BACKGROUND: Lobectomy has been established as the standard treatment for resectable non-small cell lung cancer (NSCLC) since the publication of a randomized prospective clinical trial conducted by the Lung Cancer Study Group (LCSG) in the 1990s. However, this study possesses certain drawbacks from a contemporary standpoint. Over the past decades, further studies have been conducted to comprehensively outline appropriate surgical procedures for NSCLC. Segmentectomy is considered a potential alternative for predominant ground-glass opacities (GGOs) or tumors smaller than 2 cm. However, there is limited research regarding their relative benefits. We compared oncological outcomes of patients undergoing left upper lobectomy and a "multi-segmentectomy" [trisegmentectomy (S METHODS: A retrospective study was performed in the Department of Thoracic Surgery, Zhongshan Hospital of Fudan University, that included patients who underwent lobectomy and bisegmentectomy for NSCLC in the left upper lobe from January 2009 to December 2016. Oncological outcomes, including OS and DFS, were compared between patients who underwent lobectomy and those who underwent bisegmentectomy. Subgroup analyses were completed based on the type of operation and tumor size. RESULTS: A total of 997 patients were included, with 888 undergoing left upper lobectomy, 33 undergoing lingulectomy, and 76 undergoing inherent segmentectomy. After a retrospective comparative cohort study, no significant differences were observed in OS (P=0.49) or DFS (P=0.62) between the lobectomy and bisegmentectomy groups. Subgroup analyses were performed for each type of bisegmentectomy and different tumor sizes. Despite a noted inferior OS in the lingulectomy group (P=0.049), no significant difference in OS or DFS was identified in the other subgroup comparisons (P>
0.05). CONCLUSIONS: Left upper bisegmentectomy demonstrated comparable oncological outcomes to those of left upper lobectomy, even in cases of larger tumor size (≥2 cm). However, the lingulectomy group exhibited a concerning inferiority in OS, necessitating further evaluation.