Is routine dissection of lymph node station 4L clinically significant in left lung NSCLC?

I read with special interest the article entitled “Clinical significance of 4L lymph node dissection in left lung cancer” published in Journal of Clinical Oncology in October 2018 (1). The authors did a retrospective analysis of their patients who underwent lung parenchyma resection for non-small cell lung cancer (NSCLC) of the left lung during the 5-year period 2005–2009. The main conclusions of their study were that dissection of the 4L lymph node station revealed a quite high rate of involvement by the tumor (20.9%), while 4L lymph node dissection was found to be an independent prognostic factor for improved disease-free survival (DFS) and overall survival (OS) in left lung NSCLC. In case the above-mentioned results will be reproduced in future studies, dissection of the 4L lymph node station will be definitely considered an essential step in the surgical management of left lung NSCLC which will affect the clinical practice and the guidelines for lymph node dissection of left lung NSCLC.