Predicting response to hormonal therapy and survival in men with hormone sensitive metastatic prostate cancer

Prostate cancer therapy outcome prediction: are miRNAs a suitable guide for therapeutic decisions?

BACKGROUND

Radical prostatectomy, radiotherapy, chemotherapy, and androgen-deprivation therapy are among the most common treatment options for different forms of prostate cancer (PCa). However, making therapeutic decisions is difficult due to the lack of reliable prediction markers indicating therapy outcomes in clinical practice. The involvement of miRNAs in all mechanisms of the PCa development and their easy detection characterize them as attractive PCa biomarkers. Although there are extensive data on the role of miRNAs in PCa therapy resistance and sensitivity development, the issues of whether they could be used as a guide for therapy choice and, if so, how we can progress toward this goal, remain unclear. Thus, generalizable reviews and studies which summarize, compare, and analyze data on miRNA involvement in responses to different types of PCa therapies are required.

OBJECTIVES

Data on the involvement of miRNAs in therapy responses, on the role of cross-miRNA expression in different therapies, and on miRNA targets were analyzed in order to determine the miRNA-related factors which can lend perspective to the future development of personalized predictors of PCa sensitivity/resistance to therapies.

MATERIALS AND METHODS

The data available on the miRNAs associated with different PCa therapies (resistance and sensitivity therapies) are summarized and analyzed in this study, including analyses using bioinformatics resources. Special attention was dedicated to the mechanisms of the development of therapy resistance.

RESULTS AND DISCUSSION

A comprehensive combined analysis of the current data revealed a panel of miRNAs that were shown to be most closely associated with the PCa therapy response and were found to regulate the genes involved in PCa development via cell proliferation regulation, epithelial-mesenchymal transition (EMT), apoptosis, cell-cycle progression, angiogenesis, metastasis and invasion regulation, androgen-independent development, and colony formation.

CONCLUSION

The selected miRNA-based panel has the potential to be a guide for therapeutic decision making in the effective treatment of PCa.

Neoadjuvant androgen deprivation therapy combined with abiraterone acetate in patients with locally advanced or metastatic prostate cancer: When to perform radical prostatectomy?

The surgical timing after neoadjuvant androgen-deprivation therapy (ADT) plus abiraterone acetate (AA) for patients with locally advanced or metastatic prostate cancer (PCa) is unknown. We divided patients with locally advanced or metastatic PCa into three groups according to prostate-specific antigen (PSA) nadir after neoadjuvant ADT plus AA: group 1 (PSA ≤ 0.2 ng/ml), group 2 (0.2 < PSA ≤ 4.0 ng/ml), and group 3 (PSA > 4.0 ng/ml).The median PSA baseline levels in groups 1, 2, 3 were 118.42 (32.03-457.78), 143.48 (17.7-8100.16), and153.35 (46.44-423.31) ng/ml, respectively. The median times of progression to CRPC in groups 1, 2,and 3 were 30, 26, and 26 months, respectively. Compared to patients with PSA nadir >0.2 ng/ml, patients with PSA nadir <0.2 ng/ml presented with longer PFS (p = 0.048).Our results suggested that, in patients with locally advanced or metastatic PCa, the time to progression to CRPC was longer after radical prostatectomy when PSA decreased below 0.2 ng/ml using neoadjuvant ADT plus AA.

miRNAs and androgen deprivation therapy for prostate cancer

Androgen deprivation therapy (ADT) is mainly used for the treatment of advanced, metastatic or recurrent prostate cancer (PCa). However, patients progress to ADT resistance and castration-resistant prostate cancer (CRPC) with a poor prognosis. Reliable validated markers of ADT resistance with proven clinical utility are necessary for timely correction of the therapy as well as for improvement of patient quality of life. MiRNAs involved in the ADT response and CRPC development via multiple mechanisms may act as biomarkers for patient outcomes. Available data on miRNAs associated with the ADT response (resistance and sensitivity) are summarized and analyzed in the manuscript, including analyses using bioinformatics resources. Molecular targets of miRNAs, as well as reciprocal relations between miRNAs and their targets, were studied using different databases. Special attention was dedicated to the mechanisms of ADT resistance and CRPC development, including testosterone, PI3K-AKT, VEGF pathways and associated genes. Several different approaches can be used to search for miRNAs associated with the ADT response, each of which focuses on the associated set of miRNAs - potential markers of ADT. The intersection of these approaches and combined analysis allowed us to select the most promising miRNA markers of the ADT response. Meta-analysis of the current data indicated that the selected 5 miRNAs (miRNAs - 125b, miR-21, miR-23b, miR-27b and miR-221) and 14 genes are involved in the regulation of key processes of CRPC development and represent the most promising predictors of the ADT response, further demonstrating their potential in combination therapy for advanced PCa.

Androgen Receptor Signaling in Prostate Cancer Genomic Subtypes

While many prostate cancer (PCa) cases remain indolent and treatable, others are aggressive and progress to the metastatic stage where there are limited curative therapies. Androgen receptor (AR) signaling remains an important pathway for proliferative and survival programs in PCa, making disruption of AR signaling a viable therapy option. However, most patients develop resistance to AR-targeted therapies or inherently never respond. The field has turned to PCa genomics to aid in stratifying high risk patients, and to better understand the mechanisms driving aggressive PCa and therapy resistance. While alterations to the AR gene itself occur at later stages, genomic changes at the primary stage can affect the AR axis and impact response to AR-directed therapies. Here, we review common genomic alterations in primary PCa and their influence on AR function and activity. Through a meta-analysis of multiple independent primary PCa databases, we also identified subtypes of significantly co-occurring alterations and examined their combinatorial effects on the AR axis. Further, we discussed the subsequent implications for response to AR-targeted therapies and other treatments. We identified multiple primary PCa genomic subtypes, and given their differing effects on AR activity, patient tumor genetics may be an important stratifying factor for AR therapy resistance.

Three-month early change in prostate-specific antigen levels as a predictive marker for overall survival during hormonal therapy for metastatic hormone-sensitive prostate cancer

Objective

To date, there are no useful markers for predicting the prognosis of metastatic hormone-sensitive prostate cancer (mHSPC). We evaluated the effect of early changes in prostate-specific antigen (PSA) levels after androgen deprivation therapy (ADT) on castration-resistant prostate cancer (CRPC) progression and overall survival (OS) in mHSPC patients.

Results

In 71 primary mHSPC patients treated with ADT, the median times to CRPC and OS were 15 months and 92 months, respectively. In multivariate analysis, a Gleason score of ≥ 8 (p = 0.004), an extent of disease value (EOD) of ≥ 2 (p = 0.004), and a 3-month PSA level > 1% of the pretreatment level (p = 0.017) were independent predictors of shorter time to CRPC. The area under the receiver operating characteristic curve was feasible at 0.822. A 3-month PSA level > 1% of the pretreatment level was an independent predictor of OS (p = 0.004). Three factors were independent predictors of shorter time to CRPC. A 3-month PSA level > 1% of the pretreatment level correlated with a poor prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05641-5.

Population-Based Study of Docetaxel or Abiraterone Effectiveness and Predictive Markers of Progression Free Survival in Metastatic Castration-Sensitive Prostate Cancer

BACKGROUND

Both Docetaxel (DOC) and Abiraterone (ABI) improve the survival of men with metastatic, castration sensitive prostate cancer (mCSPC). However, the outcome among mCSPC patients is highly variable, while there is a lack of predictive markers of therapeutic benefit. Furthermore, there is limited data on the comparative real-world effectiveness of adding DOC or ABI to androgen deprivation therapy (ADT).

METHODS

We conducted a retrospective analysis of 121 mCSPC patients treated at Odette Cancer Centre (Toronto, ON, Canada) between Dec 2014 and Mar 2021 (DOC n = 79, ABI n = 42). The primary endpoint studied was progression free survival (PFS), defined as the interval from start of ADT to either (i) biochemical, radiological, or symptomatic progression, (ii) start of first-line systemic therapy for castration-resistant prostate cancer (CRPC), or (iii) death, whichever occurred first. To identify independent predictive factors for PFS in the entire cohort, a Cox proportional hazard model (stepwise selection) was applied. Overall survival (OS) was among secondary endpoints.

RESULTS

After a median follow-up of 39.6 and 25.1 months in the DOC and ABI cohorts, respectively, 79.7% of men in the DOC and 40.5% in the ABI group experienced a progression event. PFS favored the ABI cohort (p = 0.0038, log-rank test), with 78.0% (95%CI 66.4-91.8%) of ABI versus 67.1% (57.5-78.3%) of DOC patients being free of progression at 12 months. In univariate analysis superior PFS was significantly related to older age at diagnosis of mCSPC, metachronous metastatic presentation, low-volume (CHAARTED), and low-risk (LATITUDE) disease, ≥90% PSA decrease at 3 months (PSA90), and PSA nadir ≤0.2 at 6 months. Age (HR = 0.955), PSA90 (HR = 0.462), and LATITUDE risk stratification (HR = 1.965) remained significantly associated with PFS in multivariable analysis. OS at 12 months was 98.7% (96.3-100%) and 92.7% (85.0-100%) in the DOC and ABI groups (p = 0.97), respectively.

CONCLUSIONS

In this real-world group of men undergoing treatment intensification with DOC or ABI for mCSPC, we did not find a significant difference in OS, but PFS was favoring ABI. Age at diagnosis of mCSPC, PSA90 at 3 months and LATITUDE risk classification are predictive factors of PFS in men with mCSPC.

18F-choline positron emission tomography/computed tomography guided laparoscopic salvage lymph node dissection in patients after radical prostatectomy

Introduction

Salvage lymph node dissection (sLND) using novel imaging methods is an interesting alternative to treat lymph node (LN) metastasis after radical prostatectomy (RP); however, recommendations for using sLND as such are still being developed.

Aim

To assess the clinical outcomes of prostate cancer (PCa) after fluorine-18-choline (18F-choline) positron emission tomography/computed tomography (PET/CT) guided sLND.

Material and methods

Ten patients who had undergone sLND under 18F-choline PET/CT guidance (positive nodes: median 1, range 1-3) and had biochemical recurrence or persistence of prostate-specific antigen (PSA: median PSA 2.05 ng/ml, range: 0.8–8.4) after RP were enrolled in this retrospective study. Complete biochemical response (cBCR) after salvage surgery was defined as PSA < 0.2 ng/ml.

Results

The median follow-up time after salvage surgery was 33 months. The median PSA level 6 weeks after sLND and at the end of follow-up was 0.93 and 2.95 ng/ml, respectively. At 6 weeks after targeted sLND only 1 patient had cBCR, whereas a PSA decrease was noted in 7 patients. No patient had cBCR at the end of follow-up.

Conclusions

Laparoscopic sLND in cases of LN metastatic PCa after RP is a feasible option with low morbidity. However, an initial cBCR occurs in a negligible proportion of patients, and a long-term response is unlikely to be achieved.

A Phase II Study of Cabozantinib and Androgen Ablation in Patients with Hormone-Naïve Metastatic Prostate Cancer

PURPOSE

Cabozantinib, an oral inhibitor of c-MET/VEGFR2 signaling, improved progression-free survival (mPFS) but not overall survival (OS) in metastatic castrate-resistant prostate cancer. We evaluated cabozantinib plus androgen deprivation therapy (ADT) in hormone-naïve metastatic prostate cancer (HNMPCa).

PATIENTS AND METHODS

Patients received ADT plus cabozantinib starting at 60 mg daily. The primary endpoint was castrate-resistant PFS by radiographic criteria, clinical progression, or receipt of additional therapy. Secondary endpoints included OS, safety, radiographic responses, and biomarker modulation.

RESULTS

Sixty-two patients received treatment. With a median follow-up of 31.2 months, the mPFS was 16.1 months (95% CI, 14.6-22.7 months), and mOS was not reached. Reductions in PSA ≥ 90%, bone-specific alkaline phosphatase ≥ 50%, and urine N-telopeptides ≥ 50% occurred in 83%, 87%, and 86% of evaluable patients, respectively. Responses in bone scan and measurable disease were observed in 81% of and 90% of evaluable patients, respectively. Most common grade 3 adverse events were hypertension (19%), diarrhea (6%), and thromboembolic events (6%), and dose reductions occurred in 85% of patients. Analysis of baseline cytokine and angiogenic factors (CAFs) revealed that higher plasma concentrations of Lumican, CXCL5, CD25, and CD30 were associated with shorter PFS as was high tumor expression of pFGFR1.

CONCLUSIONS

Cabozantinib plus ADT has promising clinical activity in HNMPCa. CAF profiles and tissue markers suggest candidate prognostic and predictive markers of cabozantinib benefit and provide insights for rational therapy combinations.

Changes in conditional net survival and dynamic prognostic factors in patients with newly diagnosed metastatic prostate cancer initially treated with androgen deprivation therapy

BACKGROUND

The purpose of this study was to identify predictive factors associated with conditional net survival in patients with metastatic hormone-naive prostate cancer (mHNPC) initially treated with androgen deprivation therapy (ADT).

METHODS

At nine hospitals in Tohoku, Japan, the medical records of 605 consecutive patients with mHNPC who initially received ADT were retrospectively reviewed. The Pohar Perme estimator was used to calculate conditional net cancer-specific survival (CSS) and overall survival (OS) for up to 5 years subsequent to the diagnosis. Using multiple imputation, proportional hazard ratios for conditional CSS and OS were calculated with adjusted Cox regression models.

RESULTS

During a median follow up of 2.95 years, 208 patients died, of which 169 died due to progressive prostate cancer. At baseline, the 5-year CSS and OS rates were 65.5% and 58.2%, respectively. Conditional 5-year net CSS and OS survival gradually increased for all the patients. In patients given a 5-year survivorship, the conditional 5-year net CSS and OS rates improved to 0.906 and 0.811, respectively. Only the extent of disease score (EOD) ≥2 remained a prognostic factor for CSS and OS up to 5 years; as survival time increased, other variables were no longer independent prognostic factors.

CONCLUSIONS

The conditional 5-year net CSS and OS in patients with mHNPC gradually increased; thus, the risk of mortality decreased with increasing survival. The patient's risk profile changed over time. EOD remained an independent prognostic factor for CSS and OS after 5-year follow-up. Conditional net survival can play a role in clinical decision-making, providing intriguing information for cancer survivors.

Risk factors for progression to castration-resistant prostate cancer in metastatic prostate cancer patients

Purpose: To investigate the risk factors for progression to castration-resistant prostate cancer (CRPC) in metastatic prostate cancer (mPCa) patients who underwent androgen deprivation therapy (ADT).

Methods: We analyzed 216 patients with mPCa who underwent ADT between January 2006 and December 2015 at the First Affiliated Hospital of Fujian Medical University. Univariate and multivariate Cox regression analysis were used to explore the risk factors for progression to CRPC. Kaplan-Meier analysis and log-rank test were used to evaluate the difference in progression-free survival (PFS).

Results: A total of 121 (56.0%) patients who underwent ADT showed progression to CRPC. Multivariate Cox regression analysis demonstrated that Gleason grade group, prostate-specific antigen nadir (nPSA), and time to PSA nadir (TTN) were risk factors for progression to CRPC in mPCa patients. Kaplan-Meier analysis demonstrated that patients in Gleason grade group ≥3, nPSA >0.2 ng/ml and TTN <6 months had shorter PFS.

Conclusion: This study demonstrated that Gleason grade group, nPSA and TTN were risk factors for progression to CRPC. Patients with higher Gleason grade group, higher nPSA and shorter TTN have shorter PFS and higher risk of progression to CRPC after ADT.

Prognostic significance of early changes in serum biomarker levels in patients with newly diagnosed metastatic prostate cancer

We evaluated the impact of early changes in serum biomarker levels on the survival of patients with metastatic hormone-sensitive prostate cancer (mHSPC) who were initially treated with androgen deprivation therapy (ADT). We retrospectively investigated 330 patients with mHSPC whose serum maker levels were at baseline and at 2–4 months. An optimal Cox regression model was established with the highest optimism-corrected concordance index based on 10-fold cross-validation. The median cancer-specific survival (CSS) and overall survival (OS) were 7.08 and 6.47 years (median follow-up, 2.53 years), respectively. In the final optimal Cox model with serum biomarker levels treated as time-varying covariates, prostate-specific antigen (PSA), hemoglobin (Hb), and alkaline phosphatase (ALP) significantly increased the risk of poor survival in the context of both CSS and OS. Kaplan–Meier curves stratified by the three risk factors of high PSA, low Hb and high ALP desmondtated that median OS were not reached with none of these factors, 6.47 years with one or two factors, and 1.76 years with all three factors.Early changes in serum biomarker levels after ADT may be good prognostic markers for the survival of patients with mHSPC.

Serum Proteomics on the Basis of Discovery of Predictive Biomarkers of Response to Androgen Deprivation Therapy in Advanced Prostate Cancer

BACKGROUND

We investigated the serum proteome of hormone-sensitive prostate cancer patients to determine candidate biomarkers associated with androgen deprivation therapy (ADT) efficacy.

PATIENTS AND METHODS

Serum proteomes generated using isobaric mass tags for relative and absolute quantitation were analyzed using reverse-phase liquid chromatography coupled to tandem mass spectrometry. The advanced hormone-sensitive prostate cancer cohorts studied were: (1) untreated "paired" pre-ADT and 4-month post-ADT hormone-sensitive patients (n = 15); (2) "early ADT failure" patients (n = 10) in whom ADT treatment failed within a short period of time; and (3) "late ADT failure" patients (n = 10) in whom ADT treatment failed after a prolonged response time. Differential abundance was assessed, and ingenuity pathway analysis (IPA) was used to identify interaction networks in selected candidates from these comparisons.

RESULTS

Between "post-ADT" and combined "early" and "late" ADT failure groups 149 differentially detected candidates were observed, and between "early" and "late" ADT failure groups 98 candidates were observed; 47 candidates were common in both comparisons. IPA network enrichment analysis of the 47 candidates identified 3 interaction networks (P < .01) including 17-β-estradiol, nuclear factor kappa-light-chain enhancer of activated B cells complex, and P38 mitogen-activated protein kinases as pathways with potential markers of response to ADT.

CONCLUSION

A global proteomic analysis identified pathways with markers of ADT response, which will need validation in independent data sets.

Phenotypes of circulating tumour cells predict time to castration resistance in metastatic castration-sensitive prostate cancer

OBJECTIVES

To identify biomarkers that predict the response to standard androgen deprivation therapy (ADT) of patients newly diagnosed with metastatic castration-sensitive prostate cancer (CSPC) in order to improve therapeutic decision-making, and to investigate whether the characterization of baseline circulating tumour cells (CTCs) would predict the effective period of standard ADT.

MATERIALS AND METHODS

The study included 108 patients newly diagnosed with high-volume metastatic CSPC. Enumeration and characterization of patients' baseline CTCs (CTCs+ and CTCs-, indicating detectable and undetectable CTCs, respectively) were performed using the CanPatrol technique, which detects markers of the epithelial to mesenchymal transition (EMT) in CTCs, and classifies CTCs into epithelial, biophenotypic and mesenchymal phenotypes.

RESULTS

After a median follow-up of 24 months, 90 patients (83.3%) progressed to castration-resistant prostate cancer (CRPC), 93 patients (86.1%) had detectable CTCs, and the median number of CTCs was 4. The rate of progression to CRPC was significantly higher for patients with mesenchymal CTCs+ than for patients with CTCs+/mesenchymal CTCs- and CTCs- (93.1% vs 71.4% and 73.3%; P = 0.013). The median time to CRPC for patients with mesenchymal CTCs+ was significantly shorter than for those with CTCs+/mesenchymal CTCs- and CTCs- (10.5 months vs 18.0 and 14.0 months; P = 0.003). Multivariate Cox regression analysis suggested that the CTC phenotype was the only independent prognostic factor influencing the progression of disease from CSPC to CRPC.

CONCLUSIONS

Characterization of baseline CTCs according to the EMT phenotype predicted the effective period of standard ADT for patients newly diagnosed with metastatic CSPC. These findings are important for counselling patients and designing clinical trials.

Impact of early changes in serum biomarkers following androgen deprivation therapy on clinical outcomes in metastatic hormone-sensitive prostate cancer

Background

Less evidence is known about the role of early changes in serum biomarker after androgen deprivation therapy (ADT) in patients with metastatic hormone-sensitive prostate cancer (mHSPC). Here we evaluated the impact of pre-treatment prognostic factors and early changes in serum biomarkers on prostate specific antigen (PSA) progression-free and overall survival rates in mHSPC.

Methods

We retrospectively reviewed the medical records of 60 mHSPC patients (median age 72 years) treated with ADT whose laboratory data at baseline and following 12 weeks were available.

Results

Forty-four patients (73%) had PSA progression and 27 patients (45.0%) died during a median follow-up of 34 months. The multivariable Cox hazard model demonstrated that a log-transformed baseline PSA level (p = 0.003) and an extent of bone disease (EOD) score of ≥3 (p = 0.004) were statistically associated with an increased risk for PSA progression whereas one unit increase in a log-transformed PSA change (baseline-12 weeks) was associated with a decreased risk for PSA progression (p = 0.004). For overall survival, a high level of alkaline phosphatase (ALP) at 12 weeks was associated with increased risk (p = 0.030) whereas a one-unit increase in the log-transformed PSA change was associated with decreased risk (p = 0.001).

Conclusions

An increased level of PSA at baseline, or an EOD score of ≥3 may be a good predictor of PSA progression, and a high level of ALP at 12 weeks may be a risk predictor of death. A larger decline in PSA at 12 weeks from the baseline was associated with both PSA progression-free and overall survival time. Early changes in serum biomarkers may be useful in predicting poor outcomes in patients with mHSPC who are initially treated with ADT.

Persistence of senescent prostate cancer cells following prolonged neoadjuvant androgen deprivation therapy

Purpose

Androgen deprivation therapy (ADT) commonly leads to incomplete cell death and the fate of persistent cells involves, in part, a senescent phenotype. Senescence is terminal growth arrest in response to cell stress that is characterized by increased lysosomal-β-galactosidase (GLB1) the origin of senescence associated-β-gal activity (SA-β-gal). In the current study senescence is examined in vivo after ADT use in a neoadjuvant trial.

Methods and materials

Tissue microarrays were generated from prostate cancer specimens (n = 126) from a multicenter neoadjuvant ADT trial. Arrays were subjected to multiplexed immunofluorescent staining for GLB1, Ki67, cleaved caspase 3 (CC3) and E-cadherin. Automated quantitative imaging was performed using Vectra™ and expression correlated with clinicopathologic features.

Results

Tissue was analyzed from 59 patients treated with neoadjuvant ADT and 67 receiving no therapy preoperatively. Median follow-up was 85.3 mo and median ADT treatment was 5 mo. In PC treated with neoadjuvant ADT, GLB1 expression increased in intermediate Gleason score (GS 6–7; p = 0.001), but not high grade (GS 8–10) cancer. Significantly higher levels of GLB1 were seen in tissues undergoing neoadjuvant ADT longer than 5 months compared to untreated tissues (p = 0.002). In contrast, apoptosis significantly increased earlier (1–4 mo) after ADT treatment (p<0.5).

Conclusions

Increased GLB1 after neoadjuvant ADT occurs primarily among more clinically favorable intermediate grade cancers and enrichment of the phenotype occurs in a temporally prolonged fashion. Senescence may explain the persistence of PCa cells after ADT. Given concerns for the detrimental longer term presence of senescent cells, targeting these cells for removal may improve outcomes.

Androgen Receptor Signaling in Salivary Gland Cancer

Salivary gland cancers comprise a small subset of human malignancies, and are classified into multiple subtypes that exhibit diverse histology, molecular biology and clinical presentation. Local disease is potentially curable with surgery, which may be combined with adjuvant radiotherapy. However, metastatic or unresectable tumors rarely respond to chemotherapy and carry a poorer prognosis. Recent molecular studies have shown evidence of androgen receptor signaling in several types of salivary gland cancer, mainly salivary duct carcinoma. Successful treatment with anti-androgen therapy in other androgen receptor-positive malignancies such as prostate and breast cancer has inspired researchers to investigate this treatment in salivary gland cancer as well. In this review, we describe the prevalence, biology, and therapeutic implications of androgen receptor signaling in salivary gland cancer.

Management of hormone-sensitive metastatic prostate cancer

Targeting gonadal androgen synthesis (often in conjunction with blockade of androgen receptor) is the cornerstone of treatment of hormone-sensitive metastatic prostate cancer (HSPC). Despite the failure of androgen deprivation therapy, most tumors maintain some dependence on androgen or androgen receptor signaling for proliferation. This article reviews the current standard of care for metastatic HSPC, mechanisms of treatment resistance, novel drugs targeting the androgen signaling pathway, biomarkers predicting response to treatment and survival, future directions, and ongoing clinical trials in HSPC.

Convergent RANK- and c-Met-mediated signaling components predict survival of patients with prostate cancer: an interracial comparative study

We reported (PLoS One 6 (12):e28670, 2011) that the activation of c-Met signaling in RANKL-overexpressing bone metastatic LNCaP cell and xenograft models increased expression of RANK, RANKL, c-Met, and phosphorylated c-Met, and mediated downstream signaling. We confirmed the significance of the RANK-mediated signaling network in castration resistant clinical human prostate cancer (PC) tissues. In this report, we used a multispectral quantum dot labeling technique to label six RANK and c-Met convergent signaling pathway mediators simultaneously in formalin fixed paraffin embedded (FFPE) tissue specimens, quantify the intensity of each expression at the sub-cellular level, and investigated their potential utility as predictors of patient survival in Caucasian-American, African-American and Chinese men. We found that RANKL and neuropilin-1 (NRP-1) expression predicts survival of Caucasian-Americans with PC. A Gleason score ≥8 combined with nuclear p-c-Met expression predicts survival in African-American PC patients. Neuropilin-1, p-NF-κB p65 and VEGF are predictors for the overall survival of Chinese men with PC. These results collectively support interracial differences in cell signaling networks that can predict the survival of PC patients.