Experimental blood test spots early breast cancer with 95% accuracy, Israeli study finds

Israeli scientists have developed an experimental blood test that identified early breast cancer — tumours no larger than 2cm that had not spread beyond the breast — with about 95% accuracy. The study was published in the journal Nature on Wednesday, 11 November, the Hebrew University and The Times of Israel reported.

The research was led by Professor Efrat Shema of the Weizmann Institute of Science and Professor Guy Ron of the Hebrew University of Jerusalem, with Noa Furth as first author. Sheba and Kaplan medical centres in Israel and researchers in France, Germany, Italy and the United States also took part.

What the test looks for

Rather than tumour cells themselves, the test looks for epigenetic signals: chemical tags on the proteins around which DNA is wound, which help decide which genes are switched on or off. The team first studied 12 tumours removed in surgery and found that cells differed even within a single tumour. They then searched the blood for matching signals.

Artificial intelligence models were trained on blood samples from 77 breast cancer patients followed for at least five years at the Mayo Clinic in Florida, and from 30 healthy women. The sample was later expanded to 188. The researchers said the results held across different breast densities and cancer subtypes.

Predicting recurrence

The test also told apart patients whose cancer returned after treatment from those whose did not with about 81% accuracy. Breast cancer comes back in 20-40% of cases, the researchers said. Shema said such markers could in future help not only to predict recurrence but also to find ways to prevent it.

The test remains experimental and has been tried on a relatively small number of samples; the reports do not say when, or whether, it might reach clinics. It does not replace mammography, which cuts the risk of dying from breast cancer by 22%. Women with questions about breast checks should talk to their family doctor.