Examination of Diagnostic Accuracy of UroVysion Fluorescence In Situ Hybridization for Bladder Cancer in a Single Community of Japanese Hospital Patients

Objective: UroVysion (Abbott Molecular, Inc., Illinois, USA) is based on multicolor fluorescence in situ hybridization (FISH). It has been used successfully in the USA following its Food and Drug Administration approval in 2001. However, the technology was not approved for use in Japan until 2017. Cystoscopy and urine cytology are the most frequently used examinations to detect bladder cancer in Japan, and there are only a few reports regarding the performance of UroVysion. Therefore, the aim of this study is to examine the diagnostic accuracy of UroVysion FISH in Japanese patients whose tumors are detected by cystoscopy before transurethral resection of bladder tumor (TURBT). Methods: From April 2018 to July 2018, a total of 40 patients who were diagnosed as having bladder tumors by cystoscopy, and therefore underwent TURBT were registered in this study. One day before TURBT, urine cytology and UroVysion FISH were used in order to compare the accuracy with which they could detect bladder carcinoma, as confirmed by pathological results of TURBT. Results: The pathological results of TURBT showed urothelial carcinoma in 33 cases. Urine cytology showed positive results for 0 cases (0%), suspicious results for 10 cases (30.3%), and negative results for 23 cases (69.7%). On the other hand, UroVysion FISH indicated 9 positive cases (27.3%) and 24 negative cases (72.7%). There were 19 cases of urothelial carcinoma (57.6%) that were not detected by either method. Conclusion: We conclude that UroVysion FISH alone is insufficient to detect bladder cancer and that cystoscopy is essential for the optimum detection or follow up of bladder cancer cases in our hospital.


Introduction
The global incidence of bladder cancer is 429,793 cases per year, and it is considered an international health problem (Mahdavifar et al., 2016), requiring an accurate diagnostic method. The standard diagnostic tools in Japan are cystoscopy and urine cytology. These tests are problematic, as cystoscopy is invasive, and urine cytology lacks sensitivity. The UroVysion test is based on multicolor fluorescence in situ hybridization (FISH) and is able to detect aneuploidy of chromosomes 3, 7, and 17, and the deletion of the 9p21 locus (Halling et al., 2000). It is reported that UroVysion FISH is superior in terms of sensitivity and is inferior in terms of specificity in a meta-analysis (Hajdinjak, 2008) and it has been used successfully in the USA following its FDA approval in 2001. As per the American Urological Association guidelines, UroVysion FISH has been approved for assessing responses to intravesical Bacillus

Examination of Diagnostic Accuracy of UroVysion Fluorescence
In Situ Hybridization for Bladder Cancer in a Single Community of Japanese Hospital Patients Takashi Nagai 1 , Takehiko Okamura 1 *, Takahiro Yanase 1 , Ryosuke Chaya 1 , Yoshinobu Moritoki 1 , Daichi Kobayashi 1 , Hidetoshi Akita 1 , Takahiro Yasui 2 Calmette-Guerin therapy and for determining the correct cytologies. As per the European Association of Urology guidelines, urinary biomarkers are recommended for use in detecting invisible tumors, particularly carcinoma in situ (CIS). In Asian countries, the indications for the use of UroVysion FISH have not been established. Moreover, there are few reports regarding the performance of UroVysion in Japan, since approval was just granted in 2017. Here, we examined the diagnostic accuracy of UroVysion FISH in patients whose tumors were detected by cystoscopy before transurethral resection of bladder tumor (TURBT).

Materials and Methods
From April 2018 to July 2018, a total of 40 patients who were diagnosed as having bladder tumors by cystoscopy, and therefore underwent TURBT were registered in Anjo Kosei Hospital, Anjo, Japan. One day before TURBT, urine cytology and UroVysion (UroVysion Bladder Cancer Kit; Abbott Molecular, Inc., Des Plaines, Illinois) were used in order to compare the accuracy with which they could detect bladder tumors. Surgically resected materials were routinely fixed in 10% buffered formalin and embedded in paraffin for sectioning and histopathological assessment of hematoxylin and eosin-stained sections. Tumor grading and staging were performed with reference to the eighth edition of the Union for International Cancer Control tumor-nodes-metastases staging classification. Urine cytology was examined by one experienced pathologist and pathological results of TURBT were examined by one of two experienced pathologists in our hospital. Multivariate analyses were conducted with logistic regression analysis. A value of p<0.05 was considered as statistically significant. All the statistical analyses were performed using EZR.
The research was performed under approval of the institutional review board of Anjo Kosei Hospital (review board number: R18-060), and all patients provided informed consent.

Results
The pathological results of TURBT showed urothelial carcinoma in 33 cases, including one case each of sarcomatoid variant and lymphoma-like variant carcinoma. There was one case of inverted papilloma, and no malignancy in the remaining 6 cases. Patient characteristics and tumor characteristics are shown in Table 1 and Table 2.
The results of urine cytology and UroVysion are shown in Table 3. Urine cytology before TURBT showed positive results for 0 cases (0%), suspicious results for 10 cases (30.3%), and negative results for 23 cases (69.7%). On the other hand, UroVysion before TURBT indicated 9 positive cases (27.3%) and 24 negative cases (72.7%). There were 19 cases (57.6%) of urothelial carcinoma that were not detected by either method. The sensitivity of urine cytology and UroVysion are 30.3% and 27.3% respectively. The specificity of urine cytology and UroVysion are both 100%. The positive predictive value of both urine cytology and UroVysion are 100%, and the negative predictive value of urine cytology and UroVysion are 23.3% and 22.6%.
The multivariate logistic regression analysis for UroVysion FISH positivity is shown in

Discussion
The standard method for diagnosing bladder cancer in Japan is cystoscopy and urine cytology, even though cystoscopy is not ideal because it is invasive, and the sensitivity of urine cytology is not optimal. Accurate and non-invasive examinations are needed for diagnosing non-muscle invasive bladder cancer (NMIBC). We selected UroVysion FISH for evaluation, as it is one of the reliable urinary markers but there are few reports on its use in the Japanese population.
The literature regarding the effectiveness of UroVysion FISH is varied. Fritsche et al., (2010)     This study could not demonstrate the superiority of UroVysion FISH over urine cytology for the detection of bladder cancer in our hospital. Our study suggests that the detection rate of bladder cancer is equivalent when either urine cytology or UroVysion FISH is used. There are some limitations in this study. Firstly, the sample size of this study was small. Second, the subjects had a heterogenous background. These limitations might contribute to our study results indicating lower sensitivity than previous studies.
In conclusion, combined urine cytology and UroVysion FISH detected almost 40% of urothelial carcinoma cases, but 60% of the cases were not detected. We conclude that UroVysion FISH alone is insufficient to detect bladder cancer, and that cystoscopy is essential for the optimum detection or follow up of bladder cancer cases in a real-world setting. The impact of the UroVysion FISH in clinical practice is limited and almost same result to urine cytology in this study. Combination of UroVysion FISH and urine cytology is considered a feasible method for the detection of NMIBC.

Statement conflict of Interest
The authors declare no conflicts of interest.