Multicenter Cohort Study of ESD and Chemo-radiotherapy for High-risk Early-stage Esophageal Cancer

Inclusion Criteria: * 1\. Esophageal cancer patients who are pathologically confirmed as pT1a-MM stage or pT1b stage after endoscopic submucosal dissection； 2. No definite contraindications for chemo-radiotherapy； 3. Informed consent has been signed； 4. Refused surgery after endoscopic submucosal dissection. Exclusion Criteria: * 1\. Severe heart, brain, lung disease or renal dysfunction; 2. Previous history of other malignancies; 3. Prior radiation or chemotherapy 4. Researchers consider it inappropriate to participate in this experiment