Utility of serial urinary tumor markers to individualize intervals between cystoscopies in the monitoring of patients with bladder carcinoma

Nuclear matrix protein 22 in bladder cancer

Bladder cancer (BC) is ranked as the ninth most common malignancy worldwide, with approximately 570,000 new cases reported annually and over 200,000 deaths. Cystoscopy remains the gold standard for the diagnosis of BC, however, its invasiveness, cost, and discomfort have driven the demand for the development of non-invasive, cost-effective alternatives. Nuclear matrix protein 22 (NMP22) is a promising non-invasive diagnostic tool, having received FDA approval. Traditional methods for detecting NMP22 require a laboratory environment equipped with specialized equipment and trained personnel, thus, the development of NMP22 detection devices holds substantial potential for application. In this review, we evaluate the NMP22 sensors developed over the past decade, including electrochemical, colorimetric, and fluorescence biosensors. These sensors have enhanced detection sensitivity and overcome the limitations of existing diagnostic methods. However, many emerging devices exhibit deficiencies that limit their potential clinical use, therefore, we propose how sensor design can be optimized to enhance the likelihood of clinical translation and discuss the future applications of NMP22 as a legacy biomarker, providing insights for the design of new sensors.

Accuracy of cytokeratin 19 fragment in the diagnosis of bladder cancer

Aim: CYFRA21-1 is a biomarker of cancer and has a promising future in the diagnosis of bladder cancer. The purpose of this study was to assess the diagnostic accuracy of CYFRA21-1 for bladder cancer. Methods: We included articles from the Cochrane Library, Web of Science, PubMed and Embase. Meta-DiSc 1.4 and Stata 12.0 were used for data analysis. Results: Twenty-eight articles were analyzed, and the results are as follows: sensitivity, specificity, PLR, NLR, DOR and AUC were 0.69 (95% CI [0.67, 0.71]), 0.81 (95% CI [0.80, 0.83]), 5.99 (95% CI [4.42, 8.11]), 0.31 (95% CI [0.25, 0.38]), 24.58 (95% CI [15.15, 39.89]) and 0.8917, respectively. Conclusion: CYFRA21-1 has a high diagnostic efficiency for bladder cancer.

Prognostic relevance of positive urine markers in patients with negative cystoscopy during surveillance of bladder cancer

Background

The role of urine markers in the surveillance of patients with non-muscle invasive bladder cancer (NMIBC) is discussed extensively. In case of negative cystoscopy the additional prognostic value of these markers has not been clearly defined yet. The present study is the first systematic approach to directly compare the ability of a urine marker panel to predict the risk of recurrence and progression in bladder cancer (BC) patients with no evidence of relapse during surveillance for NMIBC.

Methods

One hundred fourteen patients who underwent urine marker testing during surveillance for NMIBC and who had no evidence of BC recurrence were included. For all patients cytology, Fluorescence-in-situ-hybridization (FISH), immunocytology (uCyt+) and Nuclear matrix protein 22 enzyme-linked immunosorbent assay (NMP22) were performed. All patients completed at least 24 months of endoscopic and clinical follow-up of after inclusion.

Results

Within 24 months of follow-up, 38 (33.0%) patients experienced disease recurrence and 11 (9.8%) progression. Recurrence rates in patients with positive vs. negative cytology, FISH, uCyt+ and NMP22 were 52.6% vs. 21.9% (HR = 3.9; 95% CI 1.75-9.2; p < 0.001), 47.6% vs. 25.0% (HR 2.7; 1.2-6.2; p = 0.01), 43.8% vs. 22.4% (HR 3.3; 1.5-7.6; p = 0.003) and 43.8% vs. 16.7% (HR 4.2; 1.7-10.8; p = 0.001). In patients with negative cytology, a positive NMP22 test was associated with a shorter time to recurrence (p = 0.01), whereas FISH or uCyt+ were not predictive of recurrence in these patients. In the group of patients with negative cytology and negative NMP22, only 13.5% and 5.4% developed recurrence and progression after 24 months.

Conclusions

Patients with positive urine markers at time of negative cystoscopy are at increased risk of recurrence and progression. In patients with negative cytology, only NMP22 is predictive for recurrence. Patients with negative marker combinations including NMP22 harbour a low risk of recurrence. Therefore, the endoscopic follow-up regimen may be attenuated in this group of patients.

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.

Urinary markers in the everyday diagnosis of bladder cancer

Bladder cancer (BC) represents the fourth most common neoplasia in men and the ninth most common cancer in women, with a significant morbidity and mortality. Cystoscopy and voided urine cytology (involving the examination of cells in voided urine to detect the presence of cancerous cells) are currently the routine initial investigations in patients with hematuria or other symptoms suggestive of BC. Around 75-85% of the patients are diagnosed as having non-muscle-invasive bladder cancer (NMIBC). Despite the treatment, these patients have a probability of recurrence at 5 years ranging from 50 to 70% and of progression to muscle invasive disease of 10-15%. Patients with NMIBC must undergo life-long surveillance, consisting of serial cystoscopies, possibly urine cytology and ultrasonography. Cystoscopy is unsuitable for screening because of its invasiveness and costs; serial cystoscopies may cause discomfort and distress to patients. Furthermore, cystoscopy may be inconclusive, falsely positive or negative. Although urine cytology has a reasonable sensitivity for the detection of high-grade BC, it lacks sensitivity to detect low-grade tumors (sensitivity ranging from 4 to 31%). The overall sensitivity and specificity of urine cytology range from 7 to 100 and from 30 to 70%, respectively. There is a need for new urine biomarkers that may help in BC diagnosis and surveillance. A lot of urinary biomarkers with high sensitivity and/or specificity have been investigated. Although none of these markers have proven to be powerful enough to replace standard cystoscopy, some of them may represent accurate predictors of BC. A review of recent studies is presented.

Urine markers for detection and surveillance of bladder cancer

OBJECTIVES

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Combined application of cytology and molecular urine markers to improve the detection of urothelial carcinoma

BACKGROUND

The sensitivity of cytology for the detection of urothelial carcinoma (UC) is limited. Newer methods such as fluorescence in situ hybridization (FISH), immunocytology (uCyt+), and protein markers have been developed to improve urine-based detection of UC. As only little is known regarding the combined application of these markers, we investigated whether combinations of 4 of the most broadly available tests (cytology, FISH, uCyt+, and nuclear matrix protein 22 [NMP22-ELISA]) may improve their diagnostic performance.

METHODS

The study was comprised of 808 patients who were suspected of having UC. All patients underwent urethrocystoscopy and upper urinary tract imaging and, in the case of positive findings, transurethral resection/biopsy. FISH, uCyt+, cytology, and NMP22-ELISA were performed in all patients.

RESULTS

UC was diagnosed in 115 patients (14.2%). Cytology and FISH were found to be the single tests with the best overall performance (area under the curve [AUC], 0.78/0.79). Combinations of 2, 3, and 4 markers were found to increase the AUC to various extents compared with the use of single markers. Combining cytology and FISH improved the sensitivity and performance (AUC, 0.83) compared with the single tests and identified 12 tumors that were not detected by cytology alone. The percentage of WHO grade 3/carcinoma in situ tumors not detected by cytology was reduced by 62.5% when FISH was performed in cytology-negative patients. The addition of uCyt+ as a third test further improved performance (AUC, 0.86), whereas the addition of NMP22-ELISA was not found to have any additional influence on the performance of the test combination.

CONCLUSIONS

The results of the current study support the combined use of urine markers and may form the basis of further studies investigating whether risk stratification based on urine marker combinations may individualize diagnostic algorithms and the surveillance of patients suspected of having UC.

Performance of survivin mRNA as a biomarker for bladder cancer in the prospective study UroScreen

Background

Urinary biomarkers have the potential to improve the early detection of bladder cancer. Most of the various known markers, however, have only been evaluated in studies with cross-sectional design. For proper validation a longitudinal design would be preferable. We used the prospective study UroScreen to evaluate survivin, a potential biomarker that has multiple functions in carcinogenesis.

Methods/Results

Survivin was analyzed in 5,716 urine samples from 1,540 chemical workers previously exposed to aromatic amines. The workers participated in a surveillance program with yearly examinations between 2003 and 2010. RNA was extracted from urinary cells and survivin was determined by Real-Time PCR. During the study, 19 bladder tumors were detected. Multivariate generalized estimation equation (GEE) models showed that β-actin, representing RNA yield and quality, had the strongest influence on survivin positivity. Inflammation, hematuria and smoking did not confound the results. Survivin had a sensitivity of 21.1% for all and 36.4% for high-grade tumors. Specificity was 97.5%, the positive predictive value (PPV) 9.5%, and the negative predictive value (NPV) 99.0%.

Conclusions

In this prospective and so far largest study on survivin, the marker showed a good NPV and specificity but a low PPV and sensitivity. This was partly due to the low number of cases, which limits the validity of the results. Compliance, urine quality, problems with the assay, and mRNA stability influenced the performance of survivin. However, most issues could be addressed with a more reliable assay in the future. One important finding is that survivin was not influenced by confounders like inflammation and exhibited a relatively low number of false-positives. Therefore, despite the low sensitivity, survivin may still be considered as a component of a multimarker panel.

CYFRA 21-1: a potential molecular marker for noninvasive differential diagnosis of urothelial carcinoma of bladder

Establishing CYFRA 21-1 detection for noninvasive differential diagnosis of urothelial carcinoma (UC) of bladder would help to improve assessment and follow-up of patients, as well as to improve screening of high-risk groups. The study group comprised of 147 subjects including 72 patients with UC of bladder, 75 controls and 17 follow-up cases. The levels of CYFRA 21-1 in serum, urine and urinary cell lysate were estimated by high sensitivity ELISA. Our results indicate that urinary CYFRA 21-1 provides a high value of overall sensitivity for UC of bladder and is also useful even for detection of low grade tumors that might indicate possible earlier detection and treatment administration.

NMP22 is predictive of recurrence in high-risk superficial bladder cancer patients

INTRODUCTION

The nuclear matrix protein 22 (NMP22) assay has been shown to have greater sensitivity for the diagnosis and detection of recurrent urothelial carcinoma of the bladder (UCB) over that of traditional urine cytology. We assessed the use of NMP22 to predict which high-risk superficial UCB patients will have recurrence, progression or disease-related death; we compared these results to standard urine cytology.

METHODS

One hundred consecutive patients with high-risk superficial UCB were enrolled. During surveillance, urine was collected for cytology and NMP22 testing. Patients were followed for at least 6 months. Retrospective chart review was undertaken to collect data on previous tumour history, tumour characteristics, disease recurrences, progression and death. Kaplan-Meier analyses were performed to determine the significance between NMP22-positive and -negative patients in terms of recurrence-free, progression-free and overall survival. Similar analyses were performed for urine cytology.

RESULTS

From 94 eligible patients, 15 and 79 were NMP22 positive and negative, respectively. The baseline characteristics between the 2 groups were not significantly different in terms of patient characteristics, prior tumour history or intravesical therapies received. Mean recurrence-free survival time was significantly lower in the NMP22 positive group (p = 0.038); however, mean progression-free and overall survival were not significantly different between the 2 groups (p = 0.297 and 0.519, respectively). Urine cytology demonstrated no significant predictive power for disease recurrence, progression or survival.

CONCLUSION

The nuclear matrix protein 22 assay appears to have predictive value for future tumour recurrences, but not progression or overall survival in patients with high-risk superficial UCB.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Defining the role of NMP22 in bladder cancer surveillance

Despite advances in treatment and knowledge of its pathogenesis, urothelial carcinoma of the bladder remains a significant cause of morbidity and mortality. Experience with the natural course of bladder cancer has revealed that early diagnosis of primary and recurrent disease improves patient prognosis. In this regard, cystoscopy (usually in combination with urinary cytology) has long been regarded as the gold standard for the diagnosis and surveillance of bladder cancer. However, the disadvantages inherent to cystoscopy, including invasiveness and cost, have stimulated a search for alternative methods for detecting urothelial malignancy. The ideal alternative test would duplicate the high accuracy of cystoscopy for detecting bladder tumors while eschewing its invasiveness, attendant morbidity, and high cost. The vast majority of bladder cancers arise from the urothelium, which continually sheds cells as well as intracellular contents into the urine, thereby providing a potential source of cancer-specific markers. Voided cytology and urinalysis are established tests that have been the standard tools for detection of such substances. The last decade has seen the rise of a myriad of novel urine-based bladder tumor markers, including bladder tumor antigen, urinary bladder cancer antigen, fibronectin, telomerase, and nuclear matrix proteins (e.g., NMP22). The NMP22 assay in particular has been the subject of considerable study and has demonstrated some promise as a potential adjunct to cystoscopy and cytology. Through a critical review of the literature, we seek to define the role, if any, of NMP22 in the follow-up of patients with a previous history of urothelial carcinoma of the bladder.

Urinary CYFRA 21.1 is not a useful marker for the detection of recurrences in the follow-up of superficial bladder cancer

OBJECTIVES

The objective of this prospective study is to establish an appropriate cutoff value of urinary CYFRA 21.1 assay and to assess its utility combined with voided cytology and/or haemoglobin dipstick in the follow-up of patients with superficial bladder cancer.

METHODS

From December 2000 to November 2003, 446 patients in follow-up for superficial bladder cancer (Ta-T1) after transurethral resection of the bladder (TURB) were included in a prospective study. Voided urine specimens were collected 7-14 d before cystoscopy and/or TURB for CYFRA 21.1 (one sample), haemoglobin dipstick (one sample), and cytology (three samples). All samples were processed for CYFRA 21.1 and haemoglobin dipstick according to manufacturer instructions. A control group (n=185) was obtained from patients in follow-up after transurethral resection of superficial disease (without recurrences within the following 6 mo). There were 125 recurrent transitional tumours detected by cystoscopy (34 TaG1; 53 TaG2/T1G1-2; 23 Ta-1G3/Tis, and 15 T2-4). Receiver operator characteristic (ROC) curves were constructed and cutoff values were chosen. Sensitivity, specificity, PPV (positive predictive value), NPV (negative predictive value), and their 95% confidence intervals were calculated.

RESULTS

ROC curve analysis based on the previously reported cutoff value of 4ng/ml for CYFRA 21.1 demonstrated a sensitivity and specificity of 43% and 68%, respectively. At a cutoff value of 1.5ng/ml, sensitivity was 73.8% with a low specificity (41%). Further lowering of the cutoff point below 1.5ng/ml did not demonstrate a significant increase in sensitivity. Therefore, this value was chosen as the most sensitive CYFRA 21.1 cutoff point during the rest of the study. Specificity increased when all the patients treated with pelvic radiotherapy or with UTI, urethral catheterisation, and intravesical instillations within 3 previous months were not included in our analysis. CYFRA 21.1 plus cytology and the combination of CYFRA 21.1, cytology, and haemoglobin dipstick demonstrated the highest overall sensitivities, and detected 91.3% of Ta-1G3 tumours and 93.3% of T2-4 tumours. However, there were one muscle-invasive tumour, two T1G3/Tis, three T1G2, and nine T1G1 neoplasms with negative combination of cytology and CYFRA 21.1 (1,5ng/ml). All these tumours were smaller than 2cm in size; most were single tumours. Nevertheless, there were 16 tumours larger than 0.5cm (0.5-2cm), and multiple neoplasms were endoscopically detected in 14 patients. Similar results were obtained through the combination of CYFRA 21.1 (cutoff: 1.5ng/ml), cytology, and haemoglobin dipstick.

CONCLUSIONS

In our experience the low sensitivity of urinary CYFRA 21.1, even using lower cutoff values and/or a combination with cytology and/or haemoglobin dipstick, makes its application not very useful as a surveillance tool for superficial bladder carcinoma.

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

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

Bladder tumor markers beyond cytology: International Consensus Panel on bladder tumor markers

This is the first of 2 articles that summarize the findings of the International Consensus Panel on cytology and bladder tumor markers. The objectives of our panel were to reach a consensus on the areas where markers are needed, to define the attributes of an ideal tumor marker, and to identify which marker(s) would be suitable for diagnosis and/or surveillance of bladder cancer. Our panel consisted of urologists and researchers from Europe, Asia, and the United States who reviewed original articles, reviews, and book chapters on individual bladder tumor markers published in the English language mainly using the PubMed search engine. Panel members also met during 3 international meetings to write recommendations regarding bladder tumor markers. The panel found that the most practical use of noninvasive tests is to monitor bladder cancer recurrence, thereby reducing the number of surveillance cystoscopies performed each year. Markers also may be useful in the screening of high-risk individuals for early detection of bladder cancer. However, more prospective studies are needed to strengthen this argument. Case-control and cohort studies show that several markers have a higher sensitivity to detect bladder cancer. However, cytology is the superior marker in terms of specificity, although some markers in limited numbers of studies have shown specificity equivalent to that of cytology. Our panel believes that several bladder tumor markers are more accurate in detecting bladder cancer than prostate-specific antigen (PSA) is in detecting prostate cancer. However, bladder tumor markers are held to a higher standard than PSA. Therefore, use of bladder tumor markers in the management of patients with bladder cancer will require the willingness of both urologists and clinicians to accept them.

Clinical utility of cytokeratins as tumor markers

Cytokeratins, belonging to the intermediate filament (IF) protein family, are particularly useful tools in oncology diagnostics. At present, more than 20 different cytokeratins have been identified, of which cytokeratins 8, 18, and 19 are the most abundant in simple epithelial cells. Upon release from proliferating or apoptotic cells, cytokeratins provide useful markers for epithelial malignancies, distinctly reflecting ongoing cell activity. It appears that motifs in certain cytokeratins make them likely substrates for caspase degradation, and their subsequent release occurs during the intermediate events in apoptosis. The clinical value of determining soluble cytokeratin protein fragments in body fluids lies in the early detection of recurrence and the fast assessment of the efficacy of therapy response in epithelial cell carcinomas. The three most applied cytokeratin markers used in the clinic are tissue polypeptide antigen (TPA), tissue polypeptide specific antigen (TPS), and CYFRA 21-1. TPA is a broad spectrum test that measures cytokeratins 8, 18, and 19. TPS and CYFRA 21-1 assays are more specific and measure cytokeratin 18 and cytokeratin 19, respectively. By following patients with repeated testing during management, the oncologist may obtain critical information regarding the growth activity in symptomatic patients. Although their main use is to monitor treatment and evaluate response to therapy, early prognostic information particularly on tumor progression and metastasis formation is also provided for several types of cancers. Cytokeratin tumor markers can accurately predict disease status before conventional methods and offer a simple, noninvasive, cheap, and reliable tool for more efficient management.

High levels of urinary midkine in various cancer patients

Midkine (MK) is a heparin-binding growth factor, which promotes growth, migration, and survival of various cells, and MK expression is increased in many human carcinomas. We determined the urinary MK level by enzyme-linked immunoassay. Taking 311pg/mg creatinine as a cut-off level, 70% of patients with various carcinomas (n=142) gave positive values, while only 5.5% of healthy volunteers (n=330) did. In case of gastric carcinoma, 17 out of 21 patients with stage 1 tumor were positive. Urinary MK levels are expected to become a convenient marker as an aid in detection of tumors.

[The role of tumor markers in urologic consultation for screening, diagnosis, and follow-up of bladder cancer]

PURPOSE

Review the tumor markers for screening and diagnosis of transitional cell carcinoma of the bladder.

METHODS

The published literature on bladder cancer markers was identified using a MEDLINE search and critically analyzed. The sensitivity and specificity of the various markers were compared.

RESULTS

Conventional non-invasive methods for diagnosis (symptoms and urine cytology) and for screening and follow-up of transitional cell carcinoma of the bladder are not very sensitive and must not be considered sufficient. Some tumor markers seem to be a good alternative to the routine urinary cytology.

CONCLUSION

The role of tumor markers for screening and follow-up of bladder tumors as an alternative to cytology deserve consideration. In the future, more sensitive and specific markers may replace routine cystoscopy.

Use of high-throughput DNA microarrays to identify biomarkers for bladder cancer

BACKGROUND

Numerous markers have been described to correlate to some extent with tumor stage and prognosis of patients with bladder cancer. The power of many of these biomarkers in detecting superficial disease or predicting the clinical outcome of individual tumors is limited, and alternative markers are still in demand. High-throughput microarrays represent novel means for cancer research and tumor marker discovery.

APPROACH

The aim of this report was to discuss the application of DNA technologies to provide novel biomarkers for bladder cancer.

CONTENT

Specific bladder tumor subtypes have distinct gene expression profiles. The use of high-throughput DNA microarrays allows identification of the most prevalent and relevant alterations within bladder tumors. Clusters of differentially expressed genes will become biomarkers to discriminate subgroups of patients with different histopathology or clinical outcome. Additionally, the identified individual molecular targets might be further validated and developed into novel serum or urinary biomarkers for the diagnosis and/or as prognostic factors to be applied in clinical practice. The diagnosis and prognosis of bladder cancer would be enhanced by the use of such markers, and the marker itself may constitute a therapeutic target when studied in appropriate patients and control groups.

SUMMARY

Expression profiling with high-throughput DNA microarrays has the potential of providing critical clues for the management of bladder cancer patients. As the quality, standardization, and ease of use of the technology increase and the costs decrease, DNA microarrays will move from being a technology restricted to research to clinical laboratories in the near future.