Diagnostic value of fibronectin and mutant p53 in the urine of patients with bladder cancer: impact on clinicopathological features and disease recurrence

Comprehensive proteomics and platform validation of urinary biomarkers for bladder cancer diagnosis and staging

BACKGROUND

Bladder cancer (BC) is among the most common cancers diagnosed in men in the USA. The current gold standards for the diagnosis of BC are invasive or lack the sensitivity to correctly identify the disease.

METHODS

An aptamer-based screen analyzed the expression of 1317 proteins in BC compared to urology clinic controls. The top hits were subjected to systems biology analyses. Next, 30 urine proteins were ELISA-validated in an independent cohort of 68 subjects. Three of these proteins were next validated in an independent BC cohort of differing ethnicity.

RESULTS

Systems biology analysis implicated molecular functions related to the extracellular matrix, collagen, integrin, heparin, and transmembrane tyrosine kinase signaling in BC susceptibility, with HNF4A and NFKB1 emerging as key molecular regulators. STEM analysis of the dysregulated pathways implicated a functional role for the immune system, complement, and interleukins in BC disease progression. Of 21 urine proteins that discriminated BC from urology clinic controls (UC), urine D-dimer displayed the highest accuracy (0.96) and sensitivity of 97%. Furthermore, 8 urine proteins significantly discriminated MIBC from NMIBC (AUC = 0.75-0.99), with IL-8 and IgA being the best performers. Urine IgA and fibronectin exhibited the highest specificity of 80% at fixed sensitivity for identifying advanced BC.

CONCLUSIONS

Given the high sensitivity (97%) of urine D-dimer for BC, it may have a role in the initial diagnosis or detection of cancer recurrence. On the other hand, urine IL-8 and IgA may have the potential in identifying disease progression during patient follow-up. The use of these biomarkers for initial triage could have a significant impact as the current cystoscopy-based diagnostic and surveillance approach is costly and invasive when compared to a simple urine test.

Trends in urine biomarker discovery for urothelial bladder cancer: DNA, RNA, or protein?

Urothelial bladder cancer is a complex disease displaying a landscape of heterogenous molecular subtypes, mutation profiles and clinical presentations. Diagnosis and surveillance rely on flexible cystoscopy which has high accuracy, albeit accompanied by a high-cost burden for healthcare providers and discomfort for patients. Advances in "omic" technologies and computational biology have provided insights into the molecular pathogenesis of bladder cancer and provided powerful tools to identify markers for disease detection, risk stratification, and predicting responses to therapy. To date, numerous attempts have been made to discover and validate diagnostic biomarkers that could be deployed as an adjunct to the cystoscopic diagnosis and long-term surveillance of bladder cancer. We report a comprehensive literature analysis using PubMed to assess the changing trends in investigating DNA, RNA, or proteins as diagnostic urinary biomarkers over a period of 5 decades: 1970-2020. A gradual shift has been observed in research away from protein biomarkers to nucleic acids including different classes of RNA, and DNA methylation and mutation markers. Until 2000, publications involving protein biomarker discovery constituted 87% of the total number of research articles with DNA comprising 6% and RNA 7%. Since 2000 the proportion of protein biomarker articles has fallen to 40%, and DNA and RNA studies increased to 32% and 28%, respectively. Clearly research focus, perhaps driven by technological innovation, has shifted from proteins to nucleic acids. We optimistically hypothesise that, following thorough validation, a clinically useful detection test for bladder cancer based on a panel of DNA or RNA markers could become reality within 5-10 years.

The First Approved Gene Therapy Product for Cancer Ad-p53 (Gendicine): 12 Years in the Clinic

Gendicine (recombinant human p53 adenovirus), developed by Shenzhen SiBiono GeneTech Co. Ltd., was approved in 2003 by the China Food and Drug Administration (CFDA) as a first-in-class gene therapy product to treat head and neck cancer, and entered the commercial market in 2004. Gendicine is a biological therapy that is delivered via minimally invasive intratumoral injection, as well as by intracavity or intravascular infusion. The wild-type (wt) p53 protein expressed by Gendicine-transduced cells is a tumor suppressor that is activated by cellular stress, and mediates cell-cycle arrest and DNA repair, or induces apoptosis, senescence, and/or autophagy, depending upon cellular stress conditions. Based on 12 years of commercial use in >30,000 patients, and >30 published clinical studies, Gendicine has exhibited an exemplary safety record, and when combined with chemotherapy and radiotherapy has demonstrated significantly higher response rates than for standard therapies alone. In addition to head and neck cancer, Gendicine has been successfully applied to treat various other cancer types and different stages of disease. Thirteen published studies that include long-term survival data showed that Gendicine combination regimens yield progression-free survival times that are significantly longer than standard therapies alone. Although the p53 gene is mutated in >50% of all human cancers, p53 mutation status did not significantly influence efficacy outcomes and long-term survival rate for Ad-p53-treated patients. To date, Shenzhen SiBiono GeneTech has manufactured 41 batches of Gendicine in compliance with CFDA QC/QA requirements, and 169,571 vials (1.0 × 10¹² vector particles per vial) have been used to treat patients. No serious adverse events have been reported, except for vector-associated transient fever, which occurred in 50-60% of patients and persisted for only a few hours. The manufacturing accomplishments and clinical experience with Gendicine, as well as the understanding of its cellular mechanisms of action and implications, could provide valuable insights for the international gene therapy community and add valuable data to promote further developments and advancements in the gene therapy field.

Effectiveness of urine fibronectin as a non-invasive diagnostic biomarker in bladder cancer patients: a systematic review and meta-analysis

Background

Previous researches pointed out that the measurement of urine fibronectin (Fn) could be a potential diagnostic test for bladder cancer (BCa). We conducted this meta-analysis to fully assess the diagnostic value of urine Fn for BCa detection.

Methods

A systematic literature search in PubMed, ISI Web of Science, EMBASE, Cochrane library, and CBM was carried out to identify eligible studies evaluating the urine Fn in diagnosing BCa. Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) with their 95% confidence intervals (CIs) were calculated, and summary receiver operating characteristic (SROC) curves were established. We applied the STATA 13.0, Meta-Disc 1.4, and RevMan 5.3 software to the meta-analysis.

Results

Eight separate studies with 744 bladder cancer patients were enrolled in this meta-analysis. The pooled sensitivity, specificity, and DOR were 0.80 (95%CI = 0.77–0.83), 0.79 (95%CI = 0.73–0.84), and 15.18 (95%CI = 10.07–22.87), respectively, and the area under the curve (AUC) of SROC was 0.83 (95%CI = 0.79–0.86). The diagnostic power of a combined method (urine Fn combined with urine cytology) was also evaluated, and its sensitivity and AUC were significantly higher (0.86 (95%CI = 0.82–0.90) and 0.89 (95%CI = 0.86–0.92), respectively). Meta-regression along with subgroup analysis based on various covariates revealed the potential sources of the heterogeneity and the detailed diagnostic value of each subgroup. Sensitivity analysis supported that the result was robust. No threshold effect and publication bias were found in this meta-analysis.

Conclusions

Urine Fn may become a promising non-invasive biomarker for bladder cancer with a relatively satisfactory diagnostic power. And the combination of urine Fn with cytology could be an alternative option for detecting BCa in clinical practice. The potential value of urine Fn still needs to be validated in large, multi-center, and prospective studies.

Electronic supplementary material

The online version of this article (10.1186/s12957-018-1358-x) contains supplementary material, which is available to authorized users.

Identification of cancer prognosis-associated functional modules using differential co-expression networks

The rapid accumulation of cancer-related data owing to high-throughput technologies has provided unprecedented choices to understand the progression of cancer and discover functional networks in multiple cancers. Establishment of co-expression networks will help us to discover the systemic properties of carcinogenesis features and regulatory mechanisms of multiple cancers. Here, we proposed a computational workflow to identify differentially co-expressed gene modules across 8 cancer types by using combined gene differential expression analysis methods and a higher-order generalized singular value decomposition. Four co-expression modules were identified; and oncogenes and tumor suppressors were significantly enriched in these modules. Functional enrichment analysis demonstrated the significantly enriched pathways in these modules, including ECM-receptor interaction, focal adhesion and PI3K-Akt signaling pathway. The top-ranked miRNAs (mir-199, mir-29, mir-200) and transcription factors (FOXO4, E2A, NFAT, and MAZ) were identified, which play an important role in deregulating cellular energetics; and regulating angiogenesis and cancer immune system. The clinical significance of the co-expressed gene clusters was assessed by evaluating their predictability of cancer patients’ survival. The predictive power of different clusters and subclusters was demonstrated. Our results will be valuable in cancer-related gene function annotation and for the evaluation of cancer patients’ prognosis.

A Systematic Review of the Diagnostic and Prognostic Value of Urinary Protein Biomarkers in Urothelial Bladder Cancer

For over 80 years, cystoscopy has remained the gold-standard for detecting tumours of the urinary bladder. Since bladder tumours have a tendency to recur and progress, many patients are subjected to repeated cystoscopies during long-term surveillance, with the procedure being both unpleasant for the patient and expensive for healthcare providers. The identification and validation of bladder tumour specific molecular markers in urine could enable tumour detection and reduce reliance on cystoscopy, and numerous classes of biomarkers have been studied. Proteins represent the most intensively studied class of biomolecule in this setting. As an aid to researchers searching for better urinary biomarkers, we report a comprehensive systematic review of the literature and a searchable database of proteins that have been investigated to date. Our objective was to classify these proteins as: 1) those with robustly characterised sensitivity and specificity for bladder cancer detection; 2) those that show potential but further investigation is required; 3) those unlikely to warrant further investigation; and 4) those investigated as prognostic markers. This work should help to prioritise certain biomarkers for rigorous validation, whilst preventing wasted effort on proteins that have shown no association whatsoever with the disease, or only modest biomarker performance despite large-scale efforts at validation.

Urinary oncofetal ED-A fibronectin correlates with poor prognosis in patients with bladder cancer

The extracellular matrix protein fibronectin (FN) contributes to the structural integrity of tissues as well as the adhesive and migratory functions of cells. While FN is abundantly expressed in adult tissues, the expression of several alternatively spliced FN isoforms is restricted to embryonic development, tissue remodeling and cancer. These FN isoforms, designated ED-A and ED-B, are frequently expressed by cancer cells, tumor-associated fibroblasts and newly forming blood vessels. Using a highly sensitive collagen-based indirect ELISA, we evaluated the correlation of urinary ED-A and ED-B at time of cystectomy with overall survival in patients with high-grade bladder cancer (BCa). Detectable levels of total FN as well as ED-A and ED-B were found in urine from 85, 73 and 51 % of BCa patients, respectively. The presence of urinary ED-A was a significant independent predictor of 2-year overall survival (OS) after adjusting for age, tumor stage, lymph node stage, and urinary creatinine by multivariable Logistic Regression (p = 0.029, OR = 4.26, 95 % CI 1.16-15.71) and improved accuracy by 3.6 %. Furthermore, detection of ED-A in the urine was a significant discriminator of survival specifically in BCa patients with negative lymph node status (Log-Rank, p = 0.006; HR = 5.78, 95 % CI 1.39-24.13). Lastly, multivariable Cox proportional hazards analysis revealed that urinary ED-A was an independent prognostic indicator of 5-year OS rate for patients with BCa (p = 0.04, HR = 2.20, 95 % CI 1.04-4.69). Together, these data suggest that cancer-derived, alternatively spliced FN isoforms can act as prognostic indicators and that additional studies are warranted to assess the clinical utility of ED-A in BCa.

Molecular markers and Schistosoma-associated bladder carcinoma: A systematic review and meta-analysis

BACKGROUND

Molecular mechanisms and pathogenesis of schistosomal-associated bladder cancer (SABC), one of the most common malignancies in Africa and parts of the Middle East, is still unclear. Identification of host molecular markers involved in schistosomal related bladder carcinogenesis is of value in prediction of high-risk group, early detection and timely intervention.

METHODS

PubMed, Scopus, Google Scholar, Cochrane Library and African Journals Online databases were systematically searched and reviewed. A total of 63 articles reporting 41 host molecular factors were included in the meta-analysis.

RESULTS

Pooled odds ratio demonstrated associations of p53 expression, telomerase activity and sFas with SABC as compared to other schistosomal patients (p53 expression: OR=9.46, 95%CI=1.14-78.55, p=0.04; telomerase by TERT: OR=37.38, 95%CI=4.17-334.85, p=0.001; telomerase by TRAP: OR=10.36, 95%CI=6.08-17.64, p<0.00001; sFas: OR=34.37, 95%CI=3.32-355.51, p=0.003). In comparison to bladder cancers of other etiology, positive associations were found between SABC and p15 deletion, p16 deletion, telomerase activity and sFas (p15 deletion: OR=4.20, 95%CI=2.58-6.82, p<0.00001; p16 deletion: OR=4.93, 95%CI=2.52-9.65, p<0.00001; telomerase by TERT: OR=3.01, 95%CI=1.51-5.97, p=0.002; telomerase by TRAP: OR=2.66, 95%CI=1.18-6.01, p=0.02; sFas: OR=4.50, 95%CI=1.78-11.40, p=0.001). Other identified associations were reported by few numbers of studies to enable reliable interpretation.

CONCLUSIONS

Variations in gene expression or genomic alterations of some molecular markers in SABC as compared to non-SABC or other schistosomal patients were identified. These suggest minute differences in the pathogenesis and physiological profile of SABC, in relation to non-SABC.

Urine biomarkers of schistosomiais and its associated bladder cancer

Schistosomiasis (SCH) is the second only to malaria among the parasitic diseases affecting humans regarding the prevalence of infection worldwide. In this nonsystematic review, we summarize the existing data on commercially available and promising investigational urine markers for the detection of SCH and its associated bladder cancer (BC). We searched PubMed, Scopus and Cochran without time limits. We reviewed the recent literatures on urine-based markers for SCH and its associated BC. Many studies identified several urine biomarkers of Schistosoma haematobium and Schistosoma mansoni worms and their associated BC using automated, inexpensive, quantitative assays in urine. These markers may aid in early detection of bladder carcinoma and have the potential to reduce the number of follow-up cystoscopy, thus reducing healthcare costs and patient discomfort, at the same time. Nevertheless, clinical evidence is insufficient to warrant the substitution of the cystoscopic follow-up scheme by any of the currently available urine marker tests.

Ff-nano, short functionalized nanorods derived from Ff (f1, fd, or M13) filamentous bacteriophage

F-specific filamentous phage of Escherichia coli (Ff: f1, M13, or fd) are long thin filaments (860 nm × 6 nm). They have been a major workhorse in display technologies and bionanotechnology; however, some applications are limited by the high length-to-diameter ratio of Ff. Furthermore, use of functionalized Ff outside of laboratory containment is in part hampered by the fact that they are genetically modified viruses. We have now developed a system for production and purification of very short functionalized Ff-phage-derived nanorods, named Ff-nano, that are only 50 nm in length. In contrast to standard Ff-derived vectors that replicate in E. coli and contain antibiotic-resistance genes, Ff-nano are protein-DNA complexes that cannot replicate on their own and do not contain any coding sequences. These nanorods show an increased resistance to heating at 70^∘C in 1% SDS in comparison to the full-length Ff phage of the same coat composition. We demonstrate that functionalized Ff-nano particles are suitable for application as detection particles in sensitive and quantitative “dipstick” lateral flow diagnostic assay for human plasma fibronectin.

Evaluation of urinary HURP mRNA as a marker for detection of bladder cancer: relation to bilharziasis

This study was carried out to assess the efficacy of urinary hepatoma up-regulated protein (HURP) RNA in bladder cancer diagnosis and its relation to bilharziasis. Voided urine samples and blood were collected from 344 consecutive participants: 211 patients diagnosed with bladder cancer, 71 patients with benign urological disorders and 62 healthy volunteers. Serologic assessment of schistosomiasis antibody in sera, urine cytology and estimation of HURP RNA by reverse transcription polymerase chain reaction in urothelial cells was carried out in all samples. HURP RNA expression showed a significant difference among the three investigated groups. The best cutoff point for HURP RNA was determined as 0.0132 at 78.67 % sensitivity and 94 % specificity. The sensitivity of urine cytology was improved when combined with HURP RNA in detection of early stage (77.3 %), low grade (85.3 %) and bilharzial bladder cancer (78.1 %). Detection of urinary HURP RNA is a useful non-invasive test for early detection of bladder cancer and bilharzial bladder cancer and it improves sensitivity of urine cytology up to 91 %.

Evaluation of a triple combination of cytokeratin 20, p53 and CD44 for improving detection of urothelial carcinoma in urine cytology specimens

Background:

Atypical urine cytology results trigger cystoscopy or molecular tests, both of which are costly, complex and difficult to perform tests. Several immunostains are being investigated to improve cancer detection; however, cytology material is limited and restricts the use of multiple immunostains. This study was designed to determine the utility of a cocktail of three stains, cytokeratin (CK20), p53 and CD44 in urine cytology samples for improving the detection of urothelial carcinoma.

Materials and Methods:

Urine cytology specimens with cell blocks containing adequate cytologic material between 2005 and 2010 and subsequent follow-up biopsy and/or Urovysion test (102 cases including 29 negative, 56 atypical and 17 malignant) were included in the study and evaluated with the triple stain. Results were first validated on the positive and negative cases and then applied to the atypical cases to determine the utility in the diagnosis of urothelial carcinoma.

Results:

Based on the validation and published literature, two distinct immunoprofiles were defined – malignant, characterized by at least five CK20 and/or p53 positive atypical cells and reactive, all other staining patterns. The malignant immunoprofile showed 88% sensitivity, 78% specificity, 74% positive predictive value (PPV) and 90% negative predictive value (NPV) for detecting urothelial carcinoma. These values improved to 95% sensitivity and 96% NPV when low-grade urothelial carcinoma cases were excluded.

Summary:

Our results indicate that the triple stain is an inexpensive, easy to perform test most useful for differentiating high-grade urothelial carcinoma from its mimics. However Inclusion of CD44 in the cocktail did not provide additional value and is best excluded.

Integrated technologies in the post-genomic era for discovery of bladder cancer urinary markers

The incidence of bladder cancer (BC) continues to rise with high recurrence and mortality rate, especially in the past three decades. The development of accurate and successful BC treatment relies mainly on early diagnosis. BC is a heterogeneous disease reflected by the presence of many potential biomarkers associated with different disease phenotypes. Nowadays, cystoscopy and urinary cytology are considered the gold standard diagnostic tools for BC. There are many limitations to cystoscopy including being invasive, labor-intensive and carcinoma in situ of the bladder may easily be missed. Urinary cytology is still a noninvasive technique with high accuracy in high-grade BC with a median sensitivity of 35%. Furthermore, the need for a sensitive, specific, non invasive, easily accessible BC biomarker is a major clinical need. The field of urinary BC biomarkers discovery is still a rapidly evolving discipline in which more recent technologies are evaluated and often optimized if they are not clinically significant to the urologists. Most of the current strategies for BC urinary biomarker detection depend on integration of information gleaned from the fields of genomics, transcriptomics, proteomics, epigenetics, metabolomics and bionanotechnology. Effort is currently being made to identify the most potentially beneficial urinary biomarkers. The purpose of this review is to summarize and explore the efficacy of gathering the information revealed from the cooperation of different omic strategies that paves the way towards various urinary markers discovery for screening, diagnosis and prognosis of human BC.

Expression microarray meta-analysis identifies genes associated with Ras/MAPK and related pathways in progression of muscle-invasive bladder transition cell carcinoma

The effective detection and management of muscle-invasive bladder Transition Cell Carcinoma (TCC) continues to be an urgent clinical challenge. While some differences of gene expression and function in papillary (Ta), superficial (T1) and muscle-invasive (≥T2) bladder cancers have been investigated, the understanding of mechanisms involved in the progression of bladder tumors remains incomplete. Statistical methods of pathway-enrichment, cluster analysis and text-mining can extract and help interpret functional information about gene expression patterns in large sets of genomic data. The public availability of patient-derived expression microarray data allows open access and analysis of large amounts of clinical data. Using these resources, we investigated gene expression differences associated with tumor progression and muscle-invasive TCC. Gene expression was calculated relative to Ta tumors to assess progression-associated differences, revealing a network of genes related to Ras/MAPK and PI3K signaling pathways with increased expression. Further, we identified genes within this network that are similarly expressed in superficial Ta and T1 stages but altered in muscle-invasive T2 tumors, finding 7 genes (COL3A1, COL5A1, COL11A1, FN1, ErbB3, MAPK10 and CDC25C) whose expression patterns in muscle-invasive tumors are consistent in 5 to 7 independent outside microarray studies. Further, we found increased expression of the fibrillar collagen proteins COL3A1 and COL5A1 in muscle-invasive tumor samples and metastatic T24 cells. Our results suggest that increased expression of genes involved in mitogenic signaling may support the progression of muscle-invasive bladder tumors that generally lack activating mutations in these pathways, while expression changes of fibrillar collagens, fibronectin and specific signaling proteins are associated with muscle-invasive disease. These results identify potential biomarkers and targets for TCC treatments, and provide an integrated systems-level perspective of TCC pathobiology to inform future studies.

[Preliminary study of p53 and FGFR3 gene mutations in the urine for bladder tumors]

INTRODUCTION

Two major pathways are described in bladder carcinogenesis: one for invasive or high grade tumors characterized by alteration of the p53 tumor suppressor gene and the other for non-invasive tumors or low grade involving mutations FGFR3. The objective of our study was to validate the research in the urine of mutations in these two genes in patients with a bladder tumor.

PATIENTS AND METHODS

In our preliminary study, we investigated 36 patients the FGFR3 and p53 mutations in tumors and urine collected during endoscopic resection. The p53 mutations were sought in FASAY, which allows a functional analysis of the protein P53. The FGFR3 mutations were sought in SNaPshot that searches the eight most frequent mutation points of this gene.

RESULTS

For 24 patients (66% of cases), we found at least one of the two mutations in the tumor. This mutation was present in the urine in 15 patients (sensitivity=62.5%). In only one patient, we found a mutation in the urinary sediment that did not exist in the tumor (specificity=91.7%).

CONCLUSION

The search for mutations of p53 and FGFR3 in the urine was a simple and non-invasive assay, which seems superior to urinary cytology for the detection of bladder tumors, raising hopes of an interest in this bio-assay for surveillance of bladder tumors and screening risk populations.

Detection of hyaluronidase RNA and activity in urine of schistosomal and non-schistosomal bladder cancer

Diagnosis of bladder cancer is done by cystoscopy and cytology. In the last decade, many urine-based tests for bladder cancer have been developed and tested in different populations. Hence, it was relevant to assess the diagnostic significance of urinary hyaluronidase RNA and its enzyme activity in bladder cancer. Seventy patients with bladder cancer, 56 patients with benign bladder lesions, and 49 healthy controls were enrolled in this study. Voided urine samples from all subjects were used for estimation of urinary HAase RNA by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and determination of its enzymatic activity by zymography. There was a significant difference in the mean ranks and positivity rates of HAase RNA expression (P < 0.01) and its enzymatic activity among the three investigated groups: malignant, benign, and normal (P < 0.01). In detecting bladder cancer, the sensitivity of urine cytology (42.83 %) was improved to 100 % when combined with urinary Hyal RNA or Hyal enzyme activity. Detection of urinary Hyal RNA and its enzyme activity is promising noninvasive tests with high sensitivities and specificities for detection of bladder cancer.

Urinary retinoic acid receptor-β2 gene promoter methylation and hyaluronidase activity as noninvasive tests for diagnosis of bladder cancer

OBJECTIVES

We evaluated the significance of urinary retinoic acid receptor-β2 (RAR-β2) gene promoter methylation and hyaluronidase activity in comparison with voided urine cytology (VUC) in diagnosis of bladder cancer.

DESIGN AND METHODS

This study included 100 patients diagnosed with bladder cancer, 65 patients with benign urological disorders and 51 healthy volunteers. Urine supernatant was used for determining hyaluronidase activity by zymography while urine sediment was used for cytology and detection of methylated RAR-β2 gene promoter by methylation specific nested PCR.

RESULTS

The sensitivity and specificity were 53% and 90.5% for VUC, 65% and 89.7% for percent methylation fraction of RAR-β2 gene promoter, and 89% and 90.5% for hyaluronidase activity; combination of the three parameters increased sensitivity to 95%. A significant association was observed between investigated markers and advanced grade tumor.

CONCLUSIONS

Combined use of RAR-β2 gene promoter methylation, hyaluronidase activity and VUC is promising non-invasive tool for bladder cancer detection.

Aberrant methylation of RARbeta2 and APC genes in voided urine as molecular markers for early detection of bilharzial and nonbilharzial bladder cancer

BACKGROUND

Bladder cancer cells illustrate major disruptions in their DNA methylation patterns as compared with normal ones. Authors aimed to identify epigenetic molecular markers in urine for early detection of bladder cancer.

MATERIALS AND METHODS

We retrospectively analyzed the methylation status of RARβ(2) and APC genes in urine samples from 210 bladder cancer patients, 61 patients with benign urological diseases, and 49 healthy volunteers by using methylation-specific PCR.

RESULTS

Methylated RARβ(2) and APC were significantly higher in bladder cancer patients (62.8%, 59.5%) than benign (16.4%, 5%) but not detected in healthy volunteers (0%) at (P < 0.0001). Both methylated genes showed no significant difference among clinicopathologic factors; however, they were detected in all grades and stages. Among the 128 patients with bilharzial bladder cancer, 94 (73.4%) showed methylated RARβ(2) and 86 (67.2%) showed methylated APC. Homoplasmic methylation pattern of both genes were only detected in bilharzial bladder cancer cases. Both sensitivities and specificities of the methylated genes for bladder cancer detection were superior to urine cytology and when altogether combined, the sensitivities improved to (91.8%), (93.5%), (91.9%), and (80.9%) in detection of: bladder cancer, non-muscle invasive bladder cancer, low-grade tumors, and bilharzial associated bladder cancer, respectively.

CONCLUSION

Thus, methylated RARβ(2) and APC genes might be valuable urinary molecular markers for early detection of bilharzial and nonbilharzial bladder cancer.