Guideline adherence of mediastinal staging of non-small cell lung cancer: A multicentre retrospective analysis

•Adherence to the guideline on initial use of endosonography was good.•One third of endosonography procedures were performed insufficiently.•Confirmatory mediastinoscopy after negative endosonography was frequently omitted.•Significant variability in staging strategy and performance of procedures among centres.•Comparable unforeseen N2 rates after endosonography with or without mediastinoscopy. Mediastinal lymph node staging of NSCLC by initial endosonography and confirmatory mediastinoscopy is recommended by the European guideline. We assessed guideline adherence on mediastinal staging, whether staging procedures were performed systematically and unforeseen N2 rates following staging by endosonography with or without confirmatory mediastinoscopy. We performed a multicentre (n = 6) retrospective analysis of NSCLC patients without distant metastases, who were surgical candidates and had an indication for mediastinal staging in the year 2015. All patients who underwent EBUS, EUS and/or mediastinoscopy were included. Surgical lymph node dissection was the reference standard. Guideline adherence was based on the 2014 ESTS guideline. 330 consecutive patients (mean age 69 years; 61% male) were included. The overall prevalence of N2/N3 disease was 42%. Initial mediastinal staging by endosonography was done in 84% (277/330; range among centres 71-100%; p