This study is an observation, single center study to evaluate the alternations and prognostic value of peripheral blood lymphocyte (PBL) in patients diagnosed with thoracic cancers, including lung cancer, esophageal squamous cell carcinoma and thymic epithelial carcinoma underwent radiotherapy with or without chemotherapy.

Inclusion Criteria:

Age at least 18 years. ECOG PS 0-1. Pathologically confirmed NSCLC, esophageal squamous cell carcinoma or thymic epithelial tumor.

Life expectancy of more than 3 months. Patients with no indications for palliative radiotherapy in the opinion of the investigator.

Patients with a prior history of surgery are eligible if they have recovered adequately from the toxicity and/or complications of surgery.

Signed informed consent for the use of fresh tumor biopsies before and during the treatment.

Women of childbearing age and men must agree to use effective contraception during the trial.

Adequate organ function within 1 week prior to the enrollment：

1. Adequate bone marrow function: hemoglobin ≥80g/L, white blood cell (WBC) count ≥ 4.0 * 10 ^ 9/L or neutrophil count ≥ 1.5 * 10 ^ 9/L, and platelet count ≥ 100 * 10 ^ 9/L;
2. Adequate hepatic function: total bilirubin < 1.5 x upper limit of normal (ULN). Note: If total bilirubin is > 1.5 x ULN, direct bilirubin must ≤ ULN, Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) ≤2.5 ULN;
3. Adequate renal function: serum creatinine ≤ 1.5 x ULN or creatinine clearance ≥ 50 mL/min;

Exclusion Criteria:

Pregnant or lactating women. History of any other malignancy. Patients in whom palliative radiotherapy is indicated in the opinion of the investigator.

Active infection, congestive heart failure, myocardial infarction within the 6 months prior to enrollment, unstable angina pectoris or cardiac arrhythmia.

Patients who have received tumor vaccine; or administration of live, attenuated vaccine within 4 weeks before the start of treatment.

Mental disorders, drug abuse, and social condition that may negatively impact compliance in the opinion of the investigator.

Chinese patients diagnosed with NSCLC, esophageal squamous cell carcinoma or thymic epithelial tumor.