Resection of the Primary Tumor and Survival in Patients with Single-Site Synchronous Oligometastatic Non–Small Cell Lung Cancer: Propensity-Matched Analysis of the National Cancer Database

BACKGROUND: Local therapy for the primary tumor is postulated to remove resistant cancer cells as well as immunosuppressive cells from the tumor microenvironment, potentially improving response to systemic therapy (ST). We sought to determine whether resection of the primary tumor was associated with overall survival (OS) in a multicentric cohort of patients with single-site synchronous oligometastatic non–small cell lung cancer. STUDY DESIGN: Using the National Cancer Database (2018 to 2020), we evaluated patients with clinical stage IVA disease who received ST and stratified the cohort based on receipt of surgery for the primary tumor (S). We used multivariable and propensity score-matched analysis to study factors associated with S (logistic regression) and OS (Cox regression and Kaplan–Meier), respectively. RESULTS: Among 12,215 patients identified, 2.9% (N = 349) underwent S and 97.1% (N = 11,886) ST (chemotherapy or immunotherapy) without surgery. Patients who underwent S were younger, more often White, had higher income levels, were more likely to have private insurance, and were more often treated at an academic facility. Among those who received S, 22.9% (N = 80) also underwent resection of the distant metastatic site. On multivariable analysis, metastasis to bone, N+ disease, and higher T-stages were independently associated with less S. On Cox regression, S and resection of the metastatic site were associated with improved survival (hazard ratio 0.67, 95% CI 0.56 to 0.80 and hazard ratio 0.80, 95% CI 0.72 to 0.88, respectively). After propensity matching, OS was improved in patients undergoing S (median 36.8 vs 20.8 months, log-rank p < 0.001). CONCLUSIONS: Advances in ST for non–small cell lung cancer may change the paradigm of eligibility for surgery. This study demonstrates that surgical resection of the primary tumor is associated with improved OS in selected patients with single-site oligometastatic disease.