J. Ohta et al., Fluorescence in situ hybridization evaluation of c-erbB-2 gene amplification and chromosomal anomalies in bladder cancer, CLIN CANC R, 7(8), 2001, pp. 2463-2467
Oncogene amplification and chromosomal anomalies are found in many solid tu
mors and are often associated with aggressiveness of cancer. We evaluated t
he frequency and the role of c-erbB-2 gene amplification, relative increase
in c-erbB-2 gene copy number, and gain of chromosome 17 in bladder cancer.
A total of 29 bladder cancer specimens were examined using fluorescence in
situ hybridization (FISH). Dual labeling hybridization with a directly lab
eled centromere probe for chromosome 17 together with a probe for the c-erb
B-2 locus was performed. c-erbB-2 gene amplification was found in 3.4% (1 o
f 29) of specimens. Relative increase in c-erbB-2 gene copy number was foun
d in 41.4% (12 of 29) of specimens and was significantly associated with tu
mor grade (P = 0.044 by Fisher's exact test). Gain of chromosome 17 was ide
ntified in 65.5% (19 of 29) of specimens and was significantly associated w
ith tumor grade (P = 0.002 by Fisher's exact test) and tumor stage (P = 0.0
03 by Fisher's exact test). Our results suggest that cerbB-2 gene amplifica
tion, relative increase in c-erbB-2 gene copy number, and gain of chromosom
e 17 may play important roles in the development and progression of bladder
cancers. Moreover, the use of c-erbB-2 amplification, relative increase in
c-erbB-2 gene copy number, and gain of chromosome 17 using FISH, together
with tumor grade and stage, may provide a more useful clinical indicator in
bladder cancer.