The Range of Tumor Extension Should Have Precedence over the Location of the Deepest Tumor Center in Determining the Regional Lymph Node Grouping for Widely Extending Esophageal Carcinomas

Background The Japanese Guide Lines for the Clinical and Pathologic Studies on Carcinoma of the Esophagus (9th edn) give precedence to the location of the deepest tumor center rather than the range of tumor extension when determining regional lymph node grouping. We evaluated the validity of this recommendation. Methods The subjects were 49 patients with carcinomas of the distal thoracic esophagus and cardia who had undergone esophagectomy with three-field lymph node dissection. We measured variables defining tumor location, such as the distance from the esophagogastric junction (EGJ) to the proximal margin of the tumor (DJP), the distance from the EGJ to the distal margin of the tumor (DJD), and the distance from the EGJ to the deepest tumor center (DJC). To examine the relation of tumor location to lymph node metastasis in the proximal direction, the patients were divided into two groups according to the presence (14 patients) or absence (35 patients) of middle-upper mediastinal and/or cervical lymph node metastases. These two groups were compared with respect to the above variables. To analyze lymph node metastasis in the distal direction, the patients were also divided into two groups according to the presence (12 patients) or absence (37 patients) of distant abdominal lymph node metastases. These two groups were similarly compared with respect to the above variables. Results DJP was significantly longer in the patients with middle–upper mediastinal and/or cervical lymph node metastases than in those without such metastases. Multiple logistic regression analysis showed that the DJP was a better predictor of middle–upper mediastinal and/or cervical lymph node metastases than was the DJC. The DJD was significantly longer in the patients with distant abdominal lymph node metastases. Multiple logistic regression analysis also showed that the DJD was a better predictor of distant abdominal lymph node metastases than was the DJC. Conclusions The range of tumor extension is a more reliable predictor of the risk of distant lymph node metastases than is the location of the deepest tumor center in esophageal carcinoma.