Completeness of lymph node dissection in patients undergoing minimally invasive- or open surgery for non-small cell lung cancer: A nationwide study: A nationwide study

Objective: In patients with NSCLC, lymph node metastases are an important prognostic factor. Despite an accurate pre-operative work up, for optimal staging an intrapulmonary- and mediastinal lymph node dissection (LND) as part of the operation is mandatory. The aim of this study is to assess the completeness of LND in patients undergoing an intended curative resection for NSCLC in the Netherlands and to compare performance between open surgery and minimally invasive surgery (MIS). Materials and methods: The intraoperative LND was evaluated in 7460 patients who had undergone a lobectomy for clinically staged N0-1 NSCLC (2013–2018). The LND was considered complete, when three mediastinal (N2) lymph node stations, including station 7, were sampled or dissected, in addition to the lymph nodes from station 10 and 11. A comparison was made between open surgery and MIS. Results: Of 5154 patients, who had MIS, a sufficient intrapulmonary LND was performed in 47.9% and a sufficient mediastinal LND in 58.6%. A complete LND was performed in 31.6%. For 2306 patients who had an open resection, these numbers were 45.0%, 59.0%, and 30.6%, respectively. The overall between-hospital variation in a complete LND ranged between 0 and 72.5%. Conclusion: In the Netherlands, a complete LND of both intrapulmonary- and mediastinal lymph nodes is performed only in a minority of patients with clinically staged N0-1 NSCLC, with substantial between-hospital variation. No differences were seen between open surgery and MIS. Because of poor performance, completeness of lymph node dissection will be recorded as a mandatory performance indicator in our national audit, to improve the quality of resection.