A new blood test could help detect breast cancer long before symptoms arise.

An Oxford University research team made their findings through techniques normally usually used to analyze trace metal isotopes for studying climate change and planetary formation -- this allowed them to look at how the human body processes metals.

The team demonstrated changes in a patients' isotopic composition of zinc could make it possible to identify a biomarker of the first stages of breast cancer.

The researchers analyzed zinc levels in the blood of 10 participants, half of which had breast cancer, as well as a variety of tissue samples from breast cancer patients. Their new method proved to be 100 times more sensitive to changes in the isotopic composition of metals than anything seen in medicine today, allowing them to detect key differences in zinc levels when altered by cancer cells.

"It has been known for over a decade that breast cancer tissues contain high concentrations of zinc but the exact molecular mechanisms that might cause this have remained a mystery," said Dr. Fiona Larner of Oxford University's Department of Earth Sciences, who led the research. "Our work shows that techniques commonly used in earth sciences can help us to understand not only how zinc is used by [tumor] cells but also how breast cancer can lead to changes in zinc in an individual's blood - holding out the promise of an easily-detectable biomarker of early breast cancer."

The researchers hope this new insight into cancer cell behavior will help lead to new treatments that target the process in which tumors process zinc.

"Understanding how different cancers alter different trace metals within the body could enable us to develop both new diagnostic tools and new treatments that could lead to a 'two-pronged' attack on many cancers. Further research is already underway to see what changes in other metals may be caused by other cancers," Larner said.

The findings were published in a recent edition of the journal Metallomics.