Sequence for Surgical Resection of Primary Lung Tumor for Oligometastatic Non-small Cell Lung Cancer

Background: Differing surgical series for the treatment of primary lung tumor with synchronous oligometastatic stage IV non-small cell lung cancer (NSCLC) have been published; however, outcomes remain ambiguous. Methods: Patients with synchronous oligometastatic stage IV NSCLC treated from 2005 to 2017 were enrolled to identify the impact of treatment sequence (primary lung resection vs systemic treatment) on progression-free survival (PFS) and overall survival (OS). Results: Tumor resection occurred in 51 patients (84% adenocarcinoma, 55% nonsmokers, and 65% driver gene mutation) before or after systemic treatment in 33 (64.7%) and 18 (35.3%) patients, respectively. Patients who received resection first were older (62.1 vs 54 years) and at a less advanced intrathoracic stage (18% vs 44%). No significant differences were noted regarding perioperative complications (30% vs 28%), hospital length of stay (9.0 vs 10.5 days), percentage of disease progression (91% vs 94%), overall death (70% vs 78%), median PFS (14.0 vs 22.8 months), and OS (44.6 vs 53.2 months). Patients with single-organ metastasis had significantly longer PFS and OS than those with oligometastases (17.5 vs 12.8 months, P = .040; and 55.6 vs 39.8 months, P = .035), respectively. Multivariable Cox analysis identified nonsolitary metastasis as the only independent predictor of PFS (hazard ratio, 2.27; 95% confidence interval, 1.07-4.81; P = .033). Conclusions: Primary lung resection before or after induction systemic therapy may benefit patients with oligometastatic NSCLC. Future randomized clinical trials examining the effect of treatment sequence is recommended.