Adjuvant PD-1 Inhibitor for Patients With Early-stage Hepatocellular Carcinoma Following Microwave Ablation

This study tests whether adding a PD-1 inhibitor (an immunotherapy drug that helps the immune system fight cancer) after microwave ablation (a heat-based procedure that destroys liver tumors) can prevent liver cancer from returning in patients with early-stage hepatocellular carcinoma (HCC), the most common type of liver cancer. **You may be eligible if...** - You are between 18 and 75 years old - You have been diagnosed with hepatocellular carcinoma (HCC) at an early stage (BCLC 0-A) - Your cancer is confined to the liver - There is no sign of cancer returning at 2–4 weeks after ablation - You are in good functional health - You have adequate liver and blood function **You may NOT be eligible if...** - You have had other cancers or previously had HCC that recurred - You received any prior treatment for HCC - You have active infections, autoimmune disease, or immune deficiency - You have had recent bleeding from esophageal varices Talk to your doctor to see if this trial is right for you.