Stem cell test could improve leukaemia treatment

Researchers have developed a stem cell test that could rapidly predict how patients with acute myeloid leukaemia (AML) will respond to treatment.

The test is based on 17 genes that are highly expressed in leukaemia stem cellS (LSCs). Patients showing strong activation in these genes (a high LSC17 biomarker score) are less likely to respond well to standard chemotherapy treatment. The new test could help doctors to direct such patients to alternative treatments.

'The LSC17 score is the most powerful predictive and prognostic biomarker currently available for AML, and is the first stem cell-based biomarker developed in this way for any human cancer,' said Dr Jean Wang, an affiliate scientist at the Princess Margaret Cancer Centre, Toronto, and co-lead of the study. 'Clinicians will now have a tool that they can use upfront to tailor treatment to risk in AML.'

LSCs are considered the primary reason for the high rate of relapse and treatment failure in AML. As stem cells have the ability to exist in a dormant state, this makes them resistant to therapy.

In the study, published in Nature, researchers analysed LSCs from blood or bone-marrow samples from 78 AML patients and identified 17 strongly activated genes. The scores were linked to patient outcomes for 908 patients in Canada and Europe.

Genetic tests for AML are routinely performed to assess patient risk level, but results generally take weeks to arrive. By contrast, the 17-gene test score can provide similar clinical information in less than two days.

'AML is an acute condition, and every day counts,' observed Stanley Ng, a senior PhD candidate at the University of Toronto, and co-lead of the study. 'For this reason, clinicians usually start treatment right away, without waiting for the test results.'

Dr Gerrit Jan Schuurhuis of the VU University Medical Centre, Amsterdam, who was not involved in the study, pointed out that the clinical benefits of the LSC17 score remain to be assessed because 'prognostic value does not always lead to a meaningful clinical advantage'.

Nevertheless, he said the study paved the way for a more refined understanding of LSC properties at diagnosis, which could enable clinicians to design personalised and more effective therapies.

A clinical trial of the LSC17 test is planned for next year.