Quality of life in men with metastatic castration-resistant prostate cancer treated with enzalutamide or abiraterone: a systematic review and meta-analysis

Converting between the International Prostate Symptom Score (IPSS) and the Expanded Prostate Cancer Index Composite (EPIC) urinary subscales: modeling and external validation

BACKGROUND

Prostate-related quality of life can be assessed with a variety of different questionnaires. The 50-item Expanded Prostate Cancer Index Composite (EPIC) and the International Prostate Symptom Score (IPSS) are two widely used options. The goal of this study was, therefore, to develop and validate a model that is able to convert between the EPIC and the IPSS to enable comparisons across different studies.

METHODS

Three hundred forty-seven consecutive patients who had previously received radiotherapy and surgery for prostate cancer at two institutions in Switzerland and Germany were contacted via mail and instructed to complete both questionnaires. The Swiss cohort was used to train and internally validate different machine learning models using fourfold cross-validation. The German cohort was used for external validation.

RESULTS

Converting between the EPIC Urinary Irritative/Obstructive subscale and the IPSS using linear regressions resulted in mean absolute errors (MAEs) of 3.88 and 6.12, which is below the respective previously published minimal important differences (MIDs) of 5.2 and 10 points. Converting between the EPIC Urinary Summary and the IPSS was less accurate with MAEs of 5.13 and 10.45, similar to the MIDs. More complex model architectures did not result in improved performance in this study. The study was limited to the German versions of the respective questionnaires.

CONCLUSIONS

Linear regressions can be used to convert between the IPSS and the EPIC Urinary subscales. While the equations obtained in this study can be used to compare results across clinical trials, they should not be used to inform clinical decision-making in individual patients.

TRIAL REGISTRATION

This study was retrospectively registered on clinicaltrials.gov on January 14th, 2022, under the registration number NCT05192876.

Adverse Events and Androgen Receptor Signaling Inhibitors in the Treatment of Prostate Cancer: A Systematic Review and Multivariate Network Meta-analysis

CONTEXT

Androgen receptor signaling inhibitor (ARSi) agents are emerging as standard treatments for prostate cancer across the disease spectrum, but much remains unknown regarding how their side-effect profiles compare.

OBJECTIVE

To systematically evaluate the literature regarding adverse events (AEs) between the ARSi drugs abiraterone, apalutamide, darolutamide, and enzalutamide in the treatment of metastatic castration-resistant prostate cancer (mCRPC), nonmetastatic CRPC (nmCRPC), and metastatic castration-sensitive prostate cancer (mCSPC).

EVIDENCE ACQUISITION

PubMed, Web of Science, and Embase were queried for double-blind, randomized controlled trials (RCTs) of ARSi therapy up to September 2022 according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. Two teams reviewed titles and abstracts, and 14 RCTs were included for analysis.

EVIDENCE SYNTHESIS

Forest plots were used to summarize risk ratios for the most common AEs. According to surface under the cumulative ranking curve (SUCRA) values, enzalutamide was ranked as the most toxic treatment regarding hypertension outcomes (SUCRA 0%, most likely to be the bottom-ranked treatment) in both mCRPC and nmCRPC (SUCRA 0%). Enzalutamide was also ranked as the most toxic regarding headache across all prostate cancer entities (SUCRA 0%, for mCRPC, 1% for nmCRPC, and 3% for mCSPC).

CONCLUSIONS

Our findings suggest that the ARSi side-effect profiles do not significantly differ, except that enzalutamide was ranked the most toxic regarding hypertension in mCRPC and nmCRPC, and the most toxic regarding headache across all prostate cancer settings. These results highlight the importance of close blood-pressure monitoring for enzalutamide, and future research should explore possible connections between cardiovascular and neurological risk with ARSi therapy. In addition, these comparisons rely on the validity of cross-trial comparisons.

PATIENT SUMMARY

We reviewed the side-effect profiles of second-generation antiandrogen drugs for the treatment of prostate cancer. Side effects were similar, apart from higher risk of high blood pressure and headache risk with enzalutamide.

Frailty and survival among veterans treated with abiraterone or enzalutamide for metastatic castration-resistant prostate cancer

INTRODUCTION

Abiraterone and enzalutamide are treatments for metastatic castration-resistant prostate cancer (mCRPC). Due to a lack of head-to-head trials, they are prescribed interchangeably. However, the drugs have different pharmacokinetics and thus may have differing efficacy and adverse effects influenced by patient functional status and comorbid diseases. Additionally, mCRPC mainly affects older adults and since the prevalence of frailty increases with age, frailty is an important patient factor to consider in personalizing drug selection.

MATERIALS AND METHODS

We conducted a retrospective observational study of US veterans treated with abiraterone or enzalutamide for mCRPC from September 2014 to June 2017. Frailty was assessed using the Veterans Affairs Frailty Index (VA-FI), which utilizes administrative codes to assign a standardized frailty score. Patients were categorized as frail if VA-FI scores were > 0.2. The primary outcome was difference in overall survival (OS) between the two treatment groups. Cox regression modeling and propensity score matching was used to compare between abiraterone and enzalutamide treatments.

RESULTS

We identified 5,822 veterans, 57% of whom were initially treated with abiraterone and 43% with enzalutamide. Frail patients (n = 2,314; 39.7%) were older, with a mean age of 76.1 versus 74.9 years in the non-frail group (n = 3,508; 60.3%, p < 0.001) and had shorter OS compared to non-frail patients regardless of treatment group (18.5 vs. 26.6 months, p < 0.001). Among non-frail patients there was no significant difference in OS between abiraterone and enzalutamide treatment (27.7 vs 26.1 months, p = 0.07). However, frail patients treated with enzalutamide versus abiraterone had improved OS (20.7 vs 17.2 months, p < 0.001). In a propensity score matched analysis of frail patients (n = 2,070), enzalutamide was associated with greater median OS (24.1 vs 20.9 months, p < 0.001). In patients with dementia, enzalutamide was associated with longer OS (19.4 vs. 16.6 months, p = 0.003).

DISCUSSION

In this study of 5822 US veterans with mCRPC, treatment with enzalutamide was associated with improved OS compared to abiraterone among frail veterans and veterans with dementia, but not among non-frail veterans. Future studies should evaluate interactions between frailty and cancer treatments to optimize selection of therapy among frail adults.

Androgen receptor pathway inhibitors, prostate cancer, and older adults: a global Young International Society of Geriatric Oncology drug review

Prostate cancer is a disease of older adults that has undergone a significant therapeutic paradigm shift in the last decade with the emergence of novel androgen receptor pathway inhibitors (ARPis). One of the more commonly used ARPis is enzalutamide. This drug, along with darolutamide and apalutamide, initially received approvals in the metastatic castrate-resistant prostate cancer setting but is now utilized frequently in the metastatic castrate-sensitive and non-metastatic castration-resistant settings. Landmark phase III data illustrating ARPi efficacy in older adults are limited to those with excellent performance status. However, its role in unfit older prostate cancer patients remains to be explored in the context of a narrative review. This first-of-its-kind drug review aims to shed light on the most up-to-date evidence behind the unique toxicity profile of ARPis in the context of geriatric vulnerabilities such as cognitive and functional impairment, along with potential solutions and supporting evidence that exists to circumvent these issues in the vulnerable older adult.

Fatigue, health-related quality-of-life and metabolic changes in men treated with enzalutamide or abiraterone acetate plus prednisone for metastatic castration-resistant prostate cancer: A randomised clinical trial (HEAT)

INTRODUCTION

Enzalutamide and abiraterone acetate plus prednisone (AAP) have similar efficacy in metastatic castration-resistant prostate cancer (mCRPC). Herein, we compare fatigue, health-related quality-of-life (HRQoL) and metabolic changes in men with mCRPC treated with enzalutamide and AAP.

MATERIALS AND METHODS

In this single-centre, open-labelled, phase IV trial, patients with metastatic prostate cancer progressing on androgen deprivation therapy were randomly assigned to enzalutamide (160 mg daily) or AAP (1000 mg abiraterone acetate and 10 mg prednisone daily) as first-line mCRPC treatment. The primary outcome was the difference in changed fatigue (Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire). The secondary outcomes were differences in changed HRQoL (Functional Assessment of Cancer Therapy-Prostate questionnaire), body composition, weight, glucose homeostasis, lipid profile and blood pressure. All outcomes were assessed at baseline and at 12-week follow-up.

TRIAL REGISTRATION

clinicaltrialsregister.eu (2017-000099-27).

RESULTS

170 patients were randomised (1:1) to enzalutamide or AAP. The primary outcome was positive with a clinically meaningful difference in fatigue, favouring AAP (3.4 points, 95% CI 1.2; 5.6, P = 0.003). The group difference in changed HRQoL did not reach clinical significance. The most important metabolic finding was a higher increase in glycated haemoglobin (HbA1c) for AAP than enzalutamide (3.4 mmol/mol, 95% CI 2.1; 4.8, P = 0.001). Eight patients developed type 2 diabetes (T2D) in the AAP group and none in the enzalutamide group. No treatment-related serious adverse event was observed.

CONCLUSIONS

AAP resulted in less fatigue than enzalutamide in a randomised setting. This was at the expense of a higher HbA1c increase and incidence of T2D.