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 of ≥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.