Tissue-based molecular markers for bladder cancer

Bladder cancer is the second most common genitourinary malignancy in the United States, and is a major cause of morbidity and mortality. Despite aggressive treatment, survival for patients with muscle-invasive urothelial carcinoma of the bladder remains poor. Cancer stage, grade, and other clinical and pathological characteristics provide only limited prognostic information, and there is significant heterogeneity in patient outcomes using current risk stratification. Recent research into the profiling of bladder cancer at the molecular level has begun to shed light on important mechanisms of pathogenesis, as well as providing a number of potential tissue markers. These may provide useful prognostic information and guide patient selection for therapeutic strategies. This review explores recent advances in tissue-based molecular markers in bladder cancer and their potential utility. We also discuss design and statistical consideration for development and validation of molecular markers. A combination of complementary and yet independent molecular markers will likely better capture the biologic potential of each individual bladder tumor resulting in improved clinical decision-making.     

New molecular markers for bladder cancer detection

PURPOSE OF REVIEW: Bladder cancer continues to be one of the most common genitourinary malignancies. The mainstay of diagnosis remains cystoscopic visualization with transurethral biopsy or resection. As over two-thirds of bladder tumors recur, vigilant surveillance is required. Due to the invasiveness and expense of frequent cystoscopies and the lack of sensitivity of urinary cytology, especially for low-grade superficial lesions, novel molecular markers have been investigated as a means to detect bladder cancer noninvasively. RECENT FINDINGS: As our understanding of the pathogenesis of urothelial neoplasia improves, coupled with recent advances in molecular biological techniques, an array of new approaches to the diagnosis of bladder cancer has emerged. Several urine-based markers have been tested against the standard of urinary cytology with promising results. However, lack of standardization of technique and heterogeneity of bladder cancer itself may hinder the widespread dissemination of these diagnostic aids. SUMMARY: A host of new molecular markers based on the pathogenesis of bladder cancer have been investigated, such as telomerase, survivin, and multitarget fluorescence in situ hybridization, which may eventually improve detection and management of urothelial malignancies. By improving the sensitivity of urinary cytology for low-grade superficial lesions and detecting recurrent disease noninvasively early in its course, these new molecular markers might someday allow changes in the way bladder cancer is diagnosed and followed. At the present time, however, no single molecular marker provides 100% accuracy. Perhaps panels utilizing the most promising of these markers may alter bladder cancer detection and management policy.     

Current status of molecular markers for prognostication and outcome in invasive bladder cancer

What's known on the subject? and What does the study add? Currently, prognostication of patients with invasive BC is hampered owing to the inadequacy of standard clinicopathological risk factors to predict accurately individual treatment outcomes. This review provides a comprehensive albeit brief overview on current studies elucidating the potential role of different molecular markers to close this gap of evidence. It focusses on biostatistical considerations in the interpretation of study results which are essential to provide meaningful clinical conclusions for an individual patient.

OBJECTIVE

• ? To improve prognostication and the management of patients with invasive bladder cancer (BC).

METHODS

• ? Standard clinicopathological risk factors are not reliably enough to accurately predict outcomes in patients after radical treatment and guide clinicians for recommending selectively the use of adjuvant therapies.
• ? With detailed insights into the molecular pathology of BC, biomarkers have come to the fore of researchers as a potential tool to close this gap of evidence.
• ? However, their definitive role in the diagnostic and therapeutic management of patients with invasive BC has not clearly been addressed so far.

RESULTS

• ? Invasive BC are an extremely heterogenenous group of malignancies which are characterized by multiple genetic alterations involved in the carcinogenesis and development of metastatic spread. Thus, it is questionable whether any single marker will provide superior prognostication compared with a combination of markers.
• ? Current studies evaluating the predictive value of a multitude of markers have used high‐throughput technologies and investigated the gain in predictive accuracy within new nomograms which encompass well‐established clinicopathological and novel putative molecular parameters. p53 overexpression was found to be associated with increased risk of recurrence in urothelial and non‐urothelial cancer. In pT1 disease, the combination of p53, p21 and p16 as well as epigenetic alterations of myopodin expression has been shown to provide improved prognostication, and this might help to advocate more selectively the use of early radical treatment.
• ? After the bladder‐sparing approach, p53 and p21 overexpression indicate decreased probability of long‐term bladder preservation. Additionally, altered retinoblastoma expression is associated with improved survival after adjuvant chemotherapy.
• ? To provide meaningful conclusions for individual prognosis and the need of adjuvant treatment, biostatistical pitfalls in the analysis and interpretation of results have to be taken into account.

CONCLUSIONS

• ? Different molecular markers have the potential to improve prognostication of patients with invasive BC and provide improved evidence for targeted therapy in the neoadjuvant, adjuvant and metastatic setting.
• ? However, in order to advocate their routine clinical use on a sound scientific basis prospective data are still necessary.

     

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.     

Molecular markers in bladder cancer

PURPOSE OF REVIEW: Bladder cancer is a diverse disease whose molecular phenotypes are being elucidated. In this review, we summarize currently known molecular pathways and associated markers in bladder cancer. RECENT FINDINGS: Genetic and epigenetic aberrations have been closely associated with tumor pathogenesis and prognosis. Cell cycle markers have been most extensively studied. More recently, apoptotic and angiogenic pathways are being investigated. Studying the role of multiple concurrent molecular alterations improves the prognostic ability of these markers. The use of tissue microarrays and high-throughput molecular profiling is accelerating the discovery of new markers. SUMMARY: Molecular biology is paramount to our understanding of bladder cancer pathogenesis. The search for new markers, and elucidating cross-talk between markers in different pathways, is warranted. Molecular markers have the potential benefit of improving detection, prognosis and treatment of bladder cancer. In addition, understanding the molecular profile of the individual patient could usher us into a new era of improving prediction of the natural history of the disease and providing a more personalized and tailored treatment. Prospective trials are still needed, however, to objectively establish the true benefit of these markers in prognostic and therapeutic arenas.     

Comprehensive analysis of the lncRNA-miRNA-mRNA regulatory network for bladder cancer

BackgroundLong non-coding RNAs (lncRNAs) are essential regulators for various human cancers. However, these lncRNAs need to be further classified for cancer. In the present study, we identified novel competing endogenous RNA (ceRNA) network for bladder cancer (BC) and explored the gene functions of the ceRNA regulatory network.MethodsDifferential gene expression analysis were performed on The Cancer Genome Atlas Urothelial Bladder Carcinoma (TCGA-BLCA) datasets to identify differentially expressed messenger RNAs (mRNAs), lncRNAs, and microRNAs (miRNAs). Based on the competing endogenous RNA (ceRNA) hypothesis, a lncRNA-miRNA-mRNA network was constructed using the StarBase database and visualization by Cytoscape software. Functional enrichment analyses of Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were performed via R package ClusterProfiler. The protein-protein interaction network was constructed by STRING database and visualization by Cytoscape. Finally, we used CIBERSORT and the TIMER database to analyze the immune infiltrations for BC.ResultsThe regulatory network was constructed via TCGA BLCA cohort. The differential expressions of lncRNA, miRNA, and mRNA were 186, 200, and 2,661, respectively. There were 106 lncRNA, miRNA, and mRNA included in the ceRNA network. In this network, Calcium Voltage-gated Channel Auxiliary Subunit Alpha2delta1 (CACNA2D1, P<0.001), domain containing engulfment adaptor1 (GULP1, P=0.001), latent transforming growth factor beta binding protein 1 (LTBP1, P=0.006), myosin light chain kinase (MYLK, P=0.001), serpin family E member 2 (SERPINE2, P=0.002), spectrin beta non-erythrocytic 2 (SPTBN2, P=0.047), and hsa-miR-590-3p (P<0.001) significantly affected the prognosis of BC patients. Functional enrichment analyses showed that the biological functions included negative regulation of protein phosphorylation, cell morphogenesis, and sensory organ morphogenesis. Important cancer pathways of KEGG included parathyroid hormone synthesis secretion action, the notch signaling pathway, MAPK signaling pathway, the Rap1 signaling pathway, signaling pathways regulating the pluripotency of stem cells, and the transforming growth factor-β signaling pathway. Our findings demonstrated that the ceRNA network has important biological functions and a significant influence on the prognosis of BC.ConclusionsThe lncRNA-miRNA-mRNA network constructed in the present study could provide useful insight into the underlying tumorigenesis of BC, and can determine new molecular biomarkers for the diagnosis and therapeutical treatment of BC.     

Expression of potential molecular markers in prostate cancer: correlation with clinicopathological outcomes in patients undergoing radical prostatectomy

The objective of this study was to evaluate the expression levels of multiple potential molecular markers in prostate cancer to clarify the significance of these markers as prognostic indicators in patients undergoing radical prostatectomy (RP). This study included a total of 193 patients with clinically organ-confined prostate cancer who underwent RP without any neoadjuvant therapies. Expression levels of 12 proteins, including Ki-67, p53, androgen receptor (AR), matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial growth factor, Aurora-A, Bcl-2, clusterin, heat shock protein 27 (HSP27), HSP70, and HSP90, in RP specimens obtained from these 193 patients were measured by immunohistochemical staining. Of the 12 molecules, Ki-67, p53, AR, MMP-2, MMP-9, and HSP27 expression were significantly associated with several conventional prognostic factors. Univariate analysis identified these 6 markers as significant predictors for biochemical recurrence as well, while prostate-specific antigen, Gleason score, seminal vesicle invasion (SVI), surgical margin status (SMS), lymph node metastasis, and tumor volume were also significant. Of these significant factors, Ki-67 expression, SVI, and SMS appeared to be independently related to biochemical recurrence by multivariate analysis. Furthermore, there were significant differences in biochemical recurrence-free survival according to positive numbers of these three independent risk factors. These findings suggest that consideration of expression levels of potential molecular markers in RP specimens, in addition to conventional prognostic parameters, would contribute to accurate prediction of biochemical recurrence following RP in patients with clinically localized prostate cancer, and that combined evaluation of Ki-67 expression, SVI, and SMS would be particularly useful for further refinement of the system in predicting biochemical outcome.     

Economic impact of screening for bladder cancer using bladder tumor markers: a decision analysis

PURPOSE: The Food and Drug Administration recently approved the use of bladder markers such as BladderChek (NMP22; Matritech, Inc., Newton, MA) and UroVysion (Abbott Laboratories, Abbott Park, IL) for use in screening for bladder cancer. The purpose of this analysis was to assess the cost associated with implementing a widespread screening program using a noninvasive bladder tumor marker. METHODS: Data for the accuracy of NMP22 in detecting bladder cancer was gathered from a comprehensive literature review. A decision tree analysis was constructed to evaluate the total cost of screening a low and high-risk population for bladder cancer using NMP22. Sensitivity analyses were conducted to evaluate the effect of relaxing the various assumptions in the model. RESULTS: Application of the model to all men, regardless of the degree of risk, rendered a cost per cancer detected of $783,913, $269,028, and $139,305 for ages 50-59, 60-69, and 70-79 years, respectively. Screening only patients at high-risk for bladder cancer (annual incidence 6%) would yield a cost per cancer detected of $3,310. Incidence of cancer and marker specificity had the highest influence on cost per cancer detected. CONCLUSIONS: Application of NMP22 to the entire population would render an extremely high cost per cancer detected. However, application to an appropriate high-risk target population could achieve cost per cancer detected comparable to currently used screening programs for prostate, colon, and breast cancer. Further studies are needed to assess the accuracy of bladder tumor markers in detecting bladder cancer in a completely asymptomatic cohort.     

Prognostic markers in muscle invasive bladder cancer

Current tumor, node, and metastasis (TNM) staging and grading systems are insufficient to accurately predict the evolution of most invasive bladder cancers irrespective of treatment. Predicting which invasive tumors will or will not recur or metastasize early is crucial in order to dictate initial therapy and to better counsel the patient. A need for tumor markers that could be incorporated into clinical practice to add prognostic information to the conventional TNM and grading systems in terms of treatment response and prognosis is crucial. This review provides an update on the most promising reported single markers and pathways, including the cell cycle markers p53, p21 and p27, and potential targets for novel therapies, such as cyclooxygenase 2 (COX 2) and factors of angiogenesis. The critical steps remain the availability of large and well-characterized data sets to validate the combination of markers, as well as high throughput methods to study tumor molecular fingerprints, such as DNA microarrays.     

Molecular aspects of bladder cancer III. Prognostic markers of bladder cancer

The current pathological and clinical parameters provide important prognostic information, yet still have limited ability to predict the true malignant potential of most bladder tumors. In the last years, investigation of the basic mechanisms involved in carcinogenesis and tumor progression by molecular biology has provided a host of markers which are of potential diagnostic or prognostic value for bladder carcinoma. These markers may serve as tools for early and accurate prediction of tumor recurrence, progression and development of metastases and for prediction of response to therapy. The precise prediction of tumor biological behavior would facilitate treatment selection for patients who may benefit from radical surgical treatment or adjuvant therapy. We provide a current, comprehensive review of the literature on bladder tumor markers with a special emphasis on their prognostic potential. The literature suggests that currently no single marker is able to accurately predict the clinical course of bladder tumors and thus would serve as a reliable prognosticator. A combination of prognostic markers could predict which superficial tumors need an aggressive form of therapy and which invasive tumors require adjuvant therapy. Altogether, the most promising markers are, at this point, Ki-67 and p53 expression as well as matrixmetalloproteinase complex and angiogenesis.     

Current concepts of tumor markers in bladder cancer

The critical issue in characterizing the usefulness of tumor markers in screening or monitoring for urothelial cancer and in determining prognosis revolves around the question, "What do we need to know?" During surveillance of patients with low-risk disease, highly sensitive markers may detect disease persistence or early recurrence (on the basis of field-effect changes or tumor cell implantation); however, they may not indicate the possibility of progression. If cystoscopy is negative in these instances, is it appropriate to treat? Does earlier treatment actually prevent recurrence or progression? Some investigators have suggested a positive answer to the former question, although lead-time bias may a role. The issue in the latter question may be moot because low-risk disease is by definition unlikely to progress. A corresponding question is whether one should treat the patient if the marker has a low specificity. In such instances, a marker with low specificity may incur more frequent instrumentation and a panoply of additional costs. A marker may have some value in providing earlier diagnosis in low-risk disease if treatments are available to prevent clinical expression and recurrence. A tumor marker would have additional value if it could detect biologic change from low-risk to high-risk disease and permit a corresponding change in treatment. Moreover, if a marker could provide earlier diagnosis in high-risk disease, it might permit identification of those patients likely to progress at earlier and curable stages of disease. To be successful, such markers must have high sensitivity and specificity in diagnosis. It has been suggested that "a simple noninvasive highly sensitive and specific method for detecting bladder cancer would decrease the morbidity associated with current surveillance methods, improve quality of life for patients, and reduce costs by substituting a less expensive test for the more expensive endoscopic procedures" (Dr. M. Soloway, personal communication 2000). In considering this statement, it is tempting to question some of its implications. The term "simple" suggests that point-of-care tests may be the easiest, but tests that are available may be inconsistent and not sufficiently sensitive or specific. The need for a "highly sensitive and specific" test is of critical importance for applicability in the individual, even when such tests are based on the results in large populations. When considering the "morbidity of current methods," it is tempting to question whether cystoscopy is that morbid a procedure. Given the information it provides, it seems improbable that it can be readily replaced. Currently, no markers provide information over and above that provided by cystoscopy and histology- or cytology-based understanding of the biology of the disease especially in considering distinctions between low-risk and high-risk disease. The ability to "improve quality of life" will depend on the use of the predictive value made on the basis of a test's sensitivity and specificity. A false-positive test may lead to anxiety and extensive unnecessary evaluation, whereas a false-negative test may lead to missed diagnosis, delayed treatment, and the possibility of disease progression until accurate diagnosis is obtained. In each case, quality of life is compromised. "Substituting a less expensive test" depends on the benefits of that substitution and the practicality of omitting or delaying standard assessment. Costs depend on the frequency of testing, those incurred by false-positive tests, and those incurred by false-negative tests. Several caveats emerge when taking into account these various considerations. In screening for low-risk disease, the urgency of diagnosis may be less important. High sensitivity is of less importance because the risk of a missed diagnosis has less ominous repercussions. Nevertheless, high specificity is important to avoid unnecessary frequent instrumentations. In considering surveillance for low-risk disease, cytology may be more useful in indicating a change from negative (persistent or recurrent low-risk disease) to positive (high-risk disease) with the consequent need for more aggressive treatment approach. No urinary "screening" markers reliably provide this information. In considering surveillance for high-risk disease, sensitive markers would detect persistence or early recurrence. If such markers are negative, intervals between repeated cystoscopies may be prolonged; however, a high specificity is needed to ensure the validity of a truly negative interpretation. Otherwise, diagnosis may be missed and the risk from progression and the development of incurability increased. Markers for urothelial cancer must be expressed exclusively as a consequence of the presence of cancer cells. The test must be sensitive in detecting disease and must be validated in nonselected populations. It must be sensitive in excluding nondisease, and noncancer conditions must have little influence on its accuracy. There must be little or no interassay or intra-assay variability. Interpretation of an assay for a tumor marker should be all or none, or based on a threshold level. The assays must have sufficient sensitivity and specificity in populations and in the individual to have practical clinical applicability.     

Evaluation of biological markers in bladder cancer.

The value of biological markers of bladder cancer was studied in 66 patients. The markers included serum and urine carcinoembryonic antigens, serum and urine fibrinogen degradation products, total lymphocyte counts, urine lymphocytes and urine cytology. A high degree of accuracy (90 per cent) was found in correlating cytology and urinary fibrinogen degradation products with the activity of the disease. Serum and urine carcinoembryonic antigens, serum fibrinogen degradation products, total lymphocyte counts and urine lymphocytes were found to have no value in screening bladder cancer patients. Urinary fibrinogen degradation products and cytology in combination are recommended for screening and followup of patients at high risk.     

Tumor markers and prognostic parameters in urinary bladder cancer

Ideal tumor markers for use in the primary diagnosis or follow up of superficial or invasive cancers have not yet been found. Nonetheless, the literature contains references to parameters that are relevant to prognosis and to markers for bladder tumors, and many of these are certainly of value when specific questions are addressed. Urinalysis has been considerably refined and yields information on superficial tumors. Quantitative immunocytology is used to check whether prophylactic treatments are indicated and, if so, for how long; conventional cytology is helpful in the clinical follow up after BCG treatment of carcinoma in situ. In the present paper all important markers for urothelial cancer are reviewed and their value in diagnosis and treatment is discussed.     

A clinicopathological study of bladder cancer associated with upper urinary tract cancer

OBJECTIVES: To analyse the clinicopathological features of bladder cancer associated with upper urinary tract cancer (UUTC). PATIENTS AND METHODS: Among 106 patients with primary UUTC (mean age 65 years, range 45-82) who underwent surgical treatment, 44 also had bladder cancer. The patients were divided into three groups according to the timing of the appearance of bladder cancer. In group 1, 10 patients had UUTC preceding bladder cancer, group 2 comprised 14 patients with concurrent bladder cancer and group 3, 20 with subsequent bladder cancer; their clinicopathological data were analysed. RESULTS: Among several clinicopathological factors examined, only the number of UUT tumours was significantly correlated with the incidence of associated bladder cancer (P < 0.01). There was no significant difference between survival rates of patients with UUTC with and without associated bladder cancer. The incidence of high-stage or high-grade tumours in both the UUT and bladder in group 2 was higher than that in groups 1 and 3 (P < 0.05), and the survival rate in group 2 was significantly lower than in those in groups 1 and 3 (P < 0.05). Furthermore, the survival rate of patients in group 2 was significantly lower than that of all other patients (P < 0.01). CONCLUSIONS: These findings suggest that bladder cancer associated with UUTC has a different biological character depending on the timing of tumour appearance, and that patients with UUTC and concurrent bladder cancer should undergo careful follow-up and aggressive adjuvant therapy.