Is your stage III NSCLC patient truly "downstaged" to N0? EUS helpful only if positive

So you've referred your patient with stage III non-small cell lung cancer (N2 or N3 mediastinal nodes) to receive neoadjuvant chemoradiation therapy in the hopes of eliminating cancer from the mediastinal nodes, "downstaging" her to a resectable N0 status. How do you re-evaluate the lymph nodes to ensure resection may be curative?

von Bartheld et al retrospectively looked at 58 consecutive patients with N2/N3 stage III NSCLC who received neoadjuvant chemoradiation, and then underwent transesophageal ultrasound fine needle aspiration (EUS-FNA).

EUS-FNA found metastasis in 15 patients (26%). That left 43 who were negative by EUS, and 33 of them underwent mediastinoscopy, of which 58% were positive.

Take-home: EUS-FNA is a good first test in re-analyzing the mediastinal nodes after chemoradiation for stage III N2/N3 NSCLC, because if it's positive you're done. However, its low negative predictive value mean a negative test must be followed up with more invasive sampling.

von Bartheld et al. Transesophageal Ultrasound-Guided Fine-Needle Aspiration for the Mediastinal Restaging of Non-small Cell Lung Cancer.  J Thorac Oncol 2011;6:1510-1515.