The lymphatic system is the main way of tumor metastasis and diffusion. Esophageal cancer is one of the typical cancers that are prone to metastasis through the lymphatic system. At present, an increasing number of studies show that the interaction between tumor cells and lymphatic endothelial cells is the first step in tumor lymphatic metastasis, but the underlying molecular mechanism is unclear. This article reviews the role and changes of tumor-related lymphatic vessels and lymphatic endothelial cells in the process of tumor lymphatic metastasis, which lays a foundation for further study of the specific molecular mechanism of esophageal cancer lymphatic metastasis and provides a new treatment direction for esophageal cancer patients.
ObjectiveTo investigate the prognostic value of preoperative serum albumin-to-globulin ratio (AGR) and neutrophil-lymphocyte ratio (NLR) in the overall survival (OS) of patients with esophageal squamous cell carcinoma (ESCC), and to establish an individualized nomogram model and evaluate its efficacy, in order to provide a possible evaluation basis for the clinical treatment and postoperative follow-up of ESCC patients. MethodsAGR, NLR, clinicopathological and follow-up data of ESCC patients diagnosed via pathology in the Department of Thoracic Surgery, The First Affiliated Hospital of Xinjiang Medical University from 2010 to 2017 were collected. The correlation between NLR/AGR and clinicopathological data were analyzed. Kaplan-Meier analysis and log-rank test were used for survival analysis. The optimal cut-off values of AGR and NLR were determined by X-tile software, and the patients were accordingly divided into a high-level group and a low-level group. At the same time, univariate and multivariate Cox regression analyses were used to identify independent risk factors affecting OS in the ESCC patients, and a nomogram prediction model was constructed and internally verified. The diagnostic efficacy of the model was evaluated by receiver operating characteristic (ROC) curve and calibration curve, and the clinical application value was evaluated by decision curve analysis. ResultsA total of 150 patients were included in this study, including 105 males and 45 females with a mean age of 62.3±9.3 years, and the follow-up time was 1-5 years. The 5-year OS rate of patients in the high-level AGR group was significantly higher than that in the low-level group (χ2=6.339, P=0.012), and the median OS of the two groups was 25 months and 12.5 months, respectively. The 5-year OS rate of patients in the high-level NLR group was significantly lower than that in the low-level NLR group (χ2=5.603, P=0.018), and the median OS of the two groups was 18 months and 39 months, respectively. Multivariate Cox analysis showed that AGR, NLR, T stage, lymph node metastasis, N stage, and differentiation were independent risk factors for the OS of ESCC patients. The C-index of the nomogram model was 0.689 [95%CI (0.640, 0.740)] after internal validation. The area under the ROC curve of predicting 1-, 3-, and 5-year OS rate was 0.773, 0.724 and 0.725, respectively. At the same time, the calibration curve and the decision curve suggest that the model had certain efficacy in predicting survival and prognosis. ConclusionPreoperative AGR and NLR are independent risk factors for ESCC patients. High level of AGR and low level of NLR may be associated with longer OS in the patients; the nomogram model based on AGR, NLR and clinicopathological features may be used as a method to predict the survival and prognosis of ESCC patients, which is expected to provide a reference for the development of personalized treatment for patients.