Background: Local consolidative therapy (LCT) to optimize disease control is an evolving management paradigm in non-small-cell lung cancer (NSCLC) patients who present with a limited metastatic disease burden. We hypothesized that LCT to all sites of disease would be associated with improved overall survival (OS) among patients with synchronous oligometastatic NSCLC.
Patients and methods: Patients presenting to a single institution (2000-2017) with stage IV NSCLC and ≤ 3 synchronous metastases were identified. Intrathoracic nodal disease was counted as one site. Landmark and propensity-adjusted Cox regression analyses were performed to identify factors associated with OS.
Results: Of 194 patients, 143 (74%) had 2 or 3 sites of metastasis. LCT was delivered to all sites of disease in 121 patients (62%), to some but not all sites in 52 (27%), and were not used in 21 (11%). Comprehensive LCT was independently associated with improved OS (hazard ratio [HR] = 0.67; 95% confidence interval [CI], 0.46-0.97; P = .034), with the greatest therapeutic effect among patients without thoracic nodal disease, bone metastases, or > 1 metastatic site. Among patients who underwent comprehensive LCT, tumor histology (squamous: HR = 2.32; 95% CI, 1.28-4.22; P = .006), intrathoracic disease burden (T3-4: HR = 1.67; 95% CI, 0.97-2.86; P = .065; N3: HR = 1.90; 95% CI, 0.90-4.03; P = .093), and bone metastases (HR = 1.74; 95% CI, 1.02-3.00; P = .044) were associated with poor OS.
Conclusion: Comprehensive LCT was associated with improved OS in this large cohort of patients with synchronous oligometastatic NSCLC. These results support ongoing prospective efforts to characterize the therapeutic benefits associated with this management strategy.
Keywords: Metastasectomy; Oligometastases; Radiotherapy; Stereotactic ablative body radiation; Surgical therapy.
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