Fluorescence in situ hybridization identifies more aggressive types of primarily noninvasive (stage pTa) bladder cancer

Purpose: We evaluated the genetic changes in cytological specimens of bladder cancer by fluorescence in situ hybridization, and related them to stage and grade of the tumor, ploidy, p53 and Ki-67 expression, and clinical outcome to determine a simple method to identify tumors with a poorer prognosis. Materials and Methods: Using fluorescence in situ hybridization the numerical aberrations of chromosomes 7, 9 and 17 in barbotages and imprints of 50 patients with transitional cell cancer of the bladder were determined. Of the patients 29 had a primary stage pTa tumor, while 21 with stage pT1 or greater disease formed the control group. Data were compared to ploidy status, and Ki-67 and p53 immunoreactivity. Results: Repeated monosomy 9 and haploid or diploid status on static ploidy determination were found in patients with primary stage pTa tumors without recurrence. Immunoreactivity of p53 was negative in all of these patients, while there was a low percentage of positive staining for Ki-67. Patients with recurrent and progressive disease had a high incidence of trisomy 7 and 17, aneuploid status and high positivity for both immunological markers. For chromosomes 7 and 17, and ploidy status bivariate analysis showed a significant difference. Conclusions: The evaluation of chromosomal aberrations in barbotage and imprint specimens clearly establishes a relationship between chromosomal defects and aggressiveness of the tumor. The majority of nonaggressive stage pTa transitional cell carcinomas can be distinguished from potentially lethal cases by fluorescence in situ hybridization at a diagnostic point when the grading is not yet prognostic.