Objectives: Evidence from multiple clinical trials showed that local consolidative therapy (LCT) improved survival in oligometastatic non-small cell lung cancer (NSCLC) patients. In the present study, we aim to explore the potential role of microwave ablation (MWA) as LCT for epidermal growth factor receptor (EGFR)-mutant advanced NSCLC patients with extracranial oligometastasis.
Materials and methods: From January 2015 to December 2018, a total of 86 EGFR-mutant stage IIIB or IV NSCLC patients with extracranial oligometastasis were enrolled for retrospective analysis. MWA was used as LCT for all oligometastatic lesions and/or primary tumors in 34 patients without progression after first-line EGFR-TKIs therapy (consolidation group), while the other 52 patients received only TKIs until disease progression (monotherapy group). We calculated and compared the progression-free survival (PFS) and overall survival (OS) of the two groups.
Results and conclusion: Patients with MWA consolidation therapy had significantly improved PFS (median 16.7 vs. 12.9 months, HR 0.44, 95% CI 0.22-0.88, P = 0.02) and OS (median: 34.8 vs. 22.7 months, HR 0.45, 95% CI 0.24-0.88, P = 0.04) than monotherapy group. MWA for LCT was identified as the independent predictive factor for better PFS (HR 0.46, 95% CI 0.37-0.82, P < 0.01) and OS (HR 0.57, 95% CI 0.33-0.91, P = 0.02). Most toxicities were mild and well tolerated. No patient had to discontinue EGFR-TKIs because of MWA complications. These findings suggest that MWA as local consolidative therapy after first-line EGFR-TKIs treatment leads to better disease control and survival than TKIs monotherapy in EGFR-mutant advanced NSCLC patients with extracranial oligometastasis. MWA as a novel option of LCT might be considered for clinical management of these patients.
Keywords: EGFR-TKIs; Local consolidative therapy; Microwave ablation; Non-small cell lung cancer; Oligometastasis.