The aim of this study was to compare the 7th with the 6th edition of the American Joint Commission on Cancer Staging System for prognostic stratification of gastric cardiac carcinomas involving the esophagus. We retrospectively compared differences in pathological stages with patient survival between the 7th and the 6th staging systems in 142 consecutive resection cases of this cancer. Patient median age was 65 years. The male-female ratio was 3.3. The epicenter of all tumors was within 5 cm below the gastroesophageal junction. The median tumor size was 5.0 cm. Most tumors (79%) were typical adenocarcinomas and the rest showed uncommon histology types. Using the guidelines for gastric cancer, this group of cancer was better stratified by the 7th than the 6th edition of the staging system, especially for pathological nodal (pN) and overall stage pIIIC. Patients with celiac axis nodal disease had the 5-year survival rate worse than those staged at pN3A and pIIIA. Patients staged at pT3 and pN3B had the 5-year survival rate worse than those at pM1 and pIV. We showed that the overall stage of gastric cardiac carcinomas was better stratified by gastric than by esophageal cancer grouping. We conclude that these tumors are better stratified with the 7th than the 6th edition of the gastric staging system, especially for pIII cancers, and better staged by the new gastric than esophageal cancer staging system. We propose that the staging of these tumors be reverted to gastric grouping and combine pT3 and pN3B into the overall stage pIV.