Background: To determine the clinical results of radiotherapy (RT) for esophageal cancer in Japan.
Materials and methods: A questionnaire-based survey was conducted for esophageal cancer treated by definitive RT between 1999 and 2003. Clinical results of definitive RT for patients were collected from 9 major institutions. Only patients with good performance status (PS 0-2) who received a total dose of 50 Gy or more were included. Patients were classified into three groups: (A) stage I, (B) resectable stages II-III, (C) unresectable stages III-IVA. For group A, all patients treated by RT alone or chemo-radiotherapy (CRT) were included. For groups B and C, only those treated by CRT were included.
Results: In total, 167 patients were included in group A, 239 in group B, and 244 in group C. Approximately half of the patients in group A were treated by CRT. The median total RT dose ranged from 60 to 66 Gy. The median and range of the 5-year overall survival rates were 56% (48-83%) for group A, 29% (12-52%) for group B, and 19% (0-31%) for group C, respectively. A wide disparity in overall survival rates was noted among the institutions. A significant correlation between the number of patients treated per year and the 5-year overall survival rate was noted for groups B and C (both p < 0.05).
Conclusion: Although the overall survival rates for stage I esophageal cancer were excellent, a significant disparity in survival rates was noted among the institutions for stage II-IVA tumors treated by CRT.