (160 mg) daily plus leuprolide every 12 weeks (combination group), placebo plus leuprolide (leuprolide-alone group), or enzalutamide monotherapy (monotherapy group). The primary end point was metastasis-free survival, as assessed by blinded independent central review, in the combination group as compared with the leuprolide-alone group. A key secondary end point was metastasis-free survival in the monotherapy group as compared with the leuprolide-alone group. Other secondary end points were patient-reported outcomes and safety.

RESULTS

A total of 1068 patients underwent randomization: 355 were assigned to the combination group, 358 to the leuprolide-alone group, and 355 to the monotherapy group. The patients were followed for a median of 60.7 months. At 5 years, metastasis-free survival was 87.3% (95% confidence interval [CI], 83.0 to 90.6) in the combination group, 71.4% (95% CI, 65.7 to 76.3) in the leuprolide-alone group, and 80.0% (95% CI, 75.0 to 84.1) in the monotherapy group. With respect to metastasis-free survival, enzalutamide plus leuprolide was superior to leuprolide alone (hazard ratio for metastasis or death, 0.42; 95% CI, 0.30 to 0.61; P<0.001); enzalutamide monotherapy was also superior to leuprolide alone (hazard ratio for metastasis or death, 0.63; 95% CI, 0.46 to 0.87; P = 0.005). No new safety signals were observed, with no substantial between-group differences in quality-of-life measures.

CONCLUSIONS

In patients with prostate cancer with high-risk biochemical recurrence, enzalutamide plus leuprolide was superior to leuprolide alone with respect to metastasis-free survival; enzalutamide monotherapy was also superior to leuprolide alone. The safety profile of enzalutamide was consistent with that shown in previous clinical studies, with no apparent detrimental effect on quality of life. (Funded by Pfizer and Astellas Pharma; EMBARK ClinicalTrials.gov number, NCT02319837.).

Impact of performance status on efficacy of systemic therapy for prostate cancer: a meta-analysis

OBJECTIVE

To evaluate the efficacy of systemic therapies in patients with worse performance status (PS) treated for high-risk non-metastatic prostate cancer (PCa), metastatic hormone-sensitive PCa (mHSPC), and non-metastatic/metastatic castration-resistant PCa (nmCRPC/mCRPC), as there is sparse pooled data showing the effect of PS on oncological outcomes in patients with PCa.

METHODS

Three databases were queried in June 2022 for randomised controlled trials (RCTs) analysing patients with PCa treated with systemic therapy (i.e., adding androgen receptor signalling inhibitor [ARSI] or docetaxel [DOC] to androgen-deprivation therapy [ADT]). We analysed the oncological outcomes of patients with PCa with worse PS, defined as Eastern Cooperative Oncology Group PS ≥ 1, treated with combination therapies and compared these to patients with good PS. The main outcomes of interest were overall survival (OS), metastasis-free survival (MFS), and progression-free survival.

RESULTS

Overall, 25 and 18 RCTs were included for systematic review and meta-analyses/network meta-analyses, respectively. In all clinical settings, combination systemic therapies significantly improved OS in patients with worse PS as well as in those with good PS, while the MFS benefit from ARSI in the nmCRPC setting was more pronounced in patients with good PS than in those with worse PS (P = 0.002). Analysis of treatment ranking in patients with mHSPC revealed that triplet therapy had the highest likelihood of improved OS irrespective of PS; specifically, adding darolutamide to DOC + ADT had the highest likelihood of improved OS in patients with worse PS. Analyses were limited by the small proportion of patients with a PS ≥ 1 (19%-28%) and that the number of PS 2 was rarely reported.

CONCLUSIONS

Among RCTs, novel systemic therapies seem to benefit the OS of patients with PCa irrespective of PS. Our findings suggest that worse PS should not discourage treatment intensification across all disease stages.

Targeting the Androgen Signaling Axis in Prostate Cancer

Activation of the androgen receptor (AR) and AR-driven transcriptional programs is central to the pathophysiology of prostate cancer. Despite successful translational efforts in targeting AR, therapeutic resistance often occurs as a result of molecular alterations in the androgen signaling axis. The efficacy of next-generation AR-directed therapies for castration-resistant prostate cancer has provided crucial clinical validation for the continued dependence on AR signaling and introduced a range of new treatment options for men with both castration-resistant and castration-sensitive disease. Despite this, however, metastatic prostate cancer largely remains an incurable disease, highlighting the need to better understand the diverse mechanisms by which tumors thwart AR-directed therapies, which may inform new therapeutic avenues. In this review, we revisit concepts in AR signaling and current understandings of AR signaling-dependent resistance mechanisms as well as the next frontier of AR targeting in prostate cancer.

Top advances of the year: Genitourinary cancer

There have been significant advances in the treatment of urology cancers, with a number of practice-changing treatments. There is now greater clarity on the role of the use of immunotherapies in renal cell carcinoma. The use of triplet combinations with immune checkpoint inhibition with anti-vascular endothelial growth factor tyrosine kinase inhibitors in the front-line setting for metastatic disease (COSMIC313) has been explored. The use of adjuvant therapy has been complicated by a series of negative immune therapy trials. Promising results with the HIF-2α transcription factor inhibitor, belzutifan, alone or in combination with other agents, have been reported. Antibody drug conjugates, including enfortumab vedotin and sacituzumab govitecan, have continued to show activity in urothelial cancer with promising clinical outcomes. This has led to further exploration of the combination of these novel agents with immunotherapy and accelerated Food and Drug Administration approvals. Data are also discussed regarding intensification for front-line therapy of metastatic castrate sensitive prostate cancer. The combination of androgen-signaling inhibitors, docetaxel, and androgen deprivation therapy (PEACE-1, ARASENS), as well as the use of abiraterone acetate for adjuvant therapy in high-risk disease (STAMPEDE), is included. There is also growing evidence for the use of the radioligand therapy 177 Lu-PSMA-617 in metastatic castrate resistant disease, with an established overall survival benefit in this patient population (VISION, TheraP). PLAIN LANGUAGE SUMMARY: There have been many advancements in the treatment of cancers of the kidney, bladder, and prostate in the past year. Several studies using new therapies or new combinations of therapies have improved the chances of patients living longer with these cancers, especially those with advanced disease. Here, we discuss a selection of the most compelling recently published data that have changed the way these cancers are treated, as well as those that are expected to change treatment in the near future.

What is the ideal combination therapy in de novo, oligometastatic, castration-sensitive prostate cancer?

PURPOSE

To review current evidence regarding the management of de novo, oligometastatic, castration-sensitive prostate cancer (PCa).

METHODS

A literature search was conducted on PubMed/Medline and a narrative synthesis of the evidence was performed in August 2022.

RESULTS

Oligometastatic disease is an intermediate state between localized and aggressive metastatic PCa defined by ≤ 3-5 metastatic lesions, although this definition remains controversial. Conventional imaging has limited accuracy in detecting metastatic lesions, and the implementation of molecular imaging could pave the way for a more personalized treatment strategy. However, oncological data supporting this strategy are needed. Radiotherapy to the primary tumor should be considered standard treatment for oligometastatic PCa (omPCa). However, it remains to be seen whether local therapy still has an additional survival benefit in patients with de novo omPCa when treated with the most modern systemic therapy combinations. There is insufficient evidence to recommend cytoreductive radical prostatectomy as local therapy; or stereotactic body radiotherapy as metastasis-directed therapy in patients with omPCa. Current data support the use of intensified systemic therapy with androgen deprivation therapy (ADT) and next-generation hormone therapies (NHT) for patients with de novo omPCa. Docetaxel has not demonstrated benefit in low volume disease. There are insufficient data to support the use of triple therapy (i.e., ADT + NHT + Docetaxel) in low volume disease.

CONCLUSION

The present review discusses current data in de novo, omPCa regarding its definition, the increasing role of molecular imaging, the place of local and metastasis-directed therapies, and the intensification of systemic therapies.

First-line Systemic Treatment Options for Metastatic Castration-Sensitive Prostate Cancer: A Living Systematic Review and Network Meta-analysis

Importance

The effectiveness of triplet therapy compared with androgen pathway inhibitor (API) doublets in a heterogeneous patient population with metastatic castration-sensitive prostate cancer (mCSPC) is unknown.

Objective

To assess the comparative effectiveness of contemporary systemic treatment options for patients with mCSPC across clinically relevant subgroups.

Data Sources

For this systematic review and meta-analysis, Ovid MEDLINE and Embase were searched from each database's inception (MEDLINE, 1946; Embase, 1974) through June 16, 2021. Subsequently, a "living" auto search was created with weekly updates to identify new evidence as it became available.

Study Selection

Phase 3 randomized clinical trials (RCTs) assessing first-line treatment options for mCSPC.

Data Extraction and Synthesis

Two independent reviewers extracted data from eligible RCTs. The comparative effectiveness of different treatment options was assessed with a fixed-effect network meta-analysis. Data were analyzed on July 10, 2022.

Main Outcomes and Measures

Outcomes of interest included overall survival (OS), progression-free survival (PFS), grade 3 or higher adverse events, and health-related quality of life.

Results

This report included 10 RCTs with 11 043 patients and 9 unique treatment groups. Median ages of the included population ranged from 63 to 70 years. Current evidence for the overall population suggests that the darolutamide (DARO) triplet (DARO + docetaxel [D] + androgen deprivation therapy [ADT]; hazard ratio [HR], 0.68; 95% CI, 0.57-0.81), as well as the abiraterone (AAP) triplet (AAP + D + ADT; HR, 0.75; 95% CI, 0.59-0.95), are associated with improved OS compared with D doublet (D + ADT) but not compared with API doublets. Among patients with high-volume disease, AAP + D + ADT may improve OS compared with D + ADT (HR, 0.72; 95% CI, 0.55-0.95) but not compared with AAP + ADT, enzalutamide (E) + ADT, and apalutamide (APA) + ADT. For patients with low-volume disease, AAP + D + ADT may not improve OS compared with APA + ADT, AAP + ADT, E + ADT, and D + ADT.

Conclusions and Relevance

The potential benefit observed with triplet therapy must be interpreted with careful accounting for the volume of disease and the choice of doublet comparisons used in the clinical trials. These findings suggest an equipoise to how triplet regimens compare with API doublet combinations and provide direction for future clinical trials.

Visceral Metastasis Predicts Response to New Hormonal Agents in Metastatic Castration-Sensitive Prostate Cancer

Visceral metastasis (VM) and a higher number of bone metastasis generally define high volume/risk in patients with metastatic castration-sensitive prostate cancer (mCSPC). Subgroup analysis of pivotal trials did not show a clear benefit of second-generation non-steroidal anti-androgens (NSAAs) in patients with VM. However, subgroup analysis of the trial assessing abiraterone acetate, a CYP 17 inhibitor, plus prednisone (AAP) showed an improved overall survival (OS) in patients with mCSPC with VM. We searched MEDLINE, Web of Science, and congress abstracts for the phase III randomized controlled trials of second-generation NSAAs and AAP in patients with mCSPC. In this pooled analysis, we included 6485 patients from the 6 phase III trials. The rate of patients with VM was 15.2%. Interestingly, in contrast to NSAAs, AAP seems to be effective in improving OS among patients with VM (hazard ratio, HR: 0.89, 95% CI, 0.72-1.11, P = .30 for second-generation NSAAs; HR: 0.58, 95% CI, 0.40-0.84, P = .004 for AAP). In contrast, both second-generation NSAAs (HR: 0.63, 95% CI, 0.57-0.70, P < .001) and AAP (HR: 0.68, 95% CI, 0.57-0.81, P < .001) improved OS in patients without VM. In this pooled analysis, we demonstrate that while AAP provided an OS improvement in patients with VM, second-generation NSAAs did not demonstrate a similar OS benefit in this population.

Triplet Therapy in Metastatic Castrate Sensitive Prostate Cancer (mCSPC)-A Potential New Standard of Care

The treatment paradigm for metastatic castrate-sensitive prostate cancer (mCSPC) has evolved rapidly in the past decade with the approval of several life-prolonging therapies including docetaxel chemotherapy and multiple androgen receptor pathway inhibitors (ARPI) in combination with androgen deprivation therapy (ADT). Recently reported phase-three trials have demonstrated a survival benefit of upfront triplet therapy with ADT, docetaxel plus either abiraterone acetate or darolutamide when compared to ADT plus docetaxel alone. However, multiple questions including the incremental benefit of docetaxel to a combination of ADT and ARPI, the timing of ARPI, optimal patient selection for triplet therapy and clinical and genomic biomarkers still remain to be answered. Moreover, real-world data suggest suboptimal treatment intensification with many patients treated with ADT alone highlighting challenges in implementation. In this article, we review the phase-three data associated with triplet therapy in mCSPC. We also discuss the knowledge gaps that exist despite the completion of these studies and how ongoing studies are likely to change the paradigm in the near future. Finally, we provide a simple algorithm based on current data that clinicians can use in daily practice to select patients for appropriate treatment strategies.

Implications of metastatic stage at presentation in docetaxel naïve metastatic castrate resistant prostate cancer

BACKGROUND

We performed a secondary analysis of ACIS study to determine if synchronous versus metachronous metastatic presentation has any association with survival and treatment response to dual androgen receptor axis-targeted therapy (ARAT) in docetaxel naïve metastatic castrate resistant prostate cancer (mCRPC).

METHODOLOGY

In this phase III randomized controlled trial, docetaxel naïve mCRPC patients were randomized to either apalutamide or placebo combined with abiraterone and prednisone. Multivariable Cox regression models were applied to determine the adjusted association of M-stage with radiographic progression-free survival (rPFS) and overall survival (OS). To determine the heterogeneity of treatment effect based on metastatic stage (M-stage) at presentation, Cox regression was applied with interaction terms between M-stage and treatment.

RESULTS

Among 972 patients, 432 had M0, 334 had M1, while M-stage at presentation was unknown in 206. There was no association of M-stage at presentation with rPFS in patients with prior local therapy (LT) (hazard ratio for M1-stage: 1.22 [95% confidence interval: 0.82-1.82]; unknown: 1.03 [0.77-1.38]) or without prior LT (M1-stage: 0.87 [0.64-1.19]; unknown: 1.15 [0.77-1.72]) with no significant heterogeneity. Similarly, there was no association of M-stage with OS in patients with prior LT (M1-stage: 1.04 [0.81-1.33]; unknown: 0.98 [0.79-1.21]) or without prior LT (M1-stage: 0.95 [0.70-1.29]; unknown: 1.17 [0.80-1.71]) with no significant heterogeneity. Based on M-stage at presentation, we did not find any significant heterogeneity in treatment effect on rPFS (interaction p = 0.13), and OS (interaction p = 0.87).

CONCLUSION

M-stage at presentation had no association with survival in chemotherapy-naïve mCRPC. We did not find any statistically significant heterogeneity in efficacy of dual ARAT based on synchronous versus metachronous presentation.

Prostate cancer and novel pharmacological treatment options-what's new for 2022?

INTRODUCTION

Androgen deprivation therapy (ADT) plus Androgen Receptor Target Agents (ARTAs) or docetaxel are the actual standard of care in prostate cancer (PC). Several therapeutic options are available for pretreated patients: cabazitaxel, olaparib, and rucaparib for BRCA mutations, Radium-223 for selected patients with symptomatic bone metastasis, sipuleucel T, and 177 LuPSMA-617.

AREAS COVERED

This review the new potential therapeutic approaches and the most impacting recent published trials to provide an overview on the future management of PC.

EXPERT OPINION

Currently, there is a growing interest in the potential role of triplet therapies encompassing ADT, chemotherapy, and ARTAs. These strategies, explored in different settings, appeared to be particularly promising in metastatic hormone-sensitive PC. Recent trials investigating ARTAs plus poly(adenosine diphosphate-ribose) polymerase (PARPi) inhibitor provided helpful insights for patients with metastatic castration resistant disease, regardless of homologous recombination genes status. Otherwise, the publication of the complete data is awaited, and more evidence is required. In advanced settings, several combination approaches are under investigation, to date with contradictory results, such as immunotherapy plus PARPi or chemotherapy. The radionuclide ¹⁷⁷Lu-PSMA-617 proved successful outcomes in pretreated mCRPC patients. Additional studies will better clarify the appropriate candidates to each strategy and the correct treatments' sequence.

An Updated Systematic and Comprehensive Review of Cytoreductive Prostatectomy for Metastatic Prostate Cancer

(1) Background: Local therapy is highly promising in a multimodal approach strategy for patients with low-volume metastatic prostate cancer (mPCa). We aimed to systematically assess and summarize the safety, oncologic, and functional outcomes of cytoreductive prostatectomy (cRP) in mPCa. (2) Methods: Three databases were queried in September 2022 for publications that analyzed mPCa patients treated with cytoreductive prostatectomy without restrictions. The outcomes of interest were progression-free survival (PFS), cancer-specific survival (CSS), overall survival (OS), perioperative complication rates, and functional outcomes following cRP. (3) Results: Overall, 26 studies were included in this systematic review. Among eight population-based studies, cRP was associated with a reduced risk of CSS and OS compared with no local therapy (NLT) after adjusting for the effects of possible confounders. Furthermore, one population-based study showed that cRP reduced the risk of CSS even when compared with radiotherapy (RT) of the prostate after adjusting for the effects of possible confounders. In addition, one randomized controlled trial (RCT) demonstrated that local therapy (comprising 85% of cRP) significantly improved the prostate-specific antigen (PSA)-PFS and OS. Overall, cRP had acceptable perioperative complication rates and functional outcomes. (4) Conclusions: Mounting evidence suggests that cRP offers promising oncological and functional outcomes and technical feasibility and that it is associated with limited complications. Well-designed RCTs that limit selection bias in patients treated with cRP are warranted.

Characterizing Circulating Tumor Cells and Tumor-Derived Extracellular Vesicles in Metastatic Castration-Naive and Castration-Resistant Prostate Cancer Patients

Simple Summary

The composition of circulating tumor cells (CTCs) and tumor-derived extracellular vesicles (tdEVs) in the blood of 104 patients with metastatic castration-naive prostate cancer and 66 patients with metastatic castration-resistant prostate cancer was compared to explore the potential differences between these biomarkers in the two disease stages.

Abstract

Circulating tumor cell (CTC)- and/or tumor-derived extracellular vesicle (tdEV) loads in the blood of metastatic castration-resistant prostate cancer (CRPC) patients are associated with worse overall survival and can be used as predictive markers of treatment response. In this study, we investigated the quantity/quality of CTCs and tdEVs in metastatic castration-naive prostate cancer (CNPC) and CRPC patients, and whether androgen deprivation therapy (ADT) affects CTCs and tdEVs. We included 104 CNPC patients before ADT initiation and 66 CRPC patients. Blood samples from 31/104 CNPC patients were obtained 6 months after ADT. CTCs and tdEVs were identified using ACCEPT software. Based on the morphology, CTCs of metastatic CNPC and CRPC patients were subdivided by manual reviewing into six subclasses. The numbers of CTCs and tdEVs were correlated in both CNPC and CRPC patients, and both CTCs (p = 0.013) and tdEVs (p = 0.005) were significantly lower in CNPC compared to CRPC patients. Qualitative differences in CTCs were observed: CTC clusters (p = 0.006) and heterogeneously CK expressing CTCs (p = 0.041) were significantly lower in CNPC patients. CTC/tdEV numbers declined 6 months after ADT. Our study showed that next to CTC-load, qualitative CTC analysis and tdEV-load may be useful in CNPC patients.

The Treatment of Metastatic, Hormone-Sensitive Prostatic Carcinoma

BACKGROUND

For many years, the standard treatment of metastatic, hormone-sensitive prostatic carcinoma (mHSPC) was androgen deprivation therapy (ADT) alone. By lowering the testosterone level into the castration range, ADT deprives the tumor of a key growth factor.

METHODS

For this article, we evaluated the treatment recommendations contained in national and international guidelines (German S3 guidelines and those of the European Society for Medical Oncology [ESMO], European Association of Urology [EAU], and National Comprehensive Cancer Network [NCCN]), as well as pertinent publications revealed by a PubMed search and the congress abstracts of the ESMO and of the American Society of Clinical Oncology [ASCO].

RESULTS

The past few years have witnessed fundamental changes in the treatment of mHSPC. Treatment intensification with docetaxel or with the new drugs directed against the androgen receptor signal pathway (abiraterone, apalutamide and enzalutamide) has been found to lower mortality by 19-40% and is now an integral component of first-line therapy. Relevant new findings have also been obtained with threefold combinations of ADT, docetaxel, and abiraterone or darolutamide. For patients with a light tumor burden, local radiotherapy of the primary tumor improves the probability of survival at 3 years by 8% (45.4 versus 49.1 months, difference 3.6 months; 95% confidence interval, 1.0 to 6.2 months).

CONCLUSION

The treatment of mHSPC is constantly changing. Phase III trials that are now in the recruitment stage, as well as our continually improving understanding of the underlying molecular-pathological mechanisms, will be altering the treatment landscape still further in the years to come.

Triplet therapy with androgen deprivation, docetaxel, and androgen receptor signalling inhibitors in metastatic castration-sensitive prostate cancer: A meta-analysis

BACKGROUND

The addition of either docetaxel or an androgen receptor signalling pathway inhibitor (ARSi) to androgen-deprivation therapy (ADT) has become the standard of care for metastatic castration-sensitive prostate cancer (mCSPC) patients. Recent phase III data support even greater survival impact of a triplet regimen with ADT plus docetaxel plus an ARSi (abiraterone or darolutamide) compared to ADT plus docetaxel.

OBJECTIVE

To evaluate whether the addition of an ARSi to ADT improves outcomes of mCSPC patients treated with docetaxel.

METHODS

We searched MEDLINE/PubMed, the Cochrane Library, and ASCO Meeting abstracts for randomised clinical trials (RCTs) testing the combination of ARSi + ADT in mCSPC men who received docetaxel. Data extraction was conducted according to the PRISMA statement. Summary hazard ratio (HR) was calculated using random- or fixed-effects models. The statistical analyses were performed with RevMan software (v.5.2.3).

RESULTS

Five RCTs were selected. Triplet therapy improved overall survival (OS) compared to ADT + docetaxel in mCSPC patients (HR = 0.73; p < 0.00001). This intensified strategy maintained the OS benefit when the ARSi was administered concomitant to chemotherapy (HR = 0.72; p < 0.00001), but no statistical effect was detected if the ARSi was sequential to docetaxel (p = 0.44). Moreover, in the subgroup of men with de novo mCSPC, triplets significantly improved OS (HR = 0.72, p < 0.0001). The lack of access to raw data was the main limit of our analysis.

CONCLUSION

Our results support a clear survival advantage of adding an ARSi to ADT in mCSPC patients treated with docetaxel, mainly when the ARSi was administered concomitantly to chemotherapy and in the subgroup of de novo mCSPC.

Achieving Consensus for Management of Hormone-Sensitive, Low-Volume Metastatic Prostate Cancer in Italy

Metastatic hormone-sensitive prostate cancer (mHSPC) is usually categorized as high- or low-volume disease. This is relevant because low- and high-volume metastatic disease are associated with different outcomes, and thus management of the two forms should differ. Although some definitions have been reported, the concept of oligometastatic disease is not so clearly defined, giving rise to further variability in the choice of treatment, mainly between systemic agents and radiotherapy, especially in the era of metastasis-directed therapy. With the aim of providing clinicians with guidance on best practice, a group of medical and radiation oncologists, experts in prostate cancer, used the round robin method to generate a series of consensus statements on management of low-volume mHSPC. Consensus was obtained on three major areas of controversy: (1) with regard to clinical definitions of mHSPC, it was held that oligometastatic and low-volume disease refer to different concepts and should not be used interchangeably; (2) regarding therapy of de novo low-volume metastatic disease, androgen deprivation therapy alone can be considered undertreatment, and all patients should be evaluated for systemic treatment combinations; local therapy should not be denied in patients with mHSPC, regardless of the intensity of systemic therapy, and metastasis-directed therapy can be proposed in selected cases; (3) with regard to treatment of metachronous metastatic disease, patients should be evaluated for systemic treatment combinations. Metastasis-directed therapy can be proposed to delay systemic treatment in selected cases, especially if prostate-specific membrane antigen positron emission tomography staging has been performed and when indolent disease occurs. It is hoped that clinicians treating patients with mHSPC in daily practice will find this expert opinion of value.