N-telopeptide as a potential diagnostic and prognostic marker for bone metastasis in human cancers: A meta-analysis

Purpose

Whether N-telopeptide of type I collagen (NTx) can be applied for diagnosis and prognostic prediction of bone metastasis in human cancers is still conflicting. This study aimed to investigate the diagnostic and prognostic value of NTx for cancer patients with bone metastasis.

Methods

Embase, PubMed, Chinese National Knowledge Infrastructure and Wanfang databases were retrieved to collect related publications. In diagnostic meta-analysis, the sensitivity (SEN) and specificity (SPE) were calculated. Hazard ratio (HR) with 95% confidence interval (95% CI) was used in the prognostic meta-analysis. Sensitivity and publication analyses were conducted for potential heterogeneity sources.

Results

The pooled SEN and SPE were 77% (72-81%) and 80% (75-84%) for 45 diagnostic studies. A higher diagnostic efficacy was obtained from NTx combining with other markers (AUC: 0.94 (0.92-0.96)) for bone metastasis of human cancers, especially for lung cancer (AUC: 0.87 (0.84-0.90)), breast cancer (AUC: 0.83 (0.79-0.86)) and prostate cancer (AUC: 0.88 (0.85-0.90)) in Asian people (AUC: 0.86 (0.83-0.89)). For the value of NTx on prognosis of human cancers with bone metastasis, the pooled HR was 2.12 (1.74-2.58) for high versus low NTx level, indicating high NTx level would increase the risk of poor overall survival.

Conclusion

Our results indicated serum NTx combining with other markers can become a feasible biomarker for the diagnosis and prognosis prediction for bone metastasis of different cancers, including lung cancer, breast cancer and prostate cancer in Asian people.

Biomarkers for Prostate Cancer Bone Metastasis Detection and Prediction

Prostate cancer (PCa) causes deaths worldwide, ranking second after lung cancer. Bone metastasis (BM) frequently results from advanced PCa, affecting approximately 90% of patients, and it also often results in severe skeletal-related events. Traditional diagnostic methods for bone metastases, such as tissue biopsies and imaging, have substantial drawbacks. This article summarizes the significance of biomarkers in PCa accompanied with BM, including (1) bone formation markers like osteopontin (OPN), pro-collagen type I C-terminal pro-peptide (PICP), osteoprotegerin (OPG), pro-collagen type I N-terminal pro-peptide (PINP), alkaline phosphatase (ALP), and osteocalcin (OC); (2) bone resorption markers, including C-telopeptide of type I collagen (CTx), N-telopeptide of type I collagen (NTx), bone sialoprotein (BSP), tartrate-resistant acid phosphatase (TRACP), deoxypyridinoline (D-PYD), pyridoxine (PYD), and C-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP); (3) prostate-specific antigen (PSA); (4) neuroendocrine markers, such as chromogranin A (CgA), neuron-specific enolase (NSE), and pro-gastrin releasing peptide (ProGRP); (5) liquid biopsy markers, such as circulating tumor cells (CTCs), microRNA (miRNA), circulating tumor DNA (ctDNA), and cell-free DNA (cfDNA) and exosomes. In summary, some of these markers are already in widespread clinical use, while others still require further laboratory or clinical studies to validate their value for clinical application.

Revealing Prognostic Value of Skeletal-Related Parameters in Metastatic Castration-Resistant Prostate Cancer on Overall Survival: A Systematic Review and Meta-Analysis of Randomized Controlled Trial

BACKGROUND

The skeleton is a preferred site for prostate cancer metastasis, and once metastases occur, the disease becomes incurable. Increasing evidence indicates the prognostic value of skeletal-related parameters, but remains controversial.

OBJECTIVE

To perform a systematic review of the existing literature on assessing the prognostic value of alkaline phosphatase (ALP), bone-specific alkaline phosphatase (BSAP), urinary N-telopeptide (uNTx), bone scan index (BSI), and Brief Pain Inventory Short Form (BPI-SF) score in castration-resistant prostate cancer (CRPC) patients with skeleton metastasis.

EVIDENCE ACQUISITION

PubMed, Web of Science, Cochrane Library, Medline, OVID, and Embase between 2010 and 2019 were reviewed. Key terms included randomized trials, prostate cancer, alkaline phosphatase, bone-specific alkaline phosphatase, urinary N-telopeptide, bone scan index, and Brief Pain Inventory Short Form. Data were collected, checked, and analyzed from December 2019 to March 2020. Hazard ratios (HRs) and overall survival (OS) were extracted to estimate the relationship between the above parameters and OS in patients with metastatic prostate cancer (mPCa).

EVIDENCE SYNTHESIS

A total of 1,055 studies were identified via initial screening, including 1,032 from database research and 23 from other sources. After deduplication, 164 records were further excluded according to titles and abstracts. The remaining 36 potential articles were carefully screened. In the end, 15 eligible studies syntheses, which were published between 2010 and 2019, comprised data for a total of 11,378 patients, whose mean age ranged from 66 to 72 years. The sample size ranged from 82 to 1,901 patients. And the median follow-up time ranged from 24 to 55 months. Based on 15 randomized controlled trials published between 2010 and 2019, higher ALP levels (HR = 1.60, 95% CI: 1.38-1.87 P < 0.001), higher BSAP levels (HR = 1.31, 95% CI: 1.11-1.54 P = 0.001), higher uNTx levels (HR = 1.40, 95% CI: 1.29-1.52 P < 0.001), BSI progression (HR = 1.18, 95% CI: 1.08-1.29 P < 0.001), and higher BPI-SF score (HR = 1.47, 95% CI: 1.35-1.61 P < 0.001) had an association with inferior OS.

CONCLUSIONS

Higher levels of ALP/BSAP and uNTx, a higher BPI-SF score, and progression of BSI predict inferior OS in patients with mCRPC. More randomized control trials are needed to investigate the promising value of these parameters.

What is the relationship between bone turnover markers and skeletal-related events in patients with bone metastases from solid tumors and in patients with multiple myeloma? A systematic review and meta-regression analysis

Introduction

As a result of the negative impact of bone metastases on patient quality of life, it is important to identify patients at increased risk of skeletal-related events (SREs). Biochemical markers produced by osteoblasts and osteoclasts may provide an early indicator of treatment response to antiresorptive therapy. We aimed to explore the relationship between change in the urinary bone turnover marker cross-linked N-terminal telopeptide of type 1 collagen (uNTX) at the earliest time of steady state and risk of SREs.

Methods

A comprehensive search of eight bibliographic databases and two trial registries was conducted (June 2017). We included randomized controlled trials of adults (≥18 years old) with bone metastases from solid tumors (including breast, lung, prostate) or bone lesions from multiple myeloma that compared denosumab or bisphosphonate(s) with each other or a placebo. Meta-analyses were used to evaluate the relationship between uNTX and SREs. The primary outcomes were based on uNTX at week 13 and SREs in those studies.

Results

Seventeen studies (12,130 patients) were included. The analysis results indicated a positive association between uNTX reduction, measured by the between-group difference of the natural logarithm of the ratio between uNTX at week 13 and baseline, and SRE risk reduction, measured by the natural logarithm of the hazard ratio (HR) for time to first SRE between the two groups (uNTX effect on SRE risk, defined as SRE HR increase corresponding to one unit smaller in the magnitude of uNTX reduction: 0.3560, 95% confidence interval 0.0249-0.6871; P = .0390, R² = 0.7360). Results were similar for studies that reported change in uNTX from baseline to week 13 and to later than week 13. The limitation of this review is that it depends on how comprehensive study data were that could be included in the meta-regression.

Conclusions

Our findings support a positive relationship between reduction of bone turnover markers at the earliest time of steady state and reduction in longer-term risk of SREs.

Prognostic indicators of outcome for patients with skeletal metastases from carcinoma of the prostate

AIMS

The purpose of this study was to identify prognostic indicators of outcome at presentation to the orthopaedic surgeon, in patients with metastatic prostate cancer. Our aim was to use this information in a pragmatic, clinic-based approach so that surgical decision making could be optimized to benefit the patient in their remaining lifetime.

PATIENTS AND METHODS

A cohort analysis was undertaken of all patients with metastatic disease of the prostate who presented to a regional orthopaedic centre in the United Kingdom between 2003 and 2016. Biochemical data were collected in addition to disease and demographic data. These included: prostate-specific antigen (PSA) at orthopaedic presentation; haemoglobin (Hb); platelets (plt); alkaline phosphatase (ALP); albumin (Alb); and corrected calcium (CaC). Statistical analysis included Kaplan-Meier survival analysis, and a Cox proportional hazards model was fitted to the data.

RESULTS

From the departmental database, 137 episodes were identified in 136 patients with a median age at presentation of 72 years (interquartile range (IQR) 66 to 78). Most patients had stage IV disease (n = 98, 72%), and most did not undergo surgical intervention. At one-year follow-up, 50% of patients had died. Biomarkers found to be independently associated with poor survival were: low Hb, low Alb, relatively low PSA (< 30 mmol/l), and a raised ALP. Patients who needed surgical intervention had a poorer survival rate than patients who were managed nonoperatively.

CONCLUSION

The study findings are important for orthopaedic clinical practice in the management of patients with metastatic prostate cancer. The interpretation of routine blood tests can help to predict survival in patients who present with orthopaedic manifestations of prostate cancer. A lower PSA is not necessarily a good prognostic sign. We believe that simple blood testing should be carried out routinely when assessing a patient, guiding potential surgical management and palliative care in the future.

Clinical utility of bone markers in various diseases

Measurements of bone markers (BMs) in peripheral blood or urine are a pivotal part of bone research within modern clinical medicine. In recent years the use of BMs increased substantially as they can be useful either to diagnose bone (related) disease and to follow its natural history, but also to monitor the effects of interventions. However, the use of BMs is still complicated mainly due to (pre)analytical variability of these substances, limited accessibility of assays, variable cut-off values in different countries and laboratories and heterogeneous results with regard to clinical implications of measuring BMs in several studies. This review will provide the clinician with a practical guide, based on current evidence, in which circumstances to test which bone markers for optimal diagnostic purposes, in order to improve patient care in different areas of bone diseases including Paget's disease, primary osteoporosis, tumor induced osteomalacia, hypophosphatemic rickets, van Buchem disease, chronic kidney disease, rheumatoid arthritis, neoplasma/multiple myeloma, type 2 diabetes mellitus and primary hyperparathyroidism. The clinician should consider fasting state, recent fractures, aging, menopausal status, concomitant liver and kidney disease when ordering and interpreting BM measurements as these factors might result in misleading BM concentrations. We found that BMs are clearly useful in the current diagnosis of tumor induced osteomalacia, van Buchem disease, Paget's disease and hypophosphatemic rickets. In addition, BMs are useful to monitor disease activity in chronic kidney disease, Paget's disease and are useful to monitor treatment adherence in osteoporosis.

Effect of denosumab versus zoledronic acid in preventing skeletal-related events in patients with bone metastases by baseline characteristics

BACKGROUND

Analyses of phase III trials showed that denosumab was superior to zoledronic acid (ZA) in preventing skeletal-related events (SREs) irrespective of age, history of SREs, or baseline pain status. This analysis assessed the risk of SREs across additional baseline characteristics.

PATIENTS AND METHODS

Patients (N = 5543) from three phase III trials who had breast cancer, prostate cancer, or other solid tumours and one or more bone metastasis were included. Superiority of denosumab versus ZA in reducing risk of first SRE and first and subsequent SREs was assessed in subgroups defined by the Eastern Cooperative Oncology Group performance status (ECOG PS), bone metastasis location, bone metastasis number, visceral metastasis presence/absence, and urinary N-telopeptide (uNTx) level using Cox proportional hazards and Anderson-Gill models. Subgroups except bone metastasis location were also assessed for each solid tumour type.

RESULTS

Compared with ZA, denosumab significantly reduced the risk of first SRE across all subgroups (hazard ratio [HR] ranges: ECOG PS, 0.79-0.84; bone metastasis location, 0.78-0.83; bone metastasis number, 0.78-0.84; visceral metastasis presence/absence, 0.80-0.82; uNTx level, 0.73-0.86) and reduced the risk of first and subsequent SREs in all subgroups (HR ranges: ECOG PS, 0.76-0.83; bone metastasis location, 0.78-0.84; bone metastasis number, 0.79-0.81; visceral metastasis presence/absence, 0.79-0.81; uNTx level, 0.74-0.83). Similar results were observed in subgroups across tumour types.

CONCLUSION

Denosumab was superior to ZA in preventing SREs in patients with bone metastases from advanced cancer, regardless of ECOG PS, bone metastasis number, baseline visceral metastasis presence/absence, and uNTx level.

Bone-related Parameters are the Main Prognostic Factors for Overall Survival in Men with Bone Metastases from Castration-resistant Prostate Cancer

BACKGROUND

Previous studies have reported on prognostic factors for castration-resistant prostate cancer (CRPC); however, most of these studies were conducted before docetaxel chemotherapy was approved for CRPC.

OBJECTIVE

To evaluate the prognostic value of multiple parameters in men with bone metastases due to CRPC using a contemporary dataset.

DESIGN, SETTING, AND PARTICIPANTS

The analysis included 1901 patients with metastatic CRPC enrolled in an international, multicenter, randomized, double-blind phase 3 trial conducted between May 2006 and October 2009.

OUTCOME MEASURES AND STATISTICAL ANALYSIS

We developed multivariate validated Cox proportional hazards models and nomograms to estimate 12-mo and 24-mo survival probabilities and median survival time.

RESULTS AND LIMITATIONS

The median (95% confidence interval) overall survival was 20 (18, 21) mo. The final model included 12 of the 15 potential prognostic variables evaluated (concordance index 0.72). Seven bone-related variables were associated with longer survival in the final model: alkaline phosphatase ≤143 U/l (p<0.0001); bone-specific alkaline phosphatase (BSAP) <146 U/l (p<0.0001); corrected urinary N-telopeptide (uNTx) ≤50 nmol/mmol (p=0.0008); mild or no pain (Brief Pain Inventory-Short Form [BPI-SF] score ≤4) (p<0.0001); no previous skeletal-related event (SRE; p=0.0002); longer time from initial diagnosis to first bone metastasis (p<0.0001); and longer time from first bone metastasis to randomization (p<0.0001). Other significant predictors of improved survival included prostate-specific antigen (PSA) level <10 ng/ml (p<0.0001), hemoglobin >128g/l (p<0.0001), absence of visceral metastases (p<0.0001), Eastern Co-operative Oncology Group (ECOG) score ≤1 (p=0.017), and younger age (p=0.008). Nomograms were generated based on the parameters included in the final validated models (with/without uNTx and BSAP). One limitation was that lactate dehydrogenase (LDH) levels, a known prognostic factor, were not available in this study.

CONCLUSIONS

Bone-related parameters are strong prognostic variables for overall survival in patients with bone metastases from CRPC.

PATIENT SUMMARY

Survival time is variable in patients with bone metastases from prostate cancer. We found that factors related to bone help to predict how long a patient will live.

Bone turnover markers in serum and urine as diagnostic, prognostic and monitoring biomarkers of bone metastasis

Bone metastases are characterized by increased osteoblastic and/or osteolytic processes depending on the tumor type. The altogether destructive effect of metastasis formation promoted by increased metabolic activity raises the release of components from the osseous metabolism into the blood stream. These components are either enzymes directly involved in the alteration processes, metabolites/proteins that develop during this or bone matrix proteins released during this. These biomarkers are categorized in relation to their involvement in the bone formation or resorption as bone formation and resorption markers. Based on a PubMed literature search, a critical appraisal of the various biomarkers for diagnostic, prognostic, and monitoring purposes is given for patients with skeletal metastases caused by breast, prostate, lung, or renal cell carcinomas.

Prevalence of osteoporosis in prostate cancer survivors: a meta-analysis

Androgen deprivation therapy (ADT), which is used in the treatment of prostate cancer (PCa), is associated with increased morbidity. Severe bone loss is a major consequence of androgen ablation and with an increasing number of patients undergoing this treatment, the incidence of osteoporosis and fractures can be expected to increase with a significant impact on healthcare. To evaluate the prevalence of osteoporosis, we conducted a review of the literature on bone health in men with PCa undergoing ADT. A meta-analysis was conducted using the quality effects model, and sources of heterogeneity were further explored by consideration of discordant effect sizes of included studies in the meta-analysis and examining reasons thereof. Our analyses indicate that the prevalence of osteoporosis varies between 9 and 53 % with this variation partially explained by treatment duration, disease stage, ethnicity and site of osteoporosis measurement. While it is well known that a rapid decline in bone health amongst men with PCa on ADT occurs, this meta-analysis documents the high prevalence of osteoporosis in this population and reinforces the need of preventative approaches as part of usual care of PCa patients.

Failure to suppress markers of bone turnover on first-line hormone therapy for metastatic prostate cancer is associated with shorter time to skeletal-related event

BACKGROUND

Elevated markers of bone turnover are prognostic for shorter survival in castration-resistant prostate cancer. We aimed to determine the prognostic value of bone turnover markers in metastatic hormone-sensitive prostate cancer.

PATIENTS AND METHODS

Markers of bone turnover (urine deoxypyridinoline [DPD] and N-telopeptide, serum bone alkaline phosphatase (AP), and osteocalcin [OC]) from baseline and after 6 months of study were assessed in men enrolled in a prospective metastatic prostate cancer trial with androgen deprivation therapy (ADT) with or without risedronate (ClinicalTrials.gov, NCT00216060).

RESULTS

Serum samples were collected from 63 patients with bone involvement and a median follow-up of 39.7 months. A multivariate model using Cox regression-which included prostate-specific antigen (PSA) nadir, bisphosphonate treatment, and extent of metastases-showed that suppression of bone turnover markers after 6 months of therapy compared with baseline was significantly associated with longer skeletal-related event (SRE)-free survival. ADT without bisphosphonate therapy was also associated with a decline in markers of bone turnover, presumably resulting from direct anticancer activity. Elevated baseline bone turnover markers were not prognostic.

CONCLUSION

Failure to suppress bone turnover while receiving ADT, even when otherwise responding to therapy, may identify patients with hormone-sensitive metastatic prostate cancer who are destined for a shorter time to SREs and progression.

Bone-targeted therapies in metastatic castration-resistant prostate cancer: evolving paradigms

Majority of patients with metastatic castrate resistant prostate cancer (mCRPC) develop bone metastases which results in significant morbidity and mortality as a result of skeletal-related events (SREs). Several bone-targeted agents are either in clinical use or in development for prevention of SREs. Bisphosphonates were the first class of drugs investigated for prevention of SREs and zoledronic acid is the only bisphosphonate that is FDA-approved for this indication. Another bone-targeted agent is denosumab which is a fully humanized monoclonal antibody that binds to the RANK-L thereby inhibiting RANK-L mediated bone resorption. While several radiopharmaceuticals were approved for pain palliation in mCRPC including strontium and samarium, alpharadin is the first radiopharmaceutical to show significant overall survival benefit. Contemporary therapeutic options including enzalutamide and abiraterone have effects on pain palliation and SREs as well. Other novel bone-targeted agents are currently in development, including the receptor tyrosine kinase inhibitors cabozantinib and dasatinib. Emerging therapeutics in mCRPC has resulted in great strides in preventing one of the most significant sources of complications of bone metastases.

Bone targeted therapies in metastatic castration-resistant prostate cancer

Prostate cancer is the most common male cancer. About 90% of metastatic patients will develop bone metastases. Bone disease is responsible of pain, deterioration of quality of life and serious bone complications. Proliferation of prostate cancer cells in the bone marrow induces osteoclast activation and osteolysis. Targeting the bone microenvironment reduces morbidity. Relevant preclinical and clinical studies of bone-targeted therapies in castration-resistant prostate cancer were identified in PubMed and clinical trial databases. Different drugs are available or in development that target bone resorption (bisphosphonates, RANK ligand inhibitors), bone formation (endothelin 1 inhibitors), cancer cell migration (SRC-family kinase inhibitors, vascular endothelial growth factor-MET inhibitors), and survival (radiopharmaceuticals). In phase III trials, zoledronic acid, denosumab, and radium-223 were shown to significantly delay skeletal-related events. Radium-223 was also shown to improve overall survival. Biomarkers of bone resorption (urinary N-telopeptide) and bone making (alkaline phosphatase) have an independent prognostic impact. Targeting the bone microenvironment is an important component of castration-resistant prostate cancer management to reduce bone complications and improve overall survival. Biomarkers of bone turnover have an independent prognostic impact.

Novel and bone-targeted agents for CRPC

Clearly, no neoplasm other than prostate cancer has benefited from so many breakthroughs since the beginning of this decade: the past two years can be considered exceptional due to the number of emerging agents against castration-resistant prostate cancer (CRPC), which have demonstrated positive outcomes in phase III trials. Until 2010, docetaxel (Taxotere) was the only agent capable of improving survival in patients with metastatic CRPC. Since then, positive results from phase III trials have been reported for sipuleucel-T, cabazitaxel, denosumab, abiraterone, radium-223, and enzalutamide, while other promising agents including notably orteronel, ipilimumab and cabozantinib are currently under study. Taken together, the incorporation of these agents in the routine management of patients with CRPC is likely to expand their median life expectancy, which was only ∼1 year until the early 2000, to >30 months in the near future. The availability of these agents will lead to new challenges and questions, such as: Can our societies afford the costs? Should we use these agents sequentially or in combination with an incremental benefit? Can we personalise treatment based on the biology of the individual's disease? How will we develop new active compounds in the context where a half dozen approved agents may confound their potential overall survival effect?

Phase III, randomized, placebo-controlled study of docetaxel in combination with zibotentan in patients with metastatic castration-resistant prostate cancer

PURPOSE As part of the ENTHUSE (Endothelin A Use) program, the efficacy and safety of zibotentan (ZD4054), an oral specific endothelin A receptor antagonist, has been investigated in combination with docetaxel in patients with metastatic castration-resistant prostate cancer (CRPC). PATIENTS AND METHODS In this randomized, double-blind, placebo-controlled, phase III study, patients received intravenous docetaxel 75 mg/m(2) on day 1 of 21-day cycles plus oral zibotentan 10 mg or placebo once daily. The primary end point was overall survival (OS). Secondary end points included time to pain and prostate-specific antigen (PSA) progression, pain and PSA response, progression-free survival, health-related quality of life, and safety. Results A total of 1,052 patients received study treatment (docetaxel-zibotentan, n = 524; docetaxel-placebo, n = 528). At the time of data cutoff, there had been 277 and 280 deaths, respectively. There was no difference in OS for patients receiving docetaxel-zibotentan compared with those receiving docetaxel-placebo (hazard ratio, 1.00; 95% CI, 0.84 to 1.18; P = .963). No significant differences were observed on secondary end points, including time to pain progression (median 9.3 v 10.0 months, respectively) or pain response (odds ratio, 0.84; 95% CI, 0.61 to 1.16; P = .283). The median time to death was 20.0 and 19.2 months for the zibotentan and placebo groups, respectively. The most commonly reported adverse events in zibotentan-treated patients were peripheral edema (52.7%), diarrhea (35.4%), alopecia (33.9%), and nausea (33.3%). CONCLUSION Docetaxel plus zibotentan 10 mg/d did not result in a significant improvement in OS compared with docetaxel plus placebo in patients with metastatic CRPC.

New and emerging therapies for bone metastases in genitourinary cancers

CONTEXT

Bone metastases are a common feature of advanced genitourinary malignancies and a prominent cause of morbidity and mortality.

OBJECTIVE

The objective of this review is to discuss the incidence, pathophysiology, and management of bone metastases in the most prevalent genitourinary malignancies.

EVIDENCE ACQUISITION

We reviewed the relevant medical literature, with a particular emphasis on prospective randomized controlled trials. Much of the relevant clinical trial data focus on prostate cancer (PCa). We provide a nonsystematic review and our perspective on the available data.

EVIDENCE SYNTHESIS

Clinical manifestations can include pain, hypercalcemia, pathologic fractures, and spinal cord compression. Optimal systemic therapy for skeletal metastases often features a combination of disease-specific therapy and bone-targeted therapy. Some agents, such as the radiopharmaceutical radium-223, blur the line between those categories. Osteoclast inhibition is a validated strategy in the management of selected patients with bone metastases. Zoledronic acid, a bisphosphonate, is approved for the prevention of skeletal events caused by solid tumors metastatic to bone. Denosumab is a fully human monoclonal antibody that inactivates receptor activator of nuclear factor-κB ligand and is approved for the same indication. Beta-emitting radiopharmaceuticals can be effective for the palliation of pain caused by bone metastases, but their use is often limited by marrow suppression. The alpha-emitting radiopharmaceutical radium-223 has recently been shown to improve overall survival and prevent skeletal events in select men with castration-resistant PCa metastatic to bone. Multiple ongoing clinical trials are designed to examine the potential for therapeutic inhibition of additional targets such as Src and hepatocyte growth factor (MET).

CONCLUSIONS

Bone metastases cause considerable morbidity and mortality among patients with genitourinary malignancies. Optimal management requires consideration of bone-targeted therapy as well as disease-specific therapy. Further research is needed to optimize the use of existing agents and to define the therapeutic potential of novel targets.

Nonhormone therapy for metastatic castration-resistant prostate cancer: chemotherapy, bone-targeted treatments, and others

There is no doubt that more therapeutic progress has been achieved during the last 3 years for patients with metastatic castration-resistant prostate cancer (mCRPC) than during the previous 30 years. During this limited time frame, not only have six compounds (sipuleucel-T, cabazitaxel, denosumab, abiraterone, radium-223, and enzalutamide, listed in chronologic order) yielded positive results in phase III trials, we have also learned that their mechanisms of action are different, making it quite likely that part of their anticancer activity may be incremental. Most of these agents have already been approved. Further progress may well soon complete this recently enlarged armamentarium, with important trials testing new agents derived from existing families of compounds (new endocrine therapies, new immunotherapies, etc.) and exploring the activity of new families of agents (tyrosine kinase inhibitors such as cabozantinib, inhibitors of chaperone proteins like OGX-O11 and OGX-427). The availability of these agents creates a new major challenge for those who conduct clinical research in mCRPC. Will we be able to personalize therapy based on the biology of the individual's tumor, as we are already doing in other neoplasms?

Clinical usefulness of bone markers in prostate cancer with bone metastasis

Bone metastases occur in approximately 70% of patients with advanced prostate cancer. Skeletal-related events have been correlated with reduced survival and quality of life of patients with prostate cancer. Biochemical markers of bone metabolism (e.g. bone formation, bone resorption, osteoclastogenesis) might meet an unmet need for useful, non-invasive and sensitive surrogate information for following patients' skeletal health. Recently, zoledronic acid and denosumab have been proven to have the potential for preventing skeletal-related events among prostate cancer patients with bone metastasis. An improved understanding of the mechanisms underlying bone metastasis has also led to the recognition of multiple molecular targets and advances in therapy. However, estimating the efficacy of these agents is difficult. A clinical trial for castration-resistant prostate cancer is currently underway based on the definition of The Prostate Cancer Clinical Trials Working Group, and bone turnover markers are being used as conventional end-points for the clinical trial. Bone turnover markers are useful surrogate markers reflecting the effect of new therapeutic drugs and prognosis, as well as assessment of bone metastases. In particular, N-terminal cross-linked telopeptide of type 1 collagen and bone-specific alkaline phosphatase are widely used bone metabolism markers, and offer reliable surrogate markers to detect bone metastatic spread and to predict prognosis for prostate cancer patients with bone metastases.

Once-daily dasatinib: expansion of phase II study evaluating safety and efficacy of dasatinib in patients with metastatic castration-resistant prostate cancer

OBJECTIVES

To determine the activity and tolerability of 100-mg once-daily (QD) dasatinib in patients with metastatic castration-resistance prostate cancer (CRPC). Dasatinib, an oral Src family kinase inhibitor, has demonstrated both preclinical and clinical activity with twice-daily dosing in patients with metastatic CRPC.

METHODS

Chemotherapy-naive men with metastatic CRPC and increasing prostate-specific antigen levels were treated with dasatinib 100 mg QD. The primary measurement was a composite lack of disease progression, according to the Prostate Cancer Working Group 2 criteria, determined every 12 weeks during the study. The other analyses included changes in the prostate-specific antigen level, bone lesions, soft tissue disease, and bone turnover markers (urine N-telopeptide and bone alkaline phosphatase).

RESULTS

The present trial was designed before the publication of the recent Prostate Cancer Working Group 2 criteria; however, the analyses are presented to conform to the updated guidelines. A total of 48 patients received dasatinib. A lack of disease progression was observed in 21 patients (44%) at week 12 and in 8 (17%) at week 24. Urine N-telopeptide was reduced by ≥40% from baseline in 22 (51%) of 43 patients, and bone alkaline phosphatase was decreased in 26 (59%) of 44 patients. Dasatinib was well-tolerated, with only 6 patients (13%) with drug-related grade 3-4 adverse events and 3 (6%) with grade 3 adverse events. The most common treatment-related adverse events (≥20%) were fatigue, nausea, diarrhea, headache, and anorexia.

CONCLUSIONS

Dasatinib 100 mg QD has a favorable safety profile and maintains a similar degree of activity as the previously reported twice-daily dosing schedules. These data support additional study of dasatinib 100 mg QD for metastatic CRPC.

Once-daily dasatinib: expansion of phase II study evaluating safety and efficacy of dasatinib in patients with metastatic castration-resistant prostate cancer

OBJECTIVES

To determine the activity and tolerability of 100-mg once-daily (QD) dasatinib in patients with metastatic castration-resistance prostate cancer (CRPC). Dasatinib, an oral Src family kinase inhibitor, has demonstrated both preclinical and clinical activity with twice-daily dosing in patients with metastatic CRPC.

METHODS

Chemotherapy-naive men with metastatic CRPC and increasing prostate-specific antigen levels were treated with dasatinib 100 mg QD. The primary measurement was a composite lack of disease progression, according to the Prostate Cancer Working Group 2 criteria, determined every 12 weeks during the study. The other analyses included changes in the prostate-specific antigen level, bone lesions, soft tissue disease, and bone turnover markers (urine N-telopeptide and bone alkaline phosphatase).

RESULTS

The present trial was designed before the publication of the recent Prostate Cancer Working Group 2 criteria; however, the analyses are presented to conform to the updated guidelines. A total of 48 patients received dasatinib. A lack of disease progression was observed in 21 patients (44%) at week 12 and in 8 (17%) at week 24. Urine N-telopeptide was reduced by ≥40% from baseline in 22 (51%) of 43 patients, and bone alkaline phosphatase was decreased in 26 (59%) of 44 patients. Dasatinib was well-tolerated, with only 6 patients (13%) with drug-related grade 3-4 adverse events and 3 (6%) with grade 3 adverse events. The most common treatment-related adverse events (≥20%) were fatigue, nausea, diarrhea, headache, and anorexia.

CONCLUSIONS

Dasatinib 100 mg QD has a favorable safety profile and maintains a similar degree of activity as the previously reported twice-daily dosing schedules. These data support additional study of dasatinib 100 mg QD for metastatic CRPC.

Novel prognostic markers in the serum of patients with castration-resistant prostate cancer derived from quantitative analysis of the pten conditional knockout mouse proteome

BACKGROUND

Metastatic castration-resistant prostate cancer (mCRPC) is associated with a poor outcome. Prognostic information is useful and aids treatment decisions. However, current nomograms based on clinical parameters alone have weak prognostic accuracy. Therefore, the identification of new prognostic serum biomarkers could be useful.

OBJECTIVES

To assess if quantitative analysis of the phosphatase and tensin homolog (Pten) conditional knockout mouse proteome reveals significant prognostic biomarkers in mCRPC and to compare the accuracy of these biomarkers with known prognostic factors.

DESIGN, SETTING, AND PARTICIPANTS

Fifty-seven patients with mCRPC were evaluated retrospectively. Prognostic factors used in clinical nomograms were assessed from the records. New candidate biomarkers in patients' sera were derived using a cancer genetics-guided model we recently described, screening the murine Pten-dependent glycoproteome.

MEASUREMENTS

Quantification in patients' sera was performed by either mass spectrometry-based targeted proteomics or enzyme-linked immunosorbent assays. Prognostic biomarkers for survival were identified based on Kaplan-Meier models. In a second step, random forest analysis was performed to identify a prognostic signature combined from the pooled data of known predictors and newly identified biomarkers.

RESULTS AND LIMITATIONS

With univariate analysis, 13 new significant prognostic factors for survival in the sera of mCRPC patients were found with a Bonferroni-corrected level of significance <5%. Random forest analysis revealed a five-factor predictor (thrombospondin 1; C-reactive protein; poliovirus receptor-related 1; ephrin-A5; and membrane metallo-endopeptidase) with an accuracy of 96% and 94% for 12- and 24-mo survival, respectively. This means that, in our dataset, the error was reduced by 15% compared to using the Halabi et al. nomogram. The retrospective nature of the work and absence of a validating dataset is the major limitation of this work.

CONCLUSIONS

Analysis of the serum proteome in mCRPC patients based on our Pten conditional knockout model, combined with known prognostic factors, potentially improves accuracy of prognostic nomograms. These newly identified markers have to be validated in prospective studies.

Biologic tools to personalize treatment in genitourinary cancers

BACKGROUND

Genitourinary (GU) cancers are a major healthcare issue in modern oncology. In the last decade many efforts have been made to develop new treatment options but with the possible exception of renal cell carcinoma, very few steps ahead have been taken. At the same time, a wide variety of molecular markers, potentially helpful in identifying patient subpopulation most likely to benefit from a specific treatment have been identified. Our goal is to clarify if biomarkers could be used at present to personalize treatment for GU cancers.

MATERIALS AND METHODS

Literature was search using PubMed and EMBASE using different terms and combinations regarding possible prognostic and predictive markers in renal, prostate and urothelial cancers.

RESULTS

3546 articles were retrieved. After excluding duplications, preclinical studies and factors without possible predictive value 654 publications remain. N-telopeptide, HER2/neu, EGFR, and p53 in prostate cancer, sVEGF-A for RCC and EMMPRIN and Survivin in urothelial cancer were among those identified. After a careful examination of published data, none of them reached a sufficient evidence to be suggested for use outside of clinical trials.

CONCLUSIONS

To date any reliable biomarkers has been validated for tailored treatments approaches in GU cancer. Future studies focusing on this issue are urgently needed.

Evolving role of bone biomarkers in castration-resistant prostate cancer

The preferential metastasis of prostate cancer cells to bone disrupts the process of bone remodeling and results in lesions that cause significant pain and patient morbidity. Although prostate-specific antigen (PSA) is an established biomarker in prostate cancer, it provides only limited information relating to bone metastases and the treatment of metastatic bone disease with bisphosphonates or novel noncytotoxic targeted or biological agents that may provide clinical benefits without affecting PSA levels. As bone metastases develop, factors derived from bone metabolism are released into blood and urine, including N- and C-terminal peptide fragments of type 1 collagen and bone-specific alkaline phosphatase, which represent potentially useful biomarkers for monitoring metastatic bone disease. A number of clinical trials have investigated these bone biomarkers with respect to their diagnostic, prognostic, and predictive values. Results suggest that higher levels of bone biomarkers are associated with an increased risk of skeletal-related events and/or death. As a result of these findings, bone biomarkers are now being increasingly used as study end points, particularly in studies investigating novel agents with putative bone effects. Data from prospective clinical trials are needed to validate the use of bone biomarkers and to confirm that marker levels provide additional information beyond traditional methods of response evaluation for patients with metastatic prostate cancer.

Bone turnover markers as predictors of mortality risk in prostate cancer patients with bone metastases following treatment with zoledronic acid

BACKGROUND

Clinical data have limited validity for predicting the survival of prostate cancer (PCa) patients with bone metastases. There is a need to improve the predictive evidence both for clinicians and patients.

OBJECTIVE

To evaluate the predictive ability of serum bone markers for mortality risk in PCa patients with bone metastases.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a survival analysis in relation to bone markers in a subgroup of 52 patients treated with zoledronic acid (4 mg every 4 wk for 15 mo) in a prospective, multicentre trial during 2002-2005, about 4 yr after the end of the trial.

MEASUREMENTS

Serum levels of total and bone-specific alkaline phosphatase, amino-terminal procollagen propeptides of type I collagen (PINP), cross-linked N-terminal (NTx) and cross-linked C-terminal telopeptides of type I collagen (ICTP), C-terminal telopeptides of type I collagen, prostate-specific antigen from the last visit of the treatment study, and clinical data were related to the overall survival (OS) status of patients in the follow-up. Univariate and multivariate Cox regression analyses with internal bootstrapping validation and concordance index calculations were performed.

RESULTS AND LIMITATIONS

Out of the 52 patients followed, 34 died within a median follow-up of 13.8 mo, and 18 patients were alive at a median follow-up of 43.8 mo. The patients who died within the follow-up period had significantly higher concentrations of ICTP, NTx, and PINP than the surviving patients. Cox regression models with clinical data and bone markers showed that ICTP and PINP were most predictive for mortality risk in addition to the occurrence of skeletal-related complications and the continuation of treatment with zoledronic acid. Internal validation confirmed the reliability of the results, although the sample size was small.

CONCLUSIONS

PINP and ICTP can be considered suitable predictors for the OS of PCa patients with bone metastases.

Zoledronic acid impairs myeloid differentiation to tumour-associated macrophages in mesothelioma

Background:

Suppressive immune cells present in tumour microenvironments are known to augment tumour growth and hamper efficacy of antitumour therapies. The amino-bisphosphonate Zoledronic acid (ZA) is considered as an antitumour agent, as recent studies showed that ZA prolongs disease-free survival in cancer patients. The exact mechanism is a topic of debate; it has been suggested that ZA targets tumour-associated macrophages (TAMs).

Methods:

We investigate the role of ZA on the myeloid differentiation to TAMs in murine mesothelioma in vivo and in vitro. Mice were intraperitoneally inoculated with a lethal dose of mesothelioma tumour cells and treated with ZA to determine the effects on myeloid differentiation and survival.

Results:

We show that ZA impaired myeloid differentiation. Inhibition of myeloid differentiation led to a reduction in TAMs, but the number of immature myeloid cells with myeloid-derived suppressor cell (MDSC) characteristics was increased. In addition, ZA affects the phenotype of macrophages leading to reduced level of TAM-associated cytokines in the tumour microenvironment. No improvement of survival was observed.

Conclusion:

We conclude that ZA leads to a reduction in macrophages and impairs polarisation towards an M2 phenotype, but this was associated with an increase in the number of immature myeloid cells, which might diminish the effects of ZA on survival.

Molecular circuits of solid tumors: prognostic and predictive tools for bedside use

The explosion of knowledge in cancer biology in the past two decades has led to the identification of specific molecular circuits in solid tumors. These pathways reflect specific abnormalities thought to drive malignant progression. This knowledge has also generated a vast panel of cancer biomarkers although many of these biomarkers lack sufficient research and validation to be used in the clinic. This Review discusses relevant molecular prognostic and/or predictive biomarkers in the six leading tumors with the highest contribution to cancer mortality: breast, lung, colorectal, prostate, pancreatic and ovarian cancer. Each biomarker is described according to its associated clinicopathological presentation and specific associated molecular interactions. Despite only few biomarkers being currently implemented in clinical practice, a new generation of predictors is emerging that could modify the classic organ-based cancer classification (for example, defects in DNA repair, aberrant MAPK signaling and aberrant PI3K/Akt/mTOR signaling). The advent of high-throughput strategies will also probably substitute monobiomarker strategies.