Adjuvant platinum-based chemotherapy vs observation after resection of stage I–IIa (N0) NSCLC: A real-world propensity-matched analysis from TriNetX.

Abstract

e20059 Background: Lung cancer remains the leading cause of cancer-related mortality worldwide, accounting for approximately 1.8 million deaths annually, with non–small cell lung cancer (NSCLC) comprising nearly 85% of cases (Siegel et al., 2024; Sung et al., 2021). Approximately 25–30% of patients present with early-stage disease, for which surgical resection is potentially curative (Goldstraw et al., 2016). While randomized trials and meta-analyses have demonstrated a survival benefit for adjuvant platinum-based chemotherapy in resected stage II–III NSCLC (Pignon et al., 2008), its role in stage I–IIA disease without nodal involvement remains uncertain and variably applied in clinical practice (NCCN Guidelines, 2024). We compared real-world outcomes of adjuvant platinum-based chemotherapy versus observation following complete resection in patients with stage I–IIA (N0) NSCLC. Methods: We performed a retrospective cohort study using the TriNetX U.S. Collaborative Network. Adult patients with pathologic stage I or IIA NSCLC and N0 disease who underwent lung resection were included. Adjuvant chemotherapy was defined as receipt of a platinum-based doublet within 6 months after surgery, while observation was defined as no systemic therapy. Propensity score matching (1:1) balanced demographics and baseline comorbidities. Overall survival (OS) and progression-free survival (PFS) were evaluated using Kaplan–Meier methods and Cox proportional hazards models. Results: After propensity score matching, 1,107 patients remained in each cohort. Adjuvant chemotherapy was associated with significantly inferior overall survival compared with observation (hazard ratio [HR] 1.586, 95% CI 1.378–1.826; p < 0.001). Progression-free survival was also significantly worse among patients receiving adjuvant chemotherapy (HR 1.612, 95% CI 1.387–1.873; p < 0.001). Conclusions: In this large real-world propensity-matched cohort of patients with completely resected stage I–IIA (N0) NSCLC, adjuvant platinum-based chemotherapy was associated with inferior overall and progression-free survival compared with observation. These findings highlight the need for careful patient selection and underscore the importance of prospective studies to better define the role of adjuvant chemotherapy in early-stage, node-negative NSCLC. Summary of key outcomes after propensity score matching. Outcome Adjuvant Chemotherapy vs Observation (HR, 95% CI) p-value Overall Survival 1.59 (1.38–1.83) <0.001 Progression-Free Survival 1.61 (1.39–1.87) <0.001