Long-term Surgical Outcomes in Oligometastatic Non-small Cell Lung Cancer: A Single-Center Study

BACKGROUND: We reviewed the clinical outcomes of patients with oligometastatic (OM) non-small cell lung cancer (NSCLC) who received multimodal therapy including lung surgery. METHODS: We retrospectively analyzed 117 patients with OM NSCLC who underwent complete resection of the primary tumor from 2014 to 2017. RESULTS: The median follow-up duration was 2.91 years (95% confidence interval, 1.48–5.84 years). The patients included 73 men (62.4%), and 76 patients (64.9%) were under the age of 65 years. Based on histology, 97 adenocarcinomas and 14 squamous cell carcinomas were included. Biomarker analysis revealed that 53 patients tested positive for epidermal growth factor receptor, anaplastic lymphoma kinase, or ROS1 mutations, while 36 patients tested negative. Metastases were detected in the brain in 74 patients, the adrenal glands in 12 patients, bone in 5 patients, vertebrae in 4 patients, and other locations in 12 patients. Radiation therapy for organ metastasis was performed in 81 patients and surgical resection in 27 patients. The 1-year overall survival (OS) rate in these patients was 82.8%, and the 3- and 5-year OS rates were 52.6% and 37.2%, respectively. Patients with positive biomarker test results had 1-, 3-, and 5-year OS rates of 98%, 64%, and 42.7%, respectively. These patients had better OS than those with negative biomarker test results (p=0.031). Patients aged ≤65 years and those with pT1–2 cancers also showed better survival (both p=0.008). CONCLUSION: Surgical resection of primary lung cancer is a viable treatment option for selected patients with OM NSCLC in the context of multimodal therapy.