Utility of fluorescence in situ hybridization analysis for detecting upper urinary tract-urothelial carcinoma

The objective of this study was to evaluate the clinical utility of fluorescence in situ hybridization (FISH) in the detection of upper urinary tract-urothelial carcinoma (UUT-UC).

Between November 2011 and November 2015, voided urine specimens from 52 consecutive patients with UUT-UC and 26 controls were collected for both FISH test and cytology. Sensitivity and specificity of FISH test and cytology were determined and compared. The frequency of chromosomal aberrations was also analyzed.

For FISH analysis, the sensitivity was 79.5% and specificity was 96.3%. For cytology, the sensitivity was 27.3% and specificity was 100%. The overall sensitivity for FISH was significantly higher than that of in single value-based urine cytology (79.5% vs. 27.3%, respectively, P < 0.001). The sensitivities of FISH and cytology by grade were 64.3% vs. 28.6% for low-grade urothelial carcinomas (P = 0.128) and 86.7% vs. 26.7% for high-grade urothelial carcinomas (P < 0.001), respectively. Twenty-seven (77.1%) cases were positive due to the gain of two or more chromosomes in five or more urinary cells, among which, 21 (60%) cases showed positivity in all the 4 chromosomes, 7 (20%) cases matched the criterion that 10 or more cells gained a single chromosome, whereas only 1 (2.9%) case was positive because of the homozygous deletion of 9p21 in 12 or more cells.

FISH has superior sensitivity and similar specificity in the detection of UUT-UC, compared with cytology. The present findings indicated that FISH can be applied as a noninvasive diagnostic tool for suspected UUT-UC patients.