Abstract: Application of Fluorescence in situ Hybridization in the Diagnosis of Urothelial CarcinomaYiWANG, Guang SUN, Xiaoqiang LIU, Yan SUN, Chenguang LI, ChangliWU, FanWANGCorrespondence to: Guang SUN, E-mail: soloriver@163.comDepartment of Urology, The Second Hospital of Tianjin Medical University, Tianjin Institute of Urology, Tianjin 300211, ChinaThis work was supported by Scientific Funds of Ministry of Public Health (WKJ2007-3-001)Abstract Objective: To detect chromosomal aneuploidy in the urine cells of patients with urothelial carcinoma and to evaluatethe results of fluorescence in situ hybridization ( FISH ) as a non-invasive diagnostic method for detecting urothelial carcinoma. Meth-ods: Fresh urine samples from 100 patients suspected of having urothelial carcinoma and 20 healthy subjects ( controls ) were collected,and urine cytology and FISH were conducted. Abnormalities on chromosome 3, 7, 17 and 9p21 ( p160 ) were found by FISH. Throughthe comparison and statistical analysis of the experimental results and pathology, the sensitivity and specificity of the two methods wereestablished, as well as a threshold for the difference between high and low-grade carcinoma. Results: Urine samples of patients withurothelial carcinoma have many more chromosomal abnormalities than samples from the control group. The sensitivity and specificityof urine cytology were 71% and 80%, respectively. The sensitivity and specificity of FISH were 88% and 80%, respectively ( P <0.01 ). The sensitivity of FISH was higher than urine cytology. The receiver operating characteristic ( ROC ) curve was drawn using thesensitivity and specificity data. The areas under the curve were 0.758 for urine cytology and 0.842 for FISH. Conclusion: FISH is avaluable and non-invasive detecting method for patients suspected of having urothelial carcinoma. The overall sensitivity of FISH ishigher than that of urine cytology, but the specificity of the two methods is similar.Keywords FISH; Urothelial carcinoma; Bladder cancer; Diagnosis; Sensitivity