Immunotherapy after surgery may keep early lung cancer at bay

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Able to provide written informed consent form (ICF) and agree to follow study requirements and assessment schedule. * Aged 18 years or older. * Histologically confirmed stage I non - small cell lung cancer (AJCC 9th edition), with tumor size 2cm \<= T \<=4cm. * Postoperative pathological report shows at least one high-risk factor (visceral pleural invasion, lymphovascular invasion, STAS, poorly differentiated status, high-grade invasive adenocarcinoma (any structure + high grade structure \>=20%, including solid, micropapillary, or complex glands)). * ECOG performance status 0 or 1. * PD-L1 expression \>=1%. * No EGFR/ALK sensitive mutations. * Achieved complete resection (R0) . * Within 8 weeks after surgery, with full recovery from operation. * Adequate organ function. Exclusion Criteria: * Any previous treatment for current lung cancer, including radiotherapy and systemic anti-tumour therapies (chemotherapy, immunotherapy, targeted therapy, anti-angiogenesis therapy, etc.). * Prior chest radiotherapy (including lung, oesophageal, mediastinal, or breast cancer). * Patients with large - cell neuroendocrine carcinoma (LCNEC) or mixed - subtype non - small - cell lung cancer with small - cell components. * With EGFR/ALK sensitive mutations. * Underwent segmentectomy or wedge resection only. * Tumours involving main bronchi, or with obstructive pneumonia/atelectasis (partial or whole lung). * Active autoimmune disease or history of relapsing autoimmune disease. * History of interstitial lung disease, drug-induced interstitial lung disease, or radiation pneumonitis needing hormone therapy, or current active interstitial lung disease, or on relevant treatment/intervention. * Any condition needing systemic corticosteroid (\> 10 mg/d prednisone or equivalent) or other immunosuppressant within 14 days before randomisation * Used other approved systemic immunomodulators (interferon, interleukin - 2, tumour necrosis factor, thymopentin, thymosin α1, etc.) within 4 weeks before first dose. * Herbs used for cancer control within 14 days before first study * Live/attenuated vaccine receipt within 4 weeks before enrollment, or plan to receive during study or within 5 months after last tislelizumab dose. * History of significant disease or conditions affecting organ/system function, per investigator's judgment. * Severe chronic/active infection needing systemic antibacterial, antifungal, or antiviral therapy (e.g., tuberculosis) within 14 days before first study-drug dose. ·Known HIV infection. * Allogeneic stem - cell/organ transplant history. * Active malignancy within 2 years before enrollment, except the specific cancer studied and locally recurrent cancers cured (e.g., excised basal/squamous - cell skin cancer, superficial bladder cancer, cervical/ breast carcinoma in situ). * Specific conditions and/or alcohol/drug abuse or dependence that may hinder drug administration, affect outcome interpretation, or increase complication risks. * Pregnant/breastfeeding women, or men/women planning to conceive during the study. * Participation in another interventional clinical study (except observational studies or follow-up phases).