Neoantigen Dendritic Cell Vaccine and Nivolumab in HCC and Liver Metastases From CRC

This study tests whether a personalized cancer vaccine made from a patient's own tumor (a neoantigen dendritic cell vaccine) combined with nivolumab (an immune therapy) helps the immune system fight liver cancer (HCC) or colorectal cancer that has spread to the liver. **You may be eligible if...** - You have liver cancer (HCC) that is manageable with surgery or ablation, with up to 3 tumors or multiple small tumors, and good liver function (Child-Pugh 5 or 6) - OR you have colorectal cancer with liver-only metastases that is potentially removable - You have had recent imaging confirming no disease outside the liver - You are in good enough health for surgery **You may NOT be eligible if...** - Your liver function is severely impaired - Your cancer has spread beyond the liver - You have had serious immune-related side effects from prior immunotherapy - You have active autoimmune disease - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.