Fluorouracil is used in combination with other medications to treat certain types of breast cancer after surgery to remove the tumor or radiation therapy. Fluorouracil is also used to treat cancer of the pancreas and stomach cancer. Fluorouracil is in a class of medications called antimetabolites. It works by slowing or stopping the growth of cancer cells in your body.
Fluorouracil is generally used in combination with other medications to treat colon cancer or rectal cancer (cancer that begins in the large intestine) that has gotten worse or spread to other parts of the body.