[The new TNM classification of tumors of the esophagogastric junction. Surgical consequences].
The new International Union Against Cancer (UICC) classification in its seventh version has been out since January 2010. It included some important changes for the classification of esophageal and gastric carcinomas compared to the sixth version. For esophageal carcinomas this means a more detailed subdivision of the T and N stages which should, together with the newly introduced prognostic grouping (separate for squamous cell carcinoma and adenocarcinoma) enable a more precise and individualized prediction of prognosis. Another innovation is that positive lymph nodes in the esophageal drainage area, including celiac axis nodes and paraesophageal lymph nodes in the neck, are classified as regional lymph node metastases rather than distant metastatic spread, irrespective of tumor location. Hereby the lymphadenectomy specimen should include ≥ 6 lymph nodes (LN). The most controversial improvement is that adenocarcinomas of the esophagogastric junction (AEG) are all classified as esophageal carcinomas. This should acknowledge the similar prognosis of AEGs and esophageal carcinomas, which is worse compared to gastric carcinomas in other locations. Regarding the classification of gastric carcinomas the T-stages were redefined and lymph node staging (N-stage) was refined to allow for a better prediction of prognosis. The lymphadenectomy specimen after gastrectomy should hereby include ≥ 16 LNs. As the primary aim of the UICC classification is a preferably accurate prognosis prediction, the impact on a surgeon's therapeutic decision is low. For decisions regarding the type of resection the endoscopic AEG classification with the aim of R0 resections is still the instrument of choice. The value of the UICC classification is that it enables sophisticated comparisons between different treatment regimens and strategies.