Background and Objectives: For early-stage invasive lung adenocarcinoma, it remains unclear whether segmentectomy can yield outcomes equivalent to those of lobectomy. This study aimed to compare survival outcomes after segmentectomy and lobectomy among patients with stage IA invasive lung adenocarcinoma. Methods:We identified patients with stage IA (≤2 cm) invasive lung adenocarcinoma who underwent segmentectomy or lobectomy from the Surveillance, Epidemiology, and End Results database (2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015). Propensity score matching (PSM) was used to balance the baseline characteristics. Overall survival (OS) and lung cancer-specific survival (LCSS) were compared using the Kaplan-Meier method and Cox proportional hazards regression.Results: A total of 5474 patients were included. Before PSM, the 5-year OS was 78.3% for patients undergoing lobectomy vs 76.5% for patients undergoing segmentectomy (P = .166) while LCSS were 86.8% vs 83.0% (P = .015). After PSM, survival analyses showed that segmentectomy had OS (75.8% vs 76.4%; P = .694) and LCSS (82.7% vs 82.9%; P = .604) equivalent to those of lobectomy. Cox regression demonstrated that segmentectomy was equivalent to lobectomy in terms of OS and LCSS before and after PSM.Conclusion: For stage IA (≤2 cm) invasive lung adenocarcinoma, segmentectomy may have oncologic outcomes equivalent to those of lobectomy. K E Y W O R D Sinvasive, lobectomy, lung adenocarcinoma, segmentectomy

BackgroundLung adenocarcinoma (LUAD) is the most common type of lung cancer and is a severe threat to human health. Although many therapies have been applied to LUAD, the long-term survival rate of patients remains unsatisfactory. We aim to find reliable immune microenvironment-related lncRNA biomarkers to improve LUAD prognosis.MethodsESTIMATE analysis was performed to evaluate the degree of immune infiltration of each patient in TAGA LUAD cohort. Correlation analysis was used to identify the immune microenvironment-related lncRNAs. Univariate cox regression analysis, LASSO analysis, and Kaplan Meier analysis were used to construct and validate the prognostic model based on microenvironment-related lncRNAs.ResultsWe obtained 1,178 immune microenvironment-related lncRNAs after correlation analysis. One hundred and eighty of them are independent prognostic lncRNAs. Sixteen key lncRNAs were selected by LASSO method. This lncRNA-based model successfully predicted patients’ prognosis in validation cohort, and the risk score was related to pathological stage. Besides, we also found that TP53 had the highest frequency mutation in LUAD, and the mutation of TP53 in the high-risk group, which was identified by our survival model, has a poor prognosis. lncRNA-mRNA co-expression network further suggested that these lncRNAs play a vital role in the prognosis of LUAD.ConclusionHere, we filtered 16 key lncRNAs, which could predict the survival of LUAD and may be potential biomarkers and therapeutic targets.