The Research On The Application Of Fluorescence In Situ Hybridization In Chromosome 3 And 7 In Diagnosis Of Urinary Bladder Cancer

Objective: We evaluate the fluorescence in situ hybridization (FISH) assay for the diagnosis of bladder cancer in patients with hematuria through comparing the sensitivities and specificities of FISH and cytology for the detection of urinary bladder cancer.Materials and Methods: A total of 100 patients with gross or microscopic hematuria with suspected transitional cell cancer of bladder (BTCC), collected from urology department of the second hospital of Hebei Medical University from April 2008 to December 2008, were included in the study, including 24 with a history of urinary bladder cancer and 76 without a history of urinary bladder cancer. A total of 93 patients was diagnosed histologically with transitional cell cancer of bladder or upper urinary tract,staging pT_is/pT_a (22 cases), pT₁(52 cases), pT₂(14 cases) and pT₃/pT₄(5 cases). Also we collected 20 healthy controls. Fluorescence in situ hybridization (FISH) is a technique that uses fluorescently labeled DNA probes to detect chromosomal alterations in cells. FISH can detect various types of cytogenetic alterations including aneusomy (ie, abnormalities of chromosome copy number), duplication, amplification, deletion, and translocation. A mixture of fluorescent labled probes to the centromeres of chromosomes 3 and chromosomes 7 was used to detect urinary cells for chromosomal abnormalities. From counting 100 cells each of 20 healthy controls, We definite the threshold of chromosomal abnormalities. The chromosomal results of 100 patients were difined through comparing with the threshold. A positive result was defined when 3 and 7 chromosomal abnormalities exist simultaneously or amplification and deletion occur in the same chromosome. Also Urine specimens from 100 suspected patients with BTCC were analyzed by means of cytology. Sensitivity and specificity of both techniques were determined and compared. Voided urine was sent to a central laboratory for each study before cystoscopy. Suspicious lesions on cystoscopy were biopsied or resected. A centrally reviewed histopathological interpretation was used to confirm cancer and assign grade and stage.Results: The sensitivity of FISH for pT_is/pT_a ( 22 cases) , pT₁(52 cases),pT₂(14 cases) and pT₃/pT₄(5 cases) tumors were 59.10 %, 90.38 % ,92.86% and 100%,respectively. The sensitivity of urine cytology for pT_is/pT_a (22 cases), pT₁(52 cases),pT₂(14 cases) and pT₃/pT₄(5 cases) tumors were 22.72 %, 38.46 % ,78.57% and 100%, respectively. Overall sensitivity for FISH was significantly higher than the corresponding value for urine cytology (83.87% vs. 44.09%, respectively, p < 0.0001). Specificities for FISH and cytology were 85.71% and 100%, respectively (p >0.05).Conclusion: The fluorescence in situ hybridization(FISH) assay is significantly more sensitive than voided cytology for detecting bladder cancer in patients evaluated for all stages while maintaining a similar specificity. The non-invasive nature of this method and its higher sensitivity could contribute to improving the current diagnosis and screening of urinary bladder cancer.