Adjuvant Therapies or Surgery Alone for High Risk pN0 Esophageal Cancer

Inclusion Criteria:

1. Patient: No pretreatment before surgery.Informed consent signed after screening;
2. Surgery: Complete (R0) resection of tumor, with thoraco- abdominal two-field or cervico-thoraco-abdominal three-field lymph node dissection through transthoracic esophagectomy. At least 12 stations and 12 lymph nodes should be harvested, including bilateral recurrent laryngeal nerve nodes. Both open thoracotomy and minimally invasive thoracoscopic/laparoscopic approaches are allowed and histopathological examination confirmed the diagnosis of the patients with at least cleaning more or equal to 12 stations and 12 lymph nodes;
3. Histology: Thoracic esophageal squamous cell carcinoma, with no nodal involvement (pN0) after pathological examination;
4. Staging: Tumor T stage T1b-T4a according to the 7th UICC esophageal cancer staging system;
5. Definition of high risk for recurrence: meet at least one of the three below.

   A: Primary tumor located in middle or upper third of thoracic esophagus

   B: Presence of lymphovascular invasion (LVI) or submucosal metastasis

   C: Cell differentiation:Low grade or undifferentiated
6. Performance status: ECOG score 0-2;
7. Cardiac function:NYHA classification 1-2. Normal electrocardiogram;
8. Renal function: Normal serum creatinine level (SCr = 120mol/L) and creatinine clearance rate (CCr = 60 ml/min);
9. Hepatic function: Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) level less than or equal to 2.0 times the upper limit of normal (ULN). Serum alkaline phosphatase (ALP) level less than or equal to four times the upper limit of normal value. Serum total bilirubin level less than or equal to 1.5 times the upper limit of the normal value;
10. Hematopoietic function: White blood cell count (WBC) equal to or more than 4000 / μL,neutrophils (ANC) absolute count is more than or equal to 1500 / μ L, platelet count more than or equal to 100000/ μ L, hemoglobin equal to or more than 10.0 g / dl.

Exclusion Criteria:

1. Surgery through Left thoracic or transhiatal approach, whereby complete lymphadenectomy is not achieved;
2. Patients experienced severe postoperative complication and thus, are unable to tolerate any adjuvant therapy;
3. Patients who have concommitant other malignant tumor;
4. Patients with abnormal coagulation function, with bleeding tendencies (such as active peptic ulcer) or are currently receiving thrombolysis or anticoagulation therapies;
5. Severe cardiac comorbidities, including congestive heart failure,uncontrolled cardiac arrhythmia, unstable angina pectoris, myocardial infarction within six months,severe heart valve disease, or intractable hypertension;
6. Severe hepatic or renal insufficiency;
7. Poor mental status or mental disorders, poor compliance.