Supplementary Material for: Clinical significance of the preoperative inflammatory burden index in esophageal cancer

Introduction: The inflammatory burden index (IBI) serves as a prognostic marker for several cancers. Here, we evaluated the predictive value of preoperative IBI associated with the surgical and oncological outcomes of patients with esophageal cancer (EC). Methods: The IBI was formulated as C-reaction protein x neutrophil/lymphocyte. We retrospectively analyzed preoperative IBI of 147 EC patients receiving esophagectomy between 2008 and 2018. Cox proportional hazards models and multivariable logistic regression were employed to identify independent risk factors of surgical site infection and prognosis. Results: Increased preoperative IBI significantly correlated with higher tumor stage. Patients with high IBI experienced shorter overall survival (P = 0.0002) and disease-free survival (P = 0.002) compared with those with low IBI. In the adjusted Cox-proportional hazards regression models, increased IBI served as an independent prognostic factor for overall survival (hazard ratio, 3.56; 95% confidence interval, 1.79–7.34; P = 0.0003) and disease-free survival (hazard ratio, 3.03; 95% confidence interval, 1.60–5.92; P = 0.007). Multivariable analysis identified preoperative high IBI served as an independent risk factor for overall surgical site infection (odds ratio, 2.53; 95% confidence interval, 1.00–6.38; P = 0.049). Conclusion: Preoperative IBI may serve as a useful predictor of prognosis and surgical site infection of patients with EC after esophagectomy.

引言：炎症负荷指数（inflammatory burden index, IBI）可作为多种癌症的预后标志物。本研究旨在评估术前IBI对食管癌（esophageal cancer, EC）患者手术结局与肿瘤学结局的预测价值。方法：IBI的计算公式为C反应蛋白×中性粒细胞与淋巴细胞比值。我们回顾性分析了2008年至2018年间接受食管切除术的147例食管癌患者的术前IBI水平。采用Cox比例风险模型及多变量logistic回归分析，以明确手术部位感染及预后的独立危险因素。结果：术前IBI升高与更高的肿瘤分期显著相关。与IBI较低的患者相比，IBI较高的患者总生存期（P=0.0002）与无病生存期（P=0.002）均显著缩短。在校正后的Cox比例风险回归模型中，IBI升高可作为总生存期（风险比，3.56；95%置信区间，1.79–7.34；P=0.0003）及无病生存期（风险比，3.03；95%置信区间，1.60–5.92；P=0.007）的独立预后因素。多变量分析显示，术前高IBI是手术部位感染的独立危险因素（比值比，2.53；95%置信区间，1.00–6.38；P=0.049）。结论：术前IBI可作为食管癌患者食管切除术后预后及手术部位感染的有效预测指标。