Comparison of gefitinib as first- and second-line therapy for advanced lung adenocarcinoma patients with positive exon 21 or 19 del epidermal growth factor receptor mutation

摘要

Objectives: Gefitinib, a tyrosine kinase inhibitor (TKI) targeting epidermal growth factor receptor (EGFR), shows excellent clinical benefit in treating advanced non-small-cell lung cancer (NSCLC). The aim of this study was to compare the efficacy and toxicity of gefitinib as first-line therapy and second-line therapy for advanced lung adenocarcinoma patients with positive exon 21 (L858R) or exon 19 deletion of EGFR mutation. Methods: We retrospectively analyzed the clinical data of 60 EGFR -mutated advanced lung adenocarcinoma patients from July 2011 to November 2015 who have received oral gefitinib 250?mg once daily. Gefitinib was taken until disease progression, intolerable toxicity or death. Results: After a median follow-up of 792?days, one death had occurred. Among the 59 patients who survived, 17 patients progressed. Overall, the median progression-free survival (mPFS) was 10?months (95% confidence interval [CI]: 7.53–12.46?months, p <0.05). The response rate (RR) and disease control rate (DCR) were 33.33% and 71.66%, respectively. However, there was longer mPFS in the first line-therapy than that in the second-line therapy: in the first-line gefitinib therapy, mPFS was 12?months among 41 patients (95% CI: 9.58–14.41?months, p <0.05), and in the second-line therapy, mPFS was 7?months among 19 patients (95% CI: 1.31–12.68?months, p <0.05). Furthermore, in subgroup analyses examining different EGFR mutation types, we noted that mPFS was significantly longer for patients with exon 19 deletion than for those with positive exon 21in both the first-line therapy and second-line therapy. Conclusion: Patients with advance lung adenocarcinoma who were selected by positive exon 21 or 19 deletion mutations had significantly longer mPFS in the first-line therapy than that in the second-line therapy when treated with gefitinib. EGFR mutation types may influence the response to gefitinib therapy.