New Blood Test Will Help Clinicians Choose the Best Chemotherapy Drug for Women with Breast Cancer

Triple-negative breast cancer (TNBC), which affects one in five women diagnosed with the disease, is notoriously difficult to treat. Unfortunately the most common chemotherapy drug, doxorubicin, is often ineffective in women with TNBC. Until now, there has been no easy way to determine whether a woman will respond to doxorubicin. Now, this is set to change with the development of a new blood test by Australian researchers.

Women with TNBC often have a high level of prions, a type of protein in the bloodstream. When doxorubicin is administered, the drug can bind to those proteins instead of the cancer cells, decreasing the effectiveness of the treatment. The new test, developed by researchers from the QIMR Berghofer Medical Research Institute, can measure the level of prions in the blood. This can then help clinicians to decide which chemotherapy drug to use.

The principal investigator of the study, Associate Professor Andreas Möller, explains that there are other chemotherapy drug alternatives to doxorubicin. However, until now, there has been no easy way to establish which drug should be used for an individual patient.

“There is a very similar drug to doxorubicin, called epirubicin, which does not bind to prion proteins.” A/Prof Möller said. “Doctors usually use one or the other based on personal preference rather than science, but we’ve found a reason to prioritise one over the other based on protein levels.”

The study, published recently in the journal JCI Insight, tested the blood test using tissue samples from women who had breast cancer. The next step is to trial the test in a patient study, to determine if it is effective to select the best chemotherapy drug for a patient using this blood test.

It is hoped that this new blood test will lead to improved treatment outcomes, especially a reduction in mortality rates from TNBC.

NBCF are proud to have supported A/Prof Möller and his important work. This study was funded by Australian National Health & Medical Research Council.