Economic analysis of combined endoscopic and endobronchial ultrasound in the evaluation of patients with suspected non-small cell lung cancer

Abstract

Lung cancer remains the most common cause of cancer-related death in the United States. This study evaluated the costs of alternative diagnostic evaluations for patients with suspected non-small cell lung cancer (NSCLC). Researchers used a cost-minimization model to compare various diagnostic approaches in the evaluation of patients with NSCLC. It was less expensive to use an initial endoscopic ultrasound (EUS) with fine needle aspiration (FNA) to detect a mediastinal lymph node metastasis ($18,603 per patient), compared with combined EUS FNA and endobronchial ultrasound (EBUS) with FNA ($18,753). The results were sensitive to the prevalence of malignant mediastinal lymph nodes; EUS FNA remained least costly, if the probability of nodal metastases was <32.9%, as would occur in a patient without abnormal lymph nodes on computed tomography (CT). While EUS FNA combined with EBUS FNA was the most economical approach, if the rate of nodal metastases was higher, as would be the case in patients with abnormal lymph nodes on CT. Both of these strategies were less costly than bronchoscopy or mediastinoscopy. The pre-test probability of nodal metastases can determine the most cost-effective testing strategy for evaluation of a patient with NSCLC. Pre-procedure CT may be helpful in assessing probability of mediastinal nodal metastases.

Fig. 1

Decision tree illustrating seven diagnostic branches. Following initial diagnostic workup (CT, PET scan), the clinician is faced with seven possible sampling approaches in order to discern malignant mediastinal lymphadenopathy. ◻ = initial decision node; = change node; ◃ = end of evaluation for that branch. EUS = endoscopic ultrasound; FNA = fine needle aspiration; MED = mediastinoscopy; TBNA = transbronchial needle aspiration; EBUS = endobronchial ultrasound; + Bx = biopsy yielding malignancy.

Fig. 2

This figure illustrates the impact of varying the prevalence of malignant mediastinal lymph nodes (P_LN) on the cost of patient management. The costs of EUS FNA (◆) and EUS FNA+EBUS FNA (▼) are equivalent ($18,170) when P_LN is 32.9%.

Fig. 3

This figure illustrates the impact of varying the sensitivity of EUS FNA (SENS_EUS) on the cost of patient management. The costs of EUS FNA (◆) and EBUS FNA (▲) are equivalent ($19,828) when SENS_EUS is 50%.