The extending range of the tumor is a more suitable predictive risk factor for lymph node metastases than the location of the deepest tumor invasion in distal thoracic esophageal and cardiac cancer.

In the regional lymph node grouping of esophageal cancer by the Japanese Guide Line (the 9th edition), the location of the deepest tumor invasion has precedence in determination. In this study, we investigated the extending range of the tumor and the location of the deepest tumor invasion to ascertain which was the more important factor in predicting lymph node metastases. We examined 52 patients with distal thoracic esophageal and cardiac cancer who had undergone esophagectomy with three-field lymph node dis-section. Among the 52 patients, 16 were found to be positive and 36 negative, for middle-upper mediastinum and cervical lymph node metastases, and the two groups were compared in terms of detailed parameters of the tumor's location. In the result, the distance from the esophagogastric junction (EGJ) to the proximal margin of the tumor was significantly longer in the metastatic group (p=0.005). In univariate logistic regression with this parameter as the independent variable, we obtained a statistically significant result (p=0.0115, odds ratio=1.041, 95% confidence interval=1.009-1.073, R2=0.1169). On the other hand, when the distance from the EGJ to the deepest portion of the tumor was used as the independent variable, p=0.0742, odds ratio=1.045, 95% confidence interval=0.996-1.096 and R2=0.0577. Multiple logistic regression was performed with these two parameters, and the distance from the EGJ to the proximal margin of the tumor was a more important factor than the distance from the EGJ to the deepest portion of the tumor (p=0.0553 vs. 0.9161). We concluded that the extending range of the tumor was a more suitable predictive risk factor of lymph node metastases than the location of the deepest tumor invasion in distal thoracic esophageal and cardiac cancer. We should seriously consider the extending range of the tumor in the regional lymph node grouping of the Japanese Guide Line.