We investigated somatic mutations of the epidermal growth factor receptor gene in non-small cell lung cancer tumor tissue and their detection using real-time polymerase chain reaction with TaqMan-MGB probes.
Methods: The DNA was extracted from surgically resected non-small cell lung cancer tumor specimens. Genes encoding for epidermal growth factor receptor tyrosine (exons 18, 19, and 21) were amplified by nested polymerase chain reaction, sequenced, and analyzed by chromatograms with manual review. TaqMan-MGB probes were designed to detect the epidermal growth factor receptor gene mutations in the tumor tissues using real-time polymerase chain reaction.
Results: Somatic point mutations and deletions were identified in the tyrosine kinase domain of the epidermal growth factor receptor gene in 21 of 80 non-small cell lung cancer patients, including 13 patients with deletion mutations occurring in exon 19 and 8 patients with point mutations occurring in codon 858 (exon 21). The results from real-time polymerase chain reaction with TaqMan-MGB probes were completely consistent with sequencing outcomes. Both the sensitivity and specificity for detecting the epidermal growth factor receptor gene mutations using real-time polymerase chain reaction with TaqMan-MGB probes were 100%. The mutation incidence was significantly higher in female patients, nonsmokers, and patients with adenocarcinoma than in male patients, smokers, and those with nonadenocarcinomas (P < 0.05). The mutations were not related to patient's age or tumor nodal metastasis staging.
Conclusions: Somatic mutations of the epidermal growth factor receptor gene that develop in non-small cell lung cancer patients are more common in female patients, nonsmokers, and patients with adenocarcinoma. Real-time polymerase chain reaction using TaqMan-MGB probes is effective, simple, and fast in the detection of epidermal growth factor receptor gene mutations.