Scientists believe they have found a way to spot breast cancers which are more likely to spread to other parts of the body.

If successful, it could mean that individual patients could be either targeted with more powerful treatments, or spared damaging chemotherapy.

It's another demonstration of the promise of research into the human genome

Dr Carlos Caldas, University of Cambridge

The research, published in the New England Journal of Medicine, centres on a cell chemical called cyclin E.

This plays a role in the natural cycle of cell division.

Experts from the University of Texas looked at tumour tissue extracted from almost 400 patients.

One in ten

Approximately one in ten of these samples were found to have high levels of a certain form of cyclin E.

It is suggested that this chemical is constantly telling the cell to divide - making the cancer tissue grow more swiftly and aggressively.

All of these patients with high levels of cyclin E had died from a recurrence of breast cancer within five years of their first diagnosis.

None of the patients with low levels of cyclin E in their tumour tissue had died from the disease.

Breast cancer will claim the life of approximately one in three of those diagnosed with the illness.

Better test? While tests exist to help doctors determine the likely course of the illness, the researchers say that this new "marker" could prove more accurate.

In theory, women found to have high levels of the chemical in their tumours

Professor Khandan Keyomarsi, who led the research, said: "This study shows that the presence of low molecular weight forms of cyclin E has a very powerful prognostic value.

"however, we have to validate the study using newly diagnosed patients in which we are blinded to the diagnosis."

British expert Dr Carlos Caldas from the University of Cambridge said that the complexity of the technique needed to screen tumour tissue for the chemical meant that it would be "a challenge" to introduce it widely in hospital pathology labs.

He said: "This study provides fairly compelling evidence that cyclin E is another good prognostic marker for breast cancer.

"It's another demonstration of the promise of research into the human genome."