The Effect of Time to Castration Resistance on Outcomes With Abiraterone and Enzalutamide in Metastatic Prostate Cancer

Outcomes and patterns of use of Radium-223 in metastatic castration-resistant prostate cancer

Introduction

Radium-223 dichloride (Ra-223) is recommended as a treatment option for metastatic castration-resistant prostate cancer (mCRPC) patients with symptomatic bone metastases and no visceral disease, after docetaxel failure, or in patients who are not candidates to receive it. In this study, we aimed to ambispectively analyze overall survival (OS) and prognostic features in mCRPC in patients receiving Ra-223 as per clinical routine practice and identify the most suitable treatment sequence.

Patients and methods

This study is observational, multicentric, and ambispective. Eligibility criteria included mCRPC patients treated with Ra-223, with an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, without visceral metastases, and no more than three cm involved lymph nodes.

Results

A total of 145 patients were included; the median age was 73.97 years, and a Gleason score of more than or equal to 7 in 61 (48%) patients; 73 (81%) had previously received docetaxel. The most important benefit was reached by those patients who received Ra-223 in the second-line setting, with a median OS of 17 months (95% CI, 12-21), and by patients who received six cycles of treatment, with a median OS of 19 months (95% CI, 14-21). An alkaline phosphatase (ALP) decrease was also identified as a prognosis marker. When performing the multivariate analysis, the time to develop castration-resistant disease longer than 24 months was the most important prognostic factor to predict the evolution of the patients receiving Ra-223. Ra-223 was well tolerated, with thrombocytopenia, anemia, and diarrhea being the main adverse events.

Conclusion

There is a benefit for those patients who received Ra-223 in the second-line setting, regardless of prior use of docetaxel. In addition, a survival benefit for patients presenting with a decline in ALP was observed.

The prognostic value of Eastern Cooperative Oncology Group performance status on overall survival among patients with metastatic prostate cancer: a systematic review and meta-analysis

Background

There is heterogeneity in the literature regarding the strength of association between Eastern Cooperative Oncology Group performance status (ECOG PS) and mortality. We conducted a systematic review and meta-analysis of studies reporting the prognostic value of ECOG PS on overall survival (OS) in metastatic prostate cancer (mPC).

Methods

PubMed was searched from inception to March 21, 2022. A meta-analysis pooling the effect of ECOG PS categories (≥2 vs. <2, 2 vs. <2, and ≥1 vs. <1) on OS was performed separately for studies including patients with metastatic castration-resistant prostate cancer (mCRPC) and metastatic castration-sensitive prostate cancer (mCSPC) using a random-effects model. Analyses were stratified by prior chemotherapy and study type.

Results

Overall, 75 studies, comprising 32,298 patients, were included. Most studies (72/75) included patients with mCRPC. Higher ECOG PS was associated with a significant increase in mortality risk, with the highest estimate observed among patients with mCRPC with an ECOG PS of ≥2 versus <2 (hazard ratio [HR]: 2.10, 95% confidence interval [CI]: 1.87-2.37). When stratifying by study type, there was a higher risk estimate of mortality among patients with mCRPC with an ECOG PS of ≥1 versus <1 in real-world data studies (HR: 1.98, 95% CI: 1.72-2.26) compared with clinical trials (HR: 1.32, 95% CI: 1.13-1.54; p < 0.001). There were no significant differences in the HR of OS stratified by previous chemotherapy.

Conclusion

ECOG PS was a significant predictor of OS regardless of category, previous chemotherapy, and mPC population. Additional studies are needed to better characterize the effect of ECOG PS on OS in mCSPC.

Prognostic role of the duration of response to androgen deprivation therapy in patients with metastatic castration resistant prostate cancer treated with enzalutamide or abiraterone acetate

BACKGROUND

Our retrospective study aims to evaluate the prognostic role of duration of response to androgen deprivation therapy (ADT) in metastatic castration resistant prostate cancer (mCRPC) patients treated with enzalutamide (E) or abiraterone acetate (AA).

MATERIALS AND METHODS

Data about ADT start and duration were available in 255 (82%) of 311 patients treated with AA or E. Patients were divided in three groups according to ADT response (group 1 [G1]: <12 months; group 2 [G2]: 12-36 months; group 3 [G3]: >36 months). Outcome measures were progression-free survival (PFS) and overall survival (OS).

RESULTS

Patients with longer ADT response had better OS (median 17.3 months G1, 19.9 months G2, 31.6 months G3; HR G3 vs G1 0.41, 95% CI 0.25-0.64; p = 0.001) and better PFS (median 5.9 months G1, 8.8 months G2, 11.7 months G3; HR G3 vs G1 0.41, 95% CI 0.41-0.27; p < 0001). In docetaxel-naive patients, median OS was 18.8 in G1, 35.2 in G2, and not reached in G3 (HR G3 vs G1 0.33, 95% CI 0.14-0.78; p = 0.038), median PFS was 7 months G1, 9.3 months G2, and 20 months G3 (HR G3 vs G1 0.31, 95% CI 0.15-0.62; p = 0.003). In postdocetaxel patients, median OS was 13.1 months in G1, 17.2 months in G2, and 21.4 months in G3 (HR G3 vs G1 0.52, 95% CI 0.29-0.94; p = 0.082), while median PFS was 5.2 months in G1, 6.8 months in G2, and 8.3 months in G3 (HR G3 vs G1 0.54, 95% CI 0.32-0.91; p = 0.067).

CONCLUSIONS

Duration of ADT response is an independent prognostic factor of outcome with AA or E.

Hong Kong Urological Association-Hong Kong Society of Uro-Oncology consensus statements on the management of advanced prostate cancer-2019 Updates

BACKGROUND

To update the Hong Kong Urological Association-Hong Kong Society of Uro-Oncology consensus statements on the management of advanced prostate cancer, the same panelists as in the previous consensus panel held a series of meetings to discuss updated clinical evidence and experiences.

METHODS

The previous consensus statements were retained, deleted, or revised, and new statements were added. At the final meeting, all statements were reviewed and amended as appropriate, followed by panel voting.

RESULTS

There were significant changes and additions to the previous consensus statements, primarily driven by the advances in androgen receptor signaling inhibitors, treatment sequencing in metastatic castration-resistant prostate cancer, and increasing recognition of oligometastatic prostate cancer since the introduction of prostate-specific membrane antigen positron emission tomography. In this update, a total of 59 consensus statements were accepted and established.

CONCLUSIONS

The consensus panel updated consensus statements on the management of advanced prostate cancer, aiming to allow physicians in the region to keep abreast of the recent evidence on optimal clinical practices.

Impact of Time to Castration Resistance on Cytoreductive Radiotherapy in Metastatic Castration-Resistant Prostate Cancer

Background

The role of local radiotherapy in metastatic castration-resistant prostate cancer (mCRPC) remains undefined. This study aimed to identify the value of local radiotherapy and potential candidates for mCRPC.

Methods

A total of 215 patients with mCRPC treated with or without cytoreductive radiotherapy (CRT) between June 2011 and February 2019 were analyzed. Overall survival (OS) was calculated from the onset of mCRPC. The receiver-operating characteristic (ROC) curve was used to find the cutoff point for time to castration resistance (TCR).

Results

One-hundred and fifty-five (72.1%) patients received abiraterone after mCRPC, and 54 (25.1%) patients received CRT. The median TCR was 14.9 months. After a median follow-up of 31.7 months, the median OS was 33.3 months. The Eastern Cooperative Oncology Group (ECOG) performance scores 0-1, oligometastases, abiraterone after mCRPC, CRT, and TCR ≥9 months were independent prognostic factors for better OS. Stratified analyses showed improved survival when CRT was applied to patients treated with abiraterone (HR 0.44; 95% CI 0.23-0.83; P = 0.012) and TCR ≥9 months (HR 0.39; 95% CI 0.21-0.74; P = 0.004). The percentage of PSA response after radiotherapy was higher in patients with TCR ≥9 months compared to those with TCR <9 months. No grade 3 or worse adverse events after radiotherapy were reported.

Conclusions

ECOG performance score, oligometastases, abiraterone application, TCR and CRT were independent prognostic factors for OS in patients with mCRPC. Patients with a short duration of response to primary androgen deprivation therapy were less likely to benefit from CRT.

Is the duration of castration resistance predictive for sequential treatment responses in the metastatic castration-resistant prostate cancer setting?

OBJECTIVE

Prostate cancer is the second leading cause of cancer death in men. Androgen deprivation therapy (ADT) has been the primary therapeutic approach for treatment of prostate cancer. However,nearly all patients develop the castration-resistant disease . We evaluated real-world data with abiraterone and enzalutamide treatment. By this data, we aimed to analyze whether that prior short response to ADT could predict response to subsequent therapy with androgen receptor axis targeted agent (ARATA).

MATERIAL AND METHOD

We collected data from two cancer centers, 151 consecutive patients with treated abiraterone or enzalutamide in the first line of metastatic castration resistant prostat cancer (mCRPC) setting were included. The patients who received docetaxel in castration naive setting is also included. Time to castration resistance (TTCR) was defined as the duration from the initial to failure of primary ADT.

RESULTS

Patients with treated ARATA were divided into two groups according to the time to castration resistance (TTCR). Patients who became resistant to ADT up to one year had a median PFS of 6.6 months, compared to median PFS of 13.3 months for patients who responded ADT for more than 1 year. (p = 0.002). In the post-docetaxel setting, median PFS is 12.6 months of patients with treated ARATA who had TTCR for more than one year, and median PFS is 6.6 months in those who had TTCR less than one year (p = 0.007).Univariate and multivariate analyses were performed to determine the clinical factors on ARATA outcomes. Eastern Cooperative Oncology Group (ECOG) performance status(PS), median prostate-specific antigen(PSA) and time to CRPC were significantly predicted outcomes of ARATA on multivariate analysis.

CONCLUSION

TTCR is also a predictor for PFS of the patients who were treated ARATA both whole cohort and post-docetaxel.

Association between lactate dehydrogenase levels and oncologic outcomes in metastatic prostate cancer: A meta-analysis

Purpose

Previous studies have provided evidence of the high expression of lactate dehydrogenase (LDH) in multiple solid tumors; however, its prognostic relationship with metastatic prostate cancer (mPCa) remains controversial. We performed a meta‐analysis to better understand the prognostic potential of LDH in mPCa.

Methods

In our investigation, we included PubMed, Embase, Web of Science, and Cochrane Library as web‐based resources, as well as studies published before January 2020 on the predictive value of LDH in mPCa. We independently screened the studies according to the inclusion and exclusion criteria, evaluated the quality of the literature, extracted the data, and used RevMan 5.3 and STATA12.0 software for analysis.

Result

From the 38 published studies, the records of 9813 patients with mPCa were included in this meta‐analysis. We observed that higher levels of LDH in patients with mPCa were significantly associated with poorer overall survival (OS) (HR = 2.17, 95% CI: 1.91‐2.47, P < .00001) and progression‐free survival (PFS) (HR = 1.60, 95% CI: 1.20‐2.13, P = .001). The subgroup analyses indicated that the negative prognostic impact of higher levels of LDH on the oncologic outcomes of mPCa was significant regardless of ethnicity, publication year, sample size, analysis type, treatment type, age, and disease state.

Conclusion

Our analysis suggested the association between a higher level of LDH and poorer OS and PFS in patients with mPCa. As a parameter that can be conveniently evaluated, the LDH levels should be included as a valuable biomarker in the management of mPCa.

Real-world Outcomes of Sequential Androgen-receptor Targeting Therapies with or Without Interposed Life-prolonging Drugs in Metastatic Castration-resistant Prostate Cancer: Results from the Dutch Castration-resistant Prostate Cancer Registry

BACKGROUND

Cross resistance between androgen-receptor targeting therapies (ARTs) (abiraterone acetate plus prednisone [ABI+P] or enzalutamide [ENZ]) for treatment of metastatic castration-resistant prostate cancer (mCRPC) may affect responses to second ART (ART2).

OBJECTIVE

To establish treatment duration and prostate-specific antigen (PSA) response of ART2 in real-world mCRPC patients treated with or without other life-prolonging drugs (LPDs; ie, docetaxel, cabazitaxel, or radium-223) between ART1 and ART2.

DESIGN, SETTING, AND PARTICIPANTS

Castration-resistant prostate cancer patients, diagnosed between 2010 and 2016 were retrospectively registered in Castration-resistant Prostate Cancer Registry (CAPRI). Patients treated with both ARTs were clustered into two subgroups: ART1>ART2 or ART1>LPD>ART2.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Outcomes were ≥50% PSA response and treatment duration of ART2. Descriptive statistics and binary logistic regression after multiple imputations were performed.

RESULTS AND LIMITATIONS

A total of 273 patients were included with a median follow-up of 8.4 mo from ART2. Patients with ART1>ART2 were older and had favourable prognostic characteristics at ART2 baseline compared with patients with ART1>LPD>ART2. No differences between ART1>ART2 and ART1>LPD>ART2 were found in PSA response and treatment duration. Multivariate analysis suggested that PSA response of ART2 was less likely in patients with visceral metastases (odds ratio [OR] 0.143, p=0.04) and more likely in patients with a relatively longer duration of androgen-deprivation treatment (OR 1.028, p=0.01) and with ABI + P before ENZ (OR 3.192, p=0.02). A major limitation of this study was missing data, a common problem in retrospective observational research.

CONCLUSIONS

The effect of ART2 seems to be low, with a low PSA response rate and a short treatment duration irrespective of interposed chemotherapy or radium-223, especially in patients with short time on castration, visceral disease, and ENZ before ABI+P.

PATIENT SUMMARY

We observed no differences in outcomes of patients treated with sequential abiraterone acetate plus prednisone (ABI+P) and enzalutamide (ENZ) with or without interposed chemotherapy or radium-223. In general, outcomes were lower than those in randomised trials, questioning the additional effect of second treatment with ABI+P or ENZ in daily practice.

Plasma Androgen Receptor Copy Number Status at Emergence of Metastatic Castration-Resistant Prostate Cancer: A Pooled Multicohort Analysis

PURPOSE

Increases in androgen receptor (AR) copy number (CN) can be detected in plasma DNA when patients develop metastatic castration-resistant prostate cancer. We aim to evaluate the association between AR CN as a continuous variable and clinical outcome.

PATIENTS AND METHODS

PCR2023 was an international, multi-institution, open-label, phase II study of abiraterone acetate plus prednisolone (AAP) or abiraterone acetate plus dexamethasone that included plasma AR assessment as a predefined exploratory secondary end point. Plasma AR CN data (ClinicalTrials.gov identifier: NCT01867710) from this study (n = 133) were pooled with data from the following three other cohorts: cohort A, which was treated with either AAP or enzalutamide (n = 73); the PREMIERE trial (ClinicalTrials.gov identifier: NCT02288936) of biomarkers for enzalutamide (n = 94); and a phase II trial from British Columbia (ClinicalTrials.gov identifier: NCT02125357) that randomly assigned men to either AAP or enzalutamide (n = 201). The primary outcome measures for the biomarker analysis were overall survival and progression-free survival.

RESULTS

Using multivariable fractional polynomials analysis using Cox regression models, a nonlinear relationship between plasma AR CN and outcome was identified for overall survival, where initially for small incremental gains in CN there was a large added hazard ratio that plateaued at higher CN. The CN cut point associated with the highest local hazard ratio was 1.92. A similar nonlinear association was observed with progression-free survival. In an exploratory analysis of PCR2023, the time from start of long-term androgen-deprivation therapy to start of AAP or abiraterone acetate plus dexamethasone was significantly shorter in patients with plasma AR CN of 1.92 or greater than patients with plasma AR CN of less than 1.92 (43 v 130 weeks, respectively; P = .005). This was confirmed in cohort A (P = .003), the PREMIERE cohort (P = .03), and the British Colombia cohort (P = .003).

CONCLUSION

Patients with metastatic castration-resistant prostate cancer can be dichotomized by a plasma AR CN cut point of 1.92. Plasma AR CN value of 1.92 or greater identifies aggressive disease that is poorly responsive to AR targeting and is associated with a prior short response to primary androgen-deprivation therapy.

Prognostic Value of Lactate Dehydrogenase in Metastatic Prostate Cancer: A Systematic Review and Meta-analysis

The purpose of this study was to assess the prognostic value of lactate dehydrogenase (LDH) in patients with metastatic prostate cancer (PC). A systematic review and meta-analysis was performed in March 2019 according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement. Studies were deemed eligible if they compared patients with PC with high versus low LDH to determine the predictive value of LDH for overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS). We performed a formal meta-analysis for both OS and PFS. A total of 59 articles with 14,851 patients were included in the systematic review and 45 studies with 12,224 patients for the qualitative assessment. High LDH was associated with both worse OS (pooled hazard ratio [HR], 2.07; 95% confidence interval [CI], 1.75-2.44) and PFS (pooled HR, 1.08; 95% CI, 1.01-1.16). In subgroup analyses of both patients with castration-resistant prostate cancer (CRPC) and those with hormone-sensitive prostate cancer (HSPC), LDH was associated with OS (pooled HR, 2.02; 95% CI, 1.69-2.42 and pooled HR, 2.25; 95% CI, 1.78-2.84, respectively). In patients with CRPC, LDH was associated with OS in those treated with docetaxel systemic chemotherapy and androgen receptor-axis-targeting agents (pooled HR, 2.03; 95% CI, 1.37-3.00 and pooled HR, 1.79; 95% CI, 1.25-2.57, respectively). Elevated serum levels of LDH were associated with an increased risk of mortality and progression in patients with metastatic PC. LDH was independently associated with OS in both patients with CRPC and HSPC. LDH could be integrated into prognostic tools that help guide treatment strategy, thereby facilitating the shared decision-making process.

Identification of a Small Molecule That Selectively Inhibits ERG-Positive Cancer Cell Growth

Oncogenic activation of the ETS-related gene (ERG) by recurrent gene fusions (predominantly TMPRSS2-ERG) is one of the most validated and prevalent genomic alterations present in early stages of prostate cancer. In this study, we screened small-molecule libraries for inhibition of ERG protein in TMPRSS2-ERG harboring VCaP prostate cancer cells using an In-Cell Western Assay with the highly specific ERG-MAb (9FY). Among a subset of promising candidates, 1-[2-Thiazolylazo]-2-naphthol (NSC139021, hereafter ERGi-USU) was identified and further characterized. ERGi-USU selectively inhibited growth of ERG-positive cancer cell lines with minimal effect on normal prostate or endothelial cells or ERG-negative tumor cell lines. Combination of ERGi-USU with enzalutamide showed additive effects in inhibiting growth of VCaP cells. A screen of kinases revealed that ERGi-USU directly bound the ribosomal biogenesis regulator atypical kinase RIOK2 and induced ribosomal stress signature. In vivo, ERGi-USU treatment inhibited growth of ERG-positive VCaP tumor xenografts with no apparent toxicity. Structure-activity-based derivatives of ERGi-USU recapitulated the ERG-selective activity of the parental compound. Taken together, ERGi-USU acts as a highly selective inhibitor for the growth of ERG-positive cancer cells and has potential for further development of ERG-targeted therapy of prostate cancer and other malignancies.Significance: A highly selective small-molecule inhibitor of ERG, a critical driver of early stages of prostate cancer, will be imperative for prostate cancer therapy. Cancer Res; 78(13); 3659-71. ©2018 AACR.

Outcomes and Prognostic Factors in Men Receiving Androgen Deprivation Therapy for Prostate Cancer Recurrence after Radical Prostatectomy

PURPOSE

We sought to determine clinicopathological factors associated with early progression in men on androgen deprivation therapy as well as cancer specific and overall survival. We also assessed whether certain prostate specific antigen thresholds at androgen deprivation therapy initiation are associated with poorer outcomes.

MATERIALS AND METHODS

We identified 2,418 men with rising prostate specific antigen after undergoing radical prostatectomy at a single institution between 1987 and 2007 in a prospectively maintained registry. Early progression was defined as clinical progression within 2 years of initiating androgen deprivation therapy. The primary study outcome was cancer specific and overall survival.

RESULTS

The risk of early progression while on androgen deprivation therapy was lower for prostate specific antigen doubling time 3 to less than 9 months (OR 0.19) and less than 9 months or longer (OR 0.10, each p <0.001) prior to androgen deprivation therapy. Independent predictors of cancer specific survival were metastatic disease at androgen deprivation therapy initiation (HR 2.60), prostate specific antigen 5 to 50 ng/ml (HR 2.68) and 50 ng/ml or greater (HR 4.33), and doubling time 3 to less than 9 months (HR 0.54) and 9 months or longer (HR 0.45, all p <0.001). Independent predictors of overall survival were prostate specific antigen 5 to 50 ng/ml (HR 3.10) and 50 ng/ml or greater (HR 5.20, each p <0.001).

CONCLUSIONS

In men in whom androgen deprivation therapy was initiated for relapse after radical prostatectomy prostate specific antigen doubling time less than 3 months and prostate specific antigen 5 ng/ml or greater were adverse prognostic factors for early progression and cancer specific survival. Prostate specific antigen 5 ng/ml or greater also predicted shorter overall survival. Longer doubling time and prostate specific antigen less than 5 ng/ml were associated with lower risk and these men may not require immediate androgen deprivation therapy.

Prognostic Value of Automated Bone Scan Index in Men With Metastatic Castration-resistant Prostate Cancer Treated With Enzalutamide or Abiraterone Acetate

PURPOSE

Bone scan index (BSI) is an objective tool for quantifying bone metastasis load. We assessed its prognostic usefulness in patients with metastatic castration-resistant prostate cancer (CRPC) treated with enzalutamide (ENZ) or abiraterone acetate (AA).

MATERIALS AND METHODS

We analyzed 40 patients who received ENZ or AA treatment (ENZ/AA) for metastatic CRPC. The Cox proportional hazards model and a C-index were used to investigate associations between overall survival (OS) and BSI, and patient age, prostate-specific antigen, time to CRPC, previous docetaxel use, and pain.

RESULTS

Median OS after ENZ/AA was 17.8 months. All patient deaths (n = 19; 47.5%) were from prostate cancer. In multivariate analysis, decreased BSI was an independent predictor for longer OS (hazard ratio, 8.97; P = .011). Inclusion of BSI improved the C-index from 0.721 to 0.792 in predicting OS after ENZ/AA.

CONCLUSIONS

Decreased BSI after ENZ/AA independently predicts longer OS.