Study of C-MYC amplification and expression in Iranian gastric cancer samples using CISH and IHC methods.
BACKGROUND
Gastric cancer is the fourth most frequent malignancy and the second cause of cancer-related mortality worldwide. It has been suggested that in gastric carcinogenesis, the C-MYC gene has an important function. The objective of this study is to establish the preference of Chromogenic in situ hybridization (CISH) and Immunohistochemistry (IHC) in the diagnosis and prognosis of gastric cancer.


METHODS
Samples comprised of 50 randomly selected patients of whom 40 were male and 10 female. To evaluate the MYC copy number and its protein expression, CISH and IHC analyses were performed for 50 gastric adenocarcinomas, in Iran.


RESULTS
The location of the tumor in 64% of the patients was the fundus, and in 72% of patients, the tumors were of a diffuse type; 22 samples showed no amplification, and 28 samples were with amplification. MYC immunoreactivity was observed in 13 samples. Twelve samples showed both MYC amplification and MYC immunoreactivity. In addition, among the 28 CISH+ samples, 12 samples had positive signals for IHC and 16 samples had negative signals for IHC. A majority of the IHC-negative patients had no amplification, but only one patient with IHC positive had no amplification.


CONCLUSIONS
Our conclusion was that for the management and treatment of gastric cancer, and for special attention of clinicians, for prognosis and tumor progression, the CISH was a better and more feasible test than IHC, in regard to the sensitivity and specificity.
Department of Medical Genetics, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran.
Malihea
M
Khaleghian
Department of Pathology, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran.
Issa
I
Jahanzad
Department of Medical Genetics, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran.
Abbas
A
Shakoori
Department of Pathology, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran.
Farid Azmoudeh
FA
Ardalan
Department of Medical Genetics, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran.
Cyrus
C
Azimi
Cancer; Chromogenic in situ hybridization; Immunohistochemistry; MYC gene; MYC oncogene; MYC protein; gastric adenocarcinoma; gene amplification