Researchers at Toronto’s Princess Margaret Cancer Centre have landed on a new biomarker that can predict if patients with acute myeloid leukemia will respond to standard treatment. It could help identify which patients would benefit by skipping regular chemo altogether and going straight to enrolling in clinical trials.

The new biomarker, dubbed LSC17, is derived from leukemia stem cells. These cells promote cancer development and can elude chemotherapy, lying dormant and causing relapse even in patients who are in remission after therapy. LSC17 could become a new “risk scoring” tool that can predict in a matter of days how a patient will respond to treatments, the researchers said in a statement. Clinicians may then direct patients who are less likely to respond to chemo toward clinical trials assessing new treatment strategies.

The researchers measured the LSC17 “score” of 78 AML patients by examining the leukemia stem cells in their blood or bone marrow samples. The study, published in Nature, showed that patients with high scores were more likely to have poor outcomes with standard treatment, while low scores predicted that patients would fare well with chemo and achieve long-term remissions.

“We identified the minimal set of genes that were most critical for predicting survival in these other groups of AML patients, regardless of where they were treated,” said co-principal investigator Dr. Jean Wang, affiliate scientist at the Princess Margaret Cancer Centre at the University Health Network, in the statement. “With this core 17-gene score, we have shown we can rapidly measure risk in newly diagnosed AML patients.”

The test has now been adapted to work with technology from NanoString, a cancer diagnostics company. The research team is collaborating with partners in the U.S. and Europe to validate the “stemness score” and plans to test it in a clinical trial at Princess Margaret.

Acute myeloid leukemia is one of the more deadly leukemias, with a 5-year survival rate between 20 and 30%. The cancer must be addressed quickly as its spread is difficult to control. Wellcome Trust Sanger Institute scientists recently pinpointed a CRISPR target, a gene called KAT2A, that disruptsthe growth and survival of leukemia cells when it is inhibited.