Improved detection of bladder carcinoma cells in voided urine by standardized microsatellite analysis

Results Obtained from a Pivotal Validation Trial of a Microsatellite Analysis (MSA) Assay for Bladder Cancer Detection through a Statistical Approach Using a Four-Stage Pipeline of Modern Machine Learning Techniques

Several studies have shown that microsatellite changes can be profiled in urine for the detection of bladder cancer. The use of microsatellite analysis (MSA) for bladder cancer detection requires a comprehensive analysis of as many as 15 to 20 markers, based on the amplification and interpretations of many individual MSA markers, and it can be technically challenging. Here, to develop fast, more efficient, standardized, and less costly MSA for the detection of bladder cancer, we developed three multiplex-polymerase-chain-reaction-(PCR)-based MSA assays, all of which were analyzed via a genetic analyzer. First, we selected 16 MSA markers based on 9 selected publications. Based on samples from Johns Hopkins University (the JHU sample, the first set sample), we developed an MSA based on triplet, three-tube-based multiplex PCR (a Triplet MSA assay). The discovery, validation, and translation of biomarkers for the early detection of cancer are the primary focuses of the Early Detection Research Network (EDRN), an initiative of the National Cancer Institute (NCI). A prospective study sponsored by the EDRN was undertaken to determine the efficacy of a novel set of MSA markers for the early detection of bladder cancer. This work and data analysis were performed through a collaboration between academics and industry partners. In the current study, we undertook a re-analysis of the primary data from the Compass study to enhance the predictive power of the dataset in bladder cancer diagnosis. Using a four-stage pipeline of modern machine learning techniques, including outlier removal with a nonlinear model, correcting for majority/minority class imbalance, feature engineering, and the use of a model-derived variable importance measure to select predictors, we were able to increase the utility of the original dataset to predict the occurrence of bladder cancer. The results of this analysis showed an increase in accuracy (85%), sensitivity (82%), and specificity (83%) compared to the original analysis. The re-analysis of the EDRN study results using machine learning statistical analysis proved to achieve an appropriate level of accuracy, sensitivity, and specificity to support the use of the MSA for bladder cancer detection and monitoring. This assay can be a significant addition to the tools urologists use to both detect primary bladder cancers and monitor recurrent bladder cancer.

Qualification of the Microsatellite Instability Analysis (MSA) for Bladder Cancer Detection: The Technical Challenges of Concordance Analysis

Bladder cancer (here we refer to transitional carcinoma of bladder) is a major cause of morbidity and mortality in the Western world, and recent understanding of its etiology, the molecular characteristics associated with its progression, renders bladder cancer an ideal candidate for screening. Cystoscopy is invasive and sometimes carries unwanted complications, but it is the gold standard for the detection of bladder cancer. Urine cytology, while the most commonly used test as an initial screening tool, is of limited value due to its low sensitivity, particularly for low-grade tumors. Several new "molecular assays" for the diagnosis of urothelial cancer have been developed over the last two decades. Here, we have established our new bladder cancer test based on an assay established for the Early Detection Research Network (EDRN) study. As a part of the study, a quality control CLIA/College of American Pathology (CAP) accredited laboratory, (QA Lab), University of Maryland Baltimore Biomarker Reference Laboratory (UMB-BRL), performed quality assurance analysis. Quality assurance measures included a concordance study between the testing laboratory (AIBioTech), also CLIA/CAP accredited, and the QA lab to ensure that the assay was performed and the results were analyzed in a consistent manner. Therefore, following the technical transfer and training of the microsatellite analysis assay to the UMB-BRL and prior to the initiation of analysis of the clinical samples by the testing lab, a series of qualification studies were performed. This report details the steps taken to ensure qualification of the assay and illustrates the technical challenges facing biomarker validation of this kind.

Molecular Markers for Bladder Cancer Screening: An Insight into Bladder Cancer and FDA-Approved Biomarkers

Bladder cancer is one of the most financially burdensome cancers globally, from its diagnostic to its terminal stages. The impact it imposes on patients and the medical community is substantial, exacerbated by the absence of disease-specific characteristics and limited disease-free spans. Frequent recurrences, impacting nearly half of the diagnosed population, require frequent and invasive monitoring. Given the advancing comprehension of its etiology and attributes, bladder cancer is an appealing candidate for screening strategies. Cystoscopy is the current gold standard for bladder cancer detection, but it is invasive and has the potential for undesired complications and elevated costs. Although urine cytology is a supplementary tool in select instances, its efficacy is limited due to its restricted sensitivity, mainly when targeting low-grade tumors. Although most of these assays exhibit higher sensitivity than urine cytology, clinical guidelines do not currently incorporate them. Consequently, it is necessary to explore novel screening assays to identify distinctive alterations exclusive to bladder cancer. Thus, integrating potential molecular assays requires further investigation through more extensive validation studies. Within this article, we offer a comprehensive overview of the critical features of bladder cancer while conducting a thorough analysis of the FDA-approved assays designed to diagnose and monitor its recurrences.

Development of Multiplex Polymerase Chain Reaction (PCR)-Based MSA Assay for Bladder Cancer Detection

Several studies have shown that microsatellite changes can be profiled in the urine to detect bladder cancer. Microsatellite analysis (MSA) of bladder cancer detection requires a comprehensive analysis of up to 15-20 markers based on amplifying and interpreting many individual MSA markers, which can be technically challenging. To develop fast, efficient, standardized, and less costly MSA to detect bladder cancer, we developed three multiplex polymerase chain reaction (PCR) based MSA assays, all of which were analyzed by a genetic analyzer. First, we selected 16 MSA markers based on nine publications. We developed MSA assays based on triplet or three-tube-based multiplex PCR (Triplet MSA assay) using samples from Johns Hopkins University (JHU Sample, first set of samples). In the second set of samples (samples from six cancer patients and fourteen healthy individuals), our Triplet Assay with 15 MSA markers correctly predicted all 6/6 cancer samples to be cancerous and 14/14 healthy samples to be healthy. Although we could improve our report with more clinical information from patient samples and an increased number of cancer patients, our overall results suggest that our Triplet MSA Assay combined with a genetic analyzer is a potentially time- and cost-effective genetic assay for bladder cancer detection and has potential use as a dependable assay in patient care.

Off the fog to find the optimal choice: Research advances in biomarkers for early diagnosis and recurrence monitoring of bladder cancer

Bladder cancer (BC) has high morbidity and mortality rates owing to challenges in clinical diagnosis and treatment. Advanced BC is prone to recurrence after surgery, necessitating early diagnosis and recurrence monitoring to improve the prognosis of patients. Traditional detection methods for BC include cystoscopy, cytology, and imaging; however, these methods have drawbacks such as invasiveness, lack of sensitivity, and high costs. Existing reviews on BC focus on treatment and management and lack a comprehensive assessment of biomarkers. Our article reviews various biomarkers for the early diagnosis and recurrence monitoring of BC and outlines the existing challenges associated with their application and possible solutions. Furthermore, this study highlights the potential application of urine biomarkers as a non-invasive, inexpensive adjunctive test for screening high-risk populations or evaluating patients with suspected BC symptoms, thereby alleviating the discomfort and financial burden associated with cystoscopy and improving patient survival.

Significant Tumor Regression after Neoadjuvant Chemotherapy in Gastric Cancer, but Poor Survival of the Patient? Role of MHC Class I Alterations

We aimed to determine the clinical and prognostic relevance of allelic imbalance (AI) of the major histocompatibility complex (MHC) class I genes, encompassing the human leukocyte antigen (HLA) class I and beta-2 microglobulin (B2M) genes, in the context of neoadjuvant platinum/fluoropyrimidine chemotherapy (CTx). Biopsies before CTx were studied in 158 patients with adenocarcinoma of the stomach or gastroesophageal junction. The response was histopathologically evaluated. AI was detected by multiplex PCRs analysis of four or five microsatellite markers in HLA and B2M regions, respectively. AI with no marker was significantly associated with response or survival. However, subgroup analysis revealed differences. AI at marker D6S265, close to the HLA-A gene, was associated with an obvious increased risk in responding (HR, 3.62; 95% CI, 0.96-13.68, p = 0.058) but not in non-responding patients (HR, 0.92; 95% CI, 0.51-1.65, p = 0.773). Markers D6S273 and D6S2872 showed similar results. The interaction between AI at D6S265 and response to CTx was significant in a multivariable analysis (p = 0.010). No associations were observed for B2M markers. Our results underline the importance of intact neoantigen presentation specifically for responding patients and may help explain an unexpectedly poor survival of a patient despite significant tumor regression after neoadjuvant platinum/fluoropyrimidine CTx.

Microsatellite Instability Analysis (MSA) for Bladder Cancer: Past History and Future Directions

Microsatellite instability (MSI), the spontaneous loss or gain of nucleotides from repetitive DNA tracts, is a diagnostic phenotype for gastrointestinal, endometrial, colorectal, and bladder cancers; yet a landscape of instability events across a wider variety of cancer types is beginning to be discovered. The epigenetic inactivation of the MLH1 gene is often associated with sporadic MSI cancers. Recent next-generation sequencing (NGS)-based analyses have comprehensively characterized MSI-positive (MSI+) cancers, and several approaches to the detection of the MSI phenotype of tumors using NGS have been developed. Bladder cancer (here we refer to transitional carcinoma of the bladder) is a major cause of morbidity and mortality in the Western world. Cystoscopy, a gold standard for the detection of bladder cancer, is invasive and sometimes carries unwanted complications, while its cost is relatively high. Urine cytology is of limited value due to its low sensitivity, particularly to low-grade tumors. Therefore, over the last two decades, several new "molecular assays" for the diagnosis of urothelial cancer have been developed. Here, we provide an update on the development of a microsatellite instability assay (MSA) and the development of MSA associated with bladder cancers, focusing on findings obtained from urine analysis from bladder cancer patients as compared with individuals without bladder cancer. In our review, based on over 18 publications with approximately 900 sample cohorts, we provide the sensitivity (87% to 90%) and specificity (94% to 98%) of MSA. We also provide a comparative analysis between MSA and other assays, as well as discussing the details of four different FDA-approved assays. We conclude that MSA is a potentially powerful test for bladder cancer detection and may improve the quality of life of bladder cancer patients.

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.

Urinary biomarkers in bladder cancer: where do we stand?

PURPOSE OF REVIEW

To provide a current comprehensive review of the available urinary biomarkers for the detection and surveillance of bladder cancer.

RECENT FINDINGS

The limitations of urine cytology and invasive nature of cystoscopic evaluation have led to a growing search for an ideal, cost-effective biomarker with acceptable sensitivity and specificity. Current FDA approved biomarkers such as UroVysion fluorescent in situ hybridization, Immunocyt, and nuclear matrix protein 22 do not have the specificity, and thus positive predictive value to warrant their cost as a routine adjunct or replacement for cystoscopy. Several promising commercially available assays such as Cxbladder, Assure MDx, and Xpert BC may perform better than cytology in select populations. Novel genomic, epigenetic, inflammatory, and metabolomic-based assays are being analyzed as potential urinary biomarkers.

SUMMARY

Urinary biomarkers with high sensitivity and specificity are an unmet need in bladder cancer. Several new assays may meet these criteria and future research may justify use in clinical practice.

A microsatellite based multiplex PCR method for the detection of chromosomal instability in gastric cancer

Chromosomal instability (CIN) is a hallmark of distinct subclasses of tumours with potential clinical relevance. The aim of our study was to establish a time and cost effective method for the determination of CIN in gastric carcinomas (GC). We developed a microsatellite based multiplex PCR assay for the detection of allelic imbalances (AI) using experimentally defined marker specific threshold values for AI. The assay was tested in 90 formalin-fixed paraffin-embedded GC and results were compared in a subset of 30 carcinomas with the Affymetrix OncoScan assay, which detects copy number variations on genome wide level. The ratios of alterations detected by the two methods demonstrated a significant correlation (r = 0.88). Based on the results of the OncoScan assay, tumours were classified in CIN-High and CIN-Low and a threshold of the AI ratio determined with the PCR assay was defined. Accordingly, 20 of the 90 GC (22%) were CIN-Low and 70 (78%) CIN-High. A significant association of CIN-High was found with intestinal type tumours and proximal tumour localization. In conclusion, we established a PCR based method to categorize AI as surrogate for CIN, which is easy to perform and useful for the clarification of the clinical relevance of CIN in large GC cohorts.

Improving diagnostic molecular tests to monitor urothelial carcinoma recurrence

INTRODUCTION

The high recurrence rates associated with non-muscle invasive bladder cancer require close surveillance with cystoscopy, an invasive and expensive procedure with risk of missing cancer. Finding an accurate urinary biomarker that can detect recurrent disease would represent a significant advancement in management. Areas covered: This review summarizes the commercially-available urinary biomarkers including cytology, UroVysion, BTA, NMP22, uCyt+, and Cxbladder assays. Additionally, we review recent investigational urinary biomarkers that hold promise in bladder cancer surveillance. Expert commentary: The quest for a reliable urinary biomarker for bladder cancer is decades-old and seems intuitive given the direct contact of urine with malignant urothelium. Beyond urine cytology, there are many commercially-available products approved for surveillance. However, none of the assays are routinely used due to lack of sensitivity and/or specificity. As such, emerging technologies, in particular the '-omic' technologies have resulted in a proliferation of promising reports on novel biomarkers in recent literature.

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.

Nucleic acid-based biomarkers in body fluids of patients with urologic malignancies

This review focuses on the promising potential of nucleic acids in body fluids such as blood and urine as diagnostic, prognostic, predictive and monitoring biomarkers in urologic malignancies. The tremendous progress in the basic knowledge of molecular processes in cancer, as shown in the companion review on nucleic acid-based biomarkers in tissue of urologic tumors, provides a strong rationale for using these molecular changes as non-invasive markers in body fluids. The changes observed in body fluids are an integrative result, reflecting both tissue changes and processes occurring in the body fluids. The availability of sensitive methods has only recently made possible detailed studies of DNA- and RNA-based markers in body fluids. In addition to these biological aspects, methodological aspects of the determination of nucleic acids in body fluids, i.e. pre-analytical, analytical and post-analytical issues, are particularly emphasized. The characteristic changes of RNA (differential mRNA and miRNA expression) and DNA (concentrations, integrity index, mutations, microsatellite and methylation alterations) in serum/plasma and urine samples of patients suffering from the essential urologic cancers of the prostate, bladder, kidney and testis are summarized and critically discussed below. To translate the promising results into clinical practice, laboratory scientists and clinicians have to collaborate to resolve the challenges of harmonized and feasible pre-analytical and analytical conditions for the selected markers and to validate these markers in well-designed and sufficiently powered multi-center studies.

Selection of microsatellite markers for bladder cancer diagnosis without the need for corresponding blood

Microsatellite markers are used for loss-of-heterozygosity, allelic imbalance and clonality analyses in cancers. Usually, tumor DNA is compared to corresponding normal DNA. However, normal DNA is not always available and can display aberrant allele ratios due to copy number variations in the genome. Moreover, stutter peaks may complicate the analysis. To use microsatellite markers for diagnosis of recurrent bladder cancer, we aimed to select markers without stutter peaks and a constant ratio between alleles, thereby avoiding the need for a control DNA sample. We investigated 49 microsatellite markers with tri- and tetranucleotide repeats in regions commonly lost in bladder cancer. Based on analysis of 50 blood DNAs the 12 best performing markers were selected with few stutter peaks and a constant ratio between peaks heights. Per marker upper and lower cut off values for allele ratios were determined. LOH of the markers was observed in 59/104 tumor DNAs. We then determined the sensitivity of the marker panel for detection of recurrent bladder cancer by assaying 102 urine samples of these patients. Sensitivity was 63% when patients were stratified for LOH in their primary tumors. We demonstrate that up-front selection of microsatellite markers obliterates the need for a corresponding blood sample. For diagnosis of bladder cancer recurrences in urine this significantly reduces costs. Moreover, this approach facilitates retrospective analysis of archival tumor samples for allelic imbalance.

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.

Molecular markers for detection, surveillance and prognostication of bladder cancer

Many markers for the detection of bladder cancers have been tested and almost all urinary markers reported are better than cytology with regard to sensitivity, but they score lower in specificity. Currently molecular and genetic changes play an important role in the discovery of new molecular markers for detection, prognostication and surveillance. The purpose of this review is to highlight the most important urinary molecular biomarker developments that have been studied and reported recently. In the current review we have summarized the most recent and relevant published reports on molecular urinary markers. The results of this review show that the first generation of urinary markers did not add much to urinary cytology. The current generation of markers is better, but additional clinical trials are needed. Our knowledge of molecular pathways in bladder cancer is growing and new methods of marker development emerge, but the perfect marker is still to be found. Currently, there are not clinically usable molecular markers that can guide us in diagnosis or surveillance, nor guide us in lowering the frequency of urethrocystoscopy in bladder cancer.

BAMBI gene is epigenetically silenced in subset of high-grade bladder cancer

The bone morphogenetic protein (BMP) and activin membrane-bound inhibitor (BAMBI) is a transmembrane TGFRI/BMPRI-related pseudoreceptor, antagonizes transforming growth factor (TGF)-beta/BMP signaling by inhibiting the formation of functional authentic receptor complexes (TGFRI/BMPRI and TGFRII/BMPRII). On the assumption that BAMBI gene expression is epigenetically altered during human bladder cancer progression, we screened the expression of BAMBI protein by immunohistochemistry and the methylation status of the BAMBI promoter. In the normal or reactive urothelium, BAMBI expression was mostly overlapped with that of BMPRI, and a similar colocalization pattern was noted in low-grade papillary cancers. In high-grade and invasive cancers, however, mainly two reciprocal immunohistochemical expression patterns were observed: BAMBI-low/BMPRI-high, and BAMBI-high/BMPRI-low, indicating that BAMBI expression is controlled such that it does not interfere with the responsiveness of high-grade cancer cells to TGF-beta/BMP signaling. Moreover, methylation of the BAMBI gene correlated significantly with negative BAMBI expression in bladder tumors. Although BAMBI overexpression significantly increased the number of apoptotic cells in T24 line, knock-down small interfering RNA showed no remarkable change. Cell motility assay revealed that on treatment with either TGF-beta1 or BMP2, T24 and HTB9 lines showed a marked increase in the number of migrated cells which, however, decreased significantly through the forced expression of BAMBI. Since certain subsets of aggressive tumors often promote cell motility, invasion and survival by inducing epithelial-to-mesenchymal transition through TGF-beta/BMP in an autocrine and paracrine manner, hypermethylation of the BAMBI gene promoter that leads to BAMBI gene suppression may be one of the epigenetic events affecting the invasiveness or aggressiveness of bladder cancers.

Detection of urothelial bladder cancer cells in voided urine can be improved by a combination of cytology and standardized microsatellite analysis

PURPOSE

To evaluate molecular and immunohistochemical markers to develop a molecular grading of urothelial bladder cancer and to test these markers in voided urine samples.

EXPERIMENTAL DESIGN

255 consecutive biopsies from primary bladder cancer patients were evaluated on a tissue microarray. The clinical parameters gender, age, adjacent carcinoma in situ, and multifocality were collected. UroVysion fluorescence in situ hybridization (FISH) was done. Expression of cytokeratin 20, MIB1, and TP53 was analyzed by immunohistochemistry. Fibroblast growth factor receptor 3 (FGFR3) status was studied by SNaPshot mutation detection. Results were correlated with clinical outcome by Cox regression analysis. To assess the predictive power of different predictor subsets to detect high grade and tumor invasion, logistic regression models were learned. Additionally, voided urine samples of 119 patients were investigated. After cytologic examination, urine samples were matched with their biopsies and analyzed for loss of heterozygosity (LOH), FGFR3 mutation, polysomy, and p16 deletion using UroVysion FISH. Receiver operator characteristic curves for various predictor subsets were plotted.

RESULTS

In biopsies, high grade and solid growth pattern were independent prognostic factors for overall survival. A model consisting of UroVysion FISH and FGFR3 status (FISH + FGFR3) predicted high grade significantly better compared with a recently proposed molecular grade (MIB1 + FGFR3). In voided urine, the combination of cytology with LOH analysis (CYTO + LOH) reached the highest diagnostic accuracy for the detection of bladder cancer cells and performed better than cytology alone (sensitivity of 88.2% and specificity of 97.1%).

CONCLUSIONS

The combination of cytology with LOH analysis could reduce unpleasant cystoscopies for bladder cancer patients.

Bladder cancer biomarkers and their role in surveillance and screening

Early detection of bladder cancer and its recurrences is essential for improved prognosis and long-term survival. The detection and follow-up of these patients is currently based on cystoscopy, which is expensive and invasive, and, in most cases, cytology, which is non-invasive but not very sensitive. During recent years, many urine-based tests have been developed and tested in different patient populations. In this review we discuss new developments for biomarkers in bladder cancer that have potential use in surveillance and screening. In almost all publications authors compare sensitivity of the test with a concomitantly executed cystoscopy, for example, determine cross-sectional sensitivity. However, it has also been shown that false positive test results may be followed by a positive cystoscopy in the near future, showing that cystoscopy itself does not provide 100% sensitivity. This suggests that for a proper evaluation of urine-based tests, longitudinal studies should be carried out and the results communicated to the urologist.

Detection of tumours of the urinary tract in voided urine

Patients with non-muscle-invasive bladder cancer are treated by transurethral resection. About 60-70% of these patients will develop recurrences and in 11% of these cases progression to a muscle-invasive tumour occurs. Surveillance of patients by cystoscopy is therefore carried out every 3-4 months in the first 2 years and yearly thereafter. Several biomarkers have been developed that potentially can detect recurrent bladder cancer in voided urine samples and may present an alternative for the invasive cystoscopy procedure. Recently, van Rhijn reviewed the performance of several of these biomarkers regarding detection of recurrent disease in patients under surveillance. In general, sensitivities were much lower when only patients under surveillance were taken into account than when the patient cohorts included patients with primary disease or patients with high-grade tumours. In this article recent new data on those markers that displayed a sensitivity and specificity of at least 70% as mentioned in the review by van Rhijn are reviewed. The literature selected was limited to those papers in which the performance of makers was assayed only on urine samples of patients under surveillance. The markers with sensitivity and specificity over 70% that were selected from the previous study are Lewis X, NMP22, microsatellite analysis (MA), CYFRA 21.1, cytokeratin 20 and the UroVysion fluorescence in situ hybridization (FISH) test. Recent new developments such as the use of FGFR3 mutation analysis and methylation detection are also discussed. In conclusion, tests such as the UroVysion FISH test and MA are able to detect most concomitant recurrences and to predict recurrent disease. In general, lesions that are missed are pTa and low grade. With MA several upper tract recurrences were identified that were missed by cystoscopy. The value of the most promising urine tests needs to be established in longitudinal studies and exclusively on patients under surveillance for recurrent disease. A longitudinal setting allows subsequent urine samples to be tested and this increases sensitivity because a negative test outcome sometimes occurs between positive ones. Stratification of patients according to the genetic status of their primary tumours and smoking habits should be investigated. Decision models should be developed that recommend at which points in time cystoscopy or urine testing should be performed.

Bladder tumor markers: from hematuria to molecular diagnostics--where do we stand?

Bladder cancer is a common malignancy in the USA. Currently, the detection of initial tumors and recurrent disease is based on evaluation of voided urinary specimens, often followed by cystoscopy. With the high rate of recurrence, cystoscopies are regularly repeated with the aim of halting progression of the disease. For patients, this process is fraught with anxiety, pain and high cost. As a result, intense work is being done in the field of bladder tumor markers with the goal of identifying bladder cancer earlier, both in the initial diagnosis and in recurrences of known tumor. The possibility of identifying a marker that could noninvasively differentiate benign and malignant causes of hematuria, and identify recurrences prior to their pathologic progression is the objective of this area of research. Currently, a large number of tumor markers exist, each scrutinized in both the laboratory and in clinical trials. Here we present many of the most widely used and tested markers. Background details are provided as to the mechanism of detection of malignant cells, the results of recent trials and future directions of study. Some novel modalities for tumor detection are also presented. The next few years will no doubt bring newer markers and lead to the elimination of others. Studies continue to refine the role of these markers in clinical practice, but their ultimate efficacy will need to be borne out in large-scale clinical trials in a multitude of settings.

The origins of bladder cancer

Bladder cancer, arising from the transitional cells of the mucosal urothelium, may present as a noninvasive, papillary tumor protruding from the mucosal surface, or as a solid, nonpapillary tumor that invades the bladder wall and has a high propensity for metastasis. The nonpapillary tumors originate from in situ dysplasia. The most common environmental risk for bladder cancer is active smoking; occupational exposure to arsenic or other carcinogens is also a risk factor. A possible familial component to bladder cancer has been described. Conventional models of carcinogenesis suppose the existence of successive mutation events within a specific cell clone, enabling its eventual escape from regulation of cell division and maintenance of genomic integrity. Important new information has emerged from whole-organ mapping of the mucosal genome in bladders resected for invasive cancer (Majewski et al, Lab Invest; published online 5 May 2008). Mapping of genetic hits across the entire mucosa demonstrates genetic alterations in six chromosomal regions, not only in mucosal regions of evident dysplasia, but also in morphologically normal mucosa. These clonally expanded regions cover vast expanses of the bladder surface, as a 'first wave' of pre-neoplasia. Target genes in these regions are termed 'forerunner genes' (FR genes), based on the concept that these genes enable the initial clonal expansion of in situ urothelial neoplasia. Extensive further analysis of human populations with urothelial cancer implicates genetic polymorphisms in one of these genes, P2RY5, as being present in a familial cluster of cancers of multiple organs, and as imparting risk for development of bladder cancer in active smokers. P2RY5 is a gene encoded within intron 17 of RB1, a prototypic tumor suppressor gene whose expression is lost at a later stage of bladder carcinogenesis. Alterations of the FR gene status provide a novel opportunity to screen individuals at risk for the earliest stage of bladder pre-neoplasia and represent attractive targets for therapeutic and chemopreventive interventions. These findings support the hypothesis that bladder carcinogenesis is initiated by clonal expansion of genetically altered but histologically normal cells that cover broad expanses of the mucosa. Effort must now be given to identifying the biological function of these novel FR genes.

Microsatellite analysis of voided-urine samples for surveillance of low-grade non-muscle-invasive urothelial carcinoma: feasibility and clinical utility in a prospective multicenter study (Cost-Effectiveness of Follow-Up of Urinary Bladder Cancer trial [CEFUB])

BACKGROUND

Microsatellite analysis (MA) of voided-urine samples has been promoted as an alternative for cystoscopy surveillance (UCS) of patients with low-grade non-muscle-invasive papillary urothelial carcinoma (UC).

OBJECTIVE

To assess the feasibility and clinical utility of MA on voided-urine samples in a routine setting to detect or predict bladder cancer recurrences.

DESIGN, SETTING, AND PARTICIPANTS

We evaluated 228 patients monitored by MA of voided-urine samples and synchronous UCS who participated in a longitudinal prospective study in 10 hospitals. Follow-up started after diagnosis of a primary or recurrent pTa, pT1, grade 1 or grade 2 papillary UC.

MEASUREMENTS

Clinico-pathological parameters and fibroblast growth factor receptor 3 (FGFR3) gene mutation status of the inclusion tumour were determined. MA outcome was analysed in 1012 urine samples during a mean follow-up of 41 mo. Poor DNA quality prevented MA in 19% (197/1012) of the samples, leaving 815 visits for a cross-sectional analysis of sensitivity and specificity. We determined the predictive value (PPV) in a longitudinal analysis for 458 series with persistent MA results. Factors influencing diagnostic quality of MA were investigated. Kaplan-Meier analysis was performed to relate MA results to recurrence.

RESULTS AND LIMITATIONS

Cross-sectional sensitivity and specificity of MA for detection of a recurrence were 58% (49/84) and 73% (531/731), respectively. One pT1 grade 3 UC was missed. In a longitudinal analysis, the 2-yr risk to develop a recurrence reached 83% if MA outcome was persistently positive and 22% when MA was persistently negative. PPV of MA was higher with wild-type FGFR3 gene status and smoking habits. All four upper urinary tract tumours detected were preceded by a positive MA test.

CONCLUSIONS

Consecutive positive MA results are a strong predictor for future recurrences, but sensitivity needs to be improved, for example, by patient selection and testing of additional genetic markers in urine samples.

Urinary markers in bladder cancer

OBJECTIVES

Many markers for the detection of bladder cancers have been tested. Almost all urinary markers reported are better than cytology with regard to sensitivity, but they score lower in specificity. The purpose of this review is to highlight the most important urinary biomarkers studied and reported recently.

METHODS

Literature on bladder cancer markers has been reviewed regularly in the last few years. In the current review we have tried to summarise the most recent literature of urinary markers.

RESULTS

The results of this review show that the first-generation urinary markers did not add much to urinary cytology. The current generation of markers is promising but larger clinical trails are needed. The future of marker development is bright with new techniques emerging, but the perfect marker is still to be found.

CONCLUSION

Currently, no single marker can yet guide us in surveillance and lower the frequency of urethrocystoscopy.

Bladder cancer biomarkers: current developments and future implementation

PURPOSE OF REVIEW

Bladder cancer biomarker development has advanced significantly over the last decade, but has not yet been able to make a significant impact in the diagnosis and management of the disease. Many available markers are suitable, but do not meet the expectations of physicians and patients. Patients do not want to compromise accuracy in diagnosing bladder cancer for less-invasive tests. The review highlights the latest developments in bladder cancer biomarkers, including markers developed over the last year, and comments on the high standards placed on these markers which have delayed their widespread implementation into the urologic field.

RECENT FINDINGS

New markers described in the last year include soluble Fas, urothelial carcinoma-associated 1 and human chorionic gonadotropin beta type II genes. The latter two markers represent the contribution of genomic technology to this field. Also described are updates to known markers, including long-term follow-up of hematuria screening, recent studies in DNA methylation for bladder cancer diagnosis and patient perspectives on bladder tumor markers.

SUMMARY

Biomarkers for bladder cancer have been intensively scrutinized over the last decade, but despite new findings and good performance characteristics, they are currently not accepted in clinical practice.

Diagnostic significance of allelic imbalance in cancer

Allelic imbalance (AI), a deviation from the normal 1:1 ratio of maternal and paternal alleles, occurs in virtually all solid and blood-borne malignancies. The frequency and spectrum of AI in a tumor cell reflects the karyotypic complexity of the cancer genome. Hence, many investigations have assessed the extent of AI to analyze differences between normal and tumor tissues in a variety of different organs. In this review, the authors describe established and emerging technologies used to assess the extent of AI in human tissues, and their application in the diagnosis of cancer. The four major methods to be reviewed represent powerful and widely used tools for the identification of allelic imbalances accompanying cancer initiation and progression. These are fluorescent in situ hybridization, comparative genomic hybridization, single nucleotide polymorphism arrays and the use of microsatellite markers. For each method, the authors provide a brief description of the approach and elaborate on specific studies that highlight its utility in the diagnosis of human cancers.