Significance of the BTA test in bladder cancer: a multicenter trial. BTA Study Group Japan

Clinical evaluation of urine laminin-γ2 monomer as a potent biomarker for non-muscle invasive bladder cancer

BACKGROUND

To evaluate whether urine laminin-γ2 monomer (Ln-γ2m) offers a useful biomarker for patients with non-muscle-invasive bladder cancer (NMIBC).

METHODS

Participants comprised 297 patients, including 111 patients with NMIBC, 136 patients with benign genitourinary disease (BD) and 50 healthy donors (HD). Urine Ln-γ2m was prospectively measured and accuracy was analyzed. Receiver operating characteristic (ROC) curves were determined and area under the ROC curve (AUC) was calculated for urine Ln-γ2m, and compared to those of traditional urine tumor markers such as nuclear matrix protein 22 (NMP22), bladder tumor antigen (BTA) and cytology. The net benefits of combining urine markers were analyzed by decision curve analysis.

RESULTS

Mean urine Ln-γ2m was significantly higher in NMIBC than in BD or HD. The AUC for urine Ln-γ2m was significantly higher than those for urine NMP22, BTA or cytology when comparing NMIBC with HD. In patients with low-grade NMIBC, the AUC for urine Ln-γ2m was higher than the AUCs for NMP22, BTA or cytology. A net benefit of combined examination using urine Ln-γ2m/uCRN with NMP22 was demonstrated.

CONCLUSION

These results suggest urine Ln-γ2m as a potentially useful biomarker for NMIBC, particularly in cases of low-grade cancer.

Urinary laminin-γ2 is a novel biomarker of non-muscle invasive urothelial carcinoma

Lack of appropriate biomarkers has hampered early detection of urothelial cancer (UC), therefore, development of biomarkers for its diagnosis at earlier stages is of importance. Laminin‐332 (Ln‐332, formerly Ln‐5), a component of basement membranes, consists of Ln‐α3, Ln‐β3, and Ln‐γ2 polypeptides. However, monomeric Ln‐γ2 alone is frequently expressed in malignant neoplasms. If Ln‐γ2 is also expressed in UC and secreted into the urine, its detection could be useful for UC diagnosis. Here, we evaluated Ln‐γ2 levels from 60 patients with urinary diseases (including UC) by Western blotting, and detected it in approximately 53% of UC cases. Using immunohistochemistry, we confirmed Ln‐γ2 expression in UC tissues that were positive for Ln‐γ2, whereas Ln‐α3 expression was absent. We next developed a sandwich enzyme‐linked immunosorbent assay and applied it for screening 39 patients with non‐muscle invasive UC and 61 patients with benign urologic diseases. The Ln‐γ2 levels were higher in UC patients than in those with benign urologic diseases. Ln‐γ2 was detected even in patients with earlier stages of UC, such as Ta, T1, or carcinoma in situ. The sensitivity of Ln‐γ2 testing for UC was 97.4%, and the specificity was 45.9%, using a cut‐off of 0.5 μg/g∙crn. Ln‐γ2 had greater diagnostic value for detecting non‐muscle invasive UC compared to conventional urine cytology and available biomarkers for UC, and may be useful as a urine biomarker for the diagnosis and monitoring of UC.

Evidence-based clinical practice guidelines for bladder cancer (summary - JUA 2009 Edition)

In Japan, until now, the treatment of bladder cancer has been based on guidelines from overseas. The problem with this practice is that the options recommended in overseas guidelines are not necessarily suitable for Japanese clinical practice. A relatively large number of clinical trials have been conducted in Japan in the field of bladder cancer, and the Japanese Urological Association (JUA) considered it appropriate to formulate their own guidelines. These Guidelines present an overview of bladder cancer at each clinical stage, followed by clinical questions that address problems frequently faced in everyday clinical practice. In this English translation of a shortened version of the original Guidelines, we have abridged each overview, summarized each clinical question and its answer, and only included the references we considered of particular importance.

Detection of bladder tumours: role of cytology, morphology-based assays, biochemical and molecular markers

PURPOSE OF REVIEW

Cystoscopy is currently considered the gold standard for the detection of bladder tumours. The role of urine cytology in the initial detection and follow-up of patients is under discussion. Many efforts have been made to increase the detection rates and to predict the outcome of bladder cancer. In this subject review, a series of morphology-based, biochemical and molecular markers were compared with urine cytology for the detection of bladder cancer.

RECENT FINDINGS

Among the various markers reviewed, the average published sensitivity and specificity for the Bard tumour antigen test was 60 and 77%; for the nuclear matrix protein 22 test it was 67 and 72%; for the hyaluronic acid and hyaluronidase test it was 91 and 84%; for the ImmunoCyt it was 90 and 75%; for fluorescence in-situ hybridization it was 85 and 95%; for the telomerase assay it was 77 and 85%; and for the microsatellite assay it was 89 and 100%. DNA ploidy measurements, recent molecular markers and immunoassays designed to detect keratins, proteins, cell adhesion molecules, fibrinogen degradation products, and fibrinolysis markers were also included.

SUMMARY

As is clear from the brief summary of available assays, the optimal method of application is not yet clear. The integration of an assay into clinical practice takes more than just the documentation of its sensitivity and specificity. However, several of the procedures have received considerable support from urologists as assisting them in the management of their patients.

Detecting recurrent bladder cancer: new methods and biomarkers

In this review, a series of biomarkers and molecular assays are compared with conventional urothelial cytology in their ability to detect recurrent bladder cancer. The tests considered in detail include the BTA test, NMP 22 test, DNA ploidy measurements, telomerase determinations and microsatellite instability assays. Although all of these measurements show some degree of improvement for cancer detection, the microsatellite instability assay shows the highest sensitivity and specificity. Additional biomarkers considered in the review include bladder cancer tumor antigens, growth factors, cell adhesion molecules and various molecular markers including cell cycle regulatory genes and p53 mutations.

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.

The application of human complement factor H-related protein (BTA TRAK) in monitoring patients with bladder cancer

The BTA TRAK assay is a quantitative sandwich format enzyme immunoassay performed in a reference laboratory. It measures levels of human complement factor H-related protein (hCFHrp) which is similar to human complement factor H. Test characteristics reveal an overall sensitivity of 68% to 77.5% and a specificity of 50%-75%. Retrospective analysis of urine specimens employing hazard analysis suggests that BTA TRAK may have a role as a quantitative diagnostic marker in monitoring bladder cancer patients. Prospective studies are required to validate this application and other uses of the BTA TRAK assay in the management of bladder cancer patients.

Use of diagnostic categories in urinary cytology in comparison with the bladder tumour antigen (BTA) test in bladder cancer patients

In recent years the use of diagnostic categories for extragenital cytology has increasingly been discussed as an approach to improve the quality of reports. Diagnostic categories reflect the adequacy of the materials for interpretation and the presence or absence of cancer cells. There is a tendency to add intermediate groups as qualifying probably malignant cases or findings associated with a serious cancer risk. Since 1971 we have added one of the following to the final diagnosis in all cases: unsatisfactory for cytological diagnosis, negative for cancer, repeat test suggested, suspicious of cancer, and positive for cancer. To evaluate whether diagnostic categories are useful for comparison of cytological results with those of an alternative test, cytological data were compared with the results of the Bard bladder tumour antigen (BTA) test in voided urine from 119 patients (76 with and 43 without bladder cancer). The diagnostic categories enabled us to calculate sensitivities and specificities of cytology based on different thresholds or decision levels. The BTA test had significantly higher sensitivity (79%) and lower specificity (60%) than urinary cytology with three different thresholds in cytology results (sensitivities: 16-43%, specificities: 81-100%). The present findings suggest that diagnostic categories improve comparison of cytologic results with those of alternative screening and diagnostic aids such as the BTA test.