Chemotherapy and Advanced Androgen Blockage, Alone or Combined, for Metastatic Hormone-Sensitive Prostate Cancer A systematic review and Meta-Analysis

Role of cytoreductive radical prostatectomy in men with oligometastatic prostate cancer on molecular imaging

PURPOSE OF REVIEW

The implementation of PET with prostate-specific membrane antigen (PSMA) tracer as primary staging tool occurred recently. Since its introduction, a novel category of patients emerged, with negative staging at conventional imaging, and positive molecular imaging. Local treatment in these patients might be associated with improved oncological outcomes when combined with systemic therapy. However, its impact on oligometastatic prostate cancer (omPCa) remains unknown. In this review, we aimed at investigating the role of cytoreductive radical prostatectomy (cRP) in oligometastatic disease at molecular imaging.

RECENT FINDINGS

After comprehensive review of literature, two retrospective studies highlighted the feasibility, safety, and potential benefits of surgery in omPCA patients at molecular imaging. They showed that 72% of patients achieved PSA less than 0.01 ng/ml following cRP as part of a multimodal approach, 17% experienced radiographic progression, and 7% died at 27-month median follow-up. Moreover, complications postcRP after PSMA PET were modest, with a 40% rate of any adverse event, and 5% of grade more than 3. The 1-year urinary continence after cRP rate was 82%. The oncological, functional outcomes and the complication rate aligned with those observed in series of cRP after conventional imaging.

SUMMARY

cRP is feasible, well tolerated, and effective in selected patients with omPCa at PSMA PET.

Network meta-analysis of combination strategies in metastatic hormone-sensitive prostate cancer

This study compared different doublet and triplet therapies for efficacy and safety in metastatic hormone-sensitive prostate cancer (mHSPC). PubMed, EMBASE, and the Cochrane Library were comprehensively searched for eligible randomized controlled trials (RCTs) published from inception to October 2023. Interventions included abiraterone, apalutamide, enzalutamide, docetaxel, darolutamide, and androgen deprivation therapy (ADT), either as doublet or triplet therapies. The outcomes examined were overall survival (OS), progression-free survival (PFS), castration-resistant prostate cancer (CRPC)-free survival, time to symptomatic skeletal event (SSE), and toxicity. The surface under the cumulative ranking curve (SUCRA) was determined to identify the preferred treatments. Ten RCTs were included. The combination of darolutamide, docetaxel, and ADT had the highest SUCRA of 84.3 for OS, followed by combined abiraterone, docetaxel, and ADT (SUCRA = 71.6). The highest SUCRAs for PFS were observed for triplet therapies (abiraterone, docetaxel, and ADT [SUCRA = 74.9], followed by enzalutamide, docetaxel, and ADT [SUCRA = 74.3]) and other androgen receptor axis-targeted therapy-based doublet therapies (SUCRAs: 26.5-59.3). Darolutamide, docetaxel, and ADT had the highest SUCRAs, i.e ., 80.8 and 84.0 regarding CRPC-free survival and time to SSE, respectively. Regarding Grade >3 adverse events (AEs), the SUCRAs of triplet therapies (SUCRAs: 14.8-31.5) were similar to that of docetaxel and ADT (SUCRA = 39.5). Three studies had a low risk of bias in all categories; the remaining studies had at least an unclear risk of bias in at least one category. Triplet therapy demonstrated potentially enhanced effectiveness than doublet therapy in mHSPC, with acceptable safety concerns. Darolutamide might be the optimal option for triplet therapy in combination with docetaxel and 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.

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.

Simultaneous administration of EZH2 and BET inhibitors inhibits proliferation and clonogenic ability of metastatic prostate cancer cells

Androgen deprivation therapy (ADT) is a common treatment for recurrent prostate cancer (PC). However, after a certain period of responsiveness, ADT resistance occurs virtually in all patients and the disease progresses to lethal metastatic castration-resistant prostate cancer (mCRPC). Aberrant expression and function of the epigenetic modifiers EZH2 and BET over activates c-myc, an oncogenic transcription factor critically contributing to mCRPC. In the present work, we tested, for the first time, the combination of an EZH2 inhibitor with a BET inhibitor in metastatic PC cells. The combination outperformed single drugs in inhibiting cell viability, cell proliferation and clonogenic ability, and concomitantly reduced both c-myc and NF-kB expression. Although these promising results will warrant further in vivo validation, they represent the first step to establishing the rationale that the proposed combination might be suitable for mCRPC treatment, by exploiting molecular targets different from androgen receptor.

Optimal combination therapy for metastatic hormone-sensitive prostate cancer: new evidence, challenges and unanswered questions

PURPOSE OF REVIEW

To evaluate the evidence supporting treatment intensification in mHSPC, with a focus on possible indications for treatment in each clinical setting.

RECENT FINDINGS

There is a growing armamentarium of treatment options for patients with metastatic hormone-sensitive prostate cancer (mHSPC). These include combinations of treatments such as androgen deprivation therapy (ADT), docetaxel, and new antiandrogenic therapies. Treatment intensification with chemotherapy or newer hormonal agents may improve patient's oncologic outcomes, but it can also come with additional toxicities and costs. Therefore, we need to take into account individual patient factors and preferences when deciding on the optimal combination therapy. Additionally, ongoing research is needed to identify biomarkers and new image techniques that can predict response to treatment and identify the best candidate for each treatment.

SUMMARY

Challenges and unanswered questions regarding treatment intensification and de-intensification are still present. Further studies are still needed to identify which patients would benefit most from this approach to improve quality of life without compromising overall survival outcomes.

New insights into molecular signaling pathways and current advancements in prostate cancer diagnostics & therapeutics

Prostate adenocarcinoma accounts for more than 20% of deaths among males due to cancer. It is the fifth-leading cancer diagnosed in males across the globe. The mortality rate is quite high due to prostate cancer. Despite the fact that advancements in diagnostics and therapeutics have been made, there is a lack of effective drugs. Metabolic pathways are altered due to the triggering of androgen receptor (AR) signaling pathways, and elevated levels of dihydrotestosterone are produced due to defects in AR signaling that accelerate the growth of prostate cancer cells. Further, PI3K/AKT/mTOR pathways interact with AR signaling pathway and act as precursors to promote prostate cancer. Prostate cancer therapy has been classified into luminal A, luminal B, and basal subtypes. Therapeutic drugs inhibiting dihydrotestosterone and PI3K have shown to give promising results to combat prostate cancer. Many second-generation Androgen receptor signaling antagonists are given either as single agent or with the combination of other drugs. In order to develop a cure for metastasized prostate cancer cells, Androgen deprivation therapy (ADT) is applied by using surgical or chemical methods. In many cases, Prostatectomy or local radiotherapy are used to control metastasized prostate cancer. However, it has been observed that after 1.5 years to 2 years of Prostatectomy or castration, there is reoccurrence of prostate cancer and high incidence of castration resistant prostate cancer is seen in population undergone ADT. It has been observed that Androgen derivation therapy combined with drugs like abiraterone acetate or docetaxel improve overall survival rate in metastatic hormone sensitive prostate cancer (mHSPC) patients. Scientific investigations have revealed that drugs inhibiting poly ADP Ribose polymerase (PARP) are showing promising results in clinical trials in the prostate cancer population with mCRPC and DNA repair abnormalities. Recently, RISUG adv (reversible inhibition of sperm under guidance) has shown significant results against prostate cancer cell lines and MTT assay has validated substantial effects of this drug against PC3 cell lines. Current review paper highlights the advancements in prostate cancer therapeutics and new drug molecules against prostate cancer. It will provide detailed insights on the signaling pathways which need to be targeted to combat metastasized prostate cancer and castration resistant prostate cancer.

Multi-Omic Integration of Blood-Based Tumor-Associated Genomic and Lipidomic Profiles Using Machine Learning Models in Metastatic Prostate Cancer

PURPOSE

To determine prognostic and predictive clinical outcomes in metastatic hormone-sensitive prostate cancer (mHSPC) and metastatic castrate-resistant prostate cancer (mCRPC) on the basis of a combination of plasma-derived genomic alterations and lipid features in a longitudinal cohort of patients with advanced prostate cancer.

METHODS

A multifeature classifier was constructed to predict clinical outcomes using plasma-based genomic alterations detected in 120 genes and 772 lipidomic species as informative features in a cohort of 71 patients with mHSPC and 144 patients with mCRPC. Outcomes of interest were collected over 11 years of follow-up. These included in mHSPC state early failure of androgen-deprivation therapy (ADT) and exceptional responders to ADT; early death (poor prognosis) and long-term survivors in mCRPC state. The approach was to build binary classification models that identified discriminative candidates with optimal weights to predict outcomes. To achieve this, we built multi-omic feature-based classifiers using traditional machine learning (ML) methods, including logistic regression with sparse regularization, multi-kernel Gaussian process regression, and support vector machines.

RESULTS

The levels of specific ceramides (d18:1/14:0 and d18:1/17:0), and the presence of CHEK2 mutations, AR amplification, and RB1 deletion were identified as the most crucial factors associated with clinical outcomes. Using ML models, the optimal multi-omics feature combination determined resulted in AUC scores of 0.751 for predicting mHSPC survival and 0.638 for predicting ADT failure; and in mCRPC state, 0.687 for prognostication and 0.727 for exceptional survival. The models were observed to be superior than using a limited candidate number of features for developing multi-omic prognostic and predictive signatures.

CONCLUSION

Using a ML approach that incorporates multiple omic features improves the prediction accuracy for metastatic prostate cancer outcomes significantly. Validation of these models will be needed in independent data sets in future.

[New treatment approaches for and ongoing trials in metastatic hormone-sensitive prostate cancer]

BACKGROUND

For many years, therapy for metastatic hormone-sensitive prostate cancer (mHSPC) was dominated by monotherapy using androgen deprivation therapy (ADT). With the demonstration of survival benefit with intensified systemic therapy from the CHAARTED and STAMPEDE trials, this has fundamentally changed. We analyzed the phase III trials that led to the change in therapy in mHSPC. In addition, we summarized ongoing trials in mHSPC.

OBJECTIVES

The ongoing studies and current data on systemic therapy in mHSPC were analyzed.

RESULTS

Monotherapy with ADT is no longer considered the standard therapy for mHSPC. Combination therapy with ADT and novel androgen receptor targeting agents (ARTAs: abiraterone, apalutamide, enzalutamide) is now the established standard option. The added value of further intensification of therapy was demonstrated in the first trials of triple therapy with ADT + docetaxel + darolutamide or abiraterone in mHSPC. Current studies are also investigating new forms of therapy. Lutetium177-PSMA radioligand therapy is an established standard in metastatic castration-resistant prostate cancer (mCRPC) and is currently being evaluated in combination with ADT + ARTA in mHSPC. The use of PARP inhibitors (PARPi) have been established in mCRPC. Current studies are showing early evidence of benefit from novel combination therapies of PARPi + ARTA, which represent a further expansion of the therapeutic landscape. Experimental therapies are testing another combination, such as an AKT inhibitor with ARTA in patients with PTEN (phosphatase and tensin homolog) loss. Based on the proof of principle in mCRPC, this combination is now being evaluated in earlier stage mHSPC. Other experimental therapies in clinical testing include inhibitors of cyclin dependent kinases (CDK).

CONCLUSIONS

Combination therapies are the current standard of care for mHSPC, with the combination of ADT + ARTA dominating. Preliminary results underline the importance of further intensification of therapy by means of triple therapy. However, novel combinations with radioligand therapy or PARP inhibitors are also promising in the treatment of mHSPC. Preliminary results show the principle efficacy of AKT inhibitors in patients with PTEN loss, which similar to therapy with CDK4/6 inhibitors still have to prove their clinical relevance in randomized trials.

Systemic triplet therapy for metastatic hormone-sensitive prostate cancer: A systematic review and network meta-analysis

Purpose: To perform a systematic review and network meta-analysis to compare the efficacy and safety of currently available docetaxel-based systemic triplet therapies for metastatic hormone-sensitive prostate cancer (mHSPC).

Methods: We searched for eligible publications in PubMed, Embase, and Cochrane CENTRAL. Improvements in overall survival (OS) and radiographic progression-free time (rPFS) were compared indirectly using network meta-analysis and evaluated using the surface under the cumulative ranking curve (SUCRA). Other secondary endpoints, such as time to castration-resistant prostate cancer and/or adverse events (AEs), were also compared and evaluated.

Results: Five trials were selected and analyzed using a network meta-analysis. Compared to androgen deprivation therapy (ADT) plus docetaxel, darolutamide (hazard ratio [HR]: 0.68, 95% credible interval [CrI]: 0.57–0.80) and abiraterone (HR: 0.75, 95% CrI: 0.59–0.95) triplet therapy had significantly longer OS, and darolutamide triplet therapy was the first treatment ranked. Abiraterone (HR: 0.49, 95% CrI: 0.39–0.61) and enzalutamide (HR: 0.52, 95% CrI: 0.30–0.89) had significantly better rPFS than ADT plus docetaxel; however, all three therapies, including abiraterone, apalutamide, and enzalutamide, were the best options with a similar SUCRA. At most secondary endpoints, systemic triplet therapy was superior to ADT plus docetaxel. The risk of any AEs in darolutamide or abiraterone triplet therapy was comparable with ADT plus docetaxel (odds ratio [OR]: 2.53, 95% credible interval [CrI]: 0.68–12.63; OR: 1.07, 95% CrI: 0.03–36.25). Abiraterone triplet therapy had an increased risk of grade≥3 AEs (OR: 1.56, 95% CrI: 1.15–2.11).

Conclusion: Systemic triplet therapy was more effective than ADT plus docetaxel for mHSPC. Of the triplet therapy regimens, darolutamide ranked first in terms of improved OS. Abiraterone and enzalutamide triplet ranked first in terms of rFPS, however, it did not confer a statistically difference among all triplet regimens. The overall risk of AEs was comparable. More studies are required for current and potential combinations of systemic triplet therapy.

The Effect of Age on Prostate Cancer Survival

Simple Summary

It is a commonly held belief that elderly men with prostate cancer are less likely to die of their cancer than are younger men because they have a higher risk of dying of another cause. This has impact on prostate screening policies and the decision to offer aggressive treatment. It is not clear to what extent the age of diagnosis and the current age impact on prostate cancer survival. We estimated prostate cancer survival rates and annual mortality rates according to age of diagnosis using data from the SEER program. We identified 116,796 prostate cancer patients diagnosed between 1992 and 1997 and followed them for 20 years. Among men diagnosed before age 70, 17% died of prostate cancer. Among men diagnosed after age 70, 21% died of prostate cancer. For men with low-grade cancers, the annual risk of dying of cancer rose continuously with time since diagnosis and peaked in men 85 years and older.

Abstract

It is not clear to what extent the age of diagnosis and the attained age impact on cancer mortality rates in men with newly diagnosed prostate cancer. We estimated annual prostate cancer mortality rates and 20-year survival rates according to the age of diagnosis, race, grade and time since diagnosis using data from the Surveillance, Epidemiology and End-Results (SEER) program. We identified 116,796 prostate cancer patients diagnosed between 1992 and 1997 and followed them for 20 years. There were 21,896 deaths from prostate cancer. We calculated actuarial survival rates and annual prostate cancer mortality rates by age of diagnosis and by tumor grade. The risk of a man dying of prostate cancer was 17% for men diagnosed before age 70 and was 21% for those diagnosed after age 70. The mean annual prostate cancer mortality rate calculated over the 20-year period post-diagnosis was 1.5%. The annual rate increased from 0.9% for those diagnosed below age 60 to 2.1% for those diagnosed above age 70. For men with Gleason score ≥ 7 prostate cancer, the annual prostate cancer mortality rate peaked 2–3 years after diagnosis and then declined. For men diagnosed with Gleason score ≤ 6 prostate cancer, the annual prostate cancer mortality rate continued to rise 20 years after diagnosis and peaked after age 85. This suggests that high-grade prostate cancers are aggressive from the outset, but that low-grade prostate cancers may enter a state of dormancy and reactivate as the patient ages.

Androgen Annihilation Versus Advanced Androgen Blockage as First Line Treatment for Metastatic Castration Resistant Prostate Cancer: a systematic review and meta-analysis

BACKGROUND

Despite recent advances in the treatments of metastatic castration resistant prostate cancer (mCRPC), patients' prognosis remains suboptimal and novel treatment combinations are under scrutiny. On this matter, the recent ACIS trial tested the role of abiraterone plus apalutamide (androgen annihilation) in addition to androgen deprivation therapy, versus abiraterone plus androgen deprivation therapy. Herein, we performed a meta-analysis to compare overall survival (OS) and progression free survival (PFS) among patients who received androgen annihilation versus advanced androgen blockage (abiraterone or enzalutamide), in addition to conventional androgen deprivation therapy.

METHODS

A comprehensive search for all published phase III randomized control trials on first line mCRPC that evaluated advanced androgen blockage (COU-AA-302, PREVAIL) or androgen annihilation (ACIS) was conducted PubMed, EMBASE, Web of Science, and Scopus databases up to 31/12/2021. We reconstructed survival data from published Kaplan-Meier curves on overall survival (OS) and progression free survival (PFS) and meta-analyzed androgen annihilation versus advanced androgen blockage (grouping together abiraterone and enzalutamide) versus androgen deprivation therapy. The outcomes of interest were assessed using difference in restricted mean survival time (ΔRMST) at different time points.

RESULTS

Three trials were included involving 3787 patients. Overall, patients receiving androgen annihilation exhibited similar OS compared to advanced androgen blockage: ΔRMST at 36 months of -0.2 (95%CI: -1.1, 0.8, p=0.8). At 36 months, relatively to ADT alone, patients receiving androgen annihilation or advanced androgen blockage exhibited longer OS: ΔRMST of 1.6 (95%CI: 0.6, 2.7, p=0.002) and 1.8 months (95%CI: 1.1, 2.5, p<0.001), respectively. Patients receiving androgen annihilation exhibited better PFS compared to advanced androgen blockage: ΔRMST at 36 months of 2.4 months (95%CI: 1.0, 3.8, p=0.001).

CONCLUSION

We found no OS benefit for patients with mCRPC treated with androgen annihilation compared to advanced androgen blockage. This might be ascribed to an increased rate of other cause mortality that might determine the absence of an OS benefit or to the efficacy of second line therapies. Optimal treatment sequence and patient selection for androgen annihilation remain open points. However, a PFS benefit was found in case of combination therapy, whose clinical meaning is not yet clear.