Improved detection of recurrent bladder cancer using the Bard BTA stat Test

BTA stat®, NMP22® BladderChek®, UBC® Rapid Test, and CancerCheck® UBC® rapid VISUAL as urinary marker for bladder cancer: Final results of a German multicenter study

INTRODUCTION AND OBJECTIVE

BTA stat®, NMP22® BladderChek®, UBC® Rapid Test, and CancerCheck® UBC® rapid VISUAL are urinary-based rapid tests. This multicenter study is the first study comparing all available rapid tests on a large cohort of bladder cancer patients and healthy controls in one setting.

METHODS

In total 732 urine samples (second morning urine) in a real-world assessment have been analyzed. We evaluated clinical samples from 464 patients with histologically confirmed urothelial tumors of the urinary bladder (17 solitary CIS, 189 low-grade, 187 high-grade nonmuscle invasive, 71 high-grade muscle invasive), 77 patients with No Evidence of Disease (NED), and from 191 healthy controls. Urine samples were analyzed by the BTA stat®, NMP22® BladderChek®, UBC® Rapid Test point-of-care (POC) system using the concile Omega 100 POC reader, and CancerCheck® UBC® rapid VISUAL. Sensitivities and specificities were calculated by contingency analyses.

RESULTS

All investigated urinary markers detected more pathological concentrations in urine of bladder cancer patients compared to tumor-free patients. The calculated diagnostic sensitivities for BTA stat®, NMP22® BladderChek®, UBC® Rapid Test, CancerCheck® UBC® rapid VISUAL, and cytology were 62.4%, 13.4%, 58.2%, 28.6%, 36.2% for low-grade, 83.4%, 49.5%, 84.5%, 63.1%, 71.2% for high-grade nonmuscle invasive, and 95.8%, 35.2%, 76.1%, 50.7%, 67.7% for high-grade muscle-invasive bladder cancer. The specificity was 67.9%, 95.5%, 79.4%, 94.4%, and 83.7%, respectively. The area under the curve (AUC) after receiver operating characteristics (ROC) analysis for high-grade non-muscle-invasive tumors was 0.757, 0.725, 0.819, 0.787, and 0.774, respectively.

CONCLUSIONS

The analysis of more than 700 urine samples offers an objective view on urine-based rapid diagnostics. Elevated pathological concentrations of markers in urine of bladder cancer patients were detected in all investigated tests. The highest sensitivities for high-grade non-muscle-invasive tumors were calculated for BTA stat® and UBC® Rapid Test, whereas NMP22® BladderChek®, and cytology showed the highest specificities. BTA stat® and UBC® Rapid Test have the potential to be used as a clinical valuable urinary protein biomarker for the detection of high-grade non-muscle-invasive bladder cancer patients and could be included in the management of these tumors.

Proteomics for Early Detection of Non-Muscle-Invasive Bladder Cancer: Clinically Useful Urine Protein Biomarkers

Bladder cancer is the fourth most common cancer in men, and most cases are non-muscle-invasive. A high recurrence rate is a critical problem in non-muscle-invasive bladder cancer. The availability of few urine tests hinders the effective detection of superficial and small bladder tumors. Cystoscopy is the gold standard for diagnosis; however, it is associated with urinary tract infections, hematuria, and pain. Early detection is imperative, as intervention influences recurrence. Therefore, urinary biomarkers need to be developed to detect these bladder cancers. Recently, several protein candidates in the urine have been identified as biomarkers. In the present narrative review, the current status of the development of urinary protein biomarkers, including FDA-approved biomarkers, is summarized. Additionally, contemporary proteomic technologies, such as antibody-based methods, mass-spectrometry-based methods, and machine-learning-based diagnosis, are reported. Furthermore, new strategies for the rapid and correct profiling of potential biomarkers of bladder cancer in urine are introduced, along with their limitations. The advantages of urinary protein biomarkers and the development of several related technologies are highlighted in this review. Moreover, an in-depth understanding of the scientific background and available protocols in research and clinical applications of the surveillance of non-muscle bladder cancer is provided.

Biomarkers in Bladder Cancer Surveillance

Aim: This is a narrative review with an aim to summarise and describe urinary biomarkers in the surveillance of non-muscle-invasive bladder cancer (NMIBC). It provides a summary of FDA-approved protein biomarkers along with emerging ones which utilise genetic, epigenetic and exosomal markers. We discuss the current limitations of the available assays. Background: Current guidelines advice a combination of cystoscopy, imaging,and urine cytology in diagnosis and surveillance. Although cytology has a high specificity, it is limited by low sensitivity particularly in low grade tumours. There are six FDA-approved urinary assays for diagnosis and surveillance of bladder cancer. They have shown to improve sensitivity and specificity to be used alongside cytology and cystoscopy but have a lower specificity in comparison to cytology and false positives often occur in benign conditions. Recent developments in laboratory techniques has allowed for use of markers which are RNA-, DNA-based as well as extracellular vesicles in the past decade. Methods: Using the PubMed/Medline search engines as well as Google Scholar, we performed an online search using the terms "bladder cancer," "non-muscle invasive bladder cancer," and "urine biomarkers" with filter for articles in English published up to May 2021. Systematic reviews and original data of clinical trials or observational studies which contributed to the development of the biomarkers were collated. Results: Biomarkers identified were divided into FDA-approved molecular biomarkers, protein biomarkers and gene-related biomarker with a table summarising the findings of each marker with the most relevant studies. The studies conducted were mainly retrospective. Due to the early stages of development, only a few prospective studies have been done for more recently developed biomarkers and limited meta-analyses are available.Therefore a detailed evaluation of these markers are still required to decide on their clinical use. Conclusion: Advancements of analytical methods in BC has driven the research towards non-invasive liquid-based biomarkers in adjunct to urine cytology. Further large prospective studies are required to determine its feasibility in a clinical setting as they are not effective when used in isolation as they have their limitation. With the ongoing pandemic, other than reduction in costs and increased accuracy, the need for biomarkers to cope with delay in cystoscopies in diagnosis and surveillance is crucial. Thus clinical trials with direct comparison is required to improve patient care.

Prominence of urinary biomarkers for bladder cancer in the COVID-19 era: From the commercially available to new prospective candidates

Molecular markers detected in urine may improve our understanding of the evolution of bladder cancer (BCa) and its micro- and macroenvironment. Detection of such markers will identify disease earlier, allow stratification of patients according to risk, and improve prognostication and prediction of outcomes, thereby facilitating targeted therapy. However, current guidelines have yet to embrace such markers for routine management of BCa, and most research studies have focused on urine-based tumor markers. In this review, we summarize known urinary biomarkers for BCa and highlight newly identified molecules. We then discuss the challenges that must be overcome to incorporate these markers into clinical care.

Review of non-invasive urinary biomarkers in bladder cancer

Bladder cancer (BC) is the sixth-most prevalent cancer. The standard diagnostic tool of BC is cystoscopy, whereas cystoscopy has several disadvantages in terms of symptomatic invasiveness and operator-dependency. The urinary markers are attractive because the testing is non-invasive and cost-efficient, and sample collection is easy. Urinary marker is thereby a good tool to detect exfoliated tumor cell in the urine samples for the diagnosis and therapeutic surveillance of BC to supplement the limitations of the cystoscopy. However, they are not recommended as a population-based screening tool because of the low rate of BC prevalence. Although both cystoscopy and urine cytology improve BC diagnostic power, the field still needs additional non-invasive, cost-effective, and highly sensitive and specific diagnostic tools. Various urinary markers with different mechanisms and different targets have been developed and under investigation in these days. However, the accuracy of the urinary marker including its sensitivity and specificity is the most important factor for the diagnosis and surveillance in cancer that this review deals with multiple FDA-approved and non-FDA approved commercialized urinary markers with their accuracy in different purposes for BC. We then discuss more about the potential candidate targets for the future urinary markers in BC

Phenotypic Analysis of Urothelial Exfoliated Cells in Bladder Cancer via Microfluidic Immunoassays: Sialyl-Tn as a Novel Biomarker in Liquid Biopsies

Bladder cancer is the most common malignancy of the urinary tract, having one of the highest recurrence rates and progression from non-muscle to muscle invasive bladder cancer that commonly leads to metastasis. Cystoscopy and urine cytology are the standard procedures for its detection but have limited clinical sensitivity and specificity. Herein, a microfluidic device, the UriChip, was developed for the enrichment of urothelial exfoliated cells from fresh and frozen urine, based on deformability and size, and the cancer-associated glycan Sialyl-Tn explored as a putative bladder cancer urinary biomarker. Spiking experiments with bladder cancer cell lines showed an isolation efficiency of 53%, while clinical sample analyses revealed retention of cells with various morphologies and sizes. in situ immunoassays demonstrated significantly higher number of Sialyl-Tn-positive cells in fresh and frozen voided urine from bladder cancer patients, compared to healthy individuals. Of note, urothelial exfoliated cells from cryopreserved urine sediments were also successfully isolated by the UriChip, and found to express significantly high levels of Sialyl-Tn. Remarkably, Sialyl-Tn expression is correlated with tumor stage and grade. Overall, our findings demonstrate the potential of UriChip and Sialyl-Tn to detect urothelial bladder cancer cells in follow-up and long-term retrospective studies.

Urinary biomarkers in bladder cancer: A review of the current landscape and future directions

AIM

This narrative review aims to describe established and emerging urinary biomarkers in the diagnosis and surveillance of non-muscle invasive bladder cancer. It provides a comprehensive account of classical, FDA-approved protein biomarkers and discusses their limitations. Further, we discuss the role that epigenetic, genetic, and exosomal markers can play to enhance sensitivity and specificity of the available tests.

BACKGROUND

The initial diagnosis and surveillance of bladder cancer involves a combination of cystoscopy, upper urinary tract imaging, and urine cytology. Despite high specificity, cytology is limited by low sensitivity. There are currently 6 urinary assays approved by the FDA to enhance diagnosis and surveillance of bladder cancer. While these have improved diagnosis and surveillance when combined with cytology, these tests are still not sufficiently sensitive and false positives often occur in benign conditions which result in inflammation of the urinary tract. Advancements in laboratory techniques have produced significant advancements in epigenetic and genetic markers, as well as extracellular vesicles, with DNA- and RNA-based markers dominating the research in this area in recent years.

METHODS

We identified relevant published data, using the PubMed/ Medline search engines as well as Google Scholar. We performed an online search using the terms "bladder cancer", "non-muscle invasive bladder cancer" in combination with "urine biomarkers" and limited articles in English published up to February 2020. This review consolidated on all available narrative and systematic reviews published in the 5 years in this field, while also reviewing the original data of each clinical trial or observational study which led to the development of the biomarkers.

CONCLUSION

The development of laboratory techniques and understanding urine-based biomarkers in BC has fuelled the use of noninvasive liquid-based biomarkers to complement urine cytology. Nonetheless, none are sufficiently effective when used in isolation, and cytology remains the gold standard in many practices. Future efforts will be focused on using these markers in combination as a predictive signature, and moving on to validating them for use in everyday clinical practice.

Comparison of Pteridine Normalization Methods in Urine for Detection of Bladder Cancer

Pterin compounds belong to the group of biomarkers for which an increase in interest has been observed in recent years. Available literature data point to this group of compounds as potential biomarkers for cancer detection, although the biochemical justification for this claim is not yet fully understood. The aim of this study was to evaluate the usefulness of pterin compounds in the diagnosis of bladder cancer, with particular emphasis on the role of creatinine and the specific gravity of urine as factors for normalizing the concentration of pterin compounds in urine. The standardization of the concentration of pterin compounds to urine specific gravity allows the building of better classification models for screening patients with potential cancer of the bladder. Of the compounds that make up the pterin profile, isoxanthopterin appears to be a compound that can potentially be described as a biomarker of bladder cancer.

Effectiveness of bladder tumor antigen quantitative test in the diagnosis of bladder carcinoma in a schistosoma endemic area

Introduction:

Bladder carcinoma is the most common male cancer in our environment due to endemicity of schistosomiasis. Squamous-cell carcinoma is the most common histological type and patients present at an advanced stage. The objective of this study is to compare the sensitivity, specificity, and predictive values of the bladder tumor antigen quantitative test (BTA TRAK) and urine cytology in the diagnosis of bladder carcinoma in a schistosoma endemic area.

Materials and Methods:

This is a 12-month cross-sectional study of 88 patients, 52 of them with features of bladder carcinoma as study group, and 36 of them with hematuria from other urologic conditions, and benign urologic conditions and healthy volunteers as control group (CG). The mean ages of patients in the study and CGs were 47.17 ± 17.00 and 44.19 ± 18.89 years, respectively (P = 0.412). Bladder tumor antigen was assayed using enzyme-linked immunosorbent assay. Data were analyzed using SPSS version 20.0 for Windows.

Results:

The sensitivity of urine cytology and BTA TRAK in the study was 29.1% and 98.8%, respectively. The specificity of urine cytology and BTA TRAK was 95.5% and 13.6%, respectively (P = 0.05). The positive predictive values of urine cytology and BTA TRAK in the study were 96.2% and 81.7%, respectively. The negative predictive values were 25.0% and 75.0% for urine cytology and BTA TRAK, respectively.

Conclusion:

BTA TRAK is more sensitive but poorly specific as compared to that of the urine cytology for bladder cell carcinoma detection in a schistosoma endemic area.

Emerging biomarkers for the diagnosis and monitoring of urothelial carcinoma

Urothelial carcinoma (UC) arises extensively from the renal pelvis, ureter, urinary bladder, and urethra. UC represents a clinical and social challenge because of its incidence, post-treatment recurrence rate, and prognosis. Combinations of urine cytology, cystoscopy, and conventional imaging such as computed tomography are currently used for diagnosis and monitoring modalities of UC. Both the poor diagnostic accuracy of urine cytology and poor cost performance of cystoscopy and conventional imaging modalities emphasize the urgent need for advancement in clinical guidance for UC. Urine- and blood-based biomarkers for detection of UC of the bladder and upper urinary tract represent a considerable research area. Biomarkers can help to improve UC diagnosis with the aim of replacing cystoscopy and other imaging examinations in future and may enable individualizing risk stratification regarding therapy and follow-up. Over the decades, numerous studies have focused on the potential application of biomarkers for UC, including urine, circulating tumor DNA, RNAs, proteins, and extracellular vesicles. Although some biomarkers such as ImmunoCyt/uCyt+, UroVysion, NMP-22, bladder tumor antigen, CxBladder, and Xpert Bladder Cancer are currently available in clinical practice, few biomarkers achieve high sensitivity and specificity. Emerging biomarkers are continuously developed and reported in medical journals. However, there is a significant lack on following external validation using different cohorts. The positive results are needed to be confirmed by more studies with large-scale cohorts and long follow-up periods to prove the true value of novel biomarkers, followed by their adoption in clinical practice. The present paper provides an overview of the evidence based on high-impact studies regarding urine- and blood-based biomarkers and their clinical applications in bladder cancer and upper tract UC.

An up-to-date catalog of available urinary biomarkers for the surveillance of non-muscle invasive bladder cancer

OBJECTIVES

With the advent of novel genomic and transcriptomic technologies, new urinary biomarkers have been identified and tested for bladder cancer (BCa) surveillance. To summarize the current status of urinary biomarkers for the detection of recurrence and/or progression in the follow-up of non-muscle invasive BCa patients, and to assess the value of urinary biomarkers in predicting response to intravesical Bacillus Calmette-Guerin (BCG) therapy.

METHODS AND MATERIALS

A medline/pubmed© literature search was performed. The performance of commercially available and investigational biomarkers has been reviewed. End points were cancer detection (recurrence), cancer progression, and response to BCG therapy.

RESULTS

The performance requirements for biomarkers are variable according to the clinical scenario. The clinical role of urinary biomarkers in the follow-up of non-muscle invasive BCa patients remains undefined. The FDA-approved tests provide unsatisfactory sensitivity and specificity levels and their use is limited. Fluorescence in situ hybridization (FISH) has been shown to be useful in specific scenarios, mostly as a reflex test and in the setting of equivocal urinary cytology. FISH and immunocytology could conceivably be used to assess BCG response. Recently developed biomarkers have shown promising results; upcoming large trials will test their utility in specific clinical scenarios in a manner similar to a phased drug development strategy.

CONCLUSIONS

Current commercially available urinary biomarker-based tests are not sufficiently validated to be widely used in clinical practice. Several novel biomarkers are currently under investigation. Prospective multicenter analyses will be needed to establish their clinical relevance and value.

BTA-TRAK Combined with Urinary Cytology is a Reliable Urinary Indicator of Recurrent Transitional Cell Carcinoma (TCC) of the Bladder

This study evaluated the diagnostic accuracy of BTA-TRAK in combination with urinary cytology (UC) in the follow-up of patients with a history of transitional cell carcinoma (TCC) of the bladder. The overall sensitivity of BTA-TRAK, UC and the two tests combined for the detection of recurrences was 82.7% (48/58), 84.2% (48/57) and 91.2% (52/57), respectively. BTA and UC showed comparable sensitivity for superficial recurrences (76.7% (33/43) and 78.5% (33/42), respectively) and for invasive recurrences (100% (15/15)); when the two tests were used in combination, the sensitivity for superficial lesions increased to 88% (37/42). BTA-TRAK was more sensitive than UC for G1 recurrences (81.2% (13/16) vs. 68.7% (11/16)), and when the two tests were combined the sensitivity increased to 87.5% (14/16). The sensitivity of the combination was 100% (15/15) for G3 lesions. The differences in urinary BTA-TRAK levels between patients with recurrences and those without evidence of disease were statistically significant (Wilcoxon's test, p<0.05); among patients with recurrences BTA levels were significantly higher in the invasive and poorly differentiated subtypes. In the series of patients studied by us, BTA-TRAK combined with UC was shown to be a non-invasive, accurate test to predict TCC recurrences. Periodic measurement of BTA-TRAK combined with urinary cytology seems to provide additional information for the monitoring of patients treated for TCC; however, due to the presence of false positive and false negative results, this test cannot replace cystoscopy. In a selected group of patients it could, if combined with cytology and ultrasonography and if correctly used and interpreted, orient the timing and indication for cystoscopy.

Bladder Tumor Markers: A Review of the Literature

Bladder cancer is among the top eight most frequent cancers. Its natural history is related to a combination of factors that impact on its aggressiveness. Cystoscopy and urine cytology are the currently used techniques for the diagnosis and surveillance of non-invasive bladder tumors. The sensitivity of urine cytology for diagnosis is not high, particularly in low-grade tumors. The combination of voided urine cytology and new diagnostic urine tests would be ideal for the diagnosis and follow-up of bladder cancer. However, in order to have some clinical utility, new diagnostic and/or prognostic markers should achieve better predictive capacity that the currently used diagnostic tools. None of the markers evaluated over the last years showed remarkable sensitivity or specificity for the identification of any of the diverse types of bladder cancer in clinical practice. The limitations of the known prognostic markers have led to the research of new molecular markers for early detection of bladder cancer. This research focused in particular on the discovery of biomarkers capable of reducing the need for periodic cystoscopies or, ideally, offering a non-invasive examination instead. In this review, we will examine various new markers of bladder cancer and their value in the diagnosis and follow-up of non-muscle-invasive bladder cancer. When compared with urine cytology, which showed the highest specificity, most of these markers demonstrated an increased sensitivity.

The contemporary role and impact of urine-based biomarkers in bladder cancer

Despite advances in the surgical and medical treatment of bladder cancer, there have only been minor improvements in mortality and morbidity rates over the past decades. Urine-based markers help to improve diagnosing bladder cancer with the aim of complementing or probably in future replacing cystoscopy. Biomarkers may allow individualized risk stratification and support decision-making regarding therapy and follow-up. This review summarizes the existing urine-based biomarkers in bladder cancer. We conducted a comprehensive review of the literature. We conducted a PubMed/Medline based research on English language articles and selected original articles and review articles that provided both description and assessment of urinary markers at time of screening, initial diagnosis, monitoring and prognostic evaluation of urothelial bladder cancer. Our research covered studies published between 2000 and 2017. The aim of this study was to give clinicians keys to understand the existing or promising urinary markers that may become alternatives to cytology/cystoscopy pair in the near future. Many urinary markers are now available, often with superior sensitivity to cytology. Their uses have been evaluated in numerous clinical situations in addition to the time of initial diagnosis and surveillance such as cases of isolated macroscopic hematuria or atypical cytology discordant with the rest of the explorations. However, their superiority over the cytology/cystoscopy association is not demonstrated. These new markers are lacking for the most part of standardization and simplicity making their use in common practice difficult. the types and forms of these new markers are very heterogeneous among themselves and between the studies that evaluate them. Well-designed protocols and prospective, controlled trials are needed to provide the basis to determine whether integration of urine- and blood-based biomarkers into clinical decision-making will be of value for bladder cancer detection and screening in the future.

Identification of novel candidate circulating biomarkers for malignant soft tissue sarcomas: Correlation with metastatic progression

Soft tissue sarcomas (STS) are a heterogeneous group of rare tumors for which identification and validation of biological markers may improve clinical management. The fraction of low-molecular-weight (LMW) circulating proteins and fragments of proteins is a rich source of new potential biomarkers. To identify circulating biomarkers useful for STS early diagnosis and prognosis, we analyzed 53 high-grade STS sera using hydrogel core-shell nanoparticles that selectively entrap LMW proteins by size exclusion and affinity chromatography, protect them from degradation and amplify their concentration for mass spectrometry detection. Twenty-two analytes mostly involved in inflammatory and immunological response, showed a progressive increase from benign to malignant STS with a relative difference in abundance, more than 50% when compared to healthy control. 16 of these were higher in metastatic compared to non-metastatic tumors. Cox's regression analysis revealed a statistical significant association between the abundance of lactotransferrin (LTF) and complement factor H-related 5 (CFHR5) and risk of metastasis. In particular, CFHR5 was associated with the risk of metastasis. The role of circulating proteins involved in metastatic progression will be crucial for a better understanding of STS biology and patient management.

A pilot study of urinary microRNA as a biomarker for urothelial cancer

OBJECTIVE

MicroRNAs (miRNAs) are part of a class of small ribonucleic acid (RNAs). They are important regulatory molecules, involved in several cell processes, such as developmental timing, stem cell division and apoptosis. Dysregulated miRNAs have been identified in several human malignancies, including bladder cancer tissue samples, and may confer a "tumour signature" that can be exploited for diagnostic purposes. We report on a prospective pilot study investigating the diagnostic capability of miRNAs in the urine of patients with urothelial cancer.

METHODS

Voided urine samples were collected from patients with urothelial carcinoma just prior to bladder tumour resection, as well as age-matched healthy control patients. Pathology demonstrated both low- and high-grade cancer. Total RNA was isolated and quantitative reverse transcriptase-polymerase chain reaction was performed on the RNA extracts using primers for 4 miRNAs shown previously to be dysregulated in solid urothelial carcinomas with RNU6B as the endogenous control. Standard urine cytology was performed on all samples in a blinded fashion.

RESULTS

Two miRNAs of interest were dysregulated in the urine from cancer patients with miR-125b showing an average 10.42-fold decrease (p < 0.01) and miR-126 showing an average 2.70-fold increase (p = 0.30) in the cancer samples compared to the normal controls. The sensitivity and specificity of the cytology on the same urine samples were 50% and 80%, respectively. Using these 2 miRNAs only, a decision-tree prediction model was generated for a validation cohort of patients yielding a specificity of 100% and a sensitivity of 80%.

DISCUSSION

This preliminary study of candidate urinary miRNA in patients with low- and high-grade urothelial cancer demonstrated a significantly improved diagnostic accuracy over cytology. These results provide rationale for further studies on discovery and validation of candidate miRNAs in voided urine and may potentially lead to the development of a non-invasive and sensitive test for bladder cancer diagnosis and prognosis.

Molecular markers for bladder cancer screening, early diagnosis, and surveillance: the WHO/ICUD consensus

Due to the lack of disease-specific symptoms, diagnosis and follow-up of bladder cancer has remained a challenge to the urologic community. Cystoscopy, commonly accepted as a gold standard for the detection of bladder cancer, is invasive and relatively expensive, while urine cytology is of limited value specifically in low-grade disease. Over the last decades, numerous molecular assays for the diagnosis of urothelial cancer have been developed and investigated with regard to their clinical use. However, although all of these assays have been shown to have superior sensitivity as compared to urine cytology, none of them has been included in clinical guidelines. The key reason for this situation is that none of the assays has been included into clinical decision-making so far. We reviewed the current status and performance of modern molecular urine tests following systematic analysis of the value and limitations of commercially available assays. Despite considerable advances in recent years, the authors feel that at this stage the added value of molecular markers for the diagnosis of urothelial tumors has not yet been identified. Current data suggest that some of these markers may have the potential to play a role in screening and surveillance of bladder cancer. Well-designed protocols and prospective, controlled trials will be needed to provide the basis to determine whether integration of molecular markers into clinical decision-making will be of value in the future.

Bladder tumour antigen (BTA stat) test compared to the urine cytology in the diagnosis of bladder cancer: A meta-analysis

INTRODUCTION

We evaluate the diagnostic value of bladder tumour antigen (BTA stat) tests compared with urine cytology test in detecting bladder cancer.

METHODS

We searched public databases including PubMed, MEDLINE Springer, Elsevier Science Direct, Cochrane Library and Google Scholar before December 2012. To collect relevant data of BTA stat tests and urine cytology tests in patients with bladder cancer, we studied meta-analyses of sensitivity, specificity, positive likelihood ratio (LR), negative LR and diagnostic odds ratios (DOR) of BTA stat tests and cytology tests from published studies. We applied the software of Rev. Man 5.1 and Stata 11.0 to the meta-analysis.

RESULTS

A total of 13 separate studies consisting of 3462 patients with bladder cancer were considered in the meta-analysis. We found that the BTA stat test had a higher sensitivity than the urine cytology test (0.67, 95% confidence interval [CI] 0.64 to 0.69 vs. 0.43, 95% CI 0.40 to 0.46), but the specificity, positive LR, negative LR, DOR, the area under the curve (AUC) and Q index of the BTA stat test were lower compared with the urine cytology test. The results of the Egger's linear regression test showed no publication bias (p > 0.05).

CONCLUSIONS

Specificity, positive LR, negative LR, DOR, the AUC and the Q index of the urine cytology test may be superior to the BTA stat test, but the BTA stat test has greater sensitivity than the urine cytology test.

Urine markers for detection and surveillance of bladder cancer

OBJECTIVES

Bladder cancer detection and surveillance includes cystoscopy and cytology. Urinary cytology is limited by its low sensitivity for low-grade tumors. Urine markers have been extensively studied to help improve the diagnosis of bladder cancer with the goal of complementing or even replacing cystoscopy. However, to date, no marker has reached widespread use owing to insufficient evidence for clinical benefit.

MATERIAL AND METHODS

Pubmed/Medline search was conducted to identify original articles, review articles, and editorials regarding urine-based biomarkers for screening, early detection, and surveillance of urothelial carcinoma of the bladder. Searches were limited to the English language, with a time frame of 2000 to 2013. Keywords included urothelial carcinoma, bladder cancer, transitional cell carcinoma, biomarker, marker, urine, diagnosis, recurrence, and progression.

RESULTS

Although several urinary markers have shown higher sensitivity compared with cytology, it remains insufficient to replace cystoscopy. Moreover, most markers suffer from lower specificity than cytology. In this review, we aimed to summarize the current knowledge on commercially available and promising investigational urine markers for the detection and surveillance of bladder cancer.

CONCLUSIONS

Well-designed protocols and prospective, controlled trials are needed to provide the basis to determine whether integration of biomarkers into clinical decision making will be of value for bladder cancer detection and screening in the future.

Urinary markers for bladder cancer

Bladder cancer has the fifth highest incidence of all malignancies in the United States, with a propensity to recur, requiring lifelong surveillance after diagnosis. Urinary markers of disease have been of extreme interest in this field in an effort to simplify surveillance schedules and improve early detection of tumors. Many markers have been described, but most remain investigational. However, some markers have undergone clinical trials and are approved for clinical use. In this review, urinary markers and their application for screening and surveillance of bladder cancer are discussed.

microRNA detection in feces, sputum, pleural effusion and urine: novel tools for cancer screening (Review)

microRNAs (miRNAs) are short non-coding RNA sequences that play important roles in the regulation of gene expression. They have significant regulatory functions in basic cellular processes, including differentiation, proliferation and apoptosis. miRNAs are differentially expressed in tumors, compared with normal tissues. Importantly, miRNAs are also stable and abundantly present in body fluids and feces. The high reproducibility, sensitivity and specificity of miRNAs in body fluids and feces enable miRNAs to be used as potential molecular markers for cancer screening. An increasingly large number of research studies have reported the role of miRNAs in this field. In the present review, we focused mainly on the application of detecting miRNAs in stool, sputum, pleural effusion and urine, to detect colon, lung and urological cancers, highlighting the role of miRNAs in early diagnosis and prognosis.

ProEx C as an adjunct marker to improve cytological detection of urothelial carcinoma in urinary specimens

BACKGROUND

ProEx C is an antibody cocktail targeting the expression of topoisomerase IIα and minichromosome maintenance protein-2. ProEx C staining is being used to assist in diagnoses of the gynecological specimens. This study was designed to determine the utility of ProEx C in urine cytology samples for improving the detection of urothelial carcinomas where a significant number of urine cytology specimens are diagnosed as "atypia."

METHODS

Sixty urinary specimens (12 negative, 13 positive, and 35 atypical cases) were stained with ProEx C, and ProEx C results were recorded as positive when nuclear staining was only seen in at least one morphologically atypical urothelial cell.

RESULTS

All 12 benign cytology samples showed negative staining with ProEx C. Twelve of 13 cases that had a malignant cytologic diagnosis showed a positive nuclear staining of the malignant cells. Eighteen of 35 cases with atypical cytologic diagnoses showed positive nuclear staining. Of the 35 cases with "atypia," 17 had a malignant histopathologic follow-up. In this study, ProEx C stain had an overall sensitivity of 78.4%, specificity of 95.7%%, positive predictive value of 96.7%, and negative predictive value of 73.3% for the detection of urothelial carcinoma.

CONCLUSIONS

ProEx C stain is a useful adjunct test to urine cytologic analysis, even in specimens with limited cellularity. In urinary smears, this test is most useful in stratification of the "atypical" diagnoses into benign and malignant subsets. To the authors' knowledge, this is the first study of ProEx C application in urine cytology as an adjunct marker for detection of urothelial carcinoma.

Markers of bladder cancer State of the art

Biomarkers are increasingly being applied to the clinical management of patients with bladder cancer. The biomarkers in current clinical use focus on bladder cancer detection. Biomarkers for prognosis and as intermediate endpoints for chemoprevention are being evaluated in clinical trials. This review provides an overview of the performance characteristics of current clinical markers and other markers that are currently under evaluation.

Exclusion of the uniform tetraploid cells significantly improves specificity of the urine FISH assay

The urine fluorescence in situ hybridization (FISH) assay (UroVysion™), with the current scoring criteria, has a higher sensitivity than routine cytopathology but a lower specificity. Among 215 urine FISH tests we performed, 45 had associated histopathology and clinical follow up. In this study, a cell with four signals for each probe was classified as a uniform tetraploid cell (UTC); a presumed reparative cell which is currently classified as an abnormal cell in the FDA approved assay. By using the existing criteria, the tests were scored as positive or negative before and after exclusion of the UTCs. Before the exclusion, 24 positive, 13 negative, seven false positive, and one false negative result were obtained with 96% sensitivity and 65% specificity. After the exclusion, the results changed to 22 positive, 19 negative, one false positive, and three false negatives resulting in a 88% sensitivity of 88% and a 95% specificity; a significant improvement in the specificity. We conclude that exclusion of the UTCs as abnormal cells would result in a more solid performance of the FISH assay.

Analysis of fluorescence in situ hybridization, mtDNA quantification, and mtDNA sequence for the detection of early bladder cancer

We designed this study to test the sensitivities of cytology, the nuclear matrix protein 22 (NMP22) assay, and fluorescence in situ hybridization (FISH) in the early detection of urothelial carcinoma, and to identify mtDNA alterations in urinary epithelial cells. We collected 41 urine samples and 26 corresponding peripheral blood samples from patients with clinically suspected urothelial carcinoma. The FISH and NMP22 assays detected 92.1% of the cancers, and cytology detected 60.5%. In the low-grade group, NMP22 and FISH analyses were more sensitive than cytology, but in the high-grade group, all three methods showed approximately 90% sensitivity. Overall, the FISH and NMP22, or FISH and cytology assays combined detected 97.4% of cancers, while cytology with NMP22 detected 92.1%. In the low-grade group, the sensitivity of the three methods combined was above 80%, but in high-grade group, the combined sensitivity was approximately 100%. In the mtDNA control region, we detected characteristic heteroplasmic mtDNA substitution mutations in 1 patient and a mtDNA length heteroplasmic mutation in 303 polyC or 16184 poly C in 20 patients. Overall, urothelial carcinoma-specific mtDNA mutations were observed in 20 of the 26 patients (76.9%). The average mtDNA copy numbers in urine samples and corresponding peripheral blood samples (83.45 +/- 60.36 and 39.0 +/- 24.38, respectively) (mean +/- standard deviation [SD]) differed significantly (P < 0.001). The mtDNA copy numbers in the urine samples from patients with high-grade and low-grade tumors (81.83 +/- 67.78 and 86.49 +/- 46.69, respectively) did not differ significantly (P = 0.589). In conclusion, the FISH assay showed the highest sensitivity for detecting low-grade urothelial carcinoma, and mtDNA copy numbers in urine samples were higher than those in the corresponding peripheral blood samples. The frequency of mtDNA mutations in the D-loop region in patients with cancer was approximately 80% in our study. This report further supports the significance of genetic alteration in urothelial carcinoma and the clinical utility of the FISH, mtDNA quantitation polymerase chain reaction, mtDNA sequencing, and capillary electrophoresis for this purpose.

National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for use of tumor markers in liver, bladder, cervical, and gastric cancers

BACKGROUND

Updated National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.

METHODS

Published reports relevant to use of tumor markers for 4 cancer sites--liver, bladder, cervical, and gastric--were critically reviewed.

RESULTS

Alpha-fetoprotein (AFP) may be used in conjunction with abdominal ultrasound for early detection of hepatocellular carcinoma (HCC) in patients with chronic hepatitis or cirrhosis associated with hepatitis B or C virus infection. AFP concentrations >200 microg/L in cirrhotic patients with typical hypervascular lesions >2 cm in size are consistent with HCC. After a diagnosis of HCC, posttreatment monitoring with AFP is recommended as an adjunct to imaging, especially in the absence of measurable disease. Although several urine markers have been proposed for bladder cancer, none at present can replace routine cystoscopy and cytology in the management of patients with this malignancy. Some may, however, be used as complementary adjuncts to direct more effective use of clinical procedures. Although carcinoembryonic antigen and CA 19-9 have been proposed for use gastric cancer and squamous cell carcinoma antigen for use in cervical cancer, none of these markers can currently be recommended for routine clinical use.

CONCLUSIONS

Implementation of these recommendations should encourage optimal use of tumor markers for patients with liver, bladder, cervical, or gastric cancers.

Proteomic assays for the detection of urothelial cancer

Bladder cancer is one of the most expensive cancers from diagnosis to death of the patient due to life-long surveillance involving upper tract imaging, urinary cytology, and cystoscopy. Cytology has been historically used in conjunction with cystoscopy to help detect disease that may be missed by routine cystoscopy (e.g., carcinoma in situ and upper tract disease). Urine cytology is highly cytopathologist dependent and has reasonable sensitivity for detecting high grade disease. However, its sensitivity drops precipitously with regard to well-differentiated low grade cancers. Intensive investigations have been undertaken using proteomics to find an alternative to cystoscopy and cytology. Urine proteomic markers currently evaluated critically in the literature include bladder tumor antigen, nuclear matrix protein 22, BLCA-4, hyaluronic acid, hyaluronidase, cytokeratin 8, cytokeratin 18, cytokeratin 19, tissue polypeptide antigen, and tissue polypeptide-specific antigen. Markers used as alternatives to cystoscopy must be accurate with high sensitivity and specificity, cost effective for life-long surveillance, and minimally invasive to minimize the burden to the patient. To date, no proteomic marker has been developed that can replace cystoscopy for the detection of bladder cancer. However, several urinary markers appear to have higher sensitivity albeit lower specificity than cytology and can be used to supplement cystoscopy. Some of those markers are herein described in this chapter. By defining and characterizing the current state of the art in protein based markers, we are poised to evaluate and benchmark newly discovered protein biomarkers that will be isolated through new proteomics based investigations of urine.

Clinical states model for biomarkers in bladder cancer

Bladder cancer is a significant healthcare problem in the USA, with a high recurrence rate, the need for expensive continuous surveillance and limited treatment options for patients with advanced disease. Research has contributed to an understanding of the molecular pathways involved in the development and progression of bladder cancer, and that understanding has led to the discovery of potentially diagnostic, predictive and prognostic biomarkers. In this review, a clinical states model of bladder cancer is introduced and integrated into a paradigm for biomarker development. Biomarkers are systematically incorporated with predefined end points to aid in clinical management.

[The value of urinary cytology in the diagnosis of high grade urothelial tumors]

Urinary cytology is a non-invasive adjunct to cystoscopy in the diagnosis of bladder cancer. In order to assess the diagnostic accuracy of urinary cytology as an office-based method for clinically relevant high grade (G3) bladder cancer, three nationwide cytology survey tests were performed. Urine specimens from seven patients, three patients with high grade (G3) bladder cancer and four patients with urinary tract infections, were collected. A total of 1,000 cytology slides were produced from each urine specimen. Each set contained five slides (two malignant, three benign) which were sent to all participating German urologists. Three nationwide tests were performed from 1998-2000. The specimen sets were kept the same for the first and second test and in the third test two new slides were introduced. In addition to validity, the reliability was calculated for the first and second test as interobserver and intraobserver reliability according to Cohen's kappa statistics. Due to the change of two specimens in the third test in 2000 only sensitivity and specificity were calculated. A total of 335 urologists took part in the first survey test, 329 in the second and 292 in the third The sensitivity for G3 cytologies was 81.34% in the first, 87.08% in the second and 85.1% in the third survey test and the specificity was 85.87%, 83.58% and 89.15%, respectively. Interobserver reliability showed a weighted kappa value of 0.58 for the first and 0.59 for the second survey test. Calculation of intraobserver reliability was possible for 169 urologists taking part in the first and second survey test and showed a mean kappa value of 0.62. The results of the three nationwide urinary cytology tests indicate that urinary cytology has a high sensitivity in the detection of clinically relevant high grade bladder cancer. The kappa values achieved demonstrate a clear agreement of cytological diagnoses.

Urine-based assays for the detection of bladder cancer

Bladder cancer is one of the most prevalent cancers worldwide. Furthermore, nonmuscle invasive bladder cancer has a 70% rate of recurrence, making it a considerable strain to the healthcare system. Patients with bladder cancer require repeat cystoscopic examinations of the bladder to monitor for tumor recurrence. The reason these patients have to undergo these costly, painful, invasive procedures is owing to the absence of accurate urine-based assays to detect the presence of bladder cancer noninvasively. Consequently, the development of a urine-based test to detect bladder cancer would be of tremendous benefit to both patients and healthcare systems. This article reports some of the more prominent urine markers in use today. In addition, the article will highlight some new technologies that are used to investigate novel urinary markers.

Diagnosis of urothelial carcinoma from urine

Urine cytology is the most widely used noninvasive test to detect urothelial tumors. However, it is limited by its low sensitivity. On the other hand, cystoscopy is the gold standard procedure to follow patients with a history of bladder cancer but this test is invasive and costly. Therefore, there is a real need to develop new tests that can be used in bladder cancer surveillance. Several soluble and cell-based markers have been developed and most of them improve the sensitivity of cytology but the specificity is invariably decreased. Of the cell-based tests, two obtained Food and Drug Administration approval. ImmunoCyt/uCyt is a fluorescent test that uses three monoclonal antibodies and UroVysion is an in situ hybridization test, which uses four different probes to different chromosomes. Both tests have a high sensitivity to detect cancer cells and can help to predict urothelial cancer recurrence. ImmunoCyt/uCyt is somewhat better at detecting low-grade tumors but UroVysion is not affected by prior BCG treatment. However, both tests use fluorescent dyes, are time-consuming and require trained personnel. Because of their high negative predictive value, both tests may help the urologist to postpone a number of cystoscopies, especially in patients with low-risk urothelial cancer.

Urinary protein biomarkers of cancer

BACKGROUND

Although several cancer biomarkers are now in use, few have the necessary sensitivity and specificity to eliminate the need for invasive diagnostic procedures. With the expansion of proteomics, new technologies have been used to study various cancers, resulting in the discovery of several potential urine biomarkers. Urine is an ideal medium for the detection of biomarkers because of the non-invasive means of collecting samples and demonstrated shedding of cells, proteins, enzymes, nucleic acids and metabolic products into urine during various pathological processes.

OBJECTIVE

To review the contemporary literature regarding urinary protein markers of cancer.

METHODS

A PubMed search for 'urinary protein biomarkers of cancer' revealed 4679 scientific publications. The search was limited to studies published over the last 5 years and reviewed pertinent findings regarding biomarker evaluation and discovery.

RESULTS

Several urinary protein biomarkers have been described for urologic, gynecologic, gastrointestinal and neurologic tumors. Some have been selected for use in clinical practice, whereas others have been abandoned owing to inconclusive follow-up studies.

CONCLUSION

Several potential urinary protein markers for cancer exist, yet multi-institutional, prospective trials are needed to validate results before implementation in clinical scenarios.

Reflex UroVysion testing in suspicious urine cytology cases

BACKGROUND

UroVysion is a US Food and Drug Administration-approved fluorescence in situ hybridization (FISH) probe set for use in the detection of recurrent urothelial carcinoma and in patients with hematuria. The objective of the current study was to evaluate the usefulness of UroVysion as a reflex test in patients with a suspicious urine cytology diagnosis. The rationale was that a more aggressive workup might be indicated in patients with a suspicious cytology diagnosis and positive UroVysion test.

METHODS

The study population included 161 urine specimens diagnosed as suspicious over a period of 12 months. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (NPV) were calculated based on the histologic and cystoscopic correlation.

RESULTS

The results using the reporting criteria suggested by the manufacturer demonstrated a sensitivity of 68.3%, a specificity of 39.7%, a PPV of 56.8%, and a NPV of 51.9%. The results using the presence of any cytogenetic abnormality as a positive FISH test demonstrated a sensitivity of 82.9%, a specificity of 21.7%, a PPV of 54.8%, and an NPV of 51.7%.

CONCLUSIONS

A negative UroVysion test did not rule out the presence of low-grade or high-grade urothelial carcinoma in urine specimens diagnosed as suspicious. The use of less strict criteria dramatically increased the sensitivity of UroVysion FISH; however, there was a marked decrease in specificity noted. The results in this current study appear to indicate that a more aggressive workup of patients with a suspicious cytology, positive UroVysion result, and negative cystoscopic evaluation is not currently justified.

Urine cytology and urine-based markers for bladder urothelial carcinoma detection and monitoring: developments and future prospects

Bladder cancer is currently diagnosed using cystoscopy and cytology in patients with suspicious signs and symptoms. These tests are also used to monitor patients with a history of bladder cancer. The recurrence rate for bladder cancer is high, thus necessitating long-term follow-up. Urine cytology has a high sensitivity and specificity for the detection of high-grade urothelial carcinoma, but lacks the sensitivity to detect low-grade tumors. Recently, multiple noninvasive urine-based bladder cancer tests have been developed. Many markers (BTA stat®, BTA TRAK®, ImmunoCyt™, NMP22® and UroVysion™) have already been approved by the US FDA for bladder cancer surveillance, while other markers are still undergoing development, preclinical and clinical investigation. An ideal bladder cancer test would be noninvasive, highly sensitive and specific, inexpensive, easy to perform and yield highly reproducible results. Many of the tests reviewed herein meet some, but not all, of these criteria.

Surveillance of patients with bladder carcinoma using fluorescent in-situ hybridization on bladder washings

OBJECTIVES

To compare the sensitivity and specificity of the UroVysion (Abbott Laboratories Inc., Downers Grove, IL, USA) fluorescent in-situ hybridization (FISH) assay to that of urinary cytology obtained from bladder irrigation during cystoscopic surveillance in patients with bladder carcinoma.

PATIENTS AND METHODS

The medical records were retrospectively reviewed for 41 consecutive patients screened at the authors' institution between August 2000 and December 2006 for recurrence of pathologically confirmed bladder cancer. All 162 cytology examinations and 141 FISH assay results obtained from bladder washing were included. Recurrence was determined by cystoscopy, bladder biopsy and upper-tract imaging. Sensitivity, specificity, positive predictive and negative predictive values were assessed using a chi-square distribution with one degree of freedom.

RESULTS

There were 24 men and 17 women (male to female ratio 0.59), the mean (range) age was 56 (33-73) years and the mean follow-up 30 (2-57) months. At the initial diagnosis, 35 of the 41 patients (85%) had superficial tumours (stage <or= T1), while six (15%) had muscle-invasive tumours (stage >or=T2). Twenty-six (63%) had low-grade and 15 (37%) had high-grade tumours. In 16 of 141 (11%) of the FISH assays and 16 of 162 (10%) of the cytological samples that were collected from bladder irrigations, there were too few cells for an adequate analysis. The FISH assay correctly correlated with subsequent cystoscopy, bladder biopsy or upper-tract imaging in 110/125 (88%) cases but not in 15/125 (12%). Cytology correctly correlated with the subsequent evaluation in 112/146 (77%) cases but did not in 34/146 (23%). When the FISH was compared with cytology in this setting, the sensitivity was 77% (30/39) vs 74% (37/50; P > 0.1), the specificity was 93% (80/86) vs 78% (75/96; P < 0.01), the positive predictive value was 83% (30/36) vs 64% (37/58; P < 0.05), and the negative predictive value was 90% (80/89) vs 85% (75/88; P > 0.1), respectively.

CONCLUSION

The UroVysion FISH assay obtained from bladder washings during cystoscopic surveillance of patients with a history of bladder cancer provides a similar specificity but greater sensitivity than that of cytology for detecting bladder cancer recurrences. Given the better specificity and similar sensitivity of UroVysion compared with urine cytology obtained from bladder washings, a reasonable approach might be to use the UroVysion assay as the primary marker for recurrence, with urine cytology used as a complementary examination.

Fluorescence in situ hybridization: a multitarget approach in diagnosis and management of urothelial cancer

Noninvasive tests for detecting genetic or molecular alterations in urine indicative of urothelial cancer are increasingly becoming the focus of urological cancer research. Since its approval by the US FDA in 2001, the fluorescence in situ hybridization test (Vysis UroVysion) has been widely evaluated. In general, published data demonstrate better sensitivity and equal or better specificity compared with routine cytology, which is still considered the 'gold standard' in diagnosing and monitoring bladder tumors. However, the fluorescence in situ hybridization test seems to provide not only a useful tool in bladder cancer detection, but also in the diagnosis of upper urinary tract tumors, surveillance and determining therapy effectiveness. This multitarget assay that detects four different chromosomal aberrations in tumor cells is a kind of objective molecular cytology and has proven advantages over routinely used cytology.

Intérêt des marqueurs urinaires dans le diagnostic et le suivi des tumeurs urothéliales de vessie

Urothelial bladder tumours require regular surveillance: cystoscopy associated with urine cytology are reference examinations. Several new markers currently under evaluation or already validated have recently been proposed to replace cytology and potentially reduce or even replace unnecessary cystoscopies. The biological fluid studied for all of these markers is the same as that of urine cytology, i.e. urine. The authors review the results of recent studies on these new urinary markers. The results of these markers demonstrate a better global sensitivity than urine cytology, but often a lower specificity. In the majority of cases, these tests are performed during patient follow-up (NMP22, BTA, CYFRA 21-l., etc.), but do not replace cystoscopy, due to a large number of false-positives. Other techniques, such as FISH, uCyt+ or microsatellites appear to be more promising, especially for the diagnosis of low-grade tumours. The best solution in practice may consist of a combination of several markers to further improve sensitivity and to decrease the false-positive rate responsible for unnecessary cystoscopies.

Molecular Markers of Urothelial Cancer and Their Use in the Monitoring of Superficial Urothelial Cancer

Multiple molecular markers have been described for use in bladder cancer patients. Some of these have been studied more extensively than others, and it is difficult for the clinician to maintain a perspective over the myriad findings that have been made. We have reviewed a selection of markers used for surveillance with an emphasis on clinical utility. The best studied markers and those with the most promising preliminary results were selected. Only studies that included surveillance for recurrence in patients with a history of bladder cancer were considered. Each marker is briefly described and its performance in monitoring bladder cancer patients is summarized. Several promising markers are available, although only four have obtained US Food and Drug Administration approval. The clinical applications that have been studied include replacement or reduction in the number of cystoscopies performed in the surveillance of bladder cancer patients, substitution for or complementary use with urinary cytology in the same setting, predicting disease recurrence and progression, and predicting and monitoring treatment response. None of the markers have been proved sensitive and specific enough to replace cystoscopy. Others, such as nuclear matrix protein 22 (NMP22) and UroVysion, appear to have some utility when used to complement or replace cytology. The other applications have not been adequately studied for any given marker. While multiple molecular markers exist for bladder cancer, their full clinical utility will not be realized until more multicenter prospective trials are conducted to verify their efficacy and safety in the monitoring of patients with superficial bladder cancer.

[Tumor marker tests in bladder cancer]

The gold standard for detecting bladder cancer is cystoscopy which identifies nearly all papillary and sessile lesions. However, it is an invasive procedure causing some discomfort for patients. Urine cytology is the standard non-invasive marker with very high specificity, but unfavourable poor sensitivity for Ta, G1, and T1 bladder tumors. To improve early detection of bladder cancer as well as to monitor treatment response and tumor recurrence, bladder tumor markers are eligible. An ideal bladder cancer test would have the potential to replace or delay cystoscopy in the follow-up of bladder cancer patients. In recent years, the FDA approved non-invasive tumor marker tests ImmunoCyt / uCyt+, BTA TRAK, BTA stat, NMP22, NMP22 BladderChek, and UroVysion have been investigated. The tests demonstrated higher sensitivity for diagnosis of bladder cancer compared to urine cytology. Overall, the mean sensitivity and mean specificity was 64-80% and 71-95% and the mean positive and negative predictive values to detect malignancy were 49-84% and 79-95%, respectively. BTA TRAK, BTA stat, NMP22, and NMP22 BladderChek assays are limited by false-positive results in patients with benign urological diseases such as hematuria, urocystitis, renal calculi or urinary tract infections. Due to low specificity BTA TRAK, BTA stat, NMP22, and NMP22 BladderChek should not be used without first ruling out benign or malignant genitourinary disease other than bladder cancer. With the exception of UroVysion achieving 80% sensitivity and 94% specificity, none of these non-invasive tests revealed a high sensitivity and specificity at the same time, which is a main demand to be made on an ideal tumor marker. Insufficient sensitivity along with limited specificity does not allow replacing cystoscopy in diagnosis of bladder cancer or treatment decisions based on a positive test result.

Molecular markers in bladder cancer: A critical appraisal

The diagnosis of both primary and recurrent bladder tumors currently relies upon the urine cytology and cystoscopy. Neither of these diagnostic tools is completely accurate. Prognostication of bladder cancer is largely based on pathologic tumor grade and stage. Over the past 2 decades, there is accumulating evidence that like many other cancers, bladder cancer, too, has a distinct molecular signature that separates it from other cancers and normal bladder tissue. Bladder tumors of different grades and stages even possess unique, and specific genotypic and phenotypic characteristics. Although recognition of several of these molecular alterations is possible by analyzing tumor tissue, urine, and serum samples, few if any of these "molecular markers" for bladder cancer are widely used in clinical practice. These markers include some that can be applied during the diagnostic work-up of symptoms (e.g., hematuria), those under surveillance for recurrence of superficial disease and forecasting long-term prognosis, or response to chemotherapy. In this review of molecular markers for bladder cancer, effectiveness of markers in each of these categories that are identifiable in the urine of patients with bladder cancer was examined. Many of the diagnostic markers appear to hold an advantage over urine cytology in terms of sensitivity, especially for the detection of low-grade superficial tumors. However, most markers tend to be less specific than cytology, yielding more false-positives. This result is more commonly observed in patients with concurrent bladder inflammation or other benign bladder conditions. Although there are several candidate markers for assessing prognosis or response to chemotherapy, studies of large patient populations are lacking. Further studies involving larger numbers of patients are required to determine their accuracy and widespread applicability in guiding treatment of bladder cancer.