Objectives: This study investigates the association between microsatellite instability (MSI) and the risk of occult lymph node metastases (LNMs) in patients with early-stage endometrial cancer (EC) who showed no evidence of nodal involvement on preoperative imaging. Methods: A retrospective multicenter cohort study was conducted, including 237 patients with EC who underwent primary staging surgery between January 2022 and October 2024. The patients were stratified into two groups based on MSI status. The primary outcome was the prevalence of occult LNMs. Statistical analyses included univariate and multivariate logistic regression models, adjusting for potential confounders such as tumor grading and lymphovascular space invasion (LVSI). The significance of the models was assessed using the maximum likelihood method and Bayesian Information Criterion (BIC). Measures to reduce bias included blinding the data analyst, standardization of histopathological evaluation, and exclusion of patients with genetic conditions predisposing to MSI. Results: The MSI group had a significantly higher incidence of occult LNMs compared to the MSS group (19% vs. 6.7%,p= 0.005). The multivariate analysis confirmed MSI as an independent risk factor for LNMs (OR = 1.105, 95% CI 1.016–1.202,p= 0.020). The sub-analysis showed that loss ofMLH1/PMS2or bothMLH1/PMS2andMSH2/MSH6heterodimers further increased LNMs risk, independently from other risk factors. Conclusions: MSI is independently associated with a higher risk of occult LNMs in early-stage EC, suggesting a potential role for MSI profiling in refining lymph node staging strategies. Future prospective studies should assess the prognostic impact of this association and its implications for surgical decision-making.
目的：本研究旨在探讨微卫星不稳定性（MSI）与早期子宫内膜癌（EC）患者隐匿性淋巴结转移（LNMs）风险之间的关联，这些患者在术前影像学检查中均未显示淋巴结受累证据。方法：开展了一项回顾性多中心队列研究，纳入2022年1月至2024年10月期间接受初次分期手术的237例子宫内膜癌患者。根据MSI状态将患者分为两组。主要观察指标为隐匿性淋巴结转移的发生率。统计分析采用单因素及多因素逻辑回归模型，并对肿瘤分级、淋巴血管间隙浸润（LVSI）等潜在混杂因素进行校正。模型显著性通过最大似然法和贝叶斯信息准则（BIC）进行评估。为减少偏倚采取的措施包括对数据分析人员设盲、标准化组织病理学评估、排除具有MSI遗传易感性的患者。结果：与微卫星稳定（MSS）组相比，MSI组隐匿性淋巴结转移发生率显著更高（19% vs. 6.7%，p=0.005）。多因素分析证实MSI是淋巴结转移的独立危险因素（OR=1.105，95% CI 1.016–1.202，p=0.020）。亚组分析显示，MLH1/PMS2或同时缺失MLH1/PMS2与MSH2/MSH6异源二聚体表达会进一步增加淋巴结转移风险，且该风险独立于其他危险因素。结论：MSI与早期子宫内膜癌患者隐匿性淋巴结转移风险增加独立相关，提示MSI检测在优化淋巴结分期策略中具有潜在价值。未来前瞻性研究应评估该关联对预后的影响及其对手术决策的指导意义。
肿瘤(癌症)患者之家