BackgroundThis study aimed to identify the impact of margin distance on locoregional recurrence (LRR) and survival outcomes after thoracoscopic segmentectomy for non-small cell lung cancer. MethodsWe retrospectively analyzed data from prospectively collected consecutive thoracoscopic segmentectomies in a single center from January 2008 to February 2023. The restricted cubic spline of the adjusted Cox regression model for LRR displayed the breakpoint of margin distance. The Kaplan-Meier estimator with log-rank test evaluated the overall survival between the 2 groups stratified by the breakpoint, and the Aalen-Johansen estimator with the Gray test assessed the LRR-free survival and lung cancer-specific survival in the competing model. ResultsThe study included 155 patients. LRR was observed in 22 patients (14.2%), with a median time to LRR of 17.1 months (interquartile range, 6.3-26.3 months). Margin distance was found to be a predictor for LRR (hazard ratio, 0.92; P = .033). The identified breakpoint for margin distance in this cohort was 19.8 mm. Compared with this cutoff, a margin distance of 15 mm increased the risk of LRR by 65%, whereas 25 mm decreased the risk to LRR with 31%. A segmentectomy with a margin distance ≥20 mm resulted in significant improvements in overall survival (P = .020), lung cancer-specific survival (P = .010), and LRR-free survival (P < .001) compared with cases with a margin distance of <20 mm. ConclusionsMargin distance ≥20 mm decreased LRR and improved survival outcomes for thoracoscopic segmentectomy in this study.