New diagnostic and prognostic tools in bladder cancer

Raman spectroscopy biochemical characterisation of bladder cancer cisplatin resistance regulated by FDFT1: a review

Bladder cancer is the fourth most common malignancy in males. It can present across the whole continuum of severity, from mild through well-differentiated disease to extremely malignant tumours with poor survival rates. As with other vital organ malignancies, proper clinical management involves accurate diagnosis and staging. Chemotherapy consisting of a cisplatin-based regimen is the mainstay in the management of muscle-invasive bladder cancers. Control via cisplatin-based chemotherapy is threatened by the development of chemoresistance. Intracellular cholesterol biosynthesis in bladder cancer cells is considered a contributory factor in determining the chemotherapy response. Farnesyl-diphosphate farnesyltransferase 1 (FDFT1), one of the main regulatory components in cholesterol biosynthesis, may play a role in determining sensitivity towards chemotherapy compounds in bladder cancer. FDFT1-associated molecular identification might serve as an alternative or appendage strategy for early prediction of potentially chemoresistant muscle-invasive bladder cancer tissues. This can be accomplished using Raman spectroscopy. Developments in the instrumentation have led to it becoming one of the most convenient forms of analysis, and there is a highly realistic chance that it will become an effective tool in the pathology lab. Chemosensitive bladder cancer tissues tend to have a higher lipid content, more protein genes and more cholesterol metabolites. These are believed to be associated with resistance towards bladder cancer chemotherapy. Herein, Raman peak assignments have been tabulated as an aid to indicating metabolic changes in bladder cancer tissues that are potentially correlated with FDFT1 expression.

Bladder cancer screening in aluminum smelter workers

Objective:

To present results of a bladder cancer screening program conducted in 18 aluminum smelters in the United States from January 2000 to December 2010.

Methods:

Data were collected on a cohort of workers with a history of working in coal tar pitch volatile exposed areas including urine analysis for conventional cytology and ImmunoCyt/uCyt+ assay.

Results:

ImmunoCyt/uCyt+ and cytology in combination showed a sensitivity of 62.30%, a specificity of 92.60%, a negative predictive value of 99.90%, and a positive predictive value of 2.96%. Fourteen cases of bladder cancer were detected, and the standardized incidence ratio of bladder cancer was 1.18 (95% confidence interval, 0.65 to 1.99). Individuals who tested positive on either test who were later determined to be cancer free had undergone expensive and invasive tests.

Conclusions:

Evidence to support continued surveillance of this cohort has not been demonstrated.

Contemporary diagnosis of bladder cancer

BACKGROUND

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

OBJECTIVE

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

METHODS

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

CONCLUSION

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

Expression of the polycomb group protein EZH2 and its relation to outcome in patients with urothelial carcinoma of the bladder

PURPOSE

The polycomb group protein Enhancer of Zeste Homolg 2 (EZH2), a repressor of gene transcription, has been linked to the progression of various malignancies. This study was done to examine a potential correlation of EZH2 mRNA expression with clinicopathological parameters and outcome in patients with urothelial carcinoma (UC) of the bladder.

METHODS

We determined the relative EZH2 gene expression by quantitative RT-PCR in tumor specimens from a cohort of 100 patients with UC (mean follow-up 44.2 months). EZH2 expression levels were correlated to pathological tumor features and outcome.

RESULTS

Enhancer of Zeste Homolg 2 was expressed in 90% of the tumor samples. Expression levels increased in parallel with tumor stage (P = 0.002). High grade UC displayed significantly elevated EZH2 levels compared to low grade disease (P < 0.0001). High EZH2 expression was related to an abbreviated time to recurrence in muscle invasive carcinomas (pT >/= 2) (P = 0.028). No such correlation was detected in the group of superficial tumors (pT </= 1) (P = 0.191). High EZH2 expression levels were associated with an increased risk of tumor related death in the univariate analysis (relative risk, 3.1; P = 0.029). This association became non-significant when the prognostic effect of tumor stage was considered in a multivariate model.

CONCLUSIONS

Enhancer of Zeste Homolg 2 expression is related to an aggressive tumor behavior but due to its strong association with pathological features, EZH2 levels do not provide independent prognostic information.

Discrimination between Nontumor Bladder Tissue and Tumor by Raman Spectroscopy

We have applied Raman spectroscopy to discriminate between nontumor and tumor bladder tissue and to determine the biochemical differences therein. Tissue samples from 15 patients were collected, and frozen sections were made for Raman spectroscopy and histology. Twenty-five pseudocolor Raman maps were created in which each color represents a cluster of spectra measured on tissue areas of similar biochemical composition. For each cluster, the cluster-averaged spectrum (CAS) was calculated and classified as tumor and nontumor in accordance to pathohistology. Unguided hierarchical clustering was applied to display heterogeneity between and within groups of nontumor and tumor CAS. A linear discriminant analysis model was developed to discriminate between CAS from tumor and nontumor. The model was tested by a leave-one-patient-out validation, 84 of the 90 CAS (93%) were correctly classified with 94% sensitivity and 92% specificity. Biochemical differences between tumor and nontumor CAS areas were analyzed by fitting spectra of pure compounds to the CAS. Nontumor CAS showed higher collagen content while tumor CAS were characterized by higher lipid, nucleic acid, protein, and glycogen content. Raman spectroscopy enabled effective discrimination between tumor and nontumor bladder tissue based on characterized biochemical differences, despite heterogeneity expressed in both tumor and nontumor CAS.

Integral spectrophotometric analysis of 5-aminolaevulinic acid-induced fluorescence cytology of the urinary bladder

OBJECTIVE

To evaluate whether tumour cells can be detected in bladder lavage fluid samples by an objective spectrofluorometric method, as 5-aminolaevulinic acid (ALA)-induced fluorescence endoscopy (AFE) and cytology are promising valuable tools for detecting transitional cell carcinoma of the urinary bladder (TCCB).

MATERIALS AND METHODS

After instilling ALA into the urinary bladder, lavage samples were collected and their sediments analysed spectroscopically under blue excitation at approximately 400 nm wavelength. During AFE, biopsies were taken. From 62 cases, 24 patients had a histologically confirmed TCCB (group A), 28 had a history of TCCB but no evidence of disease (group B) and 10 were negative for TCCB (group C).

RESULTS

Lavage sediments of all patients fluoresced in the green spectral range, typical of cellular autofluorescence. Sediments of all patients of group A caused red fluorescence peaking at 635 nm, indicating protoporphyrin IX (PPIX). The PPIX signals derived from bleaching spectra were significantly different between benign and malignant findings (P = 0.001). There was another red fluorescence peak at approximately 620 nm; in 19 cases its intensity exceeded the intensity of the PPIX signal.

CONCLUSIONS

Spectrofluorometric analysis of lavage sample sediments can be used to detect tumour-associated red fluorescence of PPIX in TCCB. Immediate significant and objective measurements are possible, which could be further automated for the rapid diagnosis of TCCB.

Urine cytology: appropriate usage maximizes sensitivity and reduces cost

OBJECTIVE

Urine cytology is costly because of the skilled manpower required for analysis. Inappropriate requests are a significant drain both financially and on the cytopathologist's time. The present study aimed at identifying the extent and cause of this misuse and reduce it.

METHODS

An audit of urine cytology usage was undertaken using the hospital results reporting system to identify requests. Patient case notes were then obtained to gain further clinical information. Initially a 2-week period was analysed, following which departmental guidelines for requesting urine cytology were produced and circulated. The audit loop was then closed.

RESULTS

Over the initial 2-week period, 117 urine cytology requests were received. Thirty-three per cent were inappropriate, either because they were from patients with benign disease or because of duplication. Following the education programme this number fell to 6%. Expenditure on unnecessary samples thus decreased from pounds 2418 to only pounds 310, giving an annual overall saving of pounds 55,000.

CONCLUSION

Significant cost and time savings can be made if urine cytology is sent appropriately. Simple guidelines and staff education are the key to reducing inefficiency. Our findings have implications not just for cytopathology costs but for laboratory and radiology requests in general.

Overexpression of human carcinoma-associated antigen in urothelial carcinoma of the bladder

CONTEXT

Human carcinoma-associated antigen (HCA) is a mucin protein whose level is increased in the sera of patients with a variety of carcinomas. We have previously shown that prostatic carcinoma overexpresses HCA in comparison to benign prostatic tissue. To our knowledge, expression of HCA in other tumors has not been reported previously.

OBJECTIVE

The current study was designed to determine if HCA is overexpressed in urothelial carcinoma (UCa) of the bladder.

DESIGN

Forty cystectomy specimens with UCa were selected, of which 27 cases had invasive UCa, 21 cases had a noninvasive component, and 36 cases had benign urothelium. Seven cystectomy specimens with benign conditions were chosen as controls. Anti-HCA monoclonal antibody HAE3 was used for immunohistochemical staining. Results were recorded as positive (> or =5% of cells staining and staining intensity 2+ or 3+) or negative (<5% of cells staining or staining intensity <2+) and analyzed using the Fisher exact test.

RESULTS

HAE3 staining was positive in 67% of invasive UCa, 29% of noninvasive UCa, but only 5% of benign urothelium specimens. The difference in HCA expression between benign urothelium and UCa and that between invasive and noninvasive UCa was statistically significant (P =.008). No statistically significant difference was found between low-grade and high-grade noninvasive papillary UCa (P =.06).

CONCLUSIONS

Human carcinoma-associated antigen is selectively overexpressed in a significant number of cases of UCa of the bladder, suggesting the potential utility of monitoring the serum and/or urine levels of HCA in monitoring patients with HCA-positive UCa for recurrence or progression.

DNA breaks as measured by the alkaline comet assay in exfoliated cells as compared to voided urine cytology in the diagnosis of bladder cancer: a study of 105 subjects

In this study we evaluated the clinical usefulness of identifying urothelial cells with increased DNA damage with the alkaline comet assay and compare it with voided urine cytology for the assessment of markers indicative of bladder cancer. The analysis was carried out on 105 subjects having clinical suspicion of bladder cancer, and who had undergone cytology for the first time. Urine cytology and alkaline comet assay were performed on the same fresh urine samples obtained from each patient. The subjects were divided according to negative or positive cytology. The Mann-Whitney U-test showed that the comet parameters (tail moment, tail length, and % of DNA in the tail) and the numbers of comets (cells with an arbitrary cut-off value of head intensity <90% of DNA content) in subjects positive in both tests were significantly higher than in the negative group. Sensitivity, specificity, and positive and negative predictive value of the comet assay were compared with those of cytology, which is regarded as the gold standard. Sensitivity was 71.4%, specificity was 91.8%, positive and negative predictive values were 38.5 and 97.8, respectively. Two subjects negative in the comet assay were positive in cytology. Eight patients were positive in the comet assay and negative for cytology. Interestingly, one of these eight patients was later found positive for cytology. Logistic regression analysis indicates that the tail moment is significantly associated with an increased risk for positive cytology.

Impact of proteomics on bladder cancer research

Detecting bladder cancer at an early stage and predicting how a tumor will behave and act in response to therapy, as well as the identification of new targets for therapeutic intervention, are among the main areas of research that will benefit from the current explosion in the number of powerful technologies emerging within proteomics. The purpose of this article is to briefly review what has been achieved to date using proteomic technologies and to bring forward novel strategies – based on the analysis of clinically relevant samples – that promise to accelerate the translation of basic discoveries into the daily clinical practice.

Fluorescence cytology of the urinary bladder

OBJECTIVES

To assess, on the basis of the tumor-associated fluorescence characteristics of 5-aminolevulinic acid-induced fluorescence endoscopy, the value of fluorescence microscopy and compare it with standard cytologic techniques. 5-Aminolevulinic acid-induced fluorescence endoscopy has proved to be a valuable detection method with a high sensitivity for the endoscopic diagnosis of bladder cancer.

METHODS

We instilled 1.5 g of 5-aminolevulinic acid, dissolved in 50 mL of 5.7% sodium monohydrogen phosphate, into the urinary bladder of 162 patients with suspected transitional cell carcinoma 2 to 3 hours before endoscopy. A lavage solution was obtained for urinary cytology and for fluorescence cytology. The sediments were evaluated for tumor cells.

RESULTS

Transitional cells suspicious for tumor demonstrated the red 5-aminolevulinic acid-induced protoporphyrin IX fluorescence under the microscope. Fluorescence cytology identified 50 of 58 histologically confirmed neoplastic lesions (G1, 14 of 17; G2, 12 of 14; G3, 15 of 16; and carcinoma in situ, 9 of 11). With urinary cytology, we identified 46 of 58 histologically confirmed tumor lesions (G1, 9 of 17; G2, 12 of 14; G3, 15 of 16; and carcinoma in situ, 10 of 11). The sensitivity of fluorescence cytology was 86% and that of urinary cytology 79%. The specificity of fluorescence cytology was 75% and that of urinary cytology 88%.

CONCLUSIONS

Fluorescence cytology promises to be an effective procedure for the diagnosis of bladder cancer, especially in highly differentiated and flat premalignant tumor lesions. Automated analysis for an objective and a reproducible result appears possible.