BackgroundThere are scarce data of the costs of non-small cell lung cancer (NSCLC) recurrence in Spain. The objective of this study is to assess the economic burden of disease recurrence, for both locoregional and/or metastatic relapses, after appropriate early-stage NSCLC treatment in Spain.Materials and methodsA two-round consensus panel of Spanish oncologists and hospital pharmacists was conducted to collect information on patient’s flow, treatments, use of healthcare resources and sick leaves in patients with relapsed NSCLC. A decision-tree model was developed to calculate the economic burden of disease recurrence after appropriate early-stage NSCLC. Both direct and indirect costs were considered. Direct costs included drug acquisition and healthcare resources costs. Indirect costs were estimated using the human-capital approach. Unit costs were obtained from national databases (euros of 2022). A multi-way sensitivity analysis was performed to provide a range to the mean values.ResultsAmong a cohort of 100 patients with relapsed NSCLC, 45 patients would have locoregional relapse (36.3 would eventually progress to metastasis and 8.7 would be considered in remission) and 55 patients would have metastatic relapse. Over time, 91.3 patients would experience a metastatic relapse (55 as first relapse and 36.6 after previous locoregional relapse). The overall cost incurred by the 100-patients cohort is €10,095,846 (€9,336,782 direct costs, €795,064 indirect costs). The average cost of a locoregional relapse is €25,194 (€19,658 direct costs, €5536 indirect costs), while the average cost a patient with metastasis who receives up to 4 lines of treatment is €127,167 (€117,328 direct, €9839 indirect).ConclusionsTo our knowledge, this is the first study that specifically quantifies the cost of relapse in NSCLC in Spain. Our findings shown that the overall cost of a relapse after appropriate treatment of early-stage NSCLC patients is substantial, and it increases considerably in the metastatic relapse setting, mainly due to the high cost and long duration of first-line treatments.