근치적 방사선 치료 후 재발한 상피성장인자 수용체 돌연변이 비소세포폐암 환자에서 상피성장인자 수용체 티로신 키나아제 억제제의 효과

Abstract

Background For patients with recurrent EGFR mutant non-small cell lung cancer (NSCLC), EGFR tyrosine kinase inhibitor (TKI) is the standard therapy. In this study, we evaluated efficacy of EGFR TKI in EGFR mutant NSCLC patients who recurred after definitive radiotherapy (RT) or concurrent chemo-radiation therapy (CCRT) by comparing with those who recurred after surgical resection. Methods Patients with diagnosis of EGFR mutant NSCLC who received EGFR TKI after recurrence to definitive treatment (RT vs. surgery) at Asan Medical Center, Seoul, Korea were included. Survival curves between two groups were estimated by Kaplan-Meier method and compared using log-rank test. Overall survival (OS) was defined as from the initiation of EGFR TKI to any cause of death, and progression-free survival (PFS) was defined as from the initiation of EGFR TKI to objective disease progression or any cause of death. Results Total 56 patients were included in analysis (21 in RT group vs. 35 in surgery group). Clinical characteristics were similar between two groups, including disease status at recurrence (Logo-regional vs. distant metastasis). Median OS was significantly shorter in the RT group compared to the surgery group (15.6 vs. 47.2 months, P=0.001). This remained significant in multivariate analysis including potential prognostic factors (HR 3.03, 95% CI 1.45-6.25, P=0.003). Median PFS was also significantly shorter in the RT group compared to the surgery group (8.5 vs. 14.5 months, P=0.045), but adjusted HR was not statistically significant (P=0.138). Conclusion In patients with EGFR mutant NSCLC who received EGFR TKI after recurrent to definitive RT or CCRT, OS and PFS was significantly shorter compared to those who received EGFR TKI after recurrence to surgery.