When compared to conventional testing on the same samples from patients with acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS), whole-genome sequencing–based testing detected the same abnormalities—and new genetic information in about a quarter of patients, potentially changing treatment selection for more than half of those patients, researchers said in the New England Journal of Medicine.

The researchers compared samples from 235 patients with a known or suspected blood cancer who had previously undergone successful cytogenetic analysis. They found that whole-genome sequencing detected the same chromosome changes as cytogenetic analysis and, importantly, identified additional chromosome changes in 17% of the patients, some of whom had had inconclusive results with conventional testing. Overall, it provided new genetic information in 24.8% of the newly diagnosed patients and put 16.2% of those 117 patients into a new risk category.

Additionally, the results of whole-genome sequencing were available in a median of five days and as little as three days—and at a cost comparable to standard testing. More research is needed before the testing is recommended for practice, but the researchers concluded that “whole-genome sequencing provided rapid and accurate genomic profiling in patients with AML or MDS.”

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