Disease-free survival (A, B) and overall survival (C, D) were not significantly different between patients who underwent NS and patients who underwent SF among all patients with pathologic N2a1 non-small cell lung cancer before and after the matching-weights procedure. Disease-free survival: Cox model after the matching-weights procedure: (NS vs reference of SF) HR, 1.52 (95% CI, 0.99-2.34). Overall survival: Cox model after the matching-weights procedure: (NS vs reference of SF) HR, 1.26 (95% CI, 0.79-1.99). For the matching-weights analyses, each patient contributes a fraction reflecting the matching-weights; therefore, the effective sample size (numbers at risk) may not be an integer. The number of patients at risk and 95% CI estimates corresponding to each time point are presented below the figure for each group. CI, confidence interval; HR, hazard ratio; NS, neoadjuvant therapy followed by surgery; SF, surgery first.