Objective: To investigate the value of positive lymph node ratio (LNR) in predicting the prognosis of patients with esophageal cancer.
Methods: We retrieved the data of a total of 862 patients with esophageal cancer with complete clinical pathology data archived in SEER database in 2010 to 2015. The best cutoff point of LNR was selected using X-tile software. Univariate and multivariate COX proportional hazard models were used to assess the value of LNR in predicting the prognosis of patients after propensity score matching (PSM).
Results: The best cut-off point of LNR determined using X-tile 3.6.1 software was 0.16. The patients with LNR < 0.16 and those with LNR≥0.16 showed significant differences in the number of positive lymph nodes, pathological type, T stage and M stage. After 1:1 propensity score matching, the two groups showed no significant difference in the clinical data or pathological parameters. Matched univariate and multivariate COX regression analyses showed that LNR, primary tumor site and M staging were all independent risk factors affecting the prognosis of patients, and among them LNR had the most significant predictive value (LNR < 0.16 vs LNR≥0.16: HR=1.827, 95% CI: 1.140-2.929; P=0.000). The median survival time of patients with LNR < 0.16 was 31 months (95%CI: 22.556-39.444 months), as compared with 16 months (95%CI: 12.989-19.011) in patient with LNR≥0.16 (Log Rank χ2=27.392, P < 0.0001). LNR had a better accuracy than N stage for assessing the patients' prognosis with an area under the ROC curve of 0.617 (95%CI: 0.567-0.666), as compared with 0.515 (95%CI: 0.463-0.565) of N stage (z=3.008, P=0.0026).
Conclusions: LNR≥0.16 is an independent risk factor affecting the prognosis of patients with esophageal cancer and has better prognostic value than N stage.
目的: 探讨阳性淋巴结比率（LNR）对判断食管癌患者预后的价值。
方法: 选取2010年到2015年seer数据库中有完整临床病理资料的862例食管癌患者为研究对象，应用X-tile软件选取LNR的最佳截断点，在进行倾向性评分匹配（PSM）后，运用单因素和多因素COX比例风险模型探讨LNR在食管癌患者预后中的价值。
结果: X-tile 3.6.1软件筛选出LNR的最佳截断点为LNR < 0.16和LNR≥0.16。匹配前LNR < 0.16和LNR≥0.16两组患者的被检淋巴结数、病理类型、T分期和M分期差异有统计学意义；1:1匹配后，两组患者的临床资料和病理学指标差异均无统计学意义。匹配后的单因素和多因素COX回归分析结果显示，LNR、原发部位、M分期均是影响食管癌患者预后的独立危险因素，其中尤以LNR最为显著（LNR < 0.16 vs LNR≥0.16，HR= 1.827，95%CI：1.140~2.929，P=0.000）。LNR < 0.16组患者的中位生存时间为31个月（95%CI：22.556~39.444），LNR≥0.16组为16个月（95%CI：12.989~19.011），LNR < 0.16组患者的预后显著优于LNR≥0.16组，差异有显著统计学意义（Log Rank χ2= 27.392，P < 0.0001）。LNR和N分期对评估预后的准确性分析显示，LNR的ROC曲线下面积为0.617（95%CI：0.567~0.666），N分期的ROC曲线下面积为0.515（95%CI：0.463~0.565），LNR预测预后的价值明显优于N分期（z=3.008，P=0.0026）。
结论: LNR≥0.16是食管癌患者预后的独立危险因素，预后预测价值显著优于传统N分期。
Keywords: SEER database; esophageal cancer; positive lymph node ratio; prognosis.