Lobectomy is superior to segmentectomy for peripheral high grade non-small cell lung cancer ≤2 cm

Background: Current practice guidelines recommend the following criteria for segmentectomy for non-small cell lung cancer (NSCLC): size ≤2 cm, margins ≥2 cm and no lymph node involvement. We sought to further stratify the selection criteria for segmentectomy for small peripheral high-grade tumors. Methods: This retrospective database study was conducted using the Surveillance, Epidemiology and End Results (SEER) database. We queried for patients with high-grade (poorly differentiated/undifferentiated) pathological (p)T1a/b peripheral NSCLC (tumor size ≤2 cm), who underwent either lobectomy or segmentectomy between 2004 and 2015. Patients with node-positive disease or those who received any form of induction or adjuvant treatments were excluded. Results: A total of 4,332 patients met the inclusion criteria, with 3,977 patients (91.8%) treated with lobectomy and 355 patients (8.2%) who underwent segmentectomy. In a propensity matched pair analysis of 640 patients, lobectomy (n=320) showed significantly improved 5-year survival of 45.9% vs. 33.8% for segmentectomy (n=320), P<0.01. In a multivariate Cox regression analysis, lobectomy was associated with significantly improved survival (HR: 0.84, 95% CI: 0.714-0.989, P=0.036). Interestingly, married status, adenocarcinoma histology, number of lymph nodes sampled were associated with better survival (P<0.05), while advanced age and male gender had worse survival outcomes (P<0.05). Conclusions: For small peripheral NSCLC ≤2 cm and high grades of tumor differentiation, lobectomy is associated with better long-term survival outcomes as compared to segmentectomy. Additional data is needed to further stratify various NSCLC histologies with their respective grades to allow for better selection for segmentectomy.