Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) appears to be cost effective for use in non–small cell lung cancer (NSCLC) staging if the prevalence of mediastinal lymph node metastasis (MLNM) is greater than or equal to 2.5%, according to the results of single institution modeling study. In addition, the study found that confirmatory mediastinoscopy should be performed in high-risk patients in cases of negative EBUS-TBNA.

Katarzyna Czarnecka-Kujawa, MD, of the University of Toronto and Toronto General Hospital, and her colleagues performed a decision analysis to compare health outcomes and costs of four mediastinal staging strategies. They assessed the following: no invasive staging, endobronchial ultrasound-guided transbronchial need aspiration (EBUS-TBNA), mediastinoscopy, and EBUS-TBNA followed by mediastinoscopy if EBUS-TBNA results were negative. They determined incremental cost-effectiveness ratios (ICER) for all strategies and performed comprehensive sensitivity analyses using a willingness to pay threshold of $80,000 [Canadian]/quality adjusted life-year (QALY).

They used data obtained for staging, outcomes, and costs from the patients in the lung cancer program at the Toronto General Hospital from Jan. 1, 2005 to Dec. 31, 2014, as detailed in a report published in the June issue of the Journal of Thoracic and Cardiovascular Surgery (2017. doi: 10.1016/j.jtcvs.2016.12.048).

After exclusions, they utilized a final case count of 499 cases for developing their surgical and procedure cost analysis, and a total of 750 cases in their endoscopy database for endoscopy analysis. For the base-case analysis, they assumed a prevalence of mediastinal metastasis of 9%, and obtained the prevalence of a pathologic lymph nodal stage disease following EBUS-TBNA from their institutional data.

Their results showed that EBUS-TBNA followed by mediastinoscopy was the strategy that resulted in the highest QALYs, but that it had a prohibitive ICER of greater than $1.4 million/QALY. Accordingly, it may not be justifiable to use mediastinoscopy after negative EBUS-TBNA in all patients, the researchers noted. However, the researchers’ data suggest that invasive screening may be justified in a very-low-risk population (MLNM above 2.5%).

In addition, the researchers stated that “[the] benefit conveyed by detecting mediastinal metastatic disease becomes more apparent as the prevalence of MLNM increases, with confirmatory mediastinoscopy becoming cost effective in cases of negative EBUS-TBNA in patients with moderate to high probability of MLNM” (greater than 57%).

Our model points out that there is a well-defined role for the use of different modalities, including mediastinoscopy. This stresses the need for ongoing focus on maintenance of competency and skill acquisition in mediastinoscopy and EBUS-TBNA by currently practicing and future thoracic surgeons respectively,” the researchers concluded.

Dr. Czarnecka-Kujawa disclosed that she is a research consultant with Olympus America. The study was funded in part by agencies of the Austrian government.