Localization of isolated lymph node metastases in esophageal cancer -: Does it influence the sentinel node concept?

Background/Aims: As demonstrated for different malignancies the detection of sentinel nodes (SNL) helps to individualize the indication for lymphadenectomy. In esophageal cancer, the lymphatic spread involves three distinct anatomical compartments. This study analyses the localization of single lymph node metastases in esophageal cancer and discusses the possible theoretical impact on SNL navigation. Methodology: 143 patients with esophageal carcinoma were included in this retrospective analysis. All patients underwent transthoracic en-bloc esophagectomy with 2-field lymphadenectomy. A meticulous work-up of all resected lymph nodes allowed a specific assignment to defined nodal groups of the abdominal and mediastinal compartment. Of 143 patients, 80 (55.9%) were classified as pN1. Results: Twenty four of 80 patients had one single (n=15 patients) or two single (n=9 patients) lymph node metastases (total of 33 nodal metastases). Twenty four of these 33 lymph node metastases (73%) were located in the abdominal compartment. 9 of 13 patients (69%) with esophageal carcinomas above the tracheal bifurcation had isolated abdominal lymph node metastases. The overall rate of skip metastasis to the abdominal compartment was 55%. Conclusions: Isolated lymph node metastases in esophageal cancer are predominantly located in the abdominal compartment along the lesser curvature and the left gastric artery. Therefore, SNL navigation in esophageal cancer has to focus on this region and requires initial laparotomy/laparoscopy irrespective of the type of esophageal resection.