The discovery of a key trigger in the spread of an aggressive form of breast cancer could herald new treatments, scientists have said.
Researchers in Edinburgh have identified the cancer cell spreading role of a gene known as C35 in patients with HER2-positive breast cancer.
This type of cancer - where the HER2 protein encourages the growth of cancer cells - affects around 9,000 women in the UK and represents about 20% of all breast cancer cases.
Current treatment involves the drug Herceptin, which attaches itself to the protein and prevents cancer cells growing and multiplying.
By identifying the gene that causes cells to spread - and developing drugs to disable it - a team at the University of Edinburgh believe they have found a new way of halting the disease.
Research leader Dr Elad Katz, of the Breakthrough Breast Cancer Research Unit, said: "HER2-positive cancers are a group of cancers that are known to be aggressive in that they grow quicker and spread quicker.
"For a long time we have been concentrating on the protein HER2 but now we have this gene that could well be responsible for the spread of the cancer. It causes the cells to detach from the original tumour and to start spreading inside the breast and further afield.
"This is absolutely critical because what we know is that the spread of the cancer is what kills the patient.
"We are at an early stage but there is now a real possibility there could be a new treatment for women with HER2-positive breast cancer."
The research is published online in the British Journal of Cancer.