The extent of lymphadenectomy in esophageal resection for cancer should be standardized

Abstract

The incidence of esophageal cancer increases, with approximately 482,000 patients diagnosed with esophageal cancer each year. Despite the growing incidence of esophageal carcinoma, the extent of the lymphadenectomy is still under discussion. Lymph node status is an important prognostic parameter in esophageal cancer and an independent predictor of survival. Surgical strategy depends on the distribution pattern of nodal metastases but consensus on the extent of lymphadenectomy differs worldwide. For squamous cell cancer, Japanese surgeons have standardized the 2- or 3-field lymphadenectomy according to the location of the tumor. For adenocarcinoma, in the Western World accounting for 85% of all esophageal cancers, the type of lymphadenectomy to perform is not clear. Moreover, the use of neoadjuvant therapy may influence the mediastinal lymph nodes and the significance of the lymphadenectomy for survival. These aspects have challenged the traditional policy concerning lymphadenectomy, at least in the Western World. Furthermore, an extensive lymphadenectomy may improve survival but, on the other hand, may cause significant more morbidity. An overview of the literature on the extent of lymphadenectomy for esophageal cancer with respect to the supposed lymph node distribution patterns for squamous cell carcinoma and adenocarcinoma, the different lymph node classification systems, the commonly used surgical techniques and outcomes, and the proposal of observational cohort study to standardize the type of lymphadenectomy according to the type of tumor, location and use of neoadjuvant therapy will be provided.

Keywords: Esophageal cancer; esophagectomy; lymph node metastases; lymphadenectomy.

Figure 1

Station numbers of regional lymph nodes according to JES classification 11th edition (Used with the permission of the Japan Esophageal Society).

Figure 2

Lymph node maps for esophageal and esophagogastric cancers according to AJCC classification 8th edition. (A-C) Lymph node maps for esophageal cancer. Regional lymph node stations for staging esophageal cancer from left (A), right (B), and anterior (C). 1R, Right lower cervical paratracheal nodes, between the supraclavicular paratracheal space and apex of the lung. 1 L, Left lower cervical paratracheal nodes, between the supraclavicular paratracheal space and apex of the lung. 2R, Right upper paratracheal nodes, between the intersection of the caudal margin of the brachiocephalic artery with the trachea and the apex of the lung. 2L, Left upper paratracheal nodes, between the top of the aortic arch and the apex of the lung. 4R, Right lower paratracheal nodes, between the intersection of the caudal margin of the brachiocephalic artery with the trachea and cephalic border of the azygos vein. 4L, Left lower paratracheal nodes, between the top of the aortic arch and the carina. 7, Subcarinal nodes, caudal to the carina of the trachea. 8U, Upper thoracic paraesophageal lymph nodes, from the apex of the lung to the tracheal bifurcation. 8 M, Middle thoracic paraesophageal lymph nodes, from the tracheal bifurcation to the caudal margin of the inferior pulmonary vein. 8Lo, Lower thoracic paraesophageal lymph nodes, from the caudal margin of the inferior pulmonary vein to the EGJ. 9R, Pulmonary ligament nodes, within the right inferior pulmonary ligament. 9L, Pulmonary ligament nodes, within the left inferior pulmonary ligament. 15, Diaphragmatic nodes, lying on the dome of the diaphragm and adjacent to or behind its crura. 16, Paracardial nodes, immediately adjacent to the gastroesophageal junction. 17, Left gastric nodes, along the course of the left gastric artery. 18, Common hepatic nodes, immediately on the proximal common hepatic artery. 19, Splenic nodes, immediately on the proximal splenic artery. 20, Celiac nodes, at the base of the celiac artery [Used with the permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Eighth Edition (2017) published by Springer Science and Business Media LLC, www.springer.com.]