European trends in preoperative and intraoperative nodal staging: ESTS guidelines

Preoperative and intraoperative lymph node (LN) staging is of paramount importance for patients with non-small cell lung cancer. The Council of the European Society of Thoracic Surgery took the initiative to organize workshops on intraoperative and preoperative mediastinal LN staging. This resulted in specific guidelines. Relevant peer-reviewed publications on these subjects, the experience of the participants, and the opinion of the European Society of Thoracic Surgery members contributing online were used to reach a consensus. For primary staging, mediastinoscopy remains the gold standard for the superior mediastinal LNs. Invasive procedures can be omitted in patients with peripheral tumors and negative mediastinal and hilar nodes on positron emission tomography scan. Positron emission tomography-positive mediastinal findings should always be cytohistologically confirmed. New minimally invasive techniques that provide cytohistological diagnosis became available. Their specificity is high, but the negative predictive value is low. If they yield negative results, an invasive surgical technique remains indicated. For restaging, invasive techniques providing cytohistological information are advisable. Systematic nodal dissection is recommended in all cases to ensure complete resection. Lobe-specific systematic nodal dissection is acceptable for peripheral squamous T1 tumors if hilar and interlobar nodes are negative on frozen section studies. The report from the pathologist should describe the number of LNs removed and studied, the overall number of metastatic LNs in each station, and the status of the LN capsule. We hope that the adherence to these guidelines will standardize and improve preoperative and intraoperative LN staging and pathologic evaluation of non-small cell lung cancer.