Where Do We Stand in the Management of Oligometastatic Prostate Cancer? A Comprehensive Review

Clinical Outcomes of Enzalutamide in Metastatic Hormone-sensitive Prostate Cancer in Patients Aged <75 and ≥75 Years: ARCHES Post Hoc Analysis

BACKGROUND

In ARCHES, treatment intensification of androgen deprivation therapy (ADT) with enzalutamide versus placebo improved clinical outcomes in metastatic hormone-sensitive prostate cancer (mHSPC). Understanding the benefits and tolerability of enzalutamide for men aged ≥75 yr may inform disease management.

OBJECTIVE

To determine whether age is associated with clinical outcomes in mHSPC.

DESIGN, SETTING, AND PARTICIPANTS

A post hoc analysis of the multinational, double-blind, randomized, placebo-controlled, phase 3 ARCHES trial in 1150 men with mHSPC (median follow-up [mo]: <75 yr, 44.6; ≥75 yr, 44.3) was performed.

INTERVENTION

Randomization 1:1 to enzalutamide (160 mg/d) plus ADT or placebo plus ADT; stratification by disease volume and prior docetaxel use.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Overall survival (OS), radiographic progression-free survival (rPFS), safety, and other secondary endpoints were compared between age groups (<75 and ≥75 yr) and treatment arms (Cox proportional hazard models).

RESULTS AND LIMITATIONS

Men aged <75 versus ≥75 yr had longer OS (enzalutamide plus ADT: hazard ratio [HR] 0.66; 95% confidence interval [CI] 0.47-0.91; p = 0.02; placebo plus ADT: HR 0.81; 95% CI 0.60-1.09; p = 0.13) and rPFS (enzalutamide plus ADT: HR 0.78; 95% CI 0.58-1.04; p = 0.12; placebo plus ADT: HR 0.98; 95% CI 0.74-1.30; p = 0.007). Enzalutamide improved OS (<75 yr: HR 0.61; 95% CI 0.47-0.79; ≥75 yr: HR 0.76; 95% CI 0.54-1.09) and secondary efficacy endpoints without evidence of statistical heterogeneity, and was generally well tolerated in both age groups, with minimal quality-of-life impact. Older versus younger patients experienced more frequent dose interruptions (20.2% vs 10.9%) and treatment-emergent adverse events (95.2% vs 89.1%). Post hoc examination and small sample size preclude definitive conclusions.

CONCLUSIONS

Enzalutamide plus ADT improved efficacy outcomes and was generally well tolerated despite shorter treatment exposure in older patients, indicating enzalutamide's utility in patients with mHSPC aged <75 and ≥75 yr.

PATIENT SUMMARY

Enzalutamide is a drug approved to treat men with prostate cancer. In this report, we compared patients aged <75 and ≥75 yr treated with enzalutamide plus androgen deprivation therapy to determine whether age affected how long they lived without the cancer spreading to other parts of their body. We found that, although younger patients had more favorable survival outcomes, enzalutamide was associated with longer survival and reduced disease spread in both age groups.

Defining oligometastatic state in uro-oncological cancers

PURPOSE OF REVIEW

Oligometastatic tumors illustrate a distinct state between localized and systematic disease and might harbor unique biologic features. Moreover, these tumors represent a different clinical entity, with a potential of long-term disease control or even cure, therefore they receive growing attention in the field of urologic oncology.

RECENT FINDINGS

Currently, there is no consensus on the definition of oligometastatic prostate cancer, most experts limit it to a maximum of three to five lesions and involvement of no more than two organs, excluding visceral metastases. Quality data on oligometastatic bladder cancer is scarce, however, a consensus of experts defined it as a maximum of three metastatic lesions, either resectable or suitable for stereotactic therapy, without restrictions to the number of organs involved. As for kidney cancer, a maximum number of five metastases, without limitations to the location are defined as oligometastatic, with an important implication of timing of developing metastases since diagnosis of the primary tumor.

SUMMARY

Defining oligometastatic state among urological tumors reflecting their distinct biological and clinical behavior is crucial to establish a sound framework for future clinical trials, and to facilitate guideline and policy formulation for improved patient care. Advancements in molecular imaging are expected to transform the field of oligometastatic urologic tumors in the future.

Predictive Models for Assessing Patients' Response to Treatment in Metastatic Prostate Cancer: A Systematic Review

Background and objective

The treatment landscape of metastatic prostate cancer (mPCa) has evolved significantly over the past two decades. Despite this, the optimal therapy for patients with mPCa has not been determined. This systematic review identifies available predictive models that assess mPCa patients' response to treatment.

Methods

We critically reviewed MEDLINE and CENTRAL in December 2022 according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Only quantitative studies in English were included with no time restrictions. The quality of the included studies was assessed using the PROBAST tool. Data were extracted following the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews criteria.

Key findings and limitations

The search identified 616 citations, of which 15 studies were included in our review. Nine of the included studies were validated internally or externally. Only one study had a low risk of bias and a low risk concerning applicability. Many studies failed to detail model performance adequately, resulting in a high risk of bias. Where reported, the models indicated good or excellent performance.

Conclusions and clinical implications

Most of the identified predictive models require additional evaluation and validation in properly designed studies before these can be implemented in clinical practice to assist with treatment decision-making for men with mPCa.

Patient summary

In this review, we evaluate studies that predict which treatments will work best for which metastatic prostate cancer patients. We found that existing studies need further improvement before these can be used by health care professionals.

Progress in Oligometastatic Prostate Cancer: Emerging Imaging Innovations and Therapeutic Approaches

Prostate cancer (PCa) exhibits a spectrum of heterogeneity, from indolent to highly aggressive forms, with approximately 10-20% of patients experiencing metastatic PCa. Oligometastatic PCa, characterized by a limited number of metastatic lesions in specific anatomical locations, has gained attention due to advanced imaging modalities. Although patients with metastatic PCa typically receive systemic therapy, personalized treatment approaches for oligometastatic PCa are emerging, including surgical and radiotherapeutic interventions. This comprehensive review explores the latest developments in the field of oligometastatic PCa, including its biological mechanisms, advanced imaging techniques, and relevant clinical studies. Oligometastatic PCa is distinct from widespread metastases and presents challenges in patient classification. Imaging plays a crucial role in identifying and characterizing oligometastatic lesions, with new techniques such as prostate-specific membrane antigen positron emission tomography demonstrating a remarkable efficacy. The management strategies encompass cytoreductive surgery, radiotherapy targeting the primary tumor, and metastasis-directed therapy for recurrent lesions. Ongoing clinical trials are evaluating the effectiveness of these approaches. Oligometastatic PCa occupies a unique position between locally advanced and high-volume metastatic diseases. While a universally accepted definition and standardized diagnostic criteria are still evolving, emerging imaging technologies and therapeutic strategies hold promise for improving the patient outcomes in this intermediate stage of PCa.

A Systematic Review on Artificial Intelligence Evaluating Metastatic Prostatic Cancer and Lymph Nodes on PSMA PET Scans

Early detection of metastatic prostate cancer (mPCa) is crucial. Whilst the prostate-specific membrane antigen (PSMA) PET scan has high diagnostic accuracy, it suffers from inter-reader variability, and the time-consuming reporting process. This systematic review was registered on PROSPERO (ID CRD42023456044) and aims to evaluate AI's ability to enhance reporting, diagnostics, and predictive capabilities for mPCa on PSMA PET scans. Inclusion criteria covered studies using AI to evaluate mPCa on PSMA PET, excluding non-PSMA tracers. A search was conducted on Medline, Embase, and Scopus from inception to July 2023. After screening 249 studies, 11 remained eligible for inclusion. Due to the heterogeneity of studies, meta-analysis was precluded. The prediction model risk of bias assessment tool (PROBAST) indicated a low overall risk of bias in ten studies, though only one incorporated clinical parameters (such as age, and Gleason score). AI demonstrated a high accuracy (98%) in identifying lymph node involvement and metastatic disease, albeit with sensitivity variation (62-97%). Advantages included distinguishing bone lesions, estimating tumour burden, predicting treatment response, and automating tasks accurately. In conclusion, AI showcases promising capabilities in enhancing the diagnostic potential of PSMA PET scans for mPCa, addressing current limitations in efficiency and variability.

The Efficacy of Enzalutamide plus Androgen Deprivation Therapy in Oligometastatic Hormone-sensitive Prostate Cancer: A Post Hoc Analysis of ARCHES

BACKGROUND

Few phase 3 studies have evaluated optimal systemic treatment strategies for patients with oligometastatic hormone-sensitive prostate cancer (HSPC), who may be at risk of undertreatment.

OBJECTIVE

To evaluate outcomes for patients with oligometastatic and polymetastatic HSPC treated with enzalutamide plus androgen deprivation therapy (ADT) versus placebo plus ADT.

DESIGN, SETTING, AND PARTICIPANTS

This was a post hoc analysis of data for 927 patients with nonvisceral metastatic HSPC in the ARCHES trial (NCT02677896).

INTERVENTION

Patients were randomized 1:1 to enzalutamide (160 mg/d orally) plus ADT or placebo plus ADT with HSPC categorized as oligometastatic (1-5 metastases) or polymetastatic (≥6 metastases).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The treatment effect on radiographic progression-free survival (rPFS), overall survival (OS), and secondary efficacy endpoints was evaluated in terms of the number of metastases. Safety was assessed. Cox proportional hazards models were used to generate hazard ratios (HRs). The Brookmeyer and Crowley method was used to generate 95% confidence intervals (CIs) for Kaplan-Meier median values.

RESULTS AND LIMITATIONS

Enzalutamide plus ADT improved rPFS (HR 0.27, 95% CI 0.16-0.46; p < 0.001), OS (HR 0.59, 95% CI 0.40-0.87; p < 0.005), and secondary endpoints in patients with oligometastatic or polymetastatic disease (rPFS: HR 0.33, 95% CI 0.23-0.46; p < 0.001; OS: HR 0.55, 95% CI 0.41-0.74; p < 0.001). Safety profiles were generally similar across subgroups. Limitations include the small numbers of patients with fewer than three metastases.

CONCLUSIONS

This post hoc analysis demonstrated the utility of enzalutamide, irrespective of metastatic burden or type of oligometastatic disease, and suggests that earlier treatment intensification with systemic potent androgen receptor inhibition is advantageous.

PATIENT SUMMARY

This study considered two treatment options for metastatic hormone-sensitive prostate cancer in patients with one to five metastases or six or more metastases. Treatment with enzalutamide plus ADT improved survival and other outcomes over ADT alone, whether patients had few or many metastases.

Oligometastatic carcinoma prostate - An overview of the last decade

Introduction

Oligometastatic prostate cancer (OMPC) has gained profound interest lately due to its different tumor biology and our ability to use multimodality therapy for cure or prolonged survival. Selecting the appropriate patient for treatment has become the aim of treating urologists, medical oncologists, and radiation oncologists. Through this review, we try to highlight the management of OMPC in light of recent literature.

Methods

Literature search was performed on Pubmed, Scopus and Embase using keywords "Oligometastatic", " Prostate Cancer" using operators such as "And" & "Or". Relevant articles were screened and all the latest articles on this emerging entity were included in this review.

Results

All trials relevant to oligometastatic prostate cancer defining the role of surgery, radiotherapy and systemic therapy were included and appropriate inferences were drawn. Relevant studies were compiled in tabular form for this article.

Conclusion

The current standard of care of management for OMPC remains systemic therapy on the lines of hormone-sensitive metastatic prostate cancer. The evolving role of surgery, and radiotherapy along with systemic therapy is highlighted in this article.

Editorial for the Special Edition of Advanced Prostate Cancer: From Bench to Bedside

Prostate cancer is generally viewed as a slow-growing unaggressive cancer, yet it is one of the most commonly diagnosed cancers and a leading cause of morbidity and mortality in men around the world [...].