Objective   To evaluate the possibility and validity of detecting numerical aberration of chromosomes 3

7

9 and 17 by fluorescence in situ hybridization (FISH) in order to diagnose urothelial carcinoma of bladder in Chinese.    Methods   A total of 140 volunteers were recruited as subjects，including 80  hematuria patients suffering from bladder urothelial carcinoma

30 hematuria patients with benign bladder diseases

and 30 healthy individuals. Exfoliated cells from fresh urinary specimen was collected and examined by FISH using centromeric probes of chromosome 3

7

17 and region probe of 9p21. Cytology and transabdominal ultrasonography (US) was applied at the same time and all of the patients were definitely diagnosed by cystoscopy and biopsy. The sensitivity and specificity of each method in the diagnosis of bladder cancer were determined by comparative analysis.    Results   Among the 80 subjects in tumor group which were verified with pathology

68 patients showed positive by FISH

28 were positive by urine cytology

and 71 were positive by US. In non-tumor control group of 30 cases

29 showed negative and 1 false-positive by FISH

all negative by urine cytology

23 negative and 7 false-positive by US. The sensitivity and specificity of FISH，urine cytology and US on detecting bladder cancer were 85.00%

32.50%

88.75%

and 96.67%

100.00%

76.67%

respectively.    Conclusion   The sensitivity and specificity of FISH detecting 3，7，9，17 chromosome aberrations are high in the diagnosis of bladder cancer. It can be used as an effective method for assistance diagnosis of bladder cancer.