Determination of the irradiation field for clinical T1-T3N0M0 thoracic/abdominal esophageal cancer based on the postoperative pathological results.

OBJECTIVE In patients with thoracic/abdominal esophageal cancer with no clinical evidence of lymph node metastasis, there is no consensus about whether the irradiation field should include regional lymph nodes. In this study, the extent of the irradiation field for clinical stage T1-3N0M0 esophageal cancer was determined based on the postoperative pathological results. METHODS From July 1989 to June 2008, 103 patients diagnosed with clinical stage T1-3N0M0 thoracic/abdominal esophageal cancer underwent standard esophagectomy and regional lymph node dissection at the Aichi Cancer Center Hospital. Of these 103 patients, the pathological results of the resected specimens could be confirmed in 95 (92%) patients. The pathological lymphatic spread was reviewed retrospectively, and the extent of the irradiation field was determined based on the postoperative pathological results. RESULTS Of 95 patients with clinical stage T1-3N0M0 esophageal cancer, 40 (42.1%) had pathological lymph node metastases, and the frequency of nodal metastases was studied by tumor location. The rates of lymph node metastases for the upper, middle, lower and abdominal esophagus were 37.5%, 32.5%, 46% and 70%, respectively. CONCLUSIONS Pathological lymph nodes metastases are often seen after operation in clinical stage T1-3N0M0 esophageal cancer. In the present study, the optimal lymph nodes to be included in the irradiation field were determined according to the primary site in the esophagus.