Noninvasive detection and prediction of bladder cancer by fluorescence in situ hybridization analysis of exfoliated urothelial cells in voided urine

A urinary assay for mutation and methylation biomarkers in the diagnosis and recurrence prediction of non-muscle invasive bladder cancer patients

BACKGROUND

Currently, the clinical strategy for diagnosis of non-muscle invasive bladder cancer (NMIBC) such as cystoscopy and cytology are invasive and/or with limited accuracy. OncoUrine, a urinary assay for mutation and methylation biomarkers, have showed a high accuracy in the detection of upper tract urinary carcinoma (UTUC) patients with hematuria. The aim of this study is to evaluate the performance of OncoUrine in diagnosis of NMIBC patients.

METHODS

In this multicenter prospective study, a total of 203 patients were enrolled, including 60 patients present with hematuria and 143 NMIBC patients under recurrence surveillance. Urine samples were collected before cystoscopy to undergo OncoUrine test. OncoUrine performance was calculated compared to clinical standard methods in hematuria cohort and recurrence surveillance cohort, respectively. Furthermore, NMIBC patients were followed up with a median time of 20.5 months (range 0.03 to 24.03 months) to assess the predictive value of OncoUrine during recurrence monitoring.

RESULTS

For bladder cancer diagnosis, OncoUrine tested 47 samples and achieved a sensitivity/specificity/positive predictive value (PPV)/negative predictive value (NPV) of 80% (95% CI 44.2-96.5)/91.9% (95% CI 77.0-97.9)/72.7% (95% CI 39.3-92.7)/94.4% (95% CI 80.0-99.0) (kappa value 69.4%, 95% CI 44.4-94.3), indicating 72.3% of unnecessary cystoscopy. For recurrence diagnosis, OncoUrine tested 93 samples, and the sensitivity/specificity/PPV/NPV was 100% (95% CI 59.8-100.0)/68.2% (95% CI 57.1-77.7)/22.9% (95% CI 11.0-40.6)/100% (95% CI 92.3-100.0) (kappa value 27.0%, 95% CI 11.1-42.8), indicating 62.4% of spared cystoscopy. What is more, OncoUrine correctly predicted 80% (20/25) of final recurrence with 12/25 (48%) patients who were OncoUrine positive, but cystoscopy negative was followed with recurrence during follow-up. The test result of OncoUrine was also found significantly correlated with recurrence free survival (RFS) of NMIBC patients (median 34.4-month vs unreached; HR 6.0, 95% CI 2.7-13.5, P < 0.0001).

CONCLUSIONS

OncoUrine showed potential value to reduce the frequency of unnecessary cystoscopy and the healthcare cost of bladder cancer patients. Patients with positive test results represented a population who were at high risk of recurrence and thus should be subject to frequent surveillance to ensure timely detection of any potential recurrence. This study has been registered in ClinicalTrials.gov with the number NCT04994197 posted on August 2021.

UroVysionTM Fluorescence In Situ Hybridization in Urological Cancers: A Narrative Review and Future Perspectives

UroVysionTM is a fluorescence in situ hybridization assay that was developed for the detection of bladder cancer (UC accounted for 90%) in urine specimens. It consists of fluorescently labeled DNA probes to the pericentromeric regions of chromosomes 3, 7, 17 and to the 9p21 band location of the P16 tumor suppressor gene, which was approved by the Food and Drug Administration (FDA) in 2001 and 2005, respectively, for urine detection in patients with suspected bladder cancer and postoperative recurrence monitoring. Furthermore, recent studies also demonstrated that U-FISH was useful for assessing superficial bladder cancer patients' response to Bacillus Calmette-Guérin therapy and in detecting upper tract urothelial carcinoma. Therefore, positive U-FISH was well known to urologists as a molecular cytogenetic technique for the detection of UC. However, with the continuous enrichment of clinical studies at home and abroad, U-FISH has shown a broader application space in the detection of various urinary primary tumors and even metastatic tumors. This review focuses on summarizing the research status of U-FISH in UC, non-urothelial carcinoma and metastatic tumor, so as to strengthen urologists' more comprehensive understanding of the application value of U-FISH and better complete the accurate diagnosis and treatment of urological cancers.

Non-invasive diagnosis of bladder cancer by detecting telomerase activity in human urine using hybridization chain reaction and dynamic light scattering

Cystoscopy and histology are the gold standards for detection of bladder cancer. However, these methods are highly subjective, expensive, and invasive. We have developed a non-invasive method for the diagnosis of bladder cancer by detecting telomerase activity in human urine. Telomerase substrate (TS) primer is elongated with repeating sequences of (TTAGGG)n in the presence of telomerase. The elongated primer can trigger hybridization chain reaction between two hairpins H1 and H2, result in the aggregation of AuNPs due to the hybridization between the tail sequence on H1 (or H2) and DNA-AuNPs probe, and accompany with the increase of hydrodynamic diameter of AuNPs, which can be measured with dynamic light scattering (DLS). The biosensor displayed a detection limit of 4 MCF-7 cells (a signal-to-noise ratio of 3) and a dynamic range of 10-1000 cells. Moreover, only urine specimens from bladder cancer patients induced a significant change in the average hydrodynamic diameter, indicating its specificity for the non-invasive diagnosis of bladder cancer.

Multicolor FISH (UroVysion) facilitates follow-up of patients with high-grade urothelial carcinoma of the bladder

The aim of the present prospective study was to assess the diagnostic benefit of UroVysion (Vysis-Abbott Laboratories, Downers Grove, IL) in the follow-up of patients with a history of high-grade non-muscle-invasive urothelial carcinoma of the bladder (NMIBC). An unselected cohort of 25 patients with a history of high-grade NMIBC was prospectively followed up by office-based cystoscopy, cytology, and UroVysion in 210 events. The sensitivity and specificity for standard combined cystoscopy and cytology were 78% and 83%, respectively. UroVysion yielded a considerably higher detection rate with 94% and 93%, respectively. In 89% of the follow-up events of patients with a history of previous carcinoma in situ (CIS) and negative cystoscopy but a positive UroVysion finding, CIS recurrence was noticed within 5 months. UroVysion is a worthwhile approach in patients with previous CIS, a high risk for the development of CIS, or previous unequivocal cytology suggestive of CIS, especially during or shortly after instillation therapy.

Urinary fluorescence in situ hybridization assay for detecting urothelial carcinoma in Taiwanese patients

OBJECTIVES

To investigate the cytogenetic marker detected by fluorescence in situ hybridization (FISH; UroVysion, Vysis, Inc., Abbott Laboratories, Des Plaines, IL, USA) in the diagnosis of bladder cancer and upper tract urothelial carcinoma (UC) in Taiwanese patients, as FISH has been used in Western countries for detecting UC, but there are limited results in Asian populations.

PATIENTS AND METHODS

We analysed polyploidy of chromosome 3, 7, 17 and aneuploidy of chromosome 21, using uroepithelial cells collected at the first void or by instrumental extraction of urine, for bladder cancer, and shedding cells from the upper tract flushed by normal saline via ureteric catheterization or ureterorenoscopy. The criteria for positive tumour cells included three or more positive staining in two or more chromosomes showing polyploidy or <50% staining of the chromosome 9p21.

RESULTS

In all, 32 patients with bladder UC and 12 with upper tract UC were assessed. The overall sensitivity for bladder cancer by UroVysion was 96.8%. The sensitivity of the cytology test was 36% for UC of the bladder. The sensitivity for UroVysion in upper tract UC was 12/12 but the specificity was three of nine.

CONCLUSIONS

This preliminary report shows that UroVysion was a sensitive screening method for UC of the bladder and upper urinary tract.

Combined morphologic and fluorescence in situ hybridization analysis of voided urine samples for the detection and follow-up of bladder cancer in patients with benign urine cytology

BACKGROUND

Bladder cancer is among the 5 most common malignancies worldwide. Patients with bladder cancer are closely followed with periodic cystoscopies and urine cytology analyses due to the significant risk of tumor recurrence. The UroVysion fluorescence in situ hybridization (FISH) test demonstrated higher sensitivity over urine cytology in detecting bladder cancer by most comparative studies.

METHODS

In the current study, the diagnostic usefulness of a combined cytology and FISH analysis approach was tested using the Duet automatic scanning system in patients with benign urine cytology who were being monitored for recurrent urothelial carcinoma or being assessed for various urologic symptoms.

RESULTS

By combining the benefits of conventional cytology with molecular diagnostics, a more sensitive detection of bladder cancer was attained. All patients who had positive cystoscopy concomitantly with urine sampling were detected by combined analysis. Additional patients that developed transitional cell carcinoma during a follow-up period of 24 months had a previous positive result on combined analysis. Only 2 patients with a negative combined analysis result presented with late disease recurrence (20 months and 22 months, respectively, after the negative test). Therefore, negative combined analysis was found to be predictive of a lack of disease recurrence for at least 12 months. In this timeframe, the overall sensitivity, specificity, negative predictive value (NPV), and positive predictive values of the combined analysis test were 100%, 65%, 100%, and 44%, respectively.

CONCLUSIONS

Given the absolute sensitivity and NPV of the combined analysis test, the management of patients with a negative combined analysis result might be revised and allow for more flexible assessment and management of bladder cancer patients relying more on urine bound tests.

Interphase FISH as a new tool in tumor pathology

Interphase FISH (IFISH) analysis is an intriguing molecular cytogenetic approach to study chromosome abnormalities in cancer. IFISH is a high sensitivity technique because of its ability to identify aberrations on a cell-to-cell level. The possibility to perform IFISH on different types of nuclei obtained both from fresh and archived samples, makes this technique an advantageous method to identify specific chromosome aberrations in cancer and correlate them to prognosis and therapy. The aim of this review is to outline the technical aspects, the sensitivity and specificity and the current strategies for employment of IFISH in tumor pathology, and to discuss the enormous range of novel applications.

Fluorescence in situ hybridization in diagnostic cytology

Fluorescence in situ hybridization (FISH) is a technique that uses fluorescently labeled DNA probes to detect chromosomal alterations in cells. FISH can detect various types of cytogenetic alterations including aneusomy (ie, abnormalities of chromosome copy number), duplication, amplification, deletion, and translocation. Because tumor cells generally contain chromosomal alterations, FISH is able to detect cells that have chromosomal abnormalities consistent with neoplasia in exfoliative and aspiration cytology specimens. This review will discuss the utility of FISH for the detection of bladder, lung, pancreatobiliary, and esophageal carcinoma in cytologic specimens.

Aneusomy for detection of bladder cancer recurrence: a Southwest Oncology Group study

The high risk of recurrence in superficial transitional cell cancer (TCC) of the bladder prompted evaluation of whether chromosome changes detected at first recurrence were correlated with relapse or with response to fluoroquinolone treatment. Fluorescence in situ hybridization analysis was applied to desquamated cells from bladder washings obtained immediately before surgical resection. Cells were screened for numeric changes in chromosomes 7 and 9. Aberrations were identified in 38/54 patients eligible for evaluation. Although no clear associations were established owing to sample size, the results suggested that risk of progression/relapse was positively associated with loss of chromosome 9 and with polysomy, and negatively associated with gain of chromosome 7, the latter in contrast to published data. A short-term survival advantage was noted anecdotally with gain of chromosome 9.

Application of multiplex FISH, CGH and MSSCP techniques for cytogenetic and molecular analysis of transitional cell carcinoma (TCC) cells in voided urine specimens

Multiplex FISH (UroVysion), Comparative Genomic Hybridization (CGH), and Multitemperature Single-Strand Conformation Polymorphism (MSSCP) were applied for non-invasive diagnosis and prognosis of bladder cancer. The UroVysion test was positive in 80% of patients with pT1 and in 100% of patients with either pT2 or pT3 tumours. Tumours with pT3T4 stages were characterized by high numbers of chromosomal imbalances, detected by CGH. The mutation of the p53 gene was detected in 16% of patients, but only in those with pT2 or pT3 tumours.

Bladder cancer diagnosis and recurrence prognosis: Comparison of markers with emphasis on survivin

Expression of the anti-apoptotic protein survivin is hardly detectable or even absent in many differentiated adult tissues, but is upregulated in almost any type of cancer. Furthermore, high survivin mRNA or protein expression generally correlates with an adverse disease course. Both these important features of survivin expression have been investigated for diagnostic and prognostic purposes in many human cancers, including bladder cancer. In this review, the role of survivin in the detection of bladder tumors and the prediction of tumor recurrence in patients with superficial bladder cancer will be discussed and compared to that of other markers/tests. The most promising marker(s) will be outlined. Also, important requirements for a successful implementation of such markers in a hospital setting are discussed. Finally, future directions for the discovery of new diagnostic or prognostic candidate markers will be mentioned.

Combined analysis of morphology and fluorescence in situ hybridization significantly increases accuracy of bladder cancer detection in voided urine samples

OBJECTIVES

To evaluate a combined analysis approach that involves cytologic evaluation and fluorescence in situ hybridization analysis for detecting cancer cells in voided urine samples using an automated scanning station.

METHODS

Voided urine samples from 41 patients suspected of having transitional cell carcinoma were stained with May-Grünwald Giemsa stain, scanned for atypical or suspicious cells, destained, and hybridized with a mixture of fluorescent-labeled probes. Samples were tested using either the UroVysion probe or by a mix of chromosomes 3, 7, and 17 centromeric probes. A case was regarded as positive when at least one cell was abnormal in both aspects, morphology and fluorescence in situ hybridization. Patients were evaluated concomitantly by cytology, cytoscopy, and biopsy, if indicated.

RESULTS

Overall, 26 samples were positive by combined analysis. Biopsy-proven transitional cell carcinoma was positive by combined analysis in all cases (100%) and in 13 cases (61.9%) by cytology (P = 0.0133). The advantage of the combined analysis was noted mostly in low-grade and superficial tumors for which the sensitivity of cytology reached 30% (P = 0.023) and 27.27% (P = 0.0133), respectively. Specificity was 100%.

CONCLUSIONS

Our results have shown that combined analysis for the presence of transitional cell carcinoma cells is a powerful tool, providing high sensitivity and specificity, and may offer a new scheme for bladder cancer management.

Specific chromosome aberrations in peripheral blood lymphocytes are associated with risk of bladder cancer

Specific chromosome aberrations in peripheral blood lymphocytes (PBLs) in chromosomes 9 and 11 may be associated with bladder cancer. To investigate this hypothesis, in this study, we used a whole-chromosome painting technique to detect chromosomal aberrations in PBLs from 100 patients with bladder cancer and 100 matched controls. We also used a locus-specific fluorescence in situ hybridization technique to study 9p21 and cyclin D1 gene (CCND1) aberrations in PBLs of 10 patients and 10 controls and in tumor tissues of 38 additional cases. The chromosome-painting analysis showed that there were more aberrations of chromosomes 9 and 11 in bladder cancer patients than in controls. When categorized by type, the number of deletions of 9p and of translocations of chromosome 11 was significantly higher in patients than in controls (P < 0.05). Stratified analysis showed a larger odds ratio (OR) for bladder cancer in individuals with either a 9p deletion or a chromosome 11 translocation/amplification and an even larger OR in individuals with both aberrations. Using locus-specific analysis, we found that 9p21 aberrations occurred more frequently in bladder cancer patients (12.1 per 1,000 interphase cells) than in controls (6.4 per 1,000 interphase cells, P < 0.05); CCND1 translocation and amplification were observed only in bladder cancer patients. Tumor tissue analysis showed that aberrations of 9p21 (40.0 per 100 interphase cells) and CCND1 (43.8 per 100 interphase cells) were very common. Thus, we concluded that 9p deletions and translocations of chromosome 11, especially at 9p21 and CCND1, are associated with bladder cancer.

Correlation between histologic findings and cytogenetic abnormalities in bladder carcinoma: A FISH study

OBJECTIVES

To investigate the chromosomal abnormalities present in bladder carcinoma using a fluorescence in situ hybridization assay and to correlate the genetic findings with the pathologic grade and stage.

METHODS

Samples from 37 bladder carcinomas were obtained at cystectomy or transurethral resection. In all cases, a histologic evaluation and fluorescence in situ hybridization analysis were performed. Pericentromeric DNA probes for chromosomes 7, 8, 9, and 17, and locus-specific DNA-probes for the 9p21 and 9q34 bands, were used in the fluorescence in situ hybridization assay.

RESULTS

Grade 1-2 tumors were characterized by the loss of genetic material on chromosome 9 in 35.3% of cases and either no detectable alterations or multiple aneusomy events in 47.1% and 17.6% of the tumors, respectively. Polysomy was the most frequent occurrence in grade 3 and pT1-T4 carcinomas. No significant difference was found between the loss of 9p21, 9q34, or chromosome 9 and the different tumor classifications. A statistically significant difference was found in the frequency of polysomy between grade 1-2 and grade 3 tumors and between pTa and pT1-T4 tumors for chromosomes 7, 8, 9, and 17, as well as chromosome bands 9p21 and 9q34 (P <0.005).

CONCLUSIONS

These findings show that chromosome 9 losses do not correlate with the tumor grade or stage, but are the only aberrations found at a significant frequency in low-grade lesions. The results suggest that pT1 tumors are closely related to muscle-invasive tumors at the genetic level and show that polysomy of the chromosomes assessed correlates with high-grade and high-stage bladder carcinoma.

Alternatives to cytology in the management of non-muscle invasive bladder cancer

The natural history of non-muscle invasive bladder cancer is characterized by a high probability of recurrence and in the case of high-grade tumors, progression to muscle invasive cancer. This mandates a follow-up strategy designed to identify recurrences in the bladder early in their evolution in order to facilitate early intervention and ablation. Urine cytology is considered the gold standard urine biomarker. Although specificity exceeds 90% to 95%, its overall sensitivity ranges from 40% to 60% in expert hands and is both tumor grade and operator dependent. While cytology is an excellent test for detection of high-grade disease, the sensitivity is particularly weak for the detection of low grade tumors. This has spawned an entire field of research of in vitro diagnostic tests and cell-based assays in order to improve the diagnostic accuracy for detection of incident or recurrent disease. To date, the US Food and Drug Administration approved dipstick and immunoassays marketed as point-of-care tests. The point-of-care tests are intended for use as an adjunct to cystoscopy and cytology, and may have a role in the office evaluation of hematuria patients. Monoclonal antibody-based tests combined with cytology may improve the diagnostic accuracy and are superior to cytology alone. A recently approved cell-based assay, utilizing fluorescent in situ hybridization technology, may help resolve suspicious cytologies, and provide early and additional information about the biology of the bladder urothelium beyond that provided by cytology, a marker of disease relatively late in evolution. Novel promising markers are in various stages of clinical testing, and a panel of biomarkers may serve in the future as a feasible alternative to urine cytology and cystoscopy for the screening, detection, and follow-up of non-muscle invasive bladder cancer.

Fluorescence in situ hybridization performed on exfoliated urothelial cells in patients with transitional cell carcinoma of the bladder

OBJECTIVES

To evaluate comparatively fluorescence in situ hybridization (FISH) and cytology performed on exfoliated urothelial cells obtained from voided urine and bladder washings as a method of diagnosis and follow-up in patients with transitional cell carcinoma (TCC) of the bladder.

METHODS

Thirty patients with confirmed bladder TCC, 10 patients enrolled in cystoscopy follow-up for previous bladder tumors, and 10 patients with bladders free of tumor without a previous history of bladder TCC underwent cytologic examination and FISH performed on voided urine and bladder washing specimens. The FISH probes were targeted to chromosomes 7 and 9.

RESULTS

FISH had a sensitivity of 92% for high-grade tumors in both voided urine and bladder washing specimens, significantly greater than that of cytology at a sensitivity of 64% in voided urine and 67% in the bladder washing specimens (P = 0.02). The sensitivity of FISH and cytology were both low and not significantly different statistically from each other for the low-grade tumors. Monosomy of chromosome 9 correlated with early tumor recurrence. Polysomy of chromosomes 7 and 9 correlated with high-grade tumors (80% and 92%, respectively).

CONCLUSIONS

According to our results, with the local cytopathology expertise, FISH performed on urothelial cells from voided urine has a sensitivity that supersedes that of cytology, making the former a valuable complementary method in the diagnosis and follow-up of patients with bladder TCC.

Comparison of multitarget fluorescence in situ hybridization in urine with other noninvasive tests for detecting bladder cancer

OBJECTIVES

To present a single-centre study investigating aneuploidy at chromosomes 3, 7, 17 and 9p21 (e.g. loss at 9p21) using a multitarget fluorescence in situ hybridization (FISH) system, as identifying genetic alterations in urine specimens is a promising approach for the noninvasive detection of bladder cancer.

PATIENTS AND METHODS

Urine samples from 103 patients were evaluated, including those from 46 with histologically confirmed urothelial carcinoma, two with other urological malignancies, and 55 who acted as controls. The urine samples were taken before any manipulation. The validity of FISH (Urovision, Vysis, Downers Grove, Ill, USA) was compared with other noninvasive urine tests, including the BTA-Stat test, the nuclear matrix protein (NMP)-22 test, and immunocytology against 486p3/12 and LewisX. Those evaluating the tests were unaware of the clinical and histopathological data. FISH was considered positive if five or more urinary cells had gains of two or more chromosomes. The threshold for the urine tests were 10 U/mL (NMP-22), 30% positive cells (486p3/12), or 5% positive cells, respectively (LewisX).

RESULTS

The sensitivity was 69% (FISH), 67% (BTA-Stat), 69% (486p3/12), 96% (LewisX) and 71% (NMP22), respectively; the respective specificity was 89%, 78%, 76%, 33% and 66%.

CONCLUSION

Multitarget FISH had a better specificity than the other urine markers but because of its inadequate sensitivity it does not seem to be powerful enough to replace endoscopy. Optimizing the marker panel could provide a higher sensitivity.

Analytical and clinical evaluation of a new urinary tumor marker: bladder tumor fibronectin in diagnosis and follow-up of bladder cancer

Bladder cancer is the fourth most common malignant neoplasm in men and the tenth most common in women. Cystoscopy presents the gold standard for detection and monitoring of bladder cancer. However, it is an invasive and expensive procedure. Therefore, development of biomarkers for the purposes of screening, diagnosis and prediction of the prognosis in bladder cancer is required. Bladder tumor fibronectin is one of the new urinary tumor markers. The aim of this study is to evaluate the diagnostic performance of urinary bladder tumor fibronectin in detecting and monitoring bladder cancer. A total of 75 patients with the diagnosis of bladder cancer, 20 patients with the diagnosis of benign prostatic hyperplasia, 7 patients with the diagnosis of prostate cancer between the years 1996-2000, and 28 age-matched healthy individuals, were enrolled in the study. The patients were diagnosed by cystoscopy, with histopathological evaluation of the tumor, as having superficial or invasive bladder cancer. Patients were followed-up clinically with data pertinent to disease recurrence and progression. Bladder tumor fibronectin (BTF; ng/ml) was determined by solid phase, two-site chemiluminescent immunometric commercial diagnostic assay developed for the Immulite automated immunoassay system (Diagnostic Products Corporation, Los Angeles, CA, USA). All measured values were normalized by urinary creatinine, and the obtained data were evaluated by receiver-operating characteristics (ROC) curve analysis. Optimal cut-off was established at 43.4 ng/mg. This cut-off rendered overall sensitivities of 72% and specificity of 82.1%. The analytical evaluation of the BTF test displayed promising results in terms of a non-invasive in vitro test in the diagnosis of bladder cancer. Although it was not satisfactory in prediction of recurrence or progression of the disease, it correlated well with the stage, one of the most reliable prognostic factors. In conclusion, the urinary bladder tumor fibronectin test warrants further clinical evaluation.

How important is urinary cytology in the diagnosis of urological malignancies?

OBJECTIVE

To audit clinical usefulness of urine cytology examination in a subspecialised urological unit setting.

PATIENTS AND METHODS

Data from the hospital information support system on urinary cytology examinations carried out at one centre was audited over a period of 15 months. Source of urine cytology specimens, clinical profile of patients and the findings of urinary cytology were analysed and collated.

RESULTS

A total of 1400 urinary cytology specimen on 900 patients were requested during 15 months study period. Urologists requested 1092 (78%) and non-urologists (general practitioners, physician or general surgeons) requested 318 (22%) specimens. The majority of specimens, 1115 (80%) did not show any cytological evidence of malignancy. 83 specimens (6%) showed cytological evidence of malignant cells consistent with origin from a urothelial malignancy. Among this group 87% (72) were more than 50 years of age and 60 (72%) had history of gross heamaturia. 159 (11.35) cases were reported as being suspicious of malignancy or showing atypical cells requiring further evidence. A total of 43 (3.04%) specimens were poorly preserved or insufficient for diagnosis. The positivity rate amongst urologist and non-urologists request was 56% and 6% respectively (p=0.00001 value). The source in 37 (86%) specimens reported, as poorly preserved or insufficient for diagnosis was non-urologists compared to 6 (14%) from urologists with significant p value (0.00001).

CONCLUSIONS

Urinary cytology for malignant cells is a contributory investigation in the diagnosis of urological malignancy. It should be only ordered in the proper clinical situation.

Evaluation of chromosome 8 and 11 aneuploidies in washings and biopsy materials of bladder transitional cell carcinoma

We compared chromosome 8 and 11 aneuploidies on bladder biopsy tumor tissues and bladder washing samples of transitional cell carcinoma (TCC) and their relationship to tumor malignancy. Interphase fluorescence in situ hybridization (FISH) was applied to nuclei of washing material and biopsy samples of 17 patients with TCC. Incidence of cells having aneuploidy was clearly nonrandom from patient to patient. There was no significant difference in the incidence of aneuploid frequency for chromosomes 8 and 11 between biopsies of bladder tumors and bladder washing samples (P > 0.05). For chromosome 8, incidence of disomic cells (having two signals) in grade III tumors was significantly lower than in grade II tumors of both washing samples (P = 0.004) and biopsy materials (P = 0.005), indicating a high frequency of aneuploidy. The incidence of nuclei with four or more than four signals of chromosome 8 was significantly higher in grade III tumors than in grade II tumors in washing samples (P = 0.031 and 0.003, respectively). Similarly, in biopsy material, the incidence of nuclei with more than four signals of chromosome 8 was significantly higher in grade III tumors than in grade II tumors (P = 0.004). For chromosome 11, in both washing samples and biopsy materials, the incidence of disomic cells (having two signals) in grade III tumors was significantly lower than that detected in grade II tumors (P = 0.031 and 0.014, respectively), indicating a high frequency of aneuploidy. In biopsy materials, the incidence of nuclei with three or four signals was significantly higher than that in grade II tumors (P = 0.014 and 0.012, respectively). These findings suggest that FISH analysis of bladder washing samples can be effectively detected as genetic changes of bladder tumors. It might predict genetic progression of these tumors, which might be related to tumor stage, because higher stages of tumors showed a higher incidence of aneuploidies of chromosomes 8 and 11.

Are false-positive urine markers for the detection of bladder carcinoma really wrong or do they predict tumor recurrence?

INTRODUCTION AND OBJECTIVES

A problem in the interpretation of noninvasive urine tests for detection of bladder carcinoma is the finding of false-positive results. Several authors have described that patients with false-positive results are at high risk for tumor recurrence or progression. Only few data are available for comparing the clinical course of patients with false-positive test results and patients with true-negative results. We studied whether patients with false-positive results of various urine test had a higher recurrence rate than patients with true-negative results.

METHODS

Urine samples from 61 patients without evidence of active bladder carcinoma were included. Of the 61 patients, 51 had a history of bladder cancer, and 10 underwent transurethral resection for suspect of bladder carcinoma but had negative pathologic findings. Immunocytology (Lewis X and 486p3/12) was performed on bladder washings, and BTAstat and NMP22 were performed on urine samples.

RESULTS

During the follow-up period, 22 patients had one or more false-positive BTAstat test results, 25 patients had one or more false-positive NMP22 tests, 42 patients had at least one false-positive Lewis X test, and 11 patients had one or more false-positive 486p3/12 test. During a follow-up period of 3-39 months (median, 17.6 months) four patients expected a tumor recurrence. Among patients with false-positive urine test results 2 of 22 (9.1%, BTAstat), 2 of 25 (8%, NMP22), 4 of 42 (9.5%, Lewis X), and 3 of 11 (27.2%, 486p3/12) suffered from tumor recurrence. In contrast, among patients with true-negative test results 2 of 39 (5.2%, BTAstat), 2 of 36 (5.6%, NMP22), 0 of 18 (0%, Lewis X), 1 of 50 (2.0%, 486p3/12) had a tumor recurrence.

CONCLUSIONS

Patients with a false-positive urine test result do not generally have a greater risk of tumor recurrence or progression than patients with a true-negative result. In our series, only patients with false-positive 486p3/12 test result had a higher recurrence rate. Our findings do not justify a more aggressive adjuvant treatment or surveillance for patients with false-positive urine tests.

Detecting rare mutations associated with cancer risk

For more than a decade, investigators have been searching for a means of determining the risk of individuals developing cancer by detecting rare oncogenic mutations. The accumulation of mutations and the clonal evolvement of tumors provide opportunities for monitoring disease development and intervening prior to the presentation of clinical symptoms, or determining the risk of disease relapse during remission. A number of techniques, mostly polymerase chain reaction (PCR)-based, have been developed that enable the detection of rare oncogenic mutations within the range of 10(-2) to 10(-4) wild-type cells. Only a handful of procedures enable the detection of intragenic single base mutations at one mutant in 10-6 or better. These ultra-sensitive mutation detection techniques have produced some interesting results regarding single base mutation spectra and frequencies in p53, Harvey-ras, N-ras, and other reporter genes and DNA sequences in human tissues. Although there is evidence that some individuals may harbor cells or clones expressing genomic instability, the connection with the processes of carcinogenesis is still tenuous. There remains a need for rigorous epidemiological studies employing these ultra-sensitive mutation detection procedures. Since genomic instability is considered key to tumor development, the relevance of the detection of hypermutable clones in individuals is discussed in the context of cancer risk.

New diagnostic and prognostic tools in bladder cancer

Many efforts have been made to increase the detection rates and to predict the outcome of bladder cancer. Although to date cystoscopy remains the gold standard method for the detection of new or recurrent bladder cancer, its limitations were emphasized by the results of studies using fluorescence endoscopy that showed an increased detection rate and decreased recurrence after tumor resection. Urine cytology has high specificity and is used routinely as an adjunct to cystoscopy to detect invisible tumors. However, to improve on the low sensitivity of urine cytology, a number of marker tests have been developed. Optimal diagnostic accuracy appears to result from the synergistic combination of cytological markers with urine cytology. The evaluation of new and previously reported markers remains a very active field, but is still limited to inconclusive studies. Tissue and DNA microarrays represent a technological step forward for the analysis of a large number of markers and cohorts of patients that will be required definitively to establish the clinical utility of prognostic tests.

Can biological markers replace cystoscopy? An update

Cystoscopy is currently considered the gold standard for the detection of bladder tumors. The role of urine cytology in the initial detection and follow-up of patients is under discussion. New elaborative and rapid assays are available that may circumvent the low sensitivity and poor reproducibility of urine cytology. The methods that have been tested extensively are the nuclear matrix protein (NMP22) assay, the BTA stat assay, and the BTA TRAK enzyme-linked immunosorbent assay. Both outperform cytology in the detection of low-grade lesions. The specificity of both assays, however, lags behind that of cytology. The data from retrospective analyses are insufficient to justify clinical integration, and the need to replace cystoscopy with these novel assays remains to be proven.