[Numerical aberrations of chromosomes 11 and 17 detected by fish--fluorescence in situ hybridization combined with cytology in exfoliated cells from voided urine in patients with urothelial carcinoma of the bladder].

Objectives: To study the use of FISH analysis for detecting the presence of numerical alterations of chromosomes 11 and 17 combined with cytology in exfoliated cells from voided urine as a method for diagnosis and follow-up in patients with urothelial carcinoma (UC) of the bladder.

Materials and Methods: During the period April 2005 till June 2006, three groups were studied. The first group included 15 patients without UC. The second group included 25 patients undergoing evaluation for suspected UC. The third group included 25 patients enrolled in cystoscopy follow-up for previous UC. All the patients underwent cystoscopy, cytologic examination and FISH analysis for centromeric probes 11 and 17 performed on voided urine. After diagnosing the bladder UC, the tumor was staged and graded according to the pathologic findings. The sensitivity and specificity of FISH and Cytology were assessed. Data were analyzed with t-test when comparing two groups, and using ANOVA test when comparing more than two groups. These statistical analyses were executed with statistical software PRISM version 4.03.

Results: The sensitivity of FISH when using the centromeric probes of chromosomes 11 and 17 was 95.2%. The specificity was approximately 94.4%. The monosomy, trisomy, and polysomy in the patients with UC were 95.2%, 78.6% and 35.7% (p < 0.05) respectively. FISH was positive in 92.3% (24/26) in low grade tumors and in 100% (16/16) in high grade tumors (p > 0.05). The sensitivity of cytology was 31%. The cytology was positive in 23% (6/26) in low grade tumors and in 43.8% (7/16) in high grade tumors (p < 0.05).

Conclusions: FISH analysis using centromeric probes of chromosomes 11 and 17 is an effective noninvasive method for the detection of altered chromosome numbers in bladder cancer cells in urine exfoliated cells. The sensitivity of FISH is higher than that of cytology in detecting UC. The combined analysis of FISH and cytology, does improve the accuracy of cytology but does not improve the specificity. Monosomy is the most prevalent numerical aberration found in patients with UC of the bladder. FISH analysis might give better results especially when cytology is negative. This method may help to decrease the frequency of cystoscopies in the follow-up of patients with confirmed bladder UC. Using multi-probe FISH test may improve the sensitivity. However, further studies are needed to confirm our results and conclusions.