Girl with test tube

Blood test © Lab Science Career, licensed under CC BY-NC-SA 2.0

Blood test could help detect early breast cancer

Early-stage breast cancer could soon be caught using a blood test. The simple test could replace invasive biopsies as the first port of call for diagnosing the disease.

The test is based around the isotopic composition of the trace metal zinc. Different forms of the element zinc are known as isotopes, based on their weight.

All breast tissues process zinc. Under normal circumstances, lighter and heavier zinc isotopes are released into the bloodstream in certain proportions.

Breast cancer cells, however, hold on to more of the lighter zinc isotopes, leaving a higher proportion of heavier zinc in the bloodstream, compared to healthy people.

The research was led by the University of Oxford and included collaborators at Imperial College London and the Natural History Museum. The results were published earlier this week in the journal Metallomics.

Metals in the body

Dr Fiona Larner of the University of Oxford, lead author of the study, said that the results show how research in one scientific area, in this case the earth sciences, can have implications for other areas such as biology and medicine.

She said: 'Our work shows that techniques commonly used in earth sciences can help us to understand not only how zinc is used by tumour 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.'

Scientists previously knew that zinc accumulates in breast cancer tissues, but they were unsure how this happened. The new analysis has shed some light on how cancers process trace metals like zinc.

There was also a difference in the copper component in the breast tissue of one cancer patient in the study, suggesting that copper and zinc may be affected by the same process in cancer cells.

Two-pronged attack  

The preliminary study looked at only a handful of cancer patients and controls (healthy people used as a comparison), but the results are encouraging and could have more widespread implications. Further study is underway to prepare a blood test that could be widely used and to further understand the way cancers process trace metals.

'The hope is that this research is the beginning of a whole new approach,' said Dr Larner.

'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.'

Earth and life

The techniques the researchers used to examine changes in the isotopic composition of zinc in the body are usually used in earth sciences to study the formation of planets, the evolution of volcanoes and changes in climate.

Museum researchers Dr Emma Humphreys-Williams and Dr Stanislav Strekopytov partnered with Dr Larner to perform chemical analyses complementary to the isotopic analysis.

The method is far more sensitive to isotope levels than that currently used by clinicians.