Adjuvant Radiotherapy for T3N0M0 Esophageal Squamous Cell Carcinoma With Positive Circumstantial Resection Margin(a Randomized Controlled Trial)

Although preoperative chemoradiation therapy followed by surgery is the most common approach for patients with resectable esophageal cancer, the considerable number of esophageal cancer patients received operation as the first treatment modality. Accordingly, postoperative treatments have been playing an important role because of the poor survival rates of the patients who have been treated with resection alone. The existing data shows that the 5-yeal survival rate of stage T2-3N0M0(UICC 7th edition) of thoracic esophageal squamous cell carcinoma(TESCC) after surgery is about 50% ,and locoregional lymph nodes metastases is responsible for the main cause of failure while distal metastases account for relatively less ratio. Therefore, the subclinical residual tumor is affirmative even if the early disease has been undergone curable excision and local adjuvant treatment may be essential. In rectal cancer, the involvement of the circumferential resection margin (CRM) is one of the key factors for local recurrence and poor prognosis,based on reports in which CRM with < 1mm was found to be prognostically significant, whereas the clinical and prognostic significance of the CRM involvement in EC has been investigated only in a few series showing conflicting results, as some studies suggest a significant influence of CRM. There is lack of clear evidence for prophylactic radiation therapy in positive Circumferential Resection Margin(CRM) patients of TESCC now. In view of this, the randomized controlled trial will determine the clinical efficacy and toxicity of adjuvant radiotherapy in positive Circumferential Resection Margin(CRM) for thoracic esophageal squamous cell carcinoma.