Is underutilization of adjuvant therapy in resected non-small-cell lung cancer associated with socioeconomic disparities?

OBJECTIVES: Although adjuvant systemic therapy (AT) has demonstrated improved survival in patients with resected non-small-cell lung cancer (NSCLC), it remains underutilized. Recent trials demonstrating improved outcomes with adjuvant immunotherapy and targeted treatment imply that low uptake of systemic therapy in at-risk populations may widen existing outcome gaps. We, therefore, sought to determine factors associated with the underutilization of AT. METHODS: The National Cancer Database (2010-2018) was queried for patients with completely resected stage II-IIIA NSCLC and stratified based on the receipt of AT. Logistic regression was used to identify factors associated with AT delivery. The Kaplan-Meier method was applied to estimate survival after propensity-matching to adjust for confounders. RESULTS: Of 37 571 eligible patients, only 20 616 (54.9%) received AT. While AT rates increased over time, multivariable analysis showed that older age [adjusted odds ratio (aOR) 0.45, 95% confidence interval (CI) 0.43-0.47], male sex (aOR 0.88, 95% CI 0.85-0.93) and multiple comorbidities (aOR 0.86, 95% CI: 0.81-0.91) were associated with decreased AT. Socioeconomic factors were additionally associated with underutilization, including public insurance (aOR 0.70, 95% CI: 0.66-0.74), lower education indicators (aOR 0.93, 95% CI: 0.88-0.97) and living more than 10 miles from a treatment facility (aOR 0.89, 95% CI: 0.85-0.93). After propensity matching, receipt of adjuvant therapy was associated with improved overall survival (median 76.35 vs 47.57 months, P ≤ 0.001). CONCLUSIONS: AT underutilization in patients with resected stage II-III NSCLC is associated with patient, institutional and socioeconomic factors. It is critical to implement measures to address these inequities, especially in light of newer adjuvant immunotherapy and targeted therapy treatment options which are expected to improve survival.