To explore the effect of thymosin alpha 1 (Tα1) on postoperative peripheral blood circulating tumor cells and immunosenescence in patients with early-stage non-small cell lung cancer (NSCLC).

Inclusion Criteria:

• Pathologically confirmed stage I (per AJCC 8th edition) invasive NSCLC
• Resectable tumor
• undergoing lobectomy and systemic lymph node dessection
• Without a previous history of malignant tumors or other concurrent malignancies
• Naïve to any anticancer therapies or other immunostimulatory agents
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) score 0-1, with cardiac, pulmonary, hepatic, cerebral, and renal functions capable of withstanding surgery
• Aged ≥18 years and ≤75 years
• Having signed written informed consent and capable of adhering to the visit schedule and related procedures outlined in the study protocol

Exclusion Criteria:

• With a pathologically confirmed non-invasive NSCLC, including preinvasive lesions, small cell lung cancer, and benign lesions
• Post-diagnostic use of immunosuppressive medications or other immunostimulatory agents
• With known or suspected active autoimmune disease
• Allergic to thymopeptides
• With other uncontrolled serious illnesses or having acute or chronic conditions that may confound test outcomes, including active severe clinical infections ( >NCI-CTCAE grade 2 infection); diagnosed with epilepsy requiring antiepileptic treatment; on renal dialysis; with non-healing wounds, ulcers, or fractures; with a history of arteriovenous thrombotic events, including cerebrovascular accident, deep vein thrombosis, and pulmonary embolism, within six months prior to the first dose