Washington, D.C. ? A drug made by Genentech received federal approval on Friday to treat breast cancer, a decision that could represent a major shift in standards for assessing the effectiveness of cancer medicines.

Going against the recommendation of its advisory panel, the Food and Drug Administration cleared Genentech’s Avastin, which is already approved for treating lung and colon cancer, based on findings that it slowed tumor growth.

The agency has traditionally approved drugs for late-stage cancer if they extended, or improved the quality of, patients’ lives. Avastin showed neither, according to Genentech’s application.