Role of Postoperative Radiotherapy for Microscopic Margin Involvement in the Squamous Cell Carcinoma of Esophagus

PURPOSE The objective of this study was to assess the effect of postoperative radiotherapy on the outcome of esophageal cancer with microscopically positive resection margin by comparing the results with those of patients with negative resection margin. MATERIALS AND METHODS Medical records of 88 patients treated with macroscopic resection followed by postoperative radiotherapy for stage II or III squamous cell carcinoma of the esophagus from June 1984 to March 2008 were reviewed. Twelve patients had received chemotherapy. Patients were classified into two groups based on resection margin status: negative resection margin (group A, n=66) and microscopically positive resection margin (group B, n=22). Median follow-up duration of living patients was 68 months (range, 18 to 115 months). Median total radiation dose of group A and group B was 51.5 Gy (range, 45 to 69 Gy) and 52.1 Gy (range, 45 to 64 Gy), respectively. RESULTS Median overall survival and disease-free survival were 15 and 10 months, respectively. The five-year overall survival, disease-free survival, and local control rates for group A and group B were 15.9% and 16.4%, 13.5% and 9.1%, and 76.3% and 69.6%, respectively. No statistically significant difference in terms of overall survival, disease-free survival, and local control (p=0.295, p=0.209, and p=0.731, respectively) was observed between group A and group B. Seven patients experienced toxicity of grade 3 or higher. CONCLUSION A significant portion of patients with margin involvement reached long term survival after addition of postoperative radiotherapy. These results suggest a potential role of postoperative radiotherapy, especially for patients with margin involvement.