Urinary nuclear matrix protein 22 (NMP22): a diagnostic adjunct to urine cytologic examination for the detection of recurrent transitional-cell carcinoma of the bladder

MtDNA As a Cancer Marker: A Finally Closed Chapter?

Sequence alterations of the mitochondrial DNA (mtDNA) have been identified in many tu-mor types. Their nature is not entirely clear. Somatic mutation or shifts of heteroplasmic mtDNA vari-ants may play a role. These sequence alterations exhibit a sufficient frequency in all tumor types investi-gated thus far to justify their use as a tumor marker. This statement is supported by the high copy num-ber of mtDNA, which facilitates the detection of aberrant tumor-derived DNA in bodily fluids. This will be of special interest in tumors, which release a relatively high number of cells into bodily fluids, which are easily accessible, most strikingly in urinary bladder carcinoma. Due to the wide distribution of the observed base substitutions, deletions or insertions within the mitochondrial genome, high efforts for whole mtDNA sequencing (16.5 kb) from bodily fluids would be required, if the method would be in-tended for initial tumor screening. However, the usage of mtDNA for sensitive surveillance of known tumor diseases is a meaningful option, which may allow an improved non-invasive follow-up for the urinary bladder carcinoma, as compared to the currently existing cytological or molecular methods. Fol-lowing a short general introduction into mtDNA, this review demonstrates that the scenario of a sensi-tive cancer follow-up by mtDNA-analysis deserves more attention. It would be most important to inves-tigate precisely in the most relevant tumor types, if sequencing approaches in combination with simple PCR-assays for deletions/insertions in homopolymeric tracts has sufficient sensitivity to find most tu-mor-derived mtDNAs in bodily fluids.

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.

Urinary markers for bladder cancer

Bladder cancer has the fifth highest incidence of all malignancies in the United States, with a propensity to recur, requiring lifelong surveillance after diagnosis. Urinary markers of disease have been of extreme interest in this field in an effort to simplify surveillance schedules and improve early detection of tumors. Many markers have been described, but most remain investigational. However, some markers have undergone clinical trials and are approved for clinical use. In this review, urinary markers and their application for screening and surveillance of bladder cancer are discussed.

Follow-up procedures for non-muscle-invasive bladder cancer: an update

Bladder carcinoma is the most common malignancy of the urinary tract. Approximately 75-85% of patients present with a disease that is confined to the mucosa (stage Ta, carcinoma in situ) or submucosa (stage T1). The stratification of patients to low-, intermediate- and high-risk groups represents the cornerstone for the indication of adjuvant and follow-up treatment. Owing to the high recurrence rate of bladder tumors, a surveillance protocol is recommended to all patients. Currently, the combination of cystoscopy, imaging and urinary cytology represent the follow-up. A systematic review of the recent English literature on follow-up procedures of non-muscle-invasive bladder cancer is performed. The authors review the existing follow-up procedures, with a focus on novel molecular-targeted approaches. At the present time, the additional use and utility of urine-based molecular markers in the follow-up of patients remains unclear and we have to rely on cystoscopic evaluation adapted to risk group classification.

Assessing the clinical benefit of nuclear matrix protein 22 in the surveillance of patients with nonmuscle-invasive bladder cancer and negative cytology: a decision-curve analysis

BACKGROUND

Several studies have demonstrated that abnormal levels of nuclear matrix protein 22 (NMP22) are associated with bladder cancer and have led to the approval of NMP22 as a urinary biomarker by the US Food and Drug Administration. Nonetheless, the clinical significance of NMP22 remains unclear. The objective of this study was to use decision analysis to determine whether NMP22 improves medical decision-making.

METHODS

The current study included 2222 patients who had a history of nonmuscle-invasive bladder cancer and current negative cytology. The authors developed models to predict cancer recurrence or progression to muscle-invasive disease using voided NMP22 levels, cystoscopy, age, and sex. Clinical net benefit was calculated by summing the benefits (true-positives), subtracting the harms (false-positives), and weighting these values by the threshold probability at which a patient or clinician would opt for cytoscopy.

RESULTS

After cystoscopy, 581 patients (26%) had cancer identified. The NMP22 level was associated significantly with bladder cancer recurrence and progression (P < .001 for both). The use of NMP22 in a model with age and sex was associated with better patient outcomes than performing cystoscopy on everyone and produced threshold probabilities > 8% for recurrence and > 3% for progression. Only offering cystoscopy to those who had a risk > 15% reduced the number of cystoscopies by 229 while missing only 25 cancer recurrences per 1000 men with negative cytology. The current study was limited by its multicenter design.

CONCLUSIONS

For clinicians who would perform a cystoscopy at a threshold of 5% for recurrence or 1% for progression, NMP22 did not aid clinical decision-making. For less risk-averse clinicians who would only perform a cystoscopy at a threshold probability >thinsp;8% for recurrence or > 3% for progression, NMP22 helped to indicate which patients required cystoscopy and which could be spared this procedure.

Urine cytology and urine-based markers for bladder urothelial carcinoma detection and monitoring: developments and future prospects

Bladder cancer is currently diagnosed using cystoscopy and cytology in patients with suspicious signs and symptoms. These tests are also used to monitor patients with a history of bladder cancer. The recurrence rate for bladder cancer is high, thus necessitating long-term follow-up. Urine cytology has a high sensitivity and specificity for the detection of high-grade urothelial carcinoma, but lacks the sensitivity to detect low-grade tumors. Recently, multiple noninvasive urine-based bladder cancer tests have been developed. Many markers (BTA stat®, BTA TRAK®, ImmunoCyt™, NMP22® and UroVysion™) have already been approved by the US FDA for bladder cancer surveillance, while other markers are still undergoing development, preclinical and clinical investigation. An ideal bladder cancer test would be noninvasive, highly sensitive and specific, inexpensive, easy to perform and yield highly reproducible results. Many of the tests reviewed herein meet some, but not all, of these criteria.

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.

Intérêt des marqueurs urinaires dans le diagnostic et le suivi des tumeurs urothéliales de vessie

Urothelial bladder tumours require regular surveillance: cystoscopy associated with urine cytology are reference examinations. Several new markers currently under evaluation or already validated have recently been proposed to replace cytology and potentially reduce or even replace unnecessary cystoscopies. The biological fluid studied for all of these markers is the same as that of urine cytology, i.e. urine. The authors review the results of recent studies on these new urinary markers. The results of these markers demonstrate a better global sensitivity than urine cytology, but often a lower specificity. In the majority of cases, these tests are performed during patient follow-up (NMP22, BTA, CYFRA 21-l., etc.), but do not replace cystoscopy, due to a large number of false-positives. Other techniques, such as FISH, uCyt+ or microsatellites appear to be more promising, especially for the diagnosis of low-grade tumours. The best solution in practice may consist of a combination of several markers to further improve sensitivity and to decrease the false-positive rate responsible for unnecessary cystoscopies.

[Tumor marker tests in bladder cancer]

The gold standard for detecting bladder cancer is cystoscopy which identifies nearly all papillary and sessile lesions. However, it is an invasive procedure causing some discomfort for patients. Urine cytology is the standard non-invasive marker with very high specificity, but unfavourable poor sensitivity for Ta, G1, and T1 bladder tumors. To improve early detection of bladder cancer as well as to monitor treatment response and tumor recurrence, bladder tumor markers are eligible. An ideal bladder cancer test would have the potential to replace or delay cystoscopy in the follow-up of bladder cancer patients. In recent years, the FDA approved non-invasive tumor marker tests ImmunoCyt / uCyt+, BTA TRAK, BTA stat, NMP22, NMP22 BladderChek, and UroVysion have been investigated. The tests demonstrated higher sensitivity for diagnosis of bladder cancer compared to urine cytology. Overall, the mean sensitivity and mean specificity was 64-80% and 71-95% and the mean positive and negative predictive values to detect malignancy were 49-84% and 79-95%, respectively. BTA TRAK, BTA stat, NMP22, and NMP22 BladderChek assays are limited by false-positive results in patients with benign urological diseases such as hematuria, urocystitis, renal calculi or urinary tract infections. Due to low specificity BTA TRAK, BTA stat, NMP22, and NMP22 BladderChek should not be used without first ruling out benign or malignant genitourinary disease other than bladder cancer. With the exception of UroVysion achieving 80% sensitivity and 94% specificity, none of these non-invasive tests revealed a high sensitivity and specificity at the same time, which is a main demand to be made on an ideal tumor marker. Insufficient sensitivity along with limited specificity does not allow replacing cystoscopy in diagnosis of bladder cancer or treatment decisions based on a positive test result.

Molecular markers in bladder cancer: A critical appraisal

The diagnosis of both primary and recurrent bladder tumors currently relies upon the urine cytology and cystoscopy. Neither of these diagnostic tools is completely accurate. Prognostication of bladder cancer is largely based on pathologic tumor grade and stage. Over the past 2 decades, there is accumulating evidence that like many other cancers, bladder cancer, too, has a distinct molecular signature that separates it from other cancers and normal bladder tissue. Bladder tumors of different grades and stages even possess unique, and specific genotypic and phenotypic characteristics. Although recognition of several of these molecular alterations is possible by analyzing tumor tissue, urine, and serum samples, few if any of these "molecular markers" for bladder cancer are widely used in clinical practice. These markers include some that can be applied during the diagnostic work-up of symptoms (e.g., hematuria), those under surveillance for recurrence of superficial disease and forecasting long-term prognosis, or response to chemotherapy. In this review of molecular markers for bladder cancer, effectiveness of markers in each of these categories that are identifiable in the urine of patients with bladder cancer was examined. Many of the diagnostic markers appear to hold an advantage over urine cytology in terms of sensitivity, especially for the detection of low-grade superficial tumors. However, most markers tend to be less specific than cytology, yielding more false-positives. This result is more commonly observed in patients with concurrent bladder inflammation or other benign bladder conditions. Although there are several candidate markers for assessing prognosis or response to chemotherapy, studies of large patient populations are lacking. Further studies involving larger numbers of patients are required to determine their accuracy and widespread applicability in guiding treatment of bladder cancer.

RETRACTED: Highly specific urine-based marker of bladder cancer

OBJECTIVES

Bladder cancer represents a major health problem throughout the world, but advances in tumor biomarker development are revolutionizing how physicians diagnose the disease. We previously used an indirect immunoassay to demonstrate that the bladder cancer specific biomarker, BLCA-4, is present in urine samples from patients with bladder cancer, but not in samples from healthy individuals. In this study, a sandwich immunoassay was used to measure BLCA-4 in urine samples from patient populations with various urologic conditions and healthy individuals.

METHODS

Urine was collected from healthy individuals and from patients with bladder cancer, benign urologic conditions, or prostate cancer. BLCA-4 levels were evaluated by a sandwich immunoassay using two antibodies directed against distinct epitopes on BLCA-4.

RESULTS

Using a prospectively determined cutoff of an absorbance unit (OD) of 0.04, 67 of the 75 samples from patients with bladder cancer were positive for BLCA-4, resulting in an assay sensitivity of 89%. Also, 62 of the 65 samples from individuals without bladder cancer were negative for BLCA-4, resulting in an assay specificity of 95%.

CONCLUSIONS

The high sensitivity and specificity of the sandwich BLCA-4 immunoassay may allow for earlier detection and treatment of disease, thus greatly improving patient care.

Risk stratification for bladder tumor recurrence, stage and grade by urinary nuclear matrix protein 22 and cytology

PURPOSE

To test the hypothesis that voided urinary levels of nuclear matrix protein 22 (NMP22) would add to the predictive ability of urine cytology in the diagnosis, staging and grading of bladder transitional cell carcinoma (TCC), and to evaluate the diagnostic performance of different NMP22 cut-points.

MATERIALS

NMP22 level and barbotage cytology were evaluated in voided urine specimens collected before cystoscopy from 302 subjects with a history of TCC, 32 subjects with benign urologic pathologies, and 10 healthy volunteers.

RESULTS

180 patients (52%) had bladder TCC. Higher levels of NMP22 and positive cytology were independently associated with an increased risk of TCC, invasive stage, and high grade. The NMP22 value with equal sensitivity and specificity for prediction of bladder cancer was 6.5U/ml; for prediction of grade 3 TCC it was 13.5U/ml; and for prediction of invasive tumor stage it was 17.4U/ml. The NMP22 cut-point of 6.5U/ml outperformed the 10U/ml cut-point in all pathologic stages and grades. The diagnostic sensitivity of the cytology and NMP22 combined was superior across all pathologic stages and grades to that of either marker alone. NMP22 and cytology stratified patients into groups with significantly different risk for TCC presence, invasive stage, and high grade.

CONCLUSIONS

6.5U/ml is a robust NMP22 cut-point for bladder cancer surveillance. The diagnostic sensitivities of the combined NMP22 and cytology for TCC presence, stage, and grade were significantly higher than those of single marker alone. The combination of urine cytology and NMP22 could be used to tailor the frequency of cystoscopic follow up.

Current bladder cancer tests: unnecessary or beneficial?

Bladder cancer is currently diagnosed using cystoscopy and cytology in patients with suspicious signs and symptoms. These same tests are used to monitor patients with a history of bladder cancer for recurrence. The recurrence rate for bladder cancer is high, thus necessitating long-term follow-up. Urine cytology requires an experienced cytopathologist and is costly. It has high specificity, but low sensitivity for low-grade bladder tumors. Recently many non-invasive bladder cancer tests, utilizing markers found in the urine, have been developed. The FDA has approved several of these for the use is bladder cancer diagnosis, and many others are undergoing development and investigation. An ideal bladder cancer test would be non-invasive, highly sensitive and specific, inexpensive, easy to perform, and yield highly reproducible results. Many of the tests reviewed meet some, but not all, of these criteria.

Value of urinary NMP-22 in patients with renal cell carcinoma

OBJECTIVES

To investigate the preoperative and postoperative levels of urinary nuclear matrix protein-22 (NMP-22) in patients with renal cell carcinoma (RCC) and compare them with those of control patients. We also investigated and reported the relationship of NMP-22 with the pathologic grade and stage of RCC tumors. Urinary NMP-22 is currently used for monitoring patients with transitional cell carcinoma of the bladder.

METHODS

The preoperative and postoperative urinary NMP-22 levels were measured in 23 patients with RCC and 20 control patients in whom solid renal masses were ruled out by either computed tomography or renal ultrasonography. The control group consisted of patients with benign conditions from the urology, gastroenterologic surgery, and cardiovascular surgery departments. Of the 23 patients with RCC, 21 underwent radical nephrectomy and 2 underwent partial nephrectomy.

RESULTS

The preoperative urinary NMP-22 levels were significantly higher in the RCC group than in the control group (10.65 +/- 5.49 U/mL and 4.64 +/- 3.10 U/mL, respectively, P <0.001). Ten days postoperatively, the urinary NMP-22 levels had decreased from 10.65 +/- 5.49 U/mL to 5.98 +/- 3.86 U/mL in the RCC group, which was statistically significant (P <0.001). The postoperative urinary NMP-22 levels were not different from those of the control group (5.98 +/- 3.86 U/mL versus 4.64 +/- 3.10 U/mL, P = 0.176).

CONCLUSIONS

The results of this study are promising for the use of urinary NMP-22 in the evaluation of patients who are at risk of RCC because the relationship between urinary NMP-22 and the presence of RCC has been shown.

Urine based markers of urological malignancy

PURPOSE

A number of urine based markers have been and are being investigated for the diagnosis and prognostication of urological conditions. A majority of these markers have been evaluated in urological neoplasms, particularly bladder cancer. The diagnosis of bladder cancer currently relies on identifying malignant cells in the urine and subsequently visualizing the tumor on cystoscopy. This diagnosis is further confirmed by transurethral resection or biopsy. While urine cytology is specific, it is not sensitive, especially for detecting low grade disease. This characteristic has prompted the search for more accurate markers of bladder cancer. In this review we critically examine the results of studies evaluating various markers for bladder cancer.

MATERIALS AND METHODS

The published literature on urine based markers for all urological diseases, particularly bladder cancer, was identified using a MEDLINE search and critically analyzed. The sensitivity, specificity, positive and negative predictive values of the various markers were compared. The benefit of using combined markers rather than a single marker was also analyzed from published reports.

RESULTS

Most published literature on urine based markers for urological malignancies involve such markers for diagnosing and prognosticating bladder cancer. Hence, we focused mainly on urine based markers in bladder cancer. Most markers appear to have an advantage over urine cytology in terms of sensitivity, especially for detecting low grade, superficial tumors. However, most markers tend to be less specific than cytology, yielding more false-positive results. This scenario is more common in patients with concurrent bladder inflammation or other benign bladder conditions. However, there is reason to be optimistic about several new markers that appear to provide better specificity. Few urine based markers have been identified and investigated in other urological tumors.

CONCLUSIONS

Detecting bladder cancer using diagnostic markers still presents a challenge. A number of new markers are currently available that appear to be significantly more accurate than cytology. However, further studies involving a larger number of patients are required to determine their accuracy and widespread applicability for diagnosing bladder cancer. Urine based markers do not appear to have a significant role in the diagnosis or prognosis of other urological malignancies, such as prostate, kidney or testicular cancer.

Biomarkers for the detection of bladder cancer

In this subject review, a series of morphology-based and molecular markers were compared with urinary cytology for the detection of recurrent urothelial neoplasia. Among the various biomarkers reviewed, the average published sensitivity and specificity for the Bard BTA test was 60% and 77%; the NMP22 Test was 67% and 72%; the telomerase assay was 77% and 85%; and the microsatellite assay was 89% and 100%. DNA ploidy measurements and immunoassays designed to detect keratins, proteins, hyaluronidase, growth factors, cell adhesion molecules, fibrinogen degradation products, cell cycle regulators, and molecular markers were also included. Although the performance features of these biomarkers have varied and the cytologic methods to which they have been compared have not been standardized, several of the procedures have received considerable support from urologists as assisting them in the management of their patients.

Current concepts in assessment and treatment of bladder cancer

Transitional cell carcinoma of the bladder is comprised of a variety of cancer diatheses that manifest a spectrum of distinct biologic potentials. The challenge is to control superficial disease recurrence and progression and to identify invasive carcinoma at an earlier stage, when it may be more amenable to cure.

Urological malignancies and the proteomic-genomic interface

The urological malignancies, renal, bladder and prostate cancer, account for approximately 16% of all cancer cases. Unfortunately 5-year survival rates are relatively poor, largely a result of many cases not being diagnosed before the tumour has metastasised. There is a clear need for the identification of markers which will allow earlier detection of disease, and predict prognosis and response to therapy. In addition, they may be of use as therapeutic targets. Current advances in molecular biology are allowing the identification of a number of tumour-associated changes which could be of clinical use in the future. However, with the rapid technological advances being made in the field of proteomics, this approach could be integrated with genomics providing a complementary alternative, overcoming disparities between mRNA levels and protein production, and additionally allowing the identification of tumour-associated post-translational modifications. These approaches have already been used to identify novel genes and other cancer-related changes involved in the pathogenesis of urological malignancies. This review describes current progress in the genomic and proteomic study of urological malignancies, and highlights the potential of using proteomic technologies in the study of this group of diseases.