Prognostic impact of lymphadenectomy on outcomes of sublobar resection for non-small cell lung cancer ≤1 or >1 to 2 cm.

Background: Lymphadenectomy is an important part of surgical treatment for non-small cell lung cancer (NSCLC). However, the prognostic impact of lymph node (LN) dissection for patients with NSCLC <= 1 and >1 to 2 cm who underwent sublobar resection is still unclear. Methods: A group of patients numbering 7,627 with NSCLC 2 cm or less who underwent sublobar resection were identified from the Surveillance, Epidemiology, and End Results (SEER) database between January 2010 and November 2015. The overall survival (OS) and lung cancer-specific survival (LCSS) were evaluated among patients who had undergone dissection of >= 4 LNs, 1 to 3 LNs or who had no-LN dissection; log-rank and Cox proportional-hazards regression analyses were used for the evaluation. Results: Patients with NSCLC <= 2 cm who underwent >= 4 LNs dissection had better OS and LCSS compared with those who underwent dissection of 1 to 3 LNs or who had no-LN dissection after sublobar resection. Subgroup analysis showed that dissection of >= 4 LNs had better OS and LCSS than those of 1 to 3 LNs dissection in NSCLC >1 to 2 cm, whereas had similar OS and LCSS in NSCLC <= 1 cm. Multivariate Cox analysis showed that dissection of 1 to 3 LNs was not an independent risk factor of OS and LCSS than dissection of >= 4 LNs in NSCLC <= 1 cm after sublobar resection. Conclusions: The extent of LN dissection is associated with the survival outcomes in patients with NSCLC <= 2 cm after sublobar resection. Dissection >= 4 LNs should be recommended for NSCLC >1 to 2 cm, whereas surgeons can rely on surgical skills and patient profiles to decide >= 4 LNs or 1 to 3 LNs dissection for NSCLC <= 1 cm during sublobar resection.