Hopes of a breakthrough in breast cancer treatment have been raised following spectacular test results of a new vaccine.
US researchers said single doses of the drug on mice showed "overwhelmingly favourable results" - preventing cancers from forming and also stopping existing tumours from growing.
"If it works in humans the way it works in mice, this will be monumental," said lead researcher, immunologist Dr Vincent Tuohy.
Human tests of the vaccine could begin as early as next year.
Dr Tuohy, based at the Cleveland Clinic in the US, said: "We believe that this vaccine will some day be used to prevent breast cancer in adult women in the same way that vaccines have prevented many childhood diseases. If it works in humans the way it works in mice, this will be monumental. We could eliminate breast cancer."
The drug makes the immune system attack a particular protein found in most breast cancer cells and the mammary tissues of breastfeeding women. Therefore, if the human tests prove successful, the strategy would be to vaccinate women aged over 40 - when breast cancer risk begins to increase and pregnancy becomes less likely.
"The frequency of women who breastfeed in their early 40s and above is very low, so we are looking at vaccinating women against the disease from this stage of life onwards," Dr Tuohy said.
For younger women with a heightened risk of breast cancer, the vaccine may be an option to consider instead of prophylactic mastectomy.
The research is being published in the June 10 issue of Nature Medicine magazine.
Breast cancer is the most common form of cancer in Britain and kills around 12,000 women every year.