Prognosis of multi‐level N2‐positive non‐small cell lung cancer according to lymph node staging using endobronchial ultrasound‐transbronchial biopsy

BACKGROUND: The optimal treatment for stage IIIA‐N2 non‐small cell lung cancer (NSCLC) remains controversial, and multidisciplinary team approaches are needed. Downstaging after induction therapy is a good prognostic factor in surgical patients; however, re‐evaluation of nodal status before surgery is challenging. The aim of this study was to evaluate the prognosis of patients with multi‐level N2 NSCLC who received surgery or chemoradiation therapy (CRT) according to restaging using endobronchial ultrasound‐transbronchial aspiration (EBUS‐TBNA). METHODS: This was a single center, prospective study that included 16 patients with biopsy‐proven multi‐level N2 disease on initial EBUS‐TBNA that was restaged using EBUS‐TBNA after induction therapy. Cases downstaged after rebiopsy were treated surgically. Three‐year progression‐free survival (PFS) and locoregional PFS were determined using Kaplan–Meier analysis. RESULTS: Of the 16 patients (median age 58 years, male 63%), eight had persistent N2 disease and eight showed N2 clearance on restaging using EBUS‐TBNA. Ten patients underwent surgery, including two patients without N2 clearance. Recurrence and locoregional recurrence occurred in eight and five patients, respectively. The three‐year PFS was longer in patients with N2 clearance than in those with N2 persistent disease (57.1% vs. 37.5%). Patients with N2 clearance also had longer three‐year locoregional PFS than those with N2 persistent disease (71.4% vs. 62.5%). CONCLUSIONS: EBUS‐TBNA could be an effective diagnostic method for restaging in multi‐level N2 NSCLC patients after induction CRT. As this was a pilot study, further large‐scale randomized studies are needed.