Baseline neutrophil-to-lymphocyte ratio predicts the prognosis of castration-resistant prostate cancer treated with abiraterone acetate

Abiraterone acetate (AA), a CYP17 inhibitor, now has a crucial role in the treatment of castration-resistant prostate cancer (CRPC), and previous studies have reported several prognostic clinical factors for AA treatment. The neutrophil-to-lymphocyte ratio (NLR) has also been investigated for a CRPC treatments in a few reports, however it has not been identified to be a prognostic factor for AA treatment in Japanese patients. The present study aimed to assess the association of the baseline NLR with the overall survival (OS) in CPRC patients treated by AA. The present study retrospectively reviewed a total of 90 consecutive patients with CRPC treated with AA from 2011 to 2016 at Yokohama City University Medical Center and National Cancer Center Hospital East. The primary endpoint of the study was the OS, which was defined as the survival from the start of AA administration. The secondary endpoint was the prostate-specific antigen (PSA) response. PSA response was defined as a reduction in antigen levels of >50%. Complete blood cell counts were performed, and the NLR was calculated using the neutrophil and lymphocyte counts obtained on the same day or a few days prior to the initiation of AA therapy. The NLR cut-off point was determined to be 3.76 for the OS, and divided into the high NLR group of 34 patients and the low NLR group of 56 patients. A PSA response was obtained in 8 patients (23.5%) in the high NLR group and in 24 (42.9%) in the low NLR group. The difference of PSA response between the two groups was significant (P=0.037). Kaplan-Meier curves demonstrated that a high NLR [NLR ≥3.76; median OS: 8.4 months; 95% confidence interval (CI): 6.325-10.475 months] was correlated with a risk of mortality compared with a low NLR (NLR <3.76; median OS not reached). A multivariate analysis demonstrated that the NLR was an independent predictor for the OS (hazard ratio: 2.682; 95% CI: 1.143-6.293; P=0.023). The findings suggest that the NLR may be a useful novel biomarker for predicting the prognosis of CRPC patients treated with AA.

Abiraterone acetate and its use in the treatment of metastatic prostate cancer: a review

Abiraterone acetate, which targets enzymatic complexes playing a central role in steroidogenesis, demonstrated to increase survival significantly in both chemo-naive and docetaxel pretreated, becoming one of the drugs of choice for metastatic castration-resistant prostate cancer. More recently, this agent in combination to androgen deprivation therapy demonstrated to be efficacious also in metastatic castration-sensitive prostate cancer. The present review is aimed to outline the clinical development of abiraterone acetate, the pivotal trials which led to its approval for the clinical practice, new evidence about its efficacy in metastatic castration-sensitive prostate cancer, its place in the therapeutic landscape of prostate cancer and future directions of development.

Predictors of long-term response to abiraterone in patients with metastastic castration-resistant prostate cancer: a retrospective cohort study

We aimed to identify clinical predictors of long-term response to abiraterone (defined as >12 months drug exposure) in a retrospective cohort of metastatic castration-resistant prostate cancer patients treated in post-docetaxel setting at 24 Italian centers. The Cox proportional hazards model was used to analyze the association between clinical features and the duration of drug exposure. Results were expressed as hazard ratios (HR) with associated 95% confidence intervals (CI). A total of 143 patients met the inclusion criteria. Their median age was 73 years, median Gleason score 8 and median abiraterone exposure 20 months. At the univariate analysis, a significant correlation with the duration of abiraterone exposure was found for Gleason score (HR 0.82, 95% CI 0.71-0.96; p=0.012), PSA (HR 1.10, 95% CI 1.03-1.18; p=0.08) and lactic dehydrogenase levels (HR 1.22, 95% CI 1.02-1.46; p=0.027), while the association between lower alkaline phosphatase levels and treatment duration was marginally significant (HR 1.07, 95% CI 0.99-1.16; p=0.074). Only PSA and Gleason score were predictive of long-term treatment duration in the multivariate analysis. No other clinical factors resulted to be predictive of sustained response to abiraterone, including metastatic disease at diagnosis and visceral disease, suggesting that all subgroups of patients may derive a substantial clinical benefit from abiraterone treatment. These findings need to be validated in prospective, larger studies.

Cardiovascular safety of abiraterone acetate in metastatic castration-resistant prostate cancer patients: a prospective evaluation

AIM

The aim of this study is to evaluate cardiotoxicity of abiraterone acetate (AA) in metastatic castration-resistant prostate cancer patients (pts) with cardiovascular comorbidities or coronary artery disease (CAD) risk factors.

PATIENTS & METHODS

We prospectively analyzed pts receiving AA in order to evaluate correlations between cardiotoxicity onset and CAD risk factors or cardiovascular comorbidities.

RESULTS

Eighty-seven pts were enrolled, with median treatment duration of 9 months (1-44). At baseline, 84 pts (96%) had CAD risk factors. During treatment four pts (4; 6%) developed hypertension and 26 pts (30%) worsened the preexisting hypertension. Median left ventricular ejection fraction were 64 and 63% at baseline and after treatment, respectively.

CONCLUSION

AA appears to be safe in pts with cardiovascular comorbidities or CAD risk factors.

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.

Effectiveness of Deferred Combined Androgen Blockade Therapy Predicts Efficacy in Abiraterone Acetate Treated Metastatic Castration-Resistant Prostate Cancer Patients after Docetaxel

Introduction: Conventional anti-androgen regimens were widely used as an initiation or combined androgen blockade (CAB) therapy in advanced prostate cancer patients. Currently, new androgen pathway inhibitors such as abiraterone acetate (AA) and enzalutamide had been proven effective in metastatic castration resistant prostate cancer. In this study, we attempt to analyze the role of conventional anti-androgen drugs as deferred CAB therapy in castration-resistant prostate cancer patients.

Materials and Methods: From 2012 to 2017, 48 metastatic castration-resistant prostate cancer (CRPC) patients who received sequential treatments with primary androgen blockade, oral anti-androgen regimens, and docetaxel followed by AA treatment were included. We defined effective deferred CAB as any decline of PSA after add-on antiandrogen after CRPC. Patients were separated into effective and ineffective deferred CAB. Comparison between two groups in the first line androgen deprivation therapy duration, CRPC PSA level, pre-AA PSA level, chemotherapy dosages, duration, and patients progression free survival and overall survival after AA treatment were analyzed.

Results: Twenty-three patients (47.9%) achieved PSA decline after deferred CAB. Among total 48 patients, 24 patients experienced PSA decline more than 50% after AA treatment. The median PSA progression-free survival and overall survival after AA treatment in the total cohort of 48 patients were 4.4 and 24.3 months, respectively. The effective deferred CAB group showed significantly lower PSA level, lower percentage of PSA progression, higher total follow-up duration, higher percentage of surviving patients, better progression free survival, and overall survival estimate after AA treatment. Of the eight variables analyzed, effectiveness in deferred CAB showed positive association to progression free survival (HR 0.29, 95% CI 0.12–0.67, p = 0.004) and overall survival (HR 0.24, 95% CI 0.07–0.81, p = 0.022). First line androgen deprivation therapy (ADT) duration also showed positive association to overall survival (HR 0.95, 95% CI 0.91–0.99, p = 0.023).

Conclusions: Effectiveness of deferred CAB therapy was positively associated with progression free survival and overall survival of AA treatment after docetaxel. It can be used as a pre-treatment predictor.

Analytical challenges in quantifying abiraterone with LC-MS/MS in human plasma

A method was developed and validated to quantify abiraterone in human plasma. During assay development, several analytical challenges were encountered: limited stability in patient samples, adsorption to glass, coelution with metabolites and carry-over issues. Limited stability (2 h) was found for abiraterone in fresh plasma as well as whole blood at ambient temperature. When kept at 2-8°C, abiraterone in plasma was stable for 24 h and in whole blood for 8 h. Adsorption of abiraterone to glass materials was addressed by using polypropylene throughout the method. Carry-over was reduced to acceptable limits by incorporating a third mobile phase into the gradient. The chromatographic separation of abiraterone with its multiple metabolites was addressed by using a longer analytical column and adjusting the gradient. Abiraterone was extracted by protein precipitation, separated on a C18 column with gradient elution and analyzed with tandem quadrupole mass spectrometry in positive ion mode. A stable deuterated isotope was used as the internal standard. The assay ranges from 1 to 500 ng/mL. Within- and-between-day precisions and accuracies were below 13.4% and within 95-102%. This bioanalytical method was successfully validated and applied to determine plasma concentrations of abiraterone in clinical studies and in regular patient care for patients with metastatic castration-resistant prostate cancer.

Serum Pre-Albumin Predicts the Clinical Outcome in Metastatic Castration-Resistant Prostate Cancer Patients Treated With Abiraterone

Objective To determine the prognostic utility of serum pre-albumin in metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone (AA).

Patients and Methods 112 chemotherapy pretreated or chemotherapy-naive patients were scheduled for systemic treatment with AA. Serum pre-albumin levels were measured before and after 3 months of AA treatment. Univariate and multivariate analyses were performed to determine prognostic factors that were associated with PSA progression-free survival (PSA-PFS), radiographic PFS (rPFS) and overall survival (OS). The Harrell concordance index with variables only or combined pre-albumin data were used to evaluate the prognostic accuracy.

Results The group of patients with baseline pre-albumin value ≥20mg/dL had a longer OS, PSA-PFS, rPFS than those with pre-albumin value <20mg/dL. Based on the values of pre-albumin before and after 3 months of AA treatment, we divided these patients into 4 groups: high-high, high-low, low-high and low-low group. High- high group showed a significantly better OS, PSA-PFS, rPFS than other 3 groups. In multivariate analysis, low pre-albumin level remained significant predictors of OS (HR, 13.2; P<0.001), rPFS (HR, 3.7; P=0.003) and PSA-PFS (HR, 8.7; P<0.001). The estimated c-index of the multivariate model for OS increased from 0.814 without pre-albumin to 0.845 when pre-albumin added.

Conclusion Low pretreatment serum pre-albumin is a negative independent prognosticator of survival outcomes in mCRPC treated with AA and also increases the accuracy of established prognostic model. Serial pre-albumin evaluation might help clinicians guide clinical treatment of mCRPC patients.

Prognostic nutritional index predicts initial response to treatment and prognosis in metastatic castration-resistant prostate cancer patients treated with abiraterone

OBJECTIVE

To determine if prognostic nutritional index (PNI) and its variation could predict initial response to treatment and prognosis in metastatic castration-resistant prostate cancer (mCRPC) patients treated with Abiraterone (AA).

PATIENTS AND METHODS

One-hundred-twelve chemotherapy pretreated or chemotherapy-naive patients were scheduled for systemic treatment with AA. PNI levels were measured before and after one month of AA treatment. Univariate and multivariate logistic regression analyses were used to identify predictive factors of initial response to AA treatment. Univariable and Multivariable Cox regression analyses were performed to determine prognostic factors that were associated with PSA progression-free survival (PSA-PFS), radiographic PFS (rPFS) and overall survival (OS). The Harrell concordance index with variables only or combined PNI data were used to evaluate the prognostic accuracy.

RESULTS

Eighty-one (72.3%) of 112 patients showed initial response to AA treatment, in which 15 experienced PSA flare during AA treatment. In multivariate logistic regression analyses, high baseline PNI level, PSA level decrease during the first month of AA treatment and PNI level elevation during the first month of AA treatment were significantly correlated with initial response to AA treatment. In multivariate Cox regression analysis, low PNI level remained significant predictors of OS, rPFS and PSA-PFS. The estimated c-index of the multivariate model for OS increased from 0.82 without PNI to 0.83 when PNI added.

CONCLUSION

Independent of PSA level variation, PNI level elevation during the first month of AA treatment and high baseline PNI level were significantly correlated with initial response to AA treatment. In addition, low pretreatment PNI level is a negative independent prognosticator of survival outcomes in mCRPC treated with AA and also increases the accuracy of established prognostic model.

Treatment sequence in castration-resistant prostate cancer: A retrospective study in the new anti-androgen era

In recent years, abiraterone acetate (AA) and enzalutamide (EZL) have become available for the treatment of cancer. Prior clinical trials have demonstrated the benefits of these agents in males with castration-resistant prostate cancer (CRPC). The optimal sequencing of available therapies in the context of efficacy and known cross-resistance remains uncertain. Based on the mechanisms of action and accessible clinical data, AA and EZL may be indicated for the early stages of prostate cancer. Until clinical trials are conducted to determine the best treatment sequence, individualized therapy is required for each patient based on the clinicopathological characteristics. In the present study, 46 sequential patients (median age: 77, range 59-89; median serum PSA level: 56 ng/ml, range 1.5-3,211) with CRPC treated with EZL (160 mg/day) were retrospectively analyzed between June 2014 and July 2015 at the following institutions: Yamagata Prefectural Central Hospital (Yamagata, Japan); Yamagata Tokushukai Hospital (Yamagata, Japan); Ishinomaki Red Cross Hospital (Ishinomaki, Japan); Kan-etsu Hospital (Tsurugashima, Japan); Niigata Cancer Center Hospital (Niigata, Japan); Sakado Central Hospital (Sakado, Japan). A total of 18 patients were pre-treated with Docetaxel (DOC) and 28 patients were DOC-naïve. Once EZL therapy was initiated, increases in prostate specific antigen (PSA) levels were observed in 3/18 patients (17%) pre-treated with DOC and in 6/20 (30%) who were DOC-naïve. In total, 8/28 DOC-naïve patients were treated with AA without EZL. An increase in the PSA level was observed in only 1/8 (12%) cases following AA treatment in the DOC-naïve group. It was demonstrated that AA had a better efficacy in DOC-naïve patients. The efficacy of EZL was limited in AA-pre-treated patients following DOC administration.

Androgen Receptor Variant AR-V9 Is Coexpressed with AR-V7 in Prostate Cancer Metastases and Predicts Abiraterone Resistance

Purpose: Androgen receptor (AR) variant AR-V7 is a ligand-independent transcription factor that promotes prostate cancer resistance to AR-targeted therapies. Accordingly, efforts are under way to develop strategies for monitoring and inhibiting AR-V7 in castration-resistant prostate cancer (CRPC). The purpose of this study was to understand whether other AR variants may be coexpressed with AR-V7 and promote resistance to AR-targeted therapies.Experimental Design: We utilized complementary short- and long-read sequencing of intact AR mRNA isoforms to characterize AR expression in CRPC models. Coexpression of AR-V7 and AR-V9 mRNA in CRPC metastases and circulating tumor cells was assessed by RNA-seq and RT-PCR, respectively. Expression of AR-V9 protein in CRPC models was evaluated with polyclonal antisera. Multivariate analysis was performed to test whether AR variant mRNA expression in metastatic tissues was associated with a 12-week progression-free survival endpoint in a prospective clinical trial of 78 CRPC-stage patients initiating therapy with the androgen synthesis inhibitor, abiraterone acetate.Results: AR-V9 was frequently coexpressed with AR-V7. Both AR variant species were found to share a common 3' terminal cryptic exon, which rendered AR-V9 susceptible to experimental manipulations that were previously thought to target AR-V7 uniquely. AR-V9 promoted ligand-independent growth of prostate cancer cells. High AR-V9 mRNA expression in CRPC metastases was predictive of primary resistance to abiraterone acetate (HR = 4.0; 95% confidence interval, 1.31-12.2; P = 0.02).Conclusions: AR-V9 may be an important component of therapeutic resistance in CRPC. Clin Cancer Res; 23(16); 4704-15. ©2017 AACR.

Early abiraterone acetate treatment is beneficial in Japanese castration-resistant prostate cancer after failure of primary combined androgen blockade

Background

Development of novel agents targeting the androgen axis has led to improved overall survival in castration-resistant prostate cancer (CRPC). This study aimed to investigate the optimal timing of treatment with one such agent, abiraterone acetate (AA), in Japanese patients.

Materials and methods

Between July 2014 and February 2016, 106 CRPC patients were administered AA in Nagoya City University Hospital, Nagoya, Japan and in four affiliated hospitals following failure of primary combined androgen blockade (CAB). Of these, records of 69 patients treated before chemotherapy were retrospectively analyzed. Patients were divided into two AA treatment groups: (1) first- or second-line after diagnosis of CRPC, designated the Early Group, and (2) third-line onwards, designated the Deferred Group. Prostate-specific antigen (PSA) response rate, ≥ 50% PSA decline rate with treatment, progression-free survival (PFS), and overall survival (OS) were compared between the two groups. National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0 was used to classify adverse events.

Results

In 24 patients in the Early Group and 45 patients in the Deferred Group, no significant differences in baseline parameters were observed between groups. PSA response rate, ≥ 50% PSA decline rate and PFS (but not OS) were significantly better in the Early Group than in the Deferred Group. Serum aspartate aminotransferase/alanine aminotransferase elevations were the most common Grade 3 treatment-related toxicities, and were clinically manageable. In subgroup analyses of the Early Group, comparison of first-line AA with second-line AA after flutamide treatment showed no changes in PSA response rate, PFS, or OS.

Conclusion

This study suggests improved favorable outcomes of first- or second-line AA treatment in Japanese chemotherapy-naïve CRPC patients after failed CAB; statistical confirmation of such improvement was evident for PFS, but not OS. In addition, early AA treatment exhibited an acceptable safety profile.

Testicular vs adrenal sources of hydroxy-androgens in prostate cancer

Neoadjuvant androgen deprivation therapy (NADT) is one strategy for the treatment of early-stage prostate cancer; however, the long-term outcomes of NADT with radical prostatectomy including biochemical failure-free survival are not promising. One proposed mechanism is incomplete androgen ablation. In this study, we aimed to evaluate the efficiency of serum hydroxy-androgen suppression in patients with localized high-risk prostate cancer under NADT (leuprolide acetate plus abiraterone acetate and prednisone) and interrogate the primary sources of circulating hydroxy-androgens using our recently described stable isotope dilution liquid chromatography mass spectrometric method. For the first time, three androgen diols including 5-androstene-3β,17β-diol (5-adiol), 5α-androstane-3α,17β-diol (3α-adiol), 5α-androstane-3β,17β-diol (3β-adiol), the glucuronide or sulfate conjugate of 5-adiol and 3α-adiol were measured and observed to be dramatically reduced after NADT. By comparing patients that took leuprolide acetate alone vs leuprolide acetate plus abiraterone acetate and prednisone, we were able to distinguish the primary sources of these androgens and their conjugates as being of either testicular or adrenal in origin. We find that testosterone, 5α-dihydrotestosterone (DHT), 3α-adiol and 3β-adiol were predominately of testicular origin. By contrast, dehydroepiandrosterone (DHEA), epi-androsterone (epi-AST) and their conjugates, 5-adiol sulfate and glucuronide were predominately of adrenal origin. Our findings also show that NADT failed to completely suppress DHEA-sulfate levels and that two unappreciated sources of intratumoral androgens that were not suppressed by leuprolide acetate alone were 5-adiol-sulfate and epi-AST-sulfate of adrenal origin.

Impact of abiraterone on patient-related outcomes in metastatic castration-resistant prostate cancer: current perspectives

Abiraterone acetate has established a major role in the treatment paradigm of metastatic castration-resistant prostate cancer ever since pivotal trials, COU-AA-301 and COU-AA-302, have shown benefit in both the second-line and first-line (post- and pre-chemotherapy) setting, respectively, with improvement in overall survival as well as secondary end points such as prostate-specific antigen (PSA) and radiographic response rates, time to PSA progression, and progression-free survival. There has been a lot of interest and emphasis in the evaluation of patient-related outcomes (PROs) as it relates to quality of life, pain, adverse events, fatigue, and among others, in the use of different agents that have been shown to improve survival. This review examines the companion PROs in conjunction with abiraterone acetate use. This is particularly relevant since PROs are increasingly viewed as a key metric for drug label claims in granting approval across regulatory agencies, including the US Food and Drug Administration and the European Medicines Agency.

The impact of statin use on the efficacy of abiraterone acetate in patients with castration-resistant prostate cancer

BACKGROUND

Statins compete with DHEAS for influx through the SLCO2B1 transporter, which may prolong time to progression (TTP) on androgen deprivation therapy. Abiraterone acetate (AA) may also undergo SLCO-mediated transport. Based on preclinical findings showing antagonism, we hypothesized that statins may compete with AA for influx via SLCO2B1 and could negatively impact drug efficacy.

METHODS

We queried two institutional clinical databases (Dana-Farber Cancer Institute [DFCI], Johns Hopkins University [JHU]) for CRPC patients treated with AA. Treatment duration was a surrogate for TTP. Associations between statin use and AA duration were estimated using the Kaplan-Meier method. Multivariable Cox regression modeling adjusted for known prognostic factors.

RESULTS

Of the 224 DFCI and 270 JHU patients included, the majority (96%) had metastatic disease. Nearly half (41% and 45%) were statin users. In the DFCI cohort, there was a trend toward longer AA duration in statin users: 14.2 versus 9.2 months (HR 0.79, 95%CI: 0.57-1.09, P = 0.14). There was no association between statin use and AA duration in the JHU cohort: 8.3 versus 8.0 months (HR 0.89, 95%CI: 0.69-1.16, P = 0.38) in the statin users versus non-users, except for a trend in patients that had not previously received docetaxel or enzalutamide (HR 0.79; 95%CI: 0.57-1.10).

CONCLUSIONS

Contrary to our initial hypothesis, there was a trend toward longer (rather than shorter) AA duration in statin users in the entire DFCI cohort and in the enzalutamide- and docetaxel-naïve JHU patients. Together, these results do not support the hypothesis that statins interfere with AA efficacy.

Influence of abiraterone acetate on neuroendocrine differentiation in chemotherapy-naive metastatic castration-resistant prostate cancer

BACKGROUND

To determine the influence of abiraterone Acetate (AA) on neuroendocrine differentiation (NED) in patients with chemotherapy-naive metastatic castration-resistant prostate cancer (mCRPC).

METHODS

We conducted an analysis in 115 chemotherapy-naïve mCRPC patients who would be treated with chemotherapy. The serum levels of chromogranin A (CgA), neurone-specific enolase (NSE) were measured in 67 mCRPC patients without AA treatment and 48 patients after the failure of AA treatment, in which these markers were also measured in 34 patients before and after 6 months of AA treatment. Comparative t-test was used to evaluate the serial changes of serum NED markers during AA treatment and univariate and multivariate analyses were performed to test the influence of AA treatment on NED.

RESULTS

Serum CgA were NSE were evaluated to be above the upper limit of normal (ULN) in 56 (48.7%) and 29 (25.2%) patients before chemotherapy. In 34 patients with serial evaluation, serum CgA level of 14 patients and NSE of 14 patients increased after the failure of AA treatment. There was no significant difference of NED markers (CgA or NSE variation (P = 0.243) between at baseline and after the failure of AA treatment. Compared with the CgA elevation group in the first 6 months of AA treatment and baseline supranormal CgA group, the CgA decline group, and baseline normal CgA group has a much longer median PSA PFS (14.34 vs 10.00 months, P < 0.001, and 14.23 vs 10.30 months, P = 0.02) and rPFS, respectively (18.33 vs 11.37 months, P < 0.001, and 17.10 vs 12.07 months, P = 0.03). In logistic univariate analysis, AA treatment and its duration were not independent factors influencing NED.

CONCLUSIONS

We hypothesized that AA might not significantly lead to progression of NED of mCRPC in general. Furthermore, we found there was heterogeneity in changes of NED markers in different mCRPC patients during AA treatment. Serial CgA and NSE evaluation might help clinicians guide clinical treatment of mCRPC patients.

Abiraterone acetate and prednisone in chemotherapy-naïve prostate cancer patients: rationale, evidence and clinical utility

Abiraterone acetate 1000 mg/day, combined with prednisone 5 mg PO twice daily, is indicated for the treatment of metastatic castration-resistant prostate cancer (mCRPC). Abiraterone acetate is the oral prodrug of abiraterone, a specific CYP17 inhibitor that blocks androgen biosynthesis within the adrenal glands, testes and tumor microenvironment. In a phase III trial of men with asymptomatic or minimally symptomatic, chemotherapy-naïve mCRPC, treatment with oral abiraterone acetate plus prednisone led to a statistically significant improvement in the co-primary endpoints of overall survival and radiographic progression-free survival when compared with placebo plus prednisone. In long-term follow-up of phase III trials, the incidence of corticosteroid-associated adverse events was 25.5% in the abiraterone acetate plus prednisone arm compared with 23.3% in the placebo plus prednisone arm. The need for regular patient monitoring and appropriate management of symptoms during long-term use of prednisone must be placed in context with the improvement in survival seen with abiraterone plus prednisone. Within the multidisciplinary environment that is emerging to meet quality and cost imperatives, abiraterone acetate plus prednisone is suitable for use in the chemotherapy-naïve population with minimal symptoms as well as in patients who have been treated with docetaxel and may have symptomatic disease. Ongoing trials are evaluating the role of abiraterone acetate plus prednisone in patients with nonmetastatic CRPC and metastatic hormone-sensitive prostate cancer, while further trials in the mCRPC setting are evaluating its use in combination regimens.

First Line Androgen Deprivation Therapy Duration Is Associated with the Efficacy of Abiraterone Acetate Treated Metastatic Castration-Resistant Prostate Cancer after Docetaxel

Introduction: We performed a chart review study in our castration-resistant prostate cancer (CRPC) patients who received Abiraterone acetate (AA) treatment after docetaxel and identified clinical markers which can predict treatment outcome. Materials and Methods: From 2012 to 2016, 64 patients who received docetaxel after CRPC followed by AA treatment were included. Clinical parameters were recorded and analysis was performed to identify associations between pre-treatment variables and treatment outcome. Results: Thirty three patients (51.6%) achieved a decrease in PSA of 50%. The median PSA progression-free survival and overall survival in the total cohort of 64 patients were 6.6 and 24 months, respectively. Adverse events (AEs) in all grades developed in 35.9% (23/64) patients and mostly were grade 1 or 2. The most common AEs were gastric upset, hypokalemia and elevated liver function tests. Of the eight variables analyzed, first line androgen deprivation therapy (ADT) duration showed positive association to progression free survival (HR 0.98, 95% CI [0.96-0.99], p = 0.012) and overall survival (HR 0.97, 95% CI [0.94-0.99], p = 0.019). Pre-AA PSA and PSA progression ratio showed negative association only to progression free survival (HR 1.0, 95% CI [1.000-1.002], p = 0.025, HR 1.01, 95% CI [1.00-1.01], p < 0.001, respectively). Conclusion: First line ADT duration was positively associated with AA treatment efficacy in progression free survival and overall survival. It can be used as a pre-treatment predictor.

Controversies and consensus in the innovation access for cancer therapy in the European countries: on the subject of metastatic prostate cancer

Innovative cancer therapies and advances in drug development have created new hopes for patients and health providers. The purpose of this article was to evaluate the discrepancies in the assessment of the magnitude of benefit of four new drugs (abiraterone acetate, enzalutamide, cabazitaxel, radium-223 dichloride) for the treatment of metastatic castration-resistant prostate cancer (mCRPC). The comparison was done among three European countries (UK, Germany and France) and Canada, according to the statement of each country and to the European Society of Medical Oncology (ESMO) Magnitude of Clinical Benefit Scale. Whereas those drugs are authorized by the European Medical Agency, one can observed that clear discrepancies in the magnitude of benefit assessment exist between selected countries, as well as between national pricing evaluation agencies and ESMO. However, price setting and reimbursement decisions remain national responsibility with differences in assessment of the medical value of new treatment across countries, leading to a heterogeneous accessibility to cancer treatments. In conclusion, several procedures have to be implemented to overcome the patchwork of administrative assessments. Among them, the assessment of medical value should be based on independent statements of learned societies, and the harmonization of access to cancer therapy in Europe has to be driven by a common European reimbursement and pricing policy.

Role of free testosterone levels in patients with metastatic castration-resistant prostate cancer receiving second-line therapy

A range of new treatment options has recently become available for patients with advanced metastatic castration-resistant prostate cancer (mCRPC). Androgen deprivation therapy (ADT) with luteinizing hormone-releasing hormone is continued when performing chemotherapy or androgen deprivation with new second-generation therapeutic agents such as enzalutamide or abiraterone acetate. Despite the fact that free testosterone (FT) is the biologically active form, it is common practice that androgen suppression is monitored via total testosterone levels only. The aim of the present study was to evaluate the role of FT as a prognostic biomarker for cancer-specific survival (CSS) and its feasibility as an ADT monitoring biomarker in patients with mCRPC for the first time. The requirement for continued ADT in mCRPC patients is discussed within the basis of the current literature. A total of 34 patients with continuous measurements of FT levels and mCRPC status underwent therapy with docetaxel, abiraterone acetate, enzalutamide, cabozantinib, carboplatin or cabazitaxel. Data were obtained from the Departments of Urology and Urological Oncology, Hannover Medical School (Hannover, Germany) between March 2009 and April 2014. A cutoff point of 0.5 pg/ml was used to discriminate between patients according to FT levels. Statistical evaluation of CSS was performed by applying Kaplan Meier survival estimates, multivariate Cox regression analyses and log-rank tests. The median age of all 34 patients was 72 years (range, 51–86 years). The mean follow-up interval was 16.1 months (range, 0.7–55.6 months). Despite the fact that all patients were undergoing androgen deprivation, the mean serum FT levels for each patient varied; the mean FT concentration in the cohort was 0.328 pg/ml, ranging from 0.01–9.1 pg/ml. A notable difference with regard to CSS was observed for patients with regard to serum FT concentration; CSS was significantly longer for patients with a serum FT level below the cutoff level (43.6 vs. 17.3 months, respectively, P=0.0063). Upon multivariate Cox regression analysis, the mean FT concentration during treatment remained a significant prognostic factor for CSS (hazard ratio, 1.22; 95% confidence interval, 1.03–1.43; P=0.0182). In conclusion, in patients with mCRPC, the serum FT level is a strong predictor of CSS in patients under therapy with second-line anti-hormonal therapeutic medication and chemotherapy. It may be concluded that FT levels should be included into the routine control of androgen suppression while under treatment with ADT and second-generation hormonal therapy.

Targeting the androgenic pathway in elderly patients with castration-resistant prostate cancer: A meta-analysis of randomized trials

BACKGROUND

The novel hormonal drugs have recently entered in the armamentarium of therapies for treatment of metastatic castration-resistant prostate cancer (CRPC). First reports are available for their use in elderly men with CRPC.

METHOD

A meta-analysis of randomized controlled trials (RCTs) has been performed. PubMed, the Cochrane Library, and American Society of Clinical Oncology (ASCO) University Meeting were searched for data on the use of new hormonal treatment in elderly patients with CRPC.

RESULTS

Nine studies for a total of 3512 elderly patients were available for meta-analysis. Six studies reported outcomes of patients aged >75 years old while 2 studies reported on patients aged >70 years old. The pooled analysis of the androgen synthesis inhibitors revealed significantly increased overall survival (OS) due to antiandrogen agents compared with placebo or placebo and prednisone (hazard ratio (HR) for death: HR = 0.74, 95% CI: 0.67-0.82; P < 0.00001). Moreover, the new antiandrogenic therapy significantly improved the progression-free survival (HR = 0.45, 95% CI: 0.31-0.65; P < 0.0001). The incidence of any grade ≥3 adverse effect was only moderately higher during with the antiandrogenic therapy as compared to the control arms (response rate = 1.03, 95% CI: 0.88-1.20; P = 0.72).

CONCLUSION

This study confirmed that agents targeting the androgen axis (i.e., enzalutamide, abiraterone) significantly prolonged OS in elderly men with CRPC.

Early Prediction of Therapy Response to Abiraterone Acetate Using PSA Subforms in Patients with Castration Resistant Prostate Cancer

The purpose of this study was to evaluate the prognostic ability of early changes of total prostate specific antigen (tPSA), free PSA (fPSA), [−2]proPSA and the Prostate Health Index (PHI) following initiation of Abiraterone-therapy in men with castration resistant prostate cancer (mCRPC). In 25 patients, PSA-subforms were analyzed before and at 8–12 weeks under therapy as prognosticators of progression-free-survival (PFS) and overall survival (OS). Comparing patients with a PFS < vs. ≥12 months by using Mann–Whitney–Wilcoxon Tests, the relative-median-change of tPSA (−0.1% vs. −86.8%; p = 0.02), fPSA (12.1% vs. −55.3%; p = 0.03) and [−2]proPSA (8.1% vs. −59.3%; p = 0.05) differed significantly. For men with ≤ vs. >15 months of OS there was a non-significant trend for a difference in the relative-median-change of fPSA (17.0% vs. −46.3%; p = 0.06). In Kaplan–Meier analyses, declining fPSA and [−2]proPSA were associated with a longer median PFS (13 months, 95% confidence interval (CI): 9.6–16.4 vs. 10 months, 95% CI: 3.5–16.5; p = 0.11), respectively. Correspondingly, decreasing fPSA and [−2]proPSA values indicated an OS of 32 months (95% CI: not reached (NR)) compared to 21 months in men with rising values (95% CI: 7.7–34.3; p = 0.14), respectively. We concluded that the addition of fPSA- and [−2]proPSA-changes to tPSA-information might be further studied as potential markers of early Abiraterone response in mCRPC patients.

Uncontrolled diabetes predicts poor response to novel antiandrogens

Metabolic abnormalities including hyperglycemia and hyperlipidemia have been associated with worse prognosis of prostate cancer (PCa), but there are limited data regarding their impact on the prognosis of castrate-resistant prostate cancer (CRPC) and the response of novel antiandrogens, namely abiraterone acetate (AA) and enzalutamide. Retrospective analysis of 61 patients with CRPC on AA or enzalutamide, treated at the Boston Medical Center, was performed. We evaluated hemoglobin A1c (HbA1c), HDL, LDL, Triglycerides and BMI within 2months before the initiation of treatment with AA or enzalutamide and progression-free survival (PFS) under this treatment. Regression analysis and analysis of variance were used to evaluate the data. HbA1c levels were found to predict adversely the PFS on the novel agents (df (1, 37), P=0.00, R(2)=0.40, coeff=-3.28). The Kaplan-Meier analysis showed that there is significant difference in survival between the HbA1c 4.7-5.9% compared with patients with HbA1c 7.8-11.6% (6.72±1.3months, log rank test P<0.0001) LDL (P=0.07), HDL (P=0.14), and triglycerides (P=0.33) were not found to predict PFS. BMI predicted PFS positively (df (1.59), P=0.02, R(2)=0.09, coeff=0.03), but not independently of HbA1c (P=0.07). No significant implications of social and family history, previous chemotherapy regimen, and Gleason score with PFS were found. Multiple markers of patients' health state were not associated with HbA1c values. Uncontrolled diabetes can predict for poor response of CRPC patients to AA and enzalutamide determining PFS under this treatment. Elevated BMI can positively affect PFS at this stage of disease.

Progression-free and overall survival in metastatic castration-resistant prostate cancer treated with abiraterone acetate can be predicted with serial C11-acetate PET/CT

In this retrospective study, we evaluated the benefit of repeated carbon 11 (C11)-acetate positron emission tomography/computed tomography (PET/CT) to assess response in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate (AA).A total of 30 patients with mCRPC were monitored with C11-acetate PET/CT and PSA levels during their treatment with AA. Retrospective evaluation of their response was made after 102 days (median; range 70-155) of treatment. Statistical analyses were employed to detect predictors of progression-free survival (PFS) and overall survival (OS), and potential correlation between serum levels of PSA, standardized uptake values (SUVpeak), and bone lesion index measured from PET were investigated.At follow-up 10 patients exhibited partial response (PR), 10 progressive disease (PD), and 10 stable disease (SD), as assessed by PET/CT. In survival analysis, both PR and PD were significantly associated with PFS and OS. CT response was also associated with OS, but only 19/30 patients demonstrated a lesion meeting target lesion criteria according to RECIST 1.1. No PET/CT baseline characteristic was significantly associated with PFS or OS. A PSA response (reduction in the level by >50%) could also predict PFS and OS. In the subgroup lacking a PSA response, those with PD had significantly shorter OS than those with PR or SD.PFS and OS in patients with mCRPC treated with AA can be predicted from repeated C11-acetate PET/CT. This may be of particular clinical value in patients who do not exhibit a PSA response to treatment.

Common Genetic Variation in CYP17A1 and Response to Abiraterone Acetate in Patients with Metastatic Castration-Resistant Prostate Cancer

Treatment with abiraterone acetate and prednisone (AA/P) prolongs survival in metastatic castration-resistant prostate cancer (mCRPC) patients. We evaluated the genetic variation in CYP17A1 as predictive of response to AA/P. A prospective collection of germline DNA prior to AA/P initiation and follow-up of a mCRPC cohort was performed. Five common single-nucleotide polymorphisms (SNPs) in CYP17A1 identified using a haplotype-based tagging algorithm were genotyped. Clinical outcomes included biochemical response and time to biochemical progression on AA/P. Logistic regression was used to assess the association between tag SNPs and biochemical response. Proportional hazards regression was used to assess the association between tag SNPs and time to biochemical progression. Odds or hazard ratio per minor allele were estimated and p-values below 0.05 were considered statistically significant. Germline DNA was successfully genotyped for four tag SNPs in 87 patients. The median age was 73 years (54-90); the median prostate-specific antigen was 66 ng/dL (0.1-99.9). A single SNP, rs2486758, was associated with lower odds of experiencing a biochemical response (Odds ratio 0.22, 95% confidence interval 0.07-0.63, p = 0.005) and a shorter time to biochemical progression (Hazard ratio 2.23, 95% confidence interval 1.39-3.56, p < 0.001). This tag SNP located in the promoter region of CYP17A1 will need further validation as a predictive biomarker for AA/P therapy.