Event-free survival as a predictor of overall survival and recurrence burden of patients with non-small cell lung cancer receiving neoadjuvant therapy.

OBJECTIVES: Event-free survival has replaced overall survival as a primary end point in many recent and ongoing clinical trials. This study aims to examine the correlation between real-world event-free survival and overall survival and to assess the clinical and economic burden associated with disease recurrence among patients with resected stage II to III non-small cell lung cancer who received neoadjuvant therapy in the United States. METHODS: This retrospective study used the Surveillance, Epidemiology, and End Results Medicare database (2007-2019) to identify patients with newly diagnosed, resected, stage II to IIIB (N2) non-small cell lung cancer who received neoadjuvant therapy. The correlation between real-world event-free survival and overall survival was assessed using the normal scores rank correlation and landmark analysis. Overall survival, all-cause health care resource use and costs, and non-small cell lung cancer-related health care resource use and costs were compared between patients with and without recurrence. RESULTS: A total of 221 patients met the eligibility criteria (median follow-up time from neoadjuvant treatment initiation: 32.7 months). The mean age was 72.1 years, and 57.0% of patients were male. Real-world, event-free survival and overall survival are positively and significantly correlated (0.68; 95% CI, 0.52-0.79). Patients with recurrence had significantly shorter median overall survival (19.3 vs 116.9 months), 4.59 times increased risk of death (95% CI, 2.56-8.26), and significantly higher all-cause and non-small cell lung cancer-related health care resource use and costs (adjusted mean monthly costs per patient difference: $5758 and $3187, respectively [all P < .001]). CONCLUSIONS: These findings help validate event-free survival as a clinically meaningful end point and strong predictor for overall survival and highlight the need for additional novel therapies that may delay or prevent recurrence in resectable stage II and III non-small cell lung cancer.