Background: Lymph node dissection (LND) is crucial procedure during radical resection of non-small cell lung cancer (NSCLC), but the prognostic value of L4 LND remains elusive. To investigate the prognostic value of L4 LND in patients with left-side NSCLC who underwent video-assisted thoracoscopic surgery (VATS).
Methods: Three hundred twelve patients who underwent VATS between Jan.