Lymph node status is an important prognostic parameter in esophageal carcinoma and an independent predictor of survival. Distribution of metastatic lymph nodes may vary with tumor location, tumor histology, tumor invasion depth and neoadjuvant therapy. Surgical strategy depends on the distribution pattern of nodal metastases but consensus on the extent of lymphadenectomy differs worldwide. Especially for adenocarcinoma, the distribution of lymph node metastases has not yet been described in large series that report on a complete 2- or 3-field lymphadenectomy. The lack of homogeneity concerning the classification of lymph node stations makes interpretation of studies difficult and data hard to compare. It can only be concluded that esophageal cancer frequently metastasizes to the cervical, mediastinal and upper abdominal lymph nodes. The heterogeneity in the available evidence makes the choice for surgical strategy demanding, especially considering the significant morbidity involved in esophageal surgery.
An observational study will identify lymph node stations that should be resected in relation to tumor characteristics and may clarify if the same surgical strategy is justified in patients with and without neoadjuvant therapy. Furthermore, the prognostic value of different lymph node stations can be analyzed.
Aim of the present multinational observational cohort study is to evaluate the distribution of lymph node metastases in all patients with a resectable (cT1-4a N0-3 M0) esophageal or gastro-esophageal junction carcinoma in whom a transthoracic esophagectomy with at least a 2-field lymphadenectomy will be performed in order to develop a uniform worldwide staging system and to establish the optimal surgical strategy for esophageal cancer patients. In addition, the prognostic value of different lymph node stations, the distribution pattern of recurrence or metastases, the frequency of skip nodal metastases, and the ratio of nodal metastases inside and outside the radiation field will be studied.