淋巴结比率（Lymph Node Ratio，LNR）在N1b型甲状腺乳头状癌（Papillary Thyroid Cancer，PTC）的预后意义尚不明确。因此，需要明确LNR对患有N1b型PTC的患者的疾病特异性死亡率（Disease-Specific Mortality，DSM）和总体生存率（Overall Survival，OS）的影响。我们使用了接受甲状腺切除和淋巴结清扫的患者的Surveillance, Epidemiology, and End Results（SEER）数据库。使用单变量和多变量Cox比例风险模型分析和确定了与DSM和OS相关的因素。X-tile软件用于确定LNR的最佳截断值。Kaplan-Meier方法绘制了LNR的DSM生存曲线，并使用对数秩和检验进行比较。ROC曲线评估了模型的有效性。SEER数据库中共找到3223例N1b型PTC患者，时间跨度为1975年至2019年。LNR的最佳截断值为0.6。多变量Cox比例风险模型显示，年龄、种族、T3/T4分类、远处转移、手术范围、转移淋巴结数目和LNR＞0.6均为DSM的独立危险因素（均p＜0.05）。年龄、性别、T4分类、远处转移、手术范围和LNR＞0.6均为OS的独立危险因素（均p＜0.05）。Kaplan-Meier方法绘制了LNR的累积风险曲线，结果表明LNR＞0.6的患者DSM风险显著高于LNR≤0.6的患者（p＝0.002）。LNR是N1b型PTC患者DSM和OS的强有力预测因子，在PTC患者的侧颈转移分层中可作为有用的工具。© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

The prognostic significance of lymph node ratio (LNR) in N1b papillary thyroid cancer is unclear. Therefore, the impact of LNR on disease-specific mortality (DSM) and overall survival (OS) in patients with N1b papillary thyroid cancer (PTC) needs to be defined.We used the Surveillance, Epidemiology, and End Results (SEER) database of patients who had undergone thyroidectomy and lymph node dissection. Factors associated with DSM and OS were analyzed and identified using univariate and multivariate Cox proportional risk models. X-tile software was used to find the best cutoff value of LNR. Kaplan-Meier estimates for DSM were plotted for LNR and were compared with the log-rank test. The ROC curve evaluated the validity of the model.A total of 3223 patients with N1b PTC were identified in the SEER database between 1975 and 2019. The best cutoff value for LNR was 0.6. The multivariate Cox proportional risk model showed that age, race, T3/T4 classification, distant metastasis, extent of surgery, number of metastatic lymph nodes, and LNR > 0.6 were independent risk factors for DSM (all p < 0.05). Age, sex, T4 classification, distant metastasis, extent of surgery, and LNR > 0.6 were independent risk factors for OS (all p < 0.05). The Kaplan-Meier method plotted a cumulative risk curve and showed that patients with LNR > 0.6 had a significantly higher risk of DSM than patients with LNR ≤ 0.6 (p = 0.002).LNR was a powerful predictor of DSM and OS in N1b PTC patients. LNR could be a useful tool for the stratification of PTC patients with lateral neck metastases.© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.