Cost Efficacy of Endoscopic Ultrasound and Endobronchial Ultrasound with Fine Needle Aspiration (EUS-FNA+EBUS-FNA) Versus Mediastinoscopy for the Staging of Patients with Non Small Cell Lung Cancer (NSCLC) and Abnormal Mediastinal Lymph Nodes By Non-Invasive Imaging

Abstract

Background: Currently endoscopic ultrasound with fine needle aspiration (EUS-FNA) complements Mediastinoscopy (MED) in staging of patients with NSCLC who have enlarged or abnormal appearing mediastinal lymph nodes on non-invasive imaging such as CT scan. Endobronchial ulstrasound with fine needle aspiration (EBUS-FNA) is an emerging technology that can access lymph node stations traditionally accessible only by surgical intervention. The use of combined EUS-FNA + EBUS-FNA has been shown to be feasible and reaches 95% sensitivity with specificity near 100%. The cost-benefit ratio of this procedure, which can be done on the same day under conscious sedation with discharge after standard recovery time, has not been compared to MED, which requires general anesthesia and operating room time. Aim: Compare the cost-effectiveness of combined EUS-FNA + EBUS-FNA versus MED for lymph node staging in patients with NSCLC and abnormal mediastinal lymph nodes on non-invasive imaging. Methods: A decision-analytic model was used to compare the cost-effectiveness of EUS-FNA + EBUS-FNA versus MED in a hypothetical population of 100 patients with NSCLC and suspicious mediastinal lymphadenopathy by non-invasive imaging. Probability estimates were derived from the literature: probability of node positive = 70%, sensitivity and specifity of EUS-FNA + EBUS-FNA = 95% and 99%, sensitivity and specifity of mediastinoscopy = 92% and 99%. Estimated costs of the two testing strategies were obtained from median US medical care fees. The primary outcome measured was cost per correct diagnosis. Results: The cost per correct diagnosis was $1999 for EUS-FNA + EBUS-FNA and $9189 for MED. In the sensitivity analysis, EUS-FNA + EBUS-FNA remained the dominant diagnostic strategy even when EUS and EBUS were performed on separate days (resulting in additional costs), or if the sensitivity of MED increased 99%. Conclusion: EUS-FNA + EBUS-FNA is more cost-effective than MED for staging patients with NSCLC and abnormal mediastinal lymph nodes on non-invasive imaging; EUS-FNA + EBUS-FNA should be the diagnostic modality of choice for this purpose.