Role of Lower Esophageal Squamous Cell Carcinoma Margin Location on Abdominal Lymph Node Metastasis Risk

Background: Different sites of esophageal cancer are accompanied by different regional lymph node metastasis (LNM) risks. We aimed to investigate the impact of a lower tumor margin on abdominal LNM risk. Methods: We enrolled patients who underwent esophagectomy for esophageal squamous carcinoma (ESCC) from 2014 to 2017 in West China Hospital. Overall survival (OS) analysis was performed. We measured the distance between the lower tumor margin and esophagogastric junction (LED) with upper gastrointestinal contrast-enhanced X-ray (UGCXR). Multivariate logistic regression analysis and propensity score matching (PSM) were performed to explore the relationship between LED and the risk of abdominal LNM. Abdominal LNM risk in ESCC was stratified based on the location of the lower tumor margin. A model predicting abdominal LNM risk was constructed and presented with a nomogram. Results: The included patients had an abdominal LNM rate of 48.29%. In multivariate logistic regression analysis, LED was identified as a risk factor for abdominal LNM. Subgroup analysis of middle ESCC showed that patients with an LED less than 10 cm had a significantly higher rate of abdominal LNM than those with an LED greater than 10 cm. The abdominal LNM rate in middle ESCC patients with an LED less than 10 cm was 32.2%, while it was 35.1% in lower ESCC patients whose lower tumor margin did not invade the esophagogastric junction (EGJ), which was comparable after PSM. Conclusions: LED could help surgeons evaluate the risk of abdominal LNM preoperatively and better guide dissection of abdominal lymph nodes according to risk level.