A drug used to treat stage III colon cancer in patients who had surgery to remove the cancer. It is also used to treat metastatic breast cancer that has not improved after treatment with certain other anticancer drugs. Capecitabine is being studied in the treatment of other types of cancer. It is taken up by cancer cells and breaks down into 5-fluorouracil, a substance that kills tumor cells. Capecitabine is a type of antimetabolite. Also called Xeloda.