Association of the Primary Tumor Location with the Site of Tumor Recurrence after Curative Resection of Thoracic Esophageal Carcinoma

The site of surgical failure in cases of thoracic esophageal cancer (TEC) may be affected by the vertical location of the cancer in this longitudinal organ, suggesting the need to select the mode of adjuvant therapy based on location. We classified 501 TECs (92% squamous cell carcinomas) that underwent curative surgery without preoperative treatment as 13% upper thoracic (Ut), 51% middle thoracic (Mt), and 36% lower thoracic (Lt) lesions. Recurrent disease was discovered in 180 (36%) of the patients during a postoperative survey, most frequently in the cervical nodes (19%), liver (18%), abdominal paraaortic nodes (17%), and upper mediastinal nodes (17%). Although postoperative survival rates were similar (5-year survival: Ut 51%, Mt 55%, Lt 54%), the tumor recurrence site was significantly affected by the TEC vertical location, with recurrence in the cervical and upper mediastinal nodes being most frequent for Ut and Mt cases and in the liver and abdominal paraaortic nodes for Lt cases. Insufficient surgical lymph node clearance could be assessed by the recurrence index (RI), defined as the frequency of metastasis at recurrence divided by that at surgery. The RI was significantly lower for the upper abdominal nodes (4%, 8/184) than the lower mediastinal nodes (15%, 19/123) or the upper mediastinal nodes (19%, 30/154). These findings indicated that regional tumor recurrence, corresponding to the surgical field, was more frequent in the Ut and Mt cases (53% and 51%) than the Lt cases (18%); and distant recurrence was more frequent in the Lt cases (62%) than in Ut or Mt cases (25% and 36%). Thus the vertical location of the thoracic esophageal cancer can be said to affected strongly the site of tumor recurrence after curative surgery. Regional radiotherapy might be expected to have an adjuvant effect on Ut/Mt tumors and systemic chemotherapy on Lt tumors.