Genes involved in healing wounds may help predict breast cancer patients' long-term health, scientists hope.
Tumours differ in aggressiveness
US and Dutch researchers found distinct "healing" gene patterns, which they believe could reflect how aggressive a breast tumour is likely to be.
But they said more research was needed to see if the find would aid treatment.
Cancer charities echoed this caution about the study, published in the journal Proceedings of the National Academy of Sciences.
Antonia Bunnin, of Breakthrough Breast Cancer, said: "In the future it could provide a further means of helping to predict patients' prognosis and may allow clinicians to personalise treatment for women with breast cancer.
"However, further research is needed to determine whether treatment decisions based on this method are beneficial."
Laura Trapani, of Breast Cancer Care, said: "It is important for people with breast cancer to be aware that the 'wound healing process' described in the study is not related to wound healing following their breast surgery.
"Any problems with healing experienced by people after their surgery, for example infection, are not an indication of their prognosis."
Dr Patrick Brown, from Stanford University, working with a team at the Netherlands Cancer Institute, followed what happened to 295 patients with early breast cancer up to 12 years after surgery for their tumours.
They also analysed each patient's tumour to see what gene pattern it had - which genes were active and which were not.
New blood vessels
Some of the patients' cancers had gene patterns similar to those seen in wounds during healing. These included genes involved with new blood vessel growth.
When the researchers compared these patterns with the patients' outcomes they found those patients who fared the worst had similar gene patterns.
Those showing what the authors dubbed "wound response signatures" were more likely to see their cancer spread and also tended to die earlier than the other patients.
Dr Brown's team have now developed a way to assign a single numerical score to individual gene patterns.
In time, they believe doctors might be able to use this score, along with other clinical predictors, to plan more personalised treatment regimes for patients.
But they said in Proceedings of the National Academy of Sciences: "Prospective studies are needed to determine whether treatment decisions based on the wound response signature might benefit patients."