Abstract
PURPOSE: The route of lymphatic spread in esophageal cancer remains unclear. The present study aimed to determine the pattern of lymphatic metastasis in its early stages. METHODS: The data were reviewed of 1074 patients who underwent curative esophagectomy for thoracic esophageal squamous cell carcinoma and metastasis in 1-2 lymph nodes between January 2015 and December 2021. The frequencies of lymph node metastasis were analyzed by the anatomic sites and regions involved. RESULTS: Of the 1074 patients, 668 patients (62.2%) with one positive lymph node and 406 (37.8%) with two positive lymph nodes. Paracardial lymph nodes were the most frequently involved nodes (35.1%), followed by right thoracic recurrent nerve nodes (24.0%), middle thoracic paraesophageal nodes (14.7%), left thoracic recurrent nerve nodes (10.4%), subcarinal nodes (8.0%), lower thoracic paraesophageal nodes (7.8%), and upper thoracic paraesophageal nodes (5.7%). The frequency of lymph node metastasis in other sites was less than 3%. The majority of lymph node metastases occurred in the longitudinal direction to the perigastric (36.5%) and bilateral recurrent nerve regions (33.4%) and in the transverse direction to the paraesophageal region (27.7%). As the tumor location changed from the upper to the lower thoracic esophagus, the frequencies of lymph node metastasis decreased in the bilateral recurrent nerve region but increased in the perigastric region. CONCLUSION: Bilateral recurrent nerve nodes, paraesophageal lymph nodes, and perigastric nodes were the most common sites of early lymph node metastasis. Esophageal squamous cell carcinoma involves more longitudinal than transverse lymph node metastases.