WASHINGTON – The government delivered a blow to some desperate patients Friday as it ruled the blockbuster drug Avastin should no longer be used to treat advanced breast cancer.

Avastin is hailed for treating colon cancer and certain other malignancies.

But the Food and Drug Administration said it appeared to be a false hope for breast cancer: Studies haven’t found that it helps those patients live longer or brings enough other benefit to outweigh its dangerous side effects.

“I did not come to this decision lightly,” said the FDA’s commissioner, Dr. Margaret Hamburg. But she said, “Sometimes despite the hopes of investigators, patients, industry and even the FDA itself, the results of rigorous testing can be disappointing.”