Avastin was first approved to treat colon cancer. Genentech

The U.S. Food and Drug Administration withdrew approval of the drug Avastin for advanced breast cancer patients even though some claimed it’s why they are still alive.

The drug regulator announced Friday it is revoking Avastin (bevacizumab) for metastatic breast cancer after concluding that the drug has not been proven to be safe and effective for that purpose.

"This was a difficult decision," FDA Commissioner Dr. Margaret Hamburg said, adding the agency recognized the need for patients and their families to cope with metastatic breast cancer and the need for more effective treatments.

"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 tumour growth, that would justify those risks. Nor is there evidence that use of Avastin will either help them live longer or improve their quality of life."

The risks included:

• Severe high blood pressure.
• Massive bleeding.
• Heart attack or heart failure.
• Perforations in the stomach and intestines.

The treatment is not approved for funding in Ontario, British Columbia, Quebec or Nova Scotia.

"I think the number of women receiving this medication outside of a clinical trial is probably going to be pretty small, and limited to some self-paying patients," said Dr. Eitan Amir, a medical oncologist at Princess Margaret Hospital in Toronto.

Still available in Canada

Health Canada said Friday it has not arrived at final conclusions or recommendations regarding Avastin, which continues to be available for breast cancer.

"Health Canada is actively reviewing Avastin to determine whether the benefits of Avastin continue to outweigh the risks as a treatment for breast cancer. In arriving at its final conclusions, Health Canada will consider U.S. FDA decision and information by its manufacturer," the regulator said in an email.

"Health Canada will inform healthcare professionals and Canadians of any changes with respect to the status of Avastin once the review of Avastin has been completed."

In Canada, Avastin also continues to be approved for colon, kidney, lung, and a type of brain cancer called glioblastoma multiforme.

While there are still side-effects when Avastin is used for those cancers, the benefits are clear, said CBC's medical specialist Dr. Karl Kabasele.

In the U.S., doctors could continue to prescribe Avastin for breast cancer, though insurers may not pay for it.

The drug's manufacturer, Genetech, part of Roche Group, plans to study Avastin in combination with the chemotherapy drug paclitaxel in previously untreated metastatic breast cancer.

"We are disappointed with the outcome," said the company’s chief medical officer Dr. Hal Barron.

"We remain committed to the many women with this incurable disease and will continue to provide help through our patient support programs to those who may be facing obstacles to receiving their treatment in the United States."

The treatment can cost $100,000 US including infusion fees.

It is used only in patients whose breast cancer has metastasized, and is used in conjunction with chemotherapy to delay progression of the disease.

In the U.S. this summer, breast cancer patients shouted against the FDA and its panelists at a two-day hearing into the drug.

With files from The Associated Press, CBC's Kelly Crowe and The Canadian Press