Distribution Of Lymph Node Metastasis In Siewert Type ? And ? Esophagogastric Junction Adenocarcinoma Treated By Transabdominal Approach And Its Influence On Prognosis

Objective:To determine the distribution of lymph node metastasis in Siewert type ? and ? esophagogastric junction adenocarcinoma(AEG),and to explore the factors influencing the lymph node metastasis and its impact on prognosis of these kind of patients.Methods:The clinical and pathological data of 204 patients with Siewert ?/? AEG who admitted to the Second Affiliated Hospital of Zhejiang University from January 2011 to December 2018 were retrospectively analyzed.Univariate and multivariate analyses of factors influencing lymph node metastasis of patients were performed by using a chisquare test and an unconditional logistic regression model.The effect of lymph node metastasis on the prognosis of patients was performed by log-rank test.Results:204 patients with Siewert ?/? AEG were included for analysis,with 55.4% of Siewert Type ?,and 44.6% of Siewert type ?.Among them,11.27% were at early stage of AEG,and 88.73% were at advanced stage.65.7% of patients were diagnosed p T3-4 after surgery and 57.4% of them with positive lymph node metastasis.29.9% of patients took preoperative therapy.R0 resection surgery was performed in 99.0% patients,and only 1% patients were with R1 resection.The predominant stations of lymph node metastases among patients with Siewert ?/? AEG were left and right paracardial lymph node stations(15.2%-37.8%),lesser curvature lymph nodes(35.8%),nodes along left gastric artery and celiac artery(11.8%).Nodes along the distal portion of the stomach were much less often metastatic(4.4%).Univariate analysis showed that,tumor diameter(P=0.000),degree of differentiation(P=0.002),nerve invasion and vascular tumor thrombus(P=0.000),depth of tumor invasion were all influencing factors of lymph node metastasis.Multivariate unconditional logistic analysis indicated that,nerve invasion and vascular tumor thrombus,depth of tumor invasion were independent factors.The metastasis of nodes along the distal portion of the stomach were not detected in patients at early stage with Siewert ?/? AEG.While in the advanced Siewert ?/? AEG,the percent of metastasis of nodes along the distal portion of the stomach were about 4.7%-5.3%.Univariate analysis showed that,the rate of lymph nodes metastasis alone the distal portion of the stomach was much lower in Siewert type ? and well-differentiated cancer(P=0.005,P=0.009).In addition,when tumor diameter ?2cm,there was no lymph node metastasis alone the distal portion of the stomach.The 5year overall survival rate was 40% and 5year relapse-free survival rate was 32% in patients with Siewert ?/? AEG.The most frequent organ of relapse or metastasis were peritoneum and liver,secondly was anastomosis,and lung,mediastinal lymph nodes,bone,brain were much less metastatic.According to the follow-up data,the overall survival time and relapse-free time had a significant difference between lymph nodes metastasis group and without lymph nodes metastasis group in patients with p T3-4 stage.Conclusion:The transabdominal approach is safe and effective for the treatment of Siewert ?/? AEG.Nerve invasion and vascular tumor thrombus,depth of tumor invasion were independent factors for lymph node metastasis.The rate of lymph nodes metastasis alone the distal portion of the stomach in patients at early stage of Siewert ?/? AEG or at advanced stage with tumor diameter ?2cm is very low,indicated proximal gastrectomy could be performed in those patients.The organs of recurrence or metastasis of patients with Siewert ?/? AEG were most found in peritoneum and liver,preoperative chemotherapy and postoperative chemotherapy may provide a beneficial effect.