Molecular markers in bladder cancer: A critical appraisal

The clinical relevance of urine-based markers for diagnosis of bladder cancer

The aim of the present study was to evaluate the diagnostic relevance of urinary fibronectin (FN), telomerase (RTA), and cytokeratin 20 (CK20) mRNA in comparison with voided urine cytology (VUC). The study included 132 patients with bladder cancer, 60 patients with benign bladder lesions, and 48 healthy individuals. All were subjected to urine cytology, estimation of fibronectin by ELISA, RTA by TRAP, and CK20 mRNA by conventional RT-PCR in urothelial cells from voided urine. The best cutoff point for FN was determined by receiver operating characteristic curve (41.7 ng/mg protein) revealed the highest sensitivity for malignant (80%) followed by the benign (70%) than the healthy individuals (4.1%) at P < 0.001. Also, RTA and VUC showed significant difference among the three investigated groups (P < 0.001). The overall sensitivity (89.3%) and specificity (98.4%) were the highest for CK20 mRNA. Combined sensitivity of VUC with FN, RTA, and CK20 mRNA together (98.4%) was higher than either the combined sensitivity of VUC with any of them or than that of the biomarker alone. Accordingly, when the diagnostic efficacy was considered, CK20 mRNA had the highest sensitivity and specificity compared to all investigated markers.

Cancer biomarker discovery: Opportunities and pitfalls in analytical methods

Many diseases result in specific and characteristic changes in the chemical and biochemical profiles of biological fluids and tissues prior to development of clinical symptoms. These changes are often useful diagnostic and prognostic biomarkers. Identifying biomarkers that can be used for the early detection of cancer will result in more efficient treatments, reduction in suffering, and lower mortality rates. An ideal screening test should be non-invasive with high sensitivity and specificity. Proteomic and metabolomic analyses of biological samples can reveal changes in abundance levels of metabolites and proteins that when validated and confirmed through clinical trials can function as clinical tests for early detection, diagnosis, monitoring disease progression, and predicting therapeutic response. While the past decade has seen great advancements in proteomics and metabolomics research producing potential biomarkers for cancer, most of the identified biomarkers have failed to replace existing clinical tests. To become a clinically approved test, a potential biomarker should be confirmed and validated using hundreds of specimens and should be reproducible, specific, and sensitive. A search of the scientific and medical literature indicates that many studies report the discovery of potential biomarkers without proper validation and/or they do not meet the above criteria. In this manuscript, we will discuss the successes and the pitfalls of biomarker research and comment on study and experimental design, which in most cases is lacking, resulting in suboptimal biomarkers.

Bladder cancer: a review of non-muscle invasive disease

BACKGROUND

Bladder cancer is one of the most common cancers affecting men and women and thus has a profound impact on health care. The majority of patients (75%) with newly diagnosed urothelial tumors have non-muscle invasive disease confined to the bladder mucosa or the lamina propria.

METHODS

The authors review the literature as well as recently published clinical guidelines regarding the bladder cancer risk and causative factors, diagnostic and pathologic evaluation, prognostic variables, and management strategies for patients with non-muscle invasive bladder cancer.

RESULTS

Recurrence and progression remain problematic for many patients and are dependent on multiple clinical and pathological features, the most important of which are tumor stage, grade, multifocality, size, recurrence patterns, and the association with carcinoma in situ. Accurate assessment of clinical stage and tumor grade is critical in determining management and surveillance strategies. Intravesical therapies positively influence tumor recurrence rates. Disease progression rates may be impacted in high-risk patients who receive both induction bacille Calmette-Guérin (BCG) and a maintenance BCG regimen. Cystectomy still plays a pivotal role in patients with high-risk tumors and in patients who fail more conservative attempts to eradicate non-muscle invasive disease.

CONCLUSIONS

Non-muscle invasive bladder cancers represent a broad group of tumors with varying biologic potential. Successful treatment depends on the careful integration of diagnostic and surveillance tests, macroablation through transurethral resection, accurate assessment of clinical stage, and the timely and appropriate delivery of intravesical chemotherapeutic and immunomodulatory agents.

Performance of nuclear matrix protein 22 urine marker and voided urine cytology in the detection of urinary bladder tumors

BACKGROUND

Cystoscopy with urinary cytology is the gold standard for the diagnosis and follow-up of patients with tumors of the urinary bladder. The aim of the study was to evaluate the performance of the nuclear matrix protein 22 (NMP22) tumor marker test, BladderChek® point-of-care test and voided urinary cytology for the detection and follow-up of bladder tumors.

METHODS

NMP22 was measured using an ELISA assay in stabilized voided urine and using the BladderChek® test. Voided urinary cytology was performed on urine samples. Results were compared to cystoscopic findings and histopathological examination results after transurethral resection of the bladder lesion.

RESULTS

For the prediction of malignant histopathological result, sensitivity and specificity were 45.2% and 75.0%, respectively, for NMP22 at a cut-off of 7.5 kU/L, 17.7% and 100% for the BladderChek® test and 37.0% and 100% for voided urine cytology. For the prediction of suspicious or positive cystoscopic finding, sensitivity and specificity were 40.4% and 72.1%, respectively, for NMP22 at a cut-off of 7.5 kU/L, 14.8% and 93.8% for the BladderChek® test and 26.8% and 98.1% for voided urine cytology.

CONCLUSIONS

The NMP22 quantitative test showed higher sensitivity and lower specificity compared with voided urine cytology, whereas the sensitivity of the BladderChek® test was low. We could not recommend any of the three non-invasive tests as a replacement for cystoscopy for the diagnosis or follow-up of urinary bladder tumors.

Comparison of the sensitivity and specificity of urine cytology, urinary nuclear matrix protein-22 and multitarget fluorescence in situ hybridization assay in the detection of bladder cancer

OBJECTIVE

This study aimed to compare the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of urine cytology, BladderChek® nuclear matrix protein-22 (NMP22) and UroVysion™ fluorescence in situ hybridization (FISH) tests in patients with newly diagnosed bladder cancer, those with recurrent bladder cancer, and those with bladder cancer but in remission during surveillance.

MATERIAL AND METHODS

Voided urine samples obtained from 178 patients with suspected or known bladder cancer about to undergo diagnostic or surveillance cystoscopy and 25 control subjects without the disease were divided into four and used for urine culture and cytology, NMP22 BladderChek and UroVysion FISH tests. The sensitivity, specificity, PPV and NPV for each test were calculated. Comparison was made between the ability of each test to detect bladder cancer in the three category of patients listed.

RESULTS

Of the 178 patients with bladder cancer, 43 were newly diagnosed, 58 had recurrent disease and 77 were in remission. The sensitivity of each test in newly diagnosed patients was: urine cytology 28%, NMP22 88% and FISH 80%; and in patients with recurrent disease: urine cytology 33%, NMP22 57% and FISH 85%. The mean specificity for urine cytology, NMP22 and FISH was 95%, 67% and 48%, respectively.

CONCLUSION

Of the tests used in the study for detection of bladder cancer, NMP22 appeared to be most cost-effective and rapid, with relatively high sensitivity and specificity in all categories of patients. The NMP22 test may be considered a new gold standard for the assessment of patients with known or suspected bladder cancer.

Discovery of novel bladder cancer biomarkers by comparative urine proteomics using iTRAQ technology

A urine sample preparation workflow for the iTRAQ (isobaric tag for relative and absolute quantitation) technique was established. The reproducibility of this platform was evaluated and applied to discover proteins with differential levels between pooled urine samples from nontumor controls and three bladder cancer patient subgroups with different grades/stages (a total of 14 controls and 23 cancer cases in two multiplex iTRAQ runs). Combining the results of two independent clinical sample sets, a total of 638 urine proteins were identified. Among them, 55 proteins consistently showed >2-fold differences in both sample sets. Western blot analyses of individual urine samples confirmed that the levels of apolipoprotein A-I (APOA1), apolipoprotein A-II, heparin cofactor 2 precursor and peroxiredoxin-2 were significantly elevated in bladder cancer urine specimens (n = 25-74). Finally, we quantified APOA1 in a number of urine samples using a commercial ELISA and confirmed again its potential value for diagnosis (n = 126, 94.6% sensitivity and 92.0% specificity at a cutoff value of 11.16 ng/mL) and early detection (n = 71, 83.8% sensitivity and 94.0% specificity). Collectively, our results provide the first iTRAQ-based quantitative profile of bladder cancer urine proteins and represent a valuable resource for the discovery of bladder cancer markers.

Bikunin loss in urine as useful marker for bladder carcinoma

PURPOSE

We searched for bladder tumor markers by analyzing urine samples from patients with bladder cancer and normal individuals.

MATERIALS AND METHODS

Proteins in urine samples of patients with cancer and normal subjects were systematically examined by 2-dimensional electrophoresis combined with matrix assisted laser desorption ionization time-of-flight mass spectrometry. Of the proteins bikunin expression was confirmed by Western blot analysis and further evaluated. To correlate urinary bikunin levels with clinical significance we examined urine samples from patients with bladder cancer and normal controls for bikunin expression in parallel with pro-urolinase-plasminogen activator, which was previously shown to be associated with advanced bladder carcinoma.

RESULTS

A significant relationship was established between the low level and absence of bikunin, and pro-urolinase-plasminogen activator in urine samples from patients with bladder tumors.

CONCLUSIONS

Analysis of urinary proteomes may be a feasible, noninvasive and efficient strategy for searching for potential bladder tumor biomarkers. We identified bikunin loss in urine as a potential bladder carcinoma marker.

Expression of HYAL1 and survivin RNA as diagnostic molecular markers for bladder cancer

PURPOSE

Urinary tumor markers that help in the early detection of bladder cancer promise a significant improvement in sensitivity, specificity and convenience over conventional, invasive diagnostic tests. We assessed the diagnostic efficacy of hyaluronidase (HYAL1) and survivin for early bladder cancer detection.

MATERIALS AND METHODS

The study included 166 patients diagnosed with bladder carcinoma, 112 with benign bladder lesions and 100 healthy volunteers who served as controls. All underwent serological assessment of schistosomiasis antibody, urine cytology, and hyaluronidase (HYAL1) and survivin RNA estimation by qualitative and semiquantitative reverse transcriptase-polymerase chain reaction in urothelial cells from voided urine.

RESULTS

Positivity rates of HYAL1 RNA and survivin RNA on qualitative reverse transcriptase-polymerase chain reaction were significantly different among the 3 groups. Mean rank using semiquantitative method was increased in the malignant vs the other groups. The best cutoff for HYAL1 and survivin RNA was 0.25 each. Using these cutoffs HYAL1 and survivin RNA sensitivity was 91% and 75%, respectively, with absolute specificity. HYAL1 RNA detected all patients with stages 0 and I bladder cancer (p <0.037). Urine cytology sensitivity improved when combined with hyaluronidase or survivin RNA on semiquantitative reverse transcriptase-polymerase chain reaction.

CONCLUSIONS

The detection of urinary HYAL1 and survivin RNA is a promising noninvasive test for bladder cancer early detection. HYAL1 RNA was more sensitive and specific than urine cytology. Semiquantitative reverse transcriptase-polymerase chain reaction is favored for its high sensitivity and specificity.

Potential new urinary markers in the early detection of bladder cancer

PURPOSE OF REVIEW

Bladder cancer remains a highly prevalent and lethal malignancy. Early diagnosis and prompt treatment have been shown to improve survival at both initial diagnosis and recurrence. A vast number of tumor markers have been identified and rigorously evaluated in attempts to improve noninvasive diagnostic accuracy of bladder cancer. Hematuria was the first tumor marker in a field that has grown to include soluble markers, cell-surface antigens, cell-cycle-related proteins, and genetic alterations. We aim to provide a critical appraisal of newer markers and the current state of research.

RECENT FINDINGS

The number of tumor markers identified has been exponentially increasing. For a variety of reasons, many are unsuitable for clinical practice. More promising recent markers include those discovered in the fields of genomics, proteomics, and epigenetics. Much of the recent work is focused on molecular genetic pathways in bladder cancer.

SUMMARY

The field of bladder cancer tumor markers remains a rapidly evolving area in which newer markers are constantly identified, evaluated, and often discarded if they do not add significantly to the urologists' armamentarium. Newer markers rely on genetic rearrangements, molecular changes, and cell-cycle-related proteins. Work is currently being done to identify the most promising markers.

Diagnosis of urothelial carcinoma from urine

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

Molecular pathogenesis and diagnostics of bladder cancer

Despite elaborate characterization of the risk factors, bladder cancer is still a major epidemiological problem whose incidence continues to rise each year. Urothelial carcinoma is now recognized as a disease of alterations in several cellular processes. The more prevalent, less aggressive, recurrent, noninvasive tumors are characterized by constitutive activation of the Ras-MAPK pathway. The less common but more aggressive invasive tumors, which have a higher mortality rate, are characterized by alterations in the p53 and retinoblastoma pathways. Several diagnostic tests have attempted to identify these molecular alterations in tumor cells exfoliated in the urine, whereas prognostic tests have tried to identify aberrations so as to predict tumor behavior and identify therapeutic targets. The future of bladder cancer patient management will rely on the use of molecular tests to reliably diagnose the presence of disease, predict individual tumor behavior, and suggest potential targeted therapeutics.

A multicolour fluorescence in situ hybridization test predicts recurrence in patients with high-risk superficial bladder tumours undergoing intravesical therapy

OBJECTIVE

To determine whether a multicolour fluorescence in situ hybridization test (UroVysion, Abbott Molecular Inc., Des Plaines, IL, USA) in patients with high-risk superficial bladder tumours maintains its predictive ability in a multivariate model for recurrence and progression, incorporating clinical and pathological predictors of outcome.

PATIENTS AND METHODS

The charts of patients with superficial bladder cancer treated with induction or maintenance intravesical therapy (IVT) were reviewed retrospectively. UroVysion testing was used at the beginning and end of each IVT cycle, and cytology and cystoscopy 6 weeks after completing each cycle. Kaplan-Meier actuarial survival was analysed, stratified by the UroVysion result after IVT. Univariate and multivariate Cox regression analyses were used to identify significant predictors of recurrence.

RESULTS

In all, 42 patients had induction IVT with bacille Calmette-Guérin (BCG), BCG + interferon, or mitomycin. The median follow-up was 21 months. Recurrent disease was detected in 18 patients. In a univariate analysis, chronic renal insufficiency (hazard ratio 12.1, P = 0.03), positive cytology after IVT (2.7, P = 0.05), and a positive UroVysion test after IVT (8.3, P < 0.01) were predictive of failure. In the multivariate analysis, high grade disease (5.3, P = 0.05), a risk score of >6 (4.7, P = 0.02) and a positive UroVysion test after IVT (6.7, P < 0.01) were significant predictors of recurrence.

CONCLUSION

In patients with high-risk superficial bladder tumours undergoing IVT, a positive UroVysion test after treatment is highly predictive of recurrence, even in a multivariate model. Additional adjuvant therapy might be necessary in these patients to improve the outcome.

Detection of circulating tumor cells in bladder cancer patients

The methods employed for the detection of circulating bladder cancer cells (CBCs) and their use as a molecular staging tool in clinical settings are thoroughly reviewed. CBC isolation and enrichment methods are discussed according to their advantages and pitfalls along with the clinical data of PCR-based techniques used for CBC detection. In addition, we review the specificity of molecular markers that have been proposed so far for CBC identification, and we comment on the controversial clinical data, proposing laboratory approaches which may improve the clinical significance of CBC detection in bladder cancer.

The Significance of Atypical Urine Cytology in the Face of Normal Investigations—Is Extended Investigation and Follow-Up Required?

Objective:

To examine the natural history of patients identified with atypical urine cytology in the face of normal investigations, and thus provide guidance on the need for extended follow-up and investigation of such patients.

Patients and methods:

All patients identified over a 2-year period to have atypical urine cytology on Cytospin analysis and Papanicolaou staining were audited over a 5-year follow-up period. Clinical records, histopathology and radiology databases were independently searched. Patients were intensively investigated with cystoscopy and a range of upper tract imaging.

Results:

126 patients were identified to have atypical urine cytology, and 77 of these had no urothelial tumour found. In these normal patients, only 12/48 who had further samples taken showed persistent atypia. 11/77 normal patients had another urological pathology which may have explained their atypical urine cytology. No patient presenting for the first time later went on to develop urothelial malignancy in the face of negative initial investigations.

Conclusion:

In the group of patients in which cystoscopy and urography show no urothelial malignancy, the finding of atypical urinary cytology does not predict the development of later urothelial tumour, and does not require prolonged follow-up, repeat cytological testing or further imaging.

Proteomic strategies in bladder cancer: From tissue to fluid and back

We have applied protein expression profiling technologies in combination with immunohistochemistry, using fresh tissue and urine samples, to assess bladder cancer heterogeneity and prognosis as well as to generate protein markers for tumor progression and early diagnosis of the disease. Here, we review some selected lines of investigation and approaches undertaken by our laboratory, drawing on more than 15 years of experience in bladder cancer proteomics, to highlight a number of issues that may be useful for researchers entering the field. In particular, we address the identification of markers for bladder cancer progression and exemplify the potential of gel-based proteomic profiling of urine samples for the early detection of urothelial carcinomas. In addition, we provide a brief description of a novel and highly promising source of biomarkers, the tumor interstitial fluid (TIF) that perfuses the tumor microenvironment.

Contemporary diagnosis of bladder cancer

BACKGROUND

Early diagnosis of bladder cancer is mandatory, as a delay in treatment has been shown to affect prognosis. The current diagnostic standard of cystoscopy and cytology is costly, invasive and inconvenient, whereas advances in molecular biology have resulted in the evolvement of several markers.

OBJECTIVE

To review diagnostic considerations in the use of old and new technical modalities and tests for the detection of bladder cancer.

METHODS

A PubMed search of the literature concerning bladder cancer diagnosis was performed. Reviews are included on certain topics to avoid extensive reference to separate studies.

CONCLUSION

Recent technical advances have an impact on the management of patients with suspected bladder cancer. Cytology is still an important adjunct in the diagnostic work-up, whereas urine-bound tests may have a role in screening and surveillance. However, cystoscopy is the standard of care for the detection of bladder cancer. Fluorescence cystoscopy is an adjunctive tool, especially for the prompt identification of carcinoma in situ.

Clinical significance of urine heparanase in bladder cancer progression

Heparanase is an endo-beta-glucuronidase capable of cleaving heparan sulfate (HS), an activity implicated in tumor metastasis. Heparanase expression is upregulated in primary human tumors, correlating with reduced post operative survival and elevated microvessel density. An ELISA method was used to quantify heparanase in urine from 282 individuals. Urine was collected from healthy volunteers (n = 41), patients diagnosed with noncancerous pathologic disorders (n = 90), and bladder cancer patients (n = 92). Fifty-nine bladder carcinoma patients after transurethral resection (TUR) with no evidence of disease (NED) were also included. Heparanase levels were significantly elevated in urine from bladder cancer patients compared with healthy controls (P < .001) and with noncancerous urinary disorders (P < .05). Heparanase elevation strongly correlated with tumor grade (P < .001) and stage (P = .027). An optimal cutoff value of 154 pg/ml was determined. Of 199 individuals enrolled (59 patients after TUR and 24 patients with recurring disease were excluded), 65 had heparanase levels above 154 pg/ml. Only 3 of 65 (4.6%) were healthy individuals. In contrast, 52.3% (34 of 65) of individuals with heparanase levels above 154 pg/ml were bladder cancer patients. The results indicate that urine heparanase levels are elevated during bladder cancer progression, suggesting that the ELISA method may be applied for bladder cancer diagnosis.

Assessing the value of reflex fluorescence in situ hybridization testing in the diagnosis of bladder cancer when routine urine cytological examination is equivocal

PURPOSE

We evaluated the usefulness of fluorescence in situ hybridization in the treatment of patients with equivocal cytology.

MATERIALS AND METHODS

Fluorescence in situ hybridization was performed in residual urine from 124 patients with a cytological diagnosis of cell clusters (22), atypical findings (46) and suspicious findings (56) who had a same day cystoscopy result and bladder biopsy within 6 months of the cytology diagnosis. Urologists and fluorescence in situ hybridization technologists were blinded to the matching fluorescence in situ hybridization and cystoscopy results, respectively.

RESULTS

In conjunction with cystoscopy fluorescence in situ hybridization was significantly more sensitive than cystoscopy alone for detecting cancer (87% vs 67%, p <0.001) and muscle invasive cancer (94% vs 56%, p = 0.031). Of the 124 equivocal cytology specimens 58 (47%) were positive by fluorescence in situ hybridization. Of these patients 53 (91%) had subsequent evidence of carcinoma, including Ta tumors in 17, Tis in 13, T1 in 8 and T2 or greater in 15, on the first followup biopsy. Three of the 5 remaining patients with a positive fluorescence in situ hybridization result and negative first followup biopsy had evidence of cancer at a later date, including TxN+ disease in 2 and Tis in 1. A total of 66 specimens were diagnosed as negative by fluorescence in situ hybridization. Of these patients 34 (52%) had negative biopsy results, whereas the remaining 32 (48%) demonstrated bladder cancer, including Ta disease in 20, Tis in 8, T1 in 2 and T2+ in 2. Cystoscopy detected 21 of the 32 tumors (66%) not detected by fluorescence in situ hybridization, while fluorescence in situ hybridization detected 17 of the 28 (61%) not detected by cystoscopy.

CONCLUSIONS

Our data suggest that fluorescence in situ hybridization with cystoscopy can aid clinicians in the diagnosis of bladder cancer in patients with equivocal cytology.

Potential of urinary biomarkers in early bladder cancer diagnosis

Carcinoma of urinary bladder ranks among the top ten most common cancers worldwide. Approximately 80% of the disease is superficial (limited to mucosa and lamina propria) at the time of presentation. However, the majority of these tumors recur and 15-20% progress into muscle-invasive disease. Cystoscopic surveillance of the urinary bladder remains the standard of care to identify these recurrences on follow-up. Not only is this an invasive procedure, but the sensitivity of cystoscopy can be as low as 70%, so there can be up to 30% of tumors that are missed. Urinary cytology, with recognized limitations, has been used as an adjunct to this procedure, pending discovery of alternate urinary biomarkers. In the past decade there has been tremendous advancement in producing urinary biomarkers for urinary bladder cancer research, reflecting advancements in genomics and proteomics. An ideal biomarker should be able to replace cystoscopic examination and be cost effective. Unfortunately, most of the identified protein or molecular biomarkers have failed this test. This article critically appraises the status of these urinary biomarkers in urinary bladder cancer, in addition to highlighting some of the difficulties in this research area.

The value of combined use of survivin, cytokeratin 20 and mucin 7 mRNA for bladder cancer detection in voided urine

OBJECTIVES

To evaluate the value of combined use of survivin, cytokeratin (CK) 20 and mucin (MUC) 7 mRNA in comparison with voided urine cytology in the detection of bladder cancer patients.

METHODS

One hundred and fifty three patients and 20 healthy volunteers were evaluated by RT-PCR for detecting survivin, CK-20 and MUC7 mRNA in voided urine before cystoscopy. The three markers and cytology were evaluated independently or in combinations.

RESULTS

The overall sensitivity and specificity were 90.4 and 94.7% for survivin, 82.6 and 97.4% for CK-20, 62.6 and 94.7% for MUC7 and 46.0 and 100% for voided urine cytology. Combined sensitivity of voided urine cytology with the three biomarkers together was higher than either combined sensitivity of voided urine cytology with one of the biomarkers or than that of the biomarker alone.

CONCLUSIONS

Combined use of the three markers can improve the sensitivity for detecting bladder cancer.

Detailed technical analysis of urine RNA-based tumor diagnostics reveals ETS2/urokinase plasminogen activator to be a novel marker for bladder cancer

BACKGROUND

The noninvasive detection of RNA tumor markers in body fluids represents an attractive diagnostic option, but diagnostic performance of tissue-derived markers is often poorer when measured in body fluids rather than in tumors. We aimed to develop a procedure for measurement of tumor RNA in urine that would minimize donor-dependent influences on the results.

METHODS

RNA isolated from urinary cell pellet, cell-depleted fraction, and whole urine was quantified by reverse transcription quantitative-PCR. The donor-dependent influence of urine background on individual steps of the standardized procedure was analyzed using an external RNA standard. Using a test set of samples from 61 patients with bladder cancer and 37 healthy donors, we compared 4 putative RNA tumor markers identified in whole urine with 5 established, tissue-derived RNA tumor markers for the detection of bladder cancer.

RESULTS

Of the markers analyzed by this system, the RNA ratio of v-ets erythroblastosis virus E26 oncogene homolog 2 (avian; ETS2) to urokinase plasminogen activator (uPA) enabled the most specific (100%) and sensitive (75.4%) detection of bladder cancer from whole urine, with an area under the curve of 0.929 (95% CI 0.882-0.976).

CONCLUSIONS

The described methodology for RNA marker detection in urine appears to be clinically applicable. The ratio of ETS2 mRNA to uPA mRNA in urine is a potential marker for bladder cancer.

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

Successful treatment of bladder cancer depends largely on early diagnosis of primary and recurrent disease. Sensitive, specific and noninvasive procedures for detection are especially needed for grade 1 and 2 bladder tumors, because of the relatively low sensitivity of cytology. Here we introduce a novel strategy to improve the sensitivity and reliability of microsatellite analyses by employing marker-specific threshold values for loss-of-heterozygosity (LOH) at 10 loci. These individual cut-offs were experimentally determined with 35 normal control tissues and subsequently validated in a retrospective study with bladder cancer biopsies from 86 patients. In a prospective analysis of voided urines samples and matched blood probes from 91 patients, LOH-analysis, UroVysion FISH and conventional urine cytology were compared with histological findings of consecutive transurethral biopsies. Whereas all samples could be analyzed by our LOH assay, only 56 samples were suitable for all 3 analyses. The highest sensitivity was obtained with our LOH-assay/cytology approach (G1-2: 72%; G3: 96%) being only surpassed by a combination of all 3 techniques (G1-2: 83%; G3: 100%). Since over 93% of the patients with recurrent disease were identified by LOH/cytology-analyses of their voided urine samples, a monitoring scheme alternating cystoscopy with LOH/cytology-examination could now be envisioned to reduce invasive interventions and consequently improve follow-up compliance, especially in patients with low grade tumors.