Consolidative Local Ablative Therapy Improves the Survival of Patients With Synchronous Oligometastatic NSCLC Harboring EGFR Activating Mutation Treated With First-Line EGFR-TKIs

Introduction: The aim of the current study was to investigate whether consolidative local ablative therapy (LAT) can improve the survival of patients with stage IV EGFR-mutant NSCLC who have oligometastatic disease treated with first-line EGFR-tyrosine kinase inhibitor (TKI) therapy. Methods: Patients with stage IV EGFR-mutant NSCLC and no more than five metastases within 2 months of diagnosis were identified. All patients were treated with first-line EGFR-TKIs. Consolidative LAT included radiotherapy, surgery, or both. Overall survival (OS) and progression-free survival (PFS) were estimated by Kaplan-Meier curves. Results: From October 2010 to May 2016, 145 patients were enrolled, including 51 (35.2%) who received consolidative LAT to all oligometastatic sites (all-LAT group), 55 (37.9%) who received consolidative LAT to either primary tumor or oligometastatic sites (part-LAT group), and 39 (26.9%) who did not receive any consolidative LAT (non-LAT group). The median PFS in all-LAT, part-LAT, and non-LAT groups were 20.6, 15.6, and 13.9 months, respectively (p < 0.001). The median OS in all-LAT, part-LAT, and non-LAT groups were 40.9, 34.1, and 30.8 months, respectively (p < 0.001). The difference was statistically significant between the all-LAT group and part-LAT or non-LAT group but was not between the part-LAT and non-LAT group. The median OS was significantly improved with consolidative LAT for primary tumor (40.5 versus 31.5 months, p < 0.001), brain metastases (38.2 versus 29.2 months, p = 0.002), and adrenal metastases (37.1 versus 29.2 months, p = 0.032). Adverse events (grade >= 3) due to radiotherapy included pneumonitis (7.7%) and esophagitis (16.9%). Conclusions: The current study showed that consolidative LAT to all metastatic sites was a feasible option for patients with EGFR-mutant oligometastatic NSCLC during first-line EGFR-TKI treatment, with significantly improved PFS and OS compared with consolidative LAT to partial sites or observation alone. (C) 2018 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.