Background: It has been proven that epigermal growth factor receptor (EGFR) signal pathway plaied an important role in the oncogenesis and development of non-small cell lung cancer (NSCLC). EGFR tyrosine kinase inhibitors (EGFR-TKIs) are currently investigated in the treatment of NSCLC. It was suggested in previous studies that the EGFR gene mutations were correlated with the response to EGFR-TKIs therapy and prognosis of NSCLC. We studied the role of EGFR gene mutations in response to two kinds of TKIs therapy and prognosis of NSCLC in this study.
Methods: The tissue samples of 59 advanced NSCLC patients (34 patients receiving Gefitinib monotherapy and 25 patients receiving Erlotinib monotherapy) were collected, and patient charts were reviewed. The mutations in exons 19 and 21 of EGFR gene were detected by PCR-PAGE and PCR-RFLP respectively. The sequences of interested fragments were verified by direct sequencing. Relationship between EGFR mutation and response to TKIs therapy was analyzed with Chi-Square test.
Results: EGFR gene mutations were identified in 22 of 59 samples (37.3%). EGFR gene mutation rate was significantly higher in female, non-smoker and patients with adenocarcinoma than in others (50% vs 18.9%, P <0.05). The patients with EGFR gene mutation had a better response to TKIs therapy than those without (86.4% vs 54.1%,P <0.05). The patients with EGFR gene mutation had slower disease progression and longer overall survival than those without, but statistically non-significant (P >0.05).
Conclusions: EGFR gene mutation occurs more frequently in female, non-smoker and patients with adenocarcinoma. In patients with advanced NSCLC, EGFR mutation is associated with good response to EGFR-TKIs therapy.