Real-world study of disease-free survival & patient characteristics associated with disease-free survival in early-stage non-small cell lung cancer: A retrospective observational study

Introduction/ Background: Surgical resection remains standard of care for patients with early-stage non-small cell lung cancer (NSCLC), but research shows that adjuvant therapy can reduce the risk of disease recurrence. Our objective was to characterize disease-free survival (DFS) using real-world data. Materials and Methods: This was a retrospective study using the COTA real-world database derived from electronic health records in the United States (US). Adults diagnosed with stage IB-IIIA NSCLC from 2013 to 2018 who underwent complete surgical resection (index date) for NSCLC were included. DFS was analyzed using the Kaplan-Meier method. A multivariable Cox-Proportional Hazard (PH) model stratified by year of diagnosis was developed to evaluate covariates associated with DFS. Results: 703 patients met the study criteria (mean age 66.2 years, female (56%), White (82%), and median follow-up time was 37.4 months from index date. Approximately 48% of patients experienced recurrence or death with a median DFS of 42.9 months (95% CI: 37.4–52.2). Patients who received adjuvant therapy, neoadjuvant and adjuvant therapy, neoadjuvant therapy, and surgery only experienced a median DFS of 43.7, 32.3, 33.7, and 49.4 months, respectively. After adjustment, stage at diagnosis and adjuvant therapy status were significantly associated with DFS events. Conclusions: Higher stage at diagnosis and lack of adjuvant therapy were associated with greater risk of recurrence. Future research should focus on the adoption and effect of adjuvant/ neoadjuvant therapies on disease recurrence, including in patients with oncogenic driver mutations.