Screening of Epidermal Growth Factor Receptor Gene Mutation in Non-Small Cell Lung Cancer Using a PCR-Based Enzymatic Digestion Method

ABSTRACT

PURPOSE: We applied a simplified method using polymerase chain reaction (PCR)-based enzymatic digestion for the detection of epidermal growth factor receptor (EGFR) mutation. MATERIALS AND METHODS: We selected 74 samples of adenocarcinoma of the lung with EGFR exons 19 and 21 that had been previously sequenced. We designed PCR primers and chose a DNA restriction enzyme. Seventy four additional lung cancer samples were tested as a test set. For test sets, the PCR-based method was performed first, followed by validation of the result by DNA sequencing. RESULTS: In the first sample group, we found 15 (20.3%) mutations in exon 19, and 9 (12.2%) mutations in exon 21 using the sequencing method. By using the PCR-based method, we were able to identify all of the mutated samples detected by the sequencing method. The PCR-based method also detected mutations in exon 19 in three additional samples and in exon 21 in one additional sample. In the second sample group, by performing the PCR-based method, we found 10 (13.5%) and 7 (9.5%) mutations in exons 19 and 21, respectively. Additional mutations in exon 19 were identified in 2 samples by the sequencing method. However, the sequencing method failed to identify a mutation in exon 21 in one sample. CONCLUSION: The sensitivity of the PCR-based enzymatic digestion method seems to be comparable to that of the traditional sequencing method for detecting EGFR mutations. Our method can be widely used as a screening test to select patients who may benefit from EGFR targeted therapy.