Blood test offers non-invasive brain cancer diagnosticsS. Himmelstein | June 24, 2020
A non-invasive approach to the diagnosis of intracranial tumors, which currently requires high-risk surgical techniques to obtain tissue samples, has been developed by researchers from University Health Network (Canada), University of Toronto and Northwestern University. The liquid biopsy approach to successfully detect the presence of brain cancer relies on analysis of blood plasma samples.
The diagnostic makes use of a previously developed liquid biopsy technique based on DNA methylation, a mechanism of gene expression regulation that is disrupted in cancer cells. This assay used to profile circulating tumor DNA fragments in blood was combined with machine learning to improve the accuracy of brain tumor identification and classification.
The cell-free DNA circulating in blood plasma from 221 patients was compared with patient tumor samples of brain cancer pathology. Correlation of circulating tumor DNA in blood with tumor DNA profiles confirmed the ability to detect brain tumor DNA in blood samples. A machine learning program was then applied to profile tumor type on the basis of circulating tumor DNA characteristics.
The method has also proven successful in improving diagnosis of early stages of renal cell carcinoma by analysis of circulating cell-free DNA in blood plasma or urine.