EGFR基因突变在预后方面的作用仍然存在争议。我们旨在在考虑IASLC组织学分级的情况下评估EGFR基因突变在早期手术切除肺腺癌患者中的预测作用。研究对象为在2014年1月至2019年12月期间在韩国首尔三星医学中心接受EGFR基因突变检测的297名Ⅰ至ⅡA期手术切除肺腺癌患者。根据EGFR基因突变状态（EGFR-M+与EGFR-WT）和IASLC组织学分级（G1，G2和G3）比较无复发生存期（RFS），并使用Cox比例风险模型估计调整后的风险比（aHRs）和95％置信区间（CIs）。与EGFR-WT组相比，EGFR-M+组的G3肿瘤比例显着降低（16％与33％，P <0.001）。在中位随访期为41.4个月的情况下，376名患者经历了复发。在考虑组织学分级后，与EGFR-WT组相比，EGFR-M +的aHR为1.30（95％ CI：1.04-1.62，P = 0.022）。在G3患者中，EGFR-M +组的5年RFS显着低于EGFR-WT组（58.4％与71.5％，P <0.001），但在G1和G2患者中没有差异。在考虑IASLC组织学分级方面，EGFR基因突变状态与复发风险相关，尤其是在G3肿瘤中。本研究结果有助于开发新的分期系统并确定可能受益于辅助靶向治疗的患者子集。此文章受版权保护。版权所有。

The prognostic role of EGFR mutations remains controversial. We aimed to evaluate the prognostic role of EGFR mutation in consideration of the IASLC histologic grade in patients with resected early-stage lung adenocarcinoma.3,297 patients with stage I to IIA resected lung adenocarcinoma who had EGFR mutation tests between January 2014 and December 2019 at the Samsung Medical Center, Seoul, Korea were included. Recurrence-free survival (RFS) was compared by EGFR mutation status (EGFR-M+ vs. EGFR-WT) and IASLC histologic grade (G1, G2, and G3). Cox proportional hazards models were used to estimate the adjusted HRs (aHRs) and 95% confidence intervals (CIs).Compared to the EGFR-WT group, the EGFR-M+ group had a significantly lower proportion of G3 tumor (16% vs. 33%, P < 0.001). During a median follow-up of 41.4 months, 376 patients experienced recurrence. After adjusting for histologic grade, the aHR for recurrence comparing the EGFR-M+ to the EGFR-WT was 1.30 (95% CI: 1.04-1.62, p = 0.022). The EGFR-M+ group had a significantly lower 5-year RFS than the EGFR-WT group among G3 patients (58.4% vs. 71.5%, p < 0.001) but not among G1 and G2 patients.EGFR mutation status was associated with a risk of recurrence after consideration of the IASLC histologic grading, especially in G3 tumors. The results of this study would be useful for developing a new staging system and identifying a subset of patients who may benefit from adjuvant targeted therapy.This article is protected by copyright. All rights reserved.