Duration of response to first androgen deprivation therapy, time to castration resistance prostate cancer, and outcome of metastatic castration resistance prostate cancer patients treated with abiraterone acetate

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.

Initial management approach for localized/locally advanced disease is critical to guide metastatic castration-resistant prostate cancer care

BACKGROUND

Currently, several therapies are available for metastatic castration-resistant prostate cancer (mCRPC) but no specific clinical factors to personalize treatment. We first sought the prognostic value of duration on androgen-deprivation therapy (ADT) for hormone-sensitive prostate cancer (HSPC) in patients receiving androgen-receptor-signaling inhibitors (ARSI) for mCRPC.

METHODS

A multicenter cohort of mCRPC patients who started ARSI between July 2011 and October 2021 was identified. Based on their initial disease burden and duration on ADT for HSPC, primary progressive (PP) men were classified into four groups: low/intermediate-risk localized disease (LOC) and high-risk localized/locally advanced disease (LAD) and short-term (ST) < 24 vs. long-term (LT) ADT ≥ 24 months, whereas de novo (DN) mHSPC were subdivided into short-time vs. long-time to CRPC.

RESULTS

We included 919 mCRPC patients with a median age of 77 years [interquartile range (IQR) = 71-82)]. Median ADT duration in HSPC was 24 months (IQR = 14-40). Median follow-up was 91 months (IQR = 62-138), median OS and PFS from ARSI start were 20 (IQR 10-32) and 10 months (IQR = 5-19), respectively. In PP developing metastatic disease (n = 655, 71.3%), LOC and LAD with ST ADT had a greater than almost double-risk of death compared to LT ADT (LOC/ST: hazard ratio [HR] = 2.01; 95% CI 1.54-2.64; LAD/ST: HR = 1.73; 95% CI 1.34-2.24; p < 0.001). In the multivariate analysis including age, prognostic cohort, Gleason, ECOG, radical radiotherapy and prostatectomy, groups with ST ADT were associated with worse OS compared to LT ADT (LOC/ST: HR = 1.84; 95% CI 1.38-2.45; p < 0.001; LAD/ST: HR = 1.59; 95% CI 1.21-2.10; p < 0.001), along with ECOG > 2 (HR = 1.55; 95% CI 1.06-2.26; p = 0.03). There were also similar results of PFS. Moreover, long-time to CRPC in patients with history of DN mHSPC (n = 264, 28.7%) resulted in a better OS/PFS (HR = 0.76, 95% CI 0.56-1.02, p = 0.064 and HR = 0.74, 95% CI 0.55-0.99, p = 0.042, respectively).

CONCLUSIONS

Our study showed that duration on ADT for mHSPC was significantly associated with survival in mCRPC undergoing ARSI. These findings suggest a possible connection between initial management of prostate tumour and a better prognostication in mCRPC. Prospective trials are warranted.

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.

Risk stratification for the prediction of overall survival could assist treatment decision-making at diagnosis of castration-resistant prostate cancer: a multicentre collaborative study in Japan

OBJECTIVES

To assess whether a new risk stratification system according to predictors for overall survival (OS) at the diagnosis of metastatic castration-resistant prostate cancer (mCRPC) could determine treatment outcomes and assist in treatment decision-making.

PATIENTS AND METHODS

Two independent clinical cohorts of patients, treated with androgen signalling inhibitors (ASIs: abiraterone and enzalutamide) or docetaxel as a first-line treatment for mCRPC, were used in this study: a derivation cohort (196 patients with mCRPC) and an external validation cohort (211 patients with mCRPC).

RESULTS

Three independent predictors for OS, including duration of initial androgen deprivation therapy <12 months before mCRPC diagnosis, alkaline phosphatase level >350 U/dL and haemoglobin level <11 g/dL at the diagnosis of mCRPC, were defined as risk factors. Patients with zero, one and multiple risk factors were assigned to a favourable-, intermediate- and poor-risk group, respectively. The median OS values in each risk group were well separated in the derivation cohort (P < 0.001) as well as in the validation cohort (P < 0.001). Of a total of 407 patients with mCRPC, 84 were assigned to the poor-risk group with the median OS of 12 months. In this group, a trend towards longer OS favouring docetaxel compared to ASIs as the first-line treatment (medians of 17 and 12 months, respectively) was observed.

CONCLUSION

The new risk group stratification system could predict patient survival at the diagnosis of mCRPC. Given the convenience of these risk definitions, physicians may be encouraged to consider these risk groups in daily practice.

Abiraterone acetate and prednisone in the pre- and post-docetaxel setting for metastatic castration-resistant prostate cancer: a mono-institutional experience focused on cardiovascular events and their impact on clinical outcomes

Background:

The aim of this work was to to evaluate the incidence and risk factors of adverse events (AEs), focusing on cardiovascular events (CVEs) and hypokalemia, in patients treated with abiraterone acetate (AA) and prednisone (PDN) outside clinical trials, and their association with survival outcomes.

Methods:

This was a retrospective cohort study of 105 patients treated from 2011 to 2016. Incidence of AEs was descriptively summarized in the whole cohort and by subgroup (pre- versus post-docetaxel). Multivariable Cox proportional hazards models assessed factors associated with progression-free survival (PFS) and overall survival (OS).

Results:

Overall, median PFS and OS were 14.9 and 24.6 months, respectively. Prostate-specific antigen (PSA) ⩾ 10 ng/ml (p = 0.007), Gleason Score >7 (p = 0.008), Eastern Cooperative Oncology Group (ECOG) performance status (PS)1–2 (p = 0.002), duration of androgen deprivation therapy (ADT) ⩽ 43.2 months (p = 0.01), and body mass index (BMI) > 25 (p = 0.03) were associated with worse PFS; presence of pain (p = 0.01), ECOG PS1–2 (p = 0.004), duration of ADT ⩽ 43.2 (p = 0.05), and BMI > 25 (p = 0.042) were associated with worse OS. Incidence of CVEs was as follows: hypertension 17.1%, fluid retention 4.8%, cardiac disorders 8.6%. 16.2% of patients developed hypokalemia. Age ⩾ 75 years was associated with higher probability of cardiac disorders (p = 0.001) and fluid retention (p = 0.03). CVEs did not impact on PFS or OS. Hypokalemia was associated with better median OS (p = 0.036). Similar associations were observed after stratification by subgroup.

Conclusions:

Median PFS and OS estimates and incidence of CVEs and hypokalemia in our series are consistent with those of pivotal trials of AA plus PDN, confirming the efficacy and safety of this regimen also in the real-world setting. Elderly patients have higher odds of developing/worsening CVEs. However, regardless of age, CVEs were not associated with worse outcomes. Treatment-related hypokalemia seemed to be associated with longer OS, albeit this finding needs confirmation within larger, prospective series.