我们的工作重点是血清胸腺嘧啶激酶1（STK1）在预测T4期肺鳞癌（LUSC）免疫治疗预后中的作用。共纳入180例LUSC患者。根据T分期将患者分为T1-T2期和T3-T4期两组，并使用受试者工作特征曲线（ROC）确定用于预测总体生存（OS）结果的最佳截断值。下一步是使用此截断值引入单因素和多因素Cox回归模型，筛选LUSC不同T分期的预后因素。还确定了STK1与其他临床病理学因素的关联。最后，为进一步探究STK1与LUSC患者分期之间的联系，我们将分期进一步分为T1-3和T4期。我们确定了影响T4期LUSC免疫治疗患者预后的因素。首先，我们确定了预测OS结果的STK1最佳截断值为1.165 pmol/L。相关分析显示，STK1在LUSC患者中超表达于T3-4期。单因素和多因素分析表明，免疫治疗是T4期LUSC患者独立的预后因素。在接受PD-1/PD-L1抑制剂治疗的T4 LUSC患者中，STK1表达水平被发现是独立的预后因素；STK1水平高的患者死亡风险增加（95％ CI = 1.028-2.04）。STK1与更高的T分期有关，可能是进阶LUSC免疫治疗患者有效的预后标志物。©2023作者

The role of serum thymidine kinase 1 (STK1) in predicting the prognosis of T4-stage lung squamous cell carcinoma (LUSC) with immunotherapy is the focus of our work.A total of 180 LUSC patients were enrolled. In this study, according to the T stage, the patients were divided into two groups: the T1-T2 stage and the T3-T4 stage. Receiver operating characteristic (ROC) curves were used to determine the best cutoff value for predicting overall survival (OS) outcomes. The next step is to use this cutoff value to introduce univariate and multivariate Cox regression models to screen the prognostic factors in different T stages of LUSC. The association of STK1 with other clinicopathological factors was also determined. Finally, to further explore the link between STK1 and the staging of LUSC patients, we have further divided the staging into T1-3 and T4 stages. We identified factors influencing the prognosis of patients who received immunotherapy in T4 stage LUSC.First, we determined that the optimal cutoff for STK1 for predicting OS outcome was 1.165 pmol/L. Correlation analysis revealed that STK1 was over-expressed in LUSC patients at the T3-4 stage. Univariate and multivariate analysis showed that immunotherapy was an independent prognostic factor in patients with T4 stage LUSC. In the group of patients who received immunotherapy or not, the STK1 expression level was found to be an independent prognostic factor in T4 LUSC patients receiving PD-1/PD-L1 inhibitor treatment; patients with high levels of STK1 had an increased risk of death (95%CI = 1.028-2.04).STK1 is associated with a higher T stage and may be an effective prognostic marker for advanced LUSC immunotherapy patients.© 2023 The Authors.