[Correlation between EGFR gene mutation and high copy number and their association with the clinicopathological features in Chinese patients with non-small cell lung cancer]

Abstract

Objective: The purpose of this study was to investigate the correlation between gene mutation and gene copy number and their association with the clinical profiles and pathological features in Chinese patients with non-small cell lung cancer (NSCLC).

Methods: Surgical specimens of cancer tissue were collected from 118 NSCLC patients. Gene mutations in exon 19 and exon 21 were detected by real-time PCR and gene copy number was detected by fluorescence in situ hybridization (FISH). Chi-square (χ(2)) test was performed to analyze the correlation between EGFR mutation and gene copy number, and explore their association with clinicopathological features in the NSCLC patients.

Results: The mutation frequency in EGFR was 41.5% (49/118). EGFR mutations occured in 50.0% (48/96) of patients with adenocarinoma and 5.0% (1/20) of patients with squamous cell carcinoma. EGFR gene high copy number was detected in 70.3% (83/118)of the patients. The FISH-positive rate was 78.1% (75/96) in adenocarcinoma and 35.0% (7/20) in squamous cell carcinoma. EGFR mutation and high copy number mainly occurred in the adenocarcinoma, advanced stage, female gender, and non-smoking patients. There was a significant correlation between EGFR gene mutation and gene high copy number.

Conclusions: EGFR gene mutation and gene high copy number are more common in Chinese NSCLC patients with adenocarcinomas, advanced stage, non-smokers and females. There is a significant correlation between gene mutation and gene high copy number. Combined analysis of EGFR mutation and gene copy number by FISH may provide a superior approach in selecting patients who may benefit from anti-EGFR target therapy.