Numerical Chromosome 17 Aberrations in Tumor Tissue, Tumor-adjacent Mucosa and Normal Bladder Mucosa of the Patients with Bladder Cancer Detected by in situ Hybridization

Jeong, Ho Hyeon; Kim, Dong Sun; Cho, Jae Heung

Abstract

PURPOSE: The purpose of this study is to obtain informations about the accumulation of genetic alterations during the urothelial tumorigenetic processes and to define the efficiency of the polysomy of chrosome 17 as a biomarker to predict the risk of tumor recurrences by observing the differences of numerical aberrations of chromosome 17 in tumor tissue, tumor adjacent mucosa and normal bladder mucosa of the patients with bladder cancer.
MATERIALS AND METHODS
In 20 patients with the superficial transitional cell carcinoma of the bladder, tumor tissue, mucosa adjacent to the tumor and normal mucosa distant from the tumor were biopsied. The obtained specimen were probed for numerical chromosome aberrations by nonisotopic, in situ hybridization using chrosome-specific centromeric DNA probes for chrosome 17. Normal bladder mucosa obtained from 9 patients with benign prostate hyperplasia were used as controls. Data obtained from the study were analysed according to the grade of tumor and recurrence status.
RESULTS
Frequency of numerical aberrations of chromosome 17 and average polysomy counts were 75%, 8.2% in cancer tissue, 40%, 4.5% in tumor adjacent mucosa and 35%, 4.2% in normal mucosa distant from tumor, which were all significantly higher than control(0%, 2.0%). Cancer tissue showed significantly higher polysomy counts in accordance with high grade(100% vs. 61.5%) and recurrence(100% vs. 54.5%) compared to low grade and no recurrence.
CONCLUSIONS
In patients with bladder cancer, tumor adjacent mucosa and endoscopically normal looking mucosa showed higher rate of numerical aberrations of chromosome 17. As cancer tissue showed different polysomy status in accordance with high grade and frequent recurrences, in situ hybridization to detect numerical aberrations of chromosome 17 may be used as a good prognostic marker for bladder cancer.