Unresectable Fibrolamellar Carcinoma

This phase I/II trial studies the side effects and how well nivolumab, fluorouracil, and interferon alpha 2b work for the treatment of fibrolamellar cancer (liver cell cancer) that cannot be removed by surgery (unresectable). Immunotherapy with monoclonal antibodies, such as nivolumab, may help the body's immune system attack the cancer and may interfere with the ability of tumor cells to grow and spread. Chemotherapy drugs, such as fluorouracil, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Interferon alpha 2b may help stimulate the immune system to fight cancer. Giving nivolumab, fluorouracil, and interferon alpha 2b may work better in treating unresectable fibrolamellar cancer compared to fluorouracil and interferon alpha 2b alone.