The U.S. Food and Drug Administration says it is revoking its approval of the use of Avastin for women with breast cancer. FDA Commissioner Margaret A. Hamburg said the agency concluded that the drug has not been shown to be safe and effective for that use. Avastin will still remain on the market as an approved treatment for certain types of colon, lung, kidney and brain cancer, an FDA release said Friday. \"This was a difficult decision. FDA recognizes how hard it is for patients and their families to cope with metastatic breast cancer and how great a need there is for more effective treatments,\" Hamburg said. \"After reviewing the available studies it is clear that women who take Avastin for metastatic breast cancer risk potentially life-threatening side effects without proof that the use of Avastin will provide a benefit, in terms of delay in tumor growth, that would justify those risks,\" she said. The side effects include severe high blood pressure, bleeding and hemorrhaging, heart attack or heart failure, and the development of perforations in different parts of the body such as the nose, stomach, and intestines, the FDA release said.