Serum chromogranin-A-based prognosis in metastatic castration-resistant prostate cancer

Molecular biomarkers in prostate cancer tumorigenesis and clinical relevance

Prostate cancer (PCa) is the second most frequent type of cancer in men and assessing circulating tumor cells (CTCs) by liquid biopsy is a promising tool to help in cancer early detection, staging, risk of recurrence evaluation, treatment prediction and monitoring. Blood-based liquid biopsy approaches enable the enrichment, detection and characterization of CTCs by biomarker analysis. Hence, comprehending the molecular markers, their role on each stage of cancer development and progression is essential to provide information that can help in future implementation of these biomarkers in clinical assistance. In this review, we studied the molecular markers most associated with PCa CTCs to better understand their function on tumorigenesis and metastatic cascade, the methodologies utilized to analyze these biomarkers and their clinical significance, in order to summarize the available information to guide researchers in their investigations, new hypothesis formulation and target choice for the development of new diagnostic and treatment tools.

Association between concomitant proton pump inhibitor use and survival of patients with metastatic prostate cancer receiving abiraterone acetate: a post-hoc analysis of pooled data from three randomized controlled trials

BACKGROUND

Evidence suggests proton pump inhibitor (PPI) use may attenuate the effect of abiraterone acetate plus prednisone (AAP) in metastatic prostate cancer via the modification of gut microbiota. This study aimed to examine whether concomitant PPI use is associated with survival in patients with metastatic prostate cancer treated with androgen deprivation therapy (ADT) and AAP.

METHODS

Post-hoc analysis was conducted in patients with metastatic castration-sensitive prostate cancer (mCSPC) and metastatic castration-resistant prostate cancer (mCRPC) treated in the LATITUDE, COU-AA-301, and COU-AA-302 trials (ADT vs. ADT plus AAP). PPI users and non-users were compared for restricted mean overall survival time (RMOST) and restricted mean progression-free survival time (RMPFST) based on inverse probability of treatment weight (IPTW)-adjusted Kaplan-Meier curves. IPTW-adjusted Cox regression models were used to assess heterogeneity of treatment effect.

RESULTS

In patients treated with AAP, PPI use was associated with inferior RMOST [difference (95% confidence interval): -4.2 (-7.0 to -1.4)] and RMPFST [-3.5 (-6.6 to -0.4)] compared with non-users. However, RMOST and RMPFST were similar between PPI users and non-users in patients treated with ADT alone [RMOST, -2.6 (-5.8 to 0.6); RMPFST, -1.7 (-4.8 to 1.4)]. Interaction term analyses did not show evidence of heterogeneity in treatment effect between AAP and ADT, despite the prominent treatment effect shown in mCSPC vs. mCRPC.

CONCLUSIONS

PPI use may be associated with inferior survival in patients with metastatic prostate cancer who receive ADT plus AAP. Discontinuing unnecessary PPI use might improve those outcomes.

Prognostic Significance of Chromogranin A Expression in the Initial and Second Biopsies in Metastatic Prostate Cancer

Neuroendocrine differentiation (NED) characterized by the expression of neuroendocrine markers, such as chromogranin A (CgA), is frequently observed in advanced prostate cancer (PCa), the prognostic significance of which is still controversial. Here we specifically addressed the issue of the potential prognostic value of CgA expression in advanced-stage PCa patients with distant metastases and its change over time from metastatic hormone-sensitive (mHSPC) to metastatic castration-resistant prostate cancer (mCRPC). CgA expression was assessed immunohistochemically in initial biopsies of mHSPC, as well as in second biopsies of mCRPC in sixty-eight patients, and its correlation with prognosis (together with conventional clinicopathologic parameters) was analyzed using the Kaplan-Meier method and Cox proportional hazard model. We found that CgA expression was an independent adverse prognostic factor for both mHSPC (CgA positivity ≥ 1%, HR = 2.16, 95% CI: 1.04-4.26, p = 0.031) and mCRPC (CgA ≥ 10%, HR = 20.19, 95% CI: 3.04-329.9, p = 0.008). CgA positivity generally increased from mHSPC to mCRPC and was a negative prognosticator. The assessment of CgA expression may help with the clinical evaluation of advanced-stage patients with distant metastases.

Dynamic assessment of serum chromogranin A and treatment response with abiraterone acetate in metastatic castration-resistant prostate cancer

OBJECTIVE

Elevated serum chromogranin A (CGA) is associated with intrinsic or treatment-related neuroendocrine differentiation (NED) in men with metastatic castration-resistant prostate cancer (mCRPC). Fluctuations in serum CGA during treatment of mCRPC have had conflicting results. We analyzed the impact of (i) rising serum CGA and (ii) baseline CGA/PSA ratio during treatment to identify associations with abiraterone acetate (AA) therapy.

METHODS

Between June 2013 and August 2015, 92 men with mCRPC were enrolled in a prospective trial with uniform serum CGA processing performed before initiating abiraterone acetate/prednisone (AA/P) and serially after 12 weeks of AA/P treatments. Serum CGA was measured using a homogenous automated immunofluorescent assay. Patients receiving proton pump inhibitors or with abnormal renal function were excluded due to possible false elevations of serum CGA (n = 21 excluded), therefore 71 patients were analyzed. All patients underwent a composite response assessment at 12-weeks. Kaplan-Meier estimates and Cox Regression models were used to calculate the association with time-to-treatment failure analyses and overall survival.

RESULTS

An increase in chromogranin was associated with a lower risk of treatment failure (hazard ratio [HR]: 0.52, p = 0.0181). The median CGA/PSA ratio was 7.8 (2.6-16.0) and an elevated pretreatment CGA/PSA ratio above the median was associated with a lower risk of treatment failure (HR: 0.54 p value = 0.0185). An increase in CGA was not found to be associated with OS (HR: 0.71, 95% CI: 0.42-1.21, p = 0.207). An elevated baseline CGA/PSA ratio was not associated with OS (HR: 0.62, 95% CI: 0.37-1.03, p = 0.062). An increase in PSA after 12 weeks of treatment was associated with an increased risk of treatment failure (HR: 4.14, CI: 2.21-7.73, p = < 0.0001) and worse OS (HR: 2.93, CI: 1.57-4.45, p = < 0.0001).

CONCLUSIONS

We show that an increasing chromogranin on AA/P and an elevated baseline CGA/PSA in patients with mCRPC were associated with a favorable response to AA/P with no changes in survival. There may be limited clinical utility in serum CGA testing to evaluate for lethal NED as AA/P did not induce lethal NED in this cohort. This highlights that not all patients with an increasing CGA have a worse OS.

Chromogranin A: a useful biomarker in castration-resistant prostate cancer

PURPOSE

The natural history of prostate cancer (PC) almost always evolves to castration-resistant prostate cancer (CRPC) status, sometimes comprising pure or mixed neuroendocrine prostate cancers (NEPC) differentiation. In CRPC, monitoring using only prostate-specific antigen (PSA) is not optimal since neuroendocrine differentiated cells do not secrete PSA. Thus, monitoring with PSA and chromogranin A (CgA) may be useful. This review aims to evaluate evidence for the usefulness of CgA assessments during the monitoring of prostate cancer.

METHOD

This review was based on three recent meta-analysis concerning CgA and prostate cancer. Further data were obtained from PubMed and Embase databases by searches using keywords, including chromogranin A and prostate cancer.

RESULTS

CgA levels remain largely unchanged during the early PC evolution. The development of NEPC is characterised by lower PSA secretion and increased CgA secretion. Data supporting the prognostic value of high CgA baseline levels for survival are contrasting and scarce. However, increasing CgA levels early during treatment of metastatic (m)CRPC suggests resistance to treatment and predicts shorter survival, particularly in men with high baseline levels of CgA levels. In men with mCRPC, the first-line chemotherapy may be more appropriate than other agents when baseline CgA levels are high. Also, increasing CgA levels during treatment may indicate disease progression and may warrant a change of therapy.

CONCLUSION

CgA monitoring at baseline and regularly during mCRPC management may be useful for monitoring disease evolution. An increased CgA baseline levels and increasing CgA levels may assist physicians with choosing and modifying therapy.

Endocrine and paracrine characteristics of neuroendocrine prostate cancer

Prostate cancer is a common malignancy affecting men worldwide. While the vast majority of newly diagnosed prostate cancers are categorized as adenocarcinomas, a spectrum of uncommon tumor types occur including those with small cell and neuroendocrine cell features. Benign neuroendocrine cells exist in the normal prostate microenvironment, and these cells may give rise to primary neuroendocrine carcinomas. However, the more common development of neuroendocrine prostate cancer is observed after therapeutics designed to repress the signaling program regulated by the androgen receptor which is active in the majority of localized and metastatic adenocarcinomas. Neuroendocrine tumors are identified through immunohistochemical staining for common markers including chromogranin A/B, synaptophysin and neuron specific enolase (NSE). These markers are also common to neuroendocrine tumors that arise in other tissues and organs such as the gastrointestinal tract, pancreas, lung and skin. Notably, neuroendocrine prostate cancer shares biochemical features with nerve cells, particularly functions involving the secretion of a variety of peptides and proteins. These secreted factors have the potential to exert local paracrine effects, and distant endocrine effects that may modulate tumor progression, invasion, and resistance to therapy. This review discusses the spectrum of factors derived from neuroendocrine prostate cancers and their potential to influence the pathophysiology of localized and metastatic prostate cancer.

Prostate Cancer Biomarkers: From diagnosis to prognosis and precision-guided therapeutics

Prostate cancer (PCa) is one of the most commonly diagnosed malignancies and among the leading causes of cancer-related death worldwide. It is a highly heterogeneous disease, ranging from remarkably slow progression or inertia to highly aggressive and fatal disease. As therapeutic decision-making, clinical trial design and outcome highly depend on the appropriate stratification of patients to risk groups, it is imperative to differentiate between benign versus more aggressive states. The incorporation of clinically valuable prognostic and predictive biomarkers is also potentially amenable in this process, in the timely prevention of metastatic disease and in the decision for therapy selection. This review summarizes the progress that has so far been made in the identification of the genomic events that can be used for the classification, prediction and prognostication of PCa, and as major targets for clinical intervention. We include an extensive list of emerging biomarkers for which there is enough preclinical evidence to suggest that they may constitute crucial targets for achieving significant advances in the management of the disease. Finally, we highlight the main challenges that are associated with the identification of clinically significant PCa biomarkers and recommend possible ways to overcome such limitations.

Evaluation of three commercially available ELISA kits for the determination of chromogranin A

Chromogranin A (CgA) is currently the most valuable tumor biomarker for diagnostic work-up, management and follow-up of neuro-endocrine tumors (NET). The aim of our study was to compare three different commercially available CgA ELISA kits and to evaluate their analytical and clinical performance. CgA was measured with three different commercial ELISA kits on leftover sera from 40 patients: Chromoa R assay (Cis), Hu chromogranin A ELISA (Dia), and Neolisa chromogranin A (Euro). Analytical and clinical performance was evaluated by measuring precision, area under the ROC curve, sensitivity, specificity, positive and negative predictive value, correlation coefficients and Passing and Bablok regression analyses. Precision (CV%) was acceptable for all evaluated ELISA's (Cis 10.3%; Dia 9.8%; Euro 14.5%). The area under the curve (AUC) was comparable between the three assays (Cis 0.693; Dia 0.627; Euro 0.721). Sensitivity varied between 41.2% and 64.7%. Specificity ranged between 69.6% and 82.6%. Pairwise comparison revealed significant systematic and proportional differences when comparing Cis versus Dia (Cis = 25.30 + 1.94 Dia) and Euro versus Dia (Euro = 26.54 + 1.92 Dia). Analytical and clinical performance was comparable for the three ELISA's. CgA results obtained with different ELISA's are not interchangeable.AbbreviationsCgA: Chromogranin A; ELISA: Enzyme-linked immunosorbent assay; IRMA: Immunoradiometric assay; NET: Neuroendocrine tumors; PPI: Proton-pump inhibitors; RIA: Radioimmunoassay.

Identification and validation of a five apoptosis-related genes signature for prediction of disease-free survival for testicular germ cell tumors

Background

More and more studies have paid attention to the role of apoptosis in tumorigenesis. A variety of apoptosis-related genes (ARGs) are related to tumor progression and resistance to chemotherapy drugs. Therefore, this study aims to establish a prognostic marker for ARG-based testicular germ cell tumors (TCGT).

Methods

TCGT sequencing data and clinical information were downloaded from The Cancer Genome Atlas (TCGA) database and GEO database. The sequencing data of normal tissues came from the GTEx database. Through univariate COX, LASSO, and multiple COX regression analyses, we screened out key ARGs related to prognosis and constructed a risk signature and a prognostic nomogram. Finally, we performed internal and external verification to verify the signature we have established.

Results

Five ARGs, including CHGA, LPCAT1, PPP1CA, PSMB5, UBR2 were selected out and utilized to establish a novel signature. Based on this signature, TCGT patients were divided into high-risk groups and low-risk groups. The results showed that the disease-free survival (DFS) of patients in the high-risk group was lower than that in the low-risk group (P=0.02268). The subsequent univariate and multivariate Cox regression analysis further proved that the features we established are valuable independent prognostic factors (P<0.05). Also, a prognostic nomogram was created to visualize the relationship between various prognostic-related factors and the 1-, 3-, and 5-year DFS of TCGT in the TCGA cohort.

Conclusions

We constructed a new nomogram based on ARGs to predict the risk of testicular tumor recurrence. It can help clinicians better and more intuitively predict the survival of patients.

An Update on the Prognostic and Predictive Serum Biomarkers in Metastatic Prostate Cancer

Serum biomarkers are molecules produced by normal and abnormal cells. Prostate specific antigen (PSA) is an example of a serum biomarker used widely in the diagnosis and prognostication of prostate cancer. PSA has its limitations as it is organ- but not cancer-specific. The aim of this review is to summarize the current published data on the potential prognostic and predictive biomarkers in metastatic prostate cancer (mPC) that can be used in conjunction with PSA. These biomarkers include microRNAs, androgen receptor variants, bone metabolism, neuroendocrine and metabolite biomarkers, and could guide treatment selection and sequence in an era where we strive to personalized therapy.

The deleterious association between proton pump inhibitors and prostate cancer-specific mortality - a population-based cohort study

BACKGROUND

Proton pump inhibitors (PPIs) are commonly prescribed medications that have been shown to have contradicting effects on cancer. We aimed to investigate the effect of pantoprazole and other PPIs on prostate cancer (PCa) specific mortality (PCSM), use of androgen deprivation therapy (ADT), and PCa diagnosis using a large Canadian population-based cohort.

METHODS

We identified 21,512 men aged ≥ 66, with a history of a single negative prostate biopsy and no previous use of any of the analyzed medications between 1994 and 2016. Multivariable Cox regression models with time-dependent covariates were used to assess the associations of PPIs with PCa outcomes. All models included other medications with a putative chemopreventative effect on PCa-outcomes, and were adjusted for age, rurality, comorbidity, and study inclusion year.

RESULTS

Over a mean follow-up of 8.06 years (SD 5.44 years), 10,999 patients (51.1%) used a PPI, 5187 patients (24.1%) had PCa, 2043 patients (9.5%) were treated with ADT, and 805 patients (3.7%) died from PCa. For every 6 months of cumulative use, pantoprazole was associated with a 3.0% (95% CI 0.3-6.0%) increased rate of ADT use, while any use of other PPIs was associated with a 39.0% (95% CI 18.0-64.0%) increased risk of PCSM. No association was found with PCa diagnosis.

CONCLUSIONS

Upon validation of the potentially negative association of PPIs with PCa, PPI use may need to be reassessed in PCa patients.

Comprehensive analysis of serum chromogranin A and neuron-specific enolase levels in localized and castration-resistant prostate cancer

OBJECTIVES

To assess chromogranin A (CGA) and neuron-specific enolase (NSE) levels and changes in these at different stages of prostatic adenocarcinoma (PCA).

METHODS

Overall, 1095 serum samples from 395 patients, divided into three treatment groups, were analysed; the radical prostatectomy (RP) cohort (n = 157) included patients with clinically localized PCA, while the docetaxel (DOC) and the abiraterone (ABI)/enzalutamide (ENZA) cohorts included 95 and 143 patients, respectively, with metastatic castration-resistant prostate cancer. CGA, NSE and total PSA levels were measured using the KRYPTOR method.

RESULTS

Baseline CGA and NSE levels were higher in castration-resistant (DOC and ABI/ENZA cohorts) than in hormone-naïve, clinically localized PCA (P < 0.001). High baseline CGA levels were independently associated with poor overall survival in both the DOC and the ABI/ENZA cohorts, with a stronger association in the ABI/ENZA cohort. In the ABI/ENZA cohort, a > 50% CGA increase at 3 months was associated with poor survival, especially in patients with high baseline CGA levels.

CONCLUSIONS

The two- to threefold higher neuroendocrine marker levels in castration-resistant compared to hormone-naïve PCA support the presence of neuroendocrine transdifferentiation under androgen deprivation therapy. Our results showed patients with high baseline CGA levels who experienced a further CGA increase during ABI and ENZA treatment had the poorest prognosis. Serum CGA levels could help in tailoring and monitoring therapy in advanced PCA.

Evaluation of CisBio ELISA for Chromogranin A Measurement

BACKGROUND

Chromogranin A (CgA) is a nonspecific marker for the presence of neuroendocrine tumors and neuroendocrine differentiation. The objective of this study was to evaluate the performance of the CisBio CgA ELISA.

METHODS

Precision, linearity, limit of blank, and recovery of the CisBio CgA ELISA were evaluated. Seventy waste serum samples obtained from the clinical laboratory at Memorial Sloan Kettering Cancer Center were analyzed by the CisBio CgA ELISA. Results were compared to those obtained from a reference laboratory that used a proprietary ELISA for serum CgA measurement. Paired waste plasma samples were also collected from 24 of these patients to assess possible differences between CgA in serum and plasma. Finally, a preliminary reference range study was performed with samples from healthy volunteers in serum (n = 60) and plasma (n = 60).

RESULTS

Within-run and between-run precision ranged from 3.0% to 5.1% and 4.8% to 12.9%, respectively. The limit of blank was 2.4 ng/mL. Recovery ranged from 88% to 102%. A statistically significant bias was observed when the CisBio CgA assay results were compared to those of a reference laboratory. Comparison of the 2 assays yielded a slope of 9.05, intercept of -18.0, and a correlation coefficient of 0.955. CgA values in serum correlated well to values measured in plasma.

CONCLUSIONS

The analytical performance of the CisBio CgA ELISA was acceptable. However, CgA results are method-specific owing to lack of standardization and use of different antibodies. This lack of standardization results in several challenges for the clinical laboratory when evaluating a CgA assay.

Chromogranin A is a predictor of prognosis in patients with prostate cancer: a systematic review and meta-analysis

Background: The prognostic value of chromogranin-A (CHGA) as a biomarker of prostate cancer (PCa) has been evaluated extensively. However, to date the results still remain controversial. This study aims to perform a meta-analysis on previous studies in order to determine whether CHGA would be a biomarker for survival in PCa patients. Methods: MEDLINE, Embase, Web of Science, and Cochrane Library databases were searched to identify eligible studies published before September 2018, regarding the association of CHGA gene expression with survival outcomes in patients with PCa. Multivariate adjusted HRs and associated 95% CIs were calculated using random effects models. Results: Ten cohort studies involving 3,172 patients were finally included. According to the included studies, circulating CHGA levels were tested in serum, plasma, and tissues. The results showed an association between high CHGA expression and worse overall survival (OS) (HR=1.24, 95% CI: 1.07-1.44; P=0.004; I ²=77.6%) in PCa patients. However, no significant association was observed between increasing CHGA expression and shorter progression-free survival (HR=1.73, 95% CI: 0.92-3.28; P=0.090; I ²=73.9%). The results of sensitivity analysis validated the rationality and reliability of our analysis. Conclusion: Current evidence indicates that high CHGA expression is a potential marker for poor OS in PCa. Future studies are needed to explore tailored treatments that directly target CHGA for the improvement of survival in men with PCa.

Proton pump inhibitors promote the growth of androgen-sensitive prostate cancer cells through ErbB2, ERK1/2, PI3K/Akt, GSK-3β signaling and inhibition of cellular prostatic acid phosphatase

Prostate cancer (PCa) is one of the most common cancer in men. Although hormone-sensitive PCa responds to androgen-deprivation, there are no effective therapies for castration-resistant PCa. It has been recently suggested that proton pump inhibitors (PPIs) may increase the risk of certain cancers; however, association with PCa remains elusive. Here, we evaluated the tumorigenic activities of PPIs in vitro, in PCa cell lines and epithelial cells from benign prostatic hyperplasia (BPH) and in vivo, in PCa mice xenografts. PPIs increased survival and proliferation, and inhibited apoptosis in LNCaP cells. These effects were attenuated or absent in androgen-insensitive DU-145 and PC3 cells, respectively. Specifically, omeprazole (OME) promoted cell cycle progression, increased c-Myc expression, ErbB2 activity and PSA secretion. Furthermore, OME induced the phosphorylation of MAPK-ERK1/2, PI3K/Akt and GSK-3β, and blunted the expression and activity of cellular prostatic acid phosphatase. OME also increased survival, proliferation and PSA levels in BPH cells. In vivo, OME promoted tumor growth in mice bearing LNCaP xenografts. Our results indicate that PPIs display tumorigenic activities in PCa cells, suggesting that their long-term administration in patients should be carefully monitored.