Is it necessary to sample the contralateral nodal stations by EBUS-TBNA in patients with lung cancer and clinical N0 / N1 on PET-CT?

Abstract

Objectives: Systematic mediastinal staging (sampling all visible nodes measuring ≥ 5 mm from N3 station to N1, regardless of PET/CT (positron emission tomography/computed tomography) by endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is a decisive step in patients with non-small cell lung cancer (NSCLC). We analyzed the prevalence of N3 disease and the utility of systematic staging in the subgroup of patients who underwent EBUS-TBNA staging without showing mediastinal lesions on the PET/CT (N0/N1).

Material and methods: We conducted a retrospective analysis of a prospectively collected database that included 174 patients with a final diagnosis of NSCLC, with N0/N1 disease on PET/CT who underwent a systematic EBUS-TBNA staging.

Results: 174 consecutive patients were included. Systematic EBUS-TBNA detected N2 mediastinal involvement in 21 (12 %) cases, and no cases of N3 disease were detected (neither hilar nor mediastinal). Of the remaining 153 patients N0/N1 EBUS-TBNA, 122 underwent lung resection that revealed 4 cases of N2 disease while 117 were confirmed to be N0/N1. Thirty-three patients with N0/1 disease after EBUS-TBNA did not undergo surgery and were excluded for the NPV calculation. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and overall accuracy of systematic EBUS was 84 %, 100 %, 96.7 %, 100 % and 97 % respectively.

Conclusion: Systematic EBUS-TBNA is a very accurate method for lymph node staging in patients with NSCLC without mediastinal involvement on PET/CT. Pending more studies, the absence of contralateral hilar nodal involvement in our series, questions the need for a contralateral hilar sampling in this subgroup of patients.

Keywords: EBUS staging; Endobronchial ultrasound; Lung cancer; Staging lung cancer; Systematic EBUS.