Prospective evaluation of FISH for detecting upper tract urothelial carcinoma in voided urine specimens.

The aim of the present study was to estimate the diagnostic value of fluorescence in situ hybridization (FISH) analysis of tumor cells in voided urine specimens for detecting upper tract urothelial carcinoma (UTUC). Cytology and FISH analyses were conducted on voided urine collected in the morning from 125 patients with suspected UTUC. During follow-up, ureteroscopy with biopsy and histopathology were used to confirm the presence of tumors. The average follow-up time was 23.8 months (range, 6-36 months). A total of 8 patients who could not be contacted until the last follow-up were excluded from the study. Of the remaining 117 patients, 19 were histologically demonstrated to have UTUC, of whom, 3 patients had stage pTis disease, 6 had stage pTa disease, 5 had stage pT1 disease and 5 had stage pT2 disease (7 G1, 8 G2 and 4 G3). The overall sensitivity of FISH to detect UTUCs in voided urine specimens was 84.21% (16/19), whereas that of cytology was 42.11% (8/19) (P<0.05). The overall specificity of FISH to detect UTUCs in voided urine specimens was 89.80% (88/98), compared with 94.90% (93/98) of cytology (P>0.05). The positive predictive value (PPV) and negative predictive value of FISH were 80.00% (16/20) and 97.78% (88/90), respectively, whereas those of cytology were 100.00% (8/8) (P>0.05) and 90.29% (93/103) (P>0.05), respectively. The present data indicated that FISH was a method capable of detecting UTUCs in voided urine specimens with good sensitivity and specificity, although it exhibited a high rate of false positivity and low PPV.