Study to Evaluate the Efficacy and Safety of Adjuvant Tislelizumab in High-Risk Stage I NSCLC

This study is testing whether adding an immunotherapy drug called tislelizumab after surgery can reduce the chance of lung cancer returning in patients with early-stage (Stage I) non-small cell lung cancer (NSCLC) that has specific high-risk features. This type of treatment given after surgery is called adjuvant therapy. **You may be eligible if...** - You are 18 or older with confirmed Stage I NSCLC, with a tumor between 2 cm and 4 cm in size - Your post-surgery pathology shows at least one high-risk feature such as invasion of blood vessels, spread through the air spaces (STAS), poorly differentiated tumor cells, or high-grade adenocarcinoma - You have had complete surgical removal of the tumor - Your overall health and organ function are adequate to receive immunotherapy **You may NOT be eligible if...** - You have Stage II or higher lung cancer - Your tumor is smaller than 2 cm or larger than 4 cm - You have no high-risk pathological features after surgery - You have active autoimmune disease or are on systemic steroids Talk to your doctor to see if this trial is right for you.