Oncological feasibility of segmentectomy for inner-located lung cancer

Objective Oncological feasibility of segmentectomy for internal non-small cell lung cancer (NSCLC) has not been assessed adequately. We assessed the oncological feasibility of segmentectomy for inner-located NSCLC by investigating surgical margins and patient prognosis after undergoing the procedure. Methods Of the 3,555 patients who underwent resection for lung cancer between 2013 and 2019 at our institution, 659 patients who underwent segmentectomy for clinical stage 0-IA NSCLC were included in this study. Patients were separated into two groups according to whether the tumor was in the inner or outer third of the lung area. Clinical characteristics and prognoses were retrospectively compared between the groups. Results Of the included 659 cases, 183 (27.8%) were inner-located, and 476 (72.2%) had outer-located NSCLC. The surgical margin was significantly shorter in the inner-located group than in the outer group (median:16 mm vs. 25 mm, P < 0.001). The 5-year recurrence-free survival (RFS) and overall survival probabilities were 91.1%/91.8% (P = 0.530) and 94.1%/95.6% (P = 0.345) for inner/outer-located groups, respectively. Multivariate analysis showed that clinical stage IA2 or 3 (P = 0.043), lymphovascular invasion (P < 0.001), and surgical margins < 20 mm (P = 0.017) were independent prognostic factors for RFS. The location of the inner or outer tumors was not related to the prognosis. Conclusions For clinical stage 0–IA NSCLC, tumor location in the inner two-thirds of the lung was not associated with prognosis after segmentectomy. As one of the independent prognostic factors is margin distance, segmentectomy for inner-located NSCLC would be oncologically acceptable when an adequate surgical margin is secured.