Blood Test May Revolutionize Brain Cancer Diagnosis

By LabMedica International staff writers
Posted on 09 Sep 2014

High-throughput sequencing studies of tumor genomes have produced new molecular markers that have enhanced classification of glioblastoma multiforme (GBM) and highlighted molecular pathways that propagate pathogenesis and progression.

When a patient shows symptoms of a brain tumor, a magnetic resonance imaging (MRI) is performed to locate tumors, but it cannot determine whether the tumor is benign or malignant, often necessitating costly and occasionally dangerous or inconclusive biopsies. A simple blood test to detect genetic markers could change all that.

Image: Histopathology of glioblastoma multiforme in the brain showing vascular endothelial proliferation (Photo courtesy of Dimitri P. Agamanolis, MD).

Scientists at the Virginia Bioinformatics Institute (Blacksburg, VA, USA) analyzed 390 normal germline exome sequenced DNA and compared them with exome sequences from germlines of 136 subjects with World Health Organization (WHO; Geneva, Switzerland) grade II and III lower-grade glioma (LGG) and 252 individuals with WHO grade IV glioblastoma.

Exome sequencing data, from HiSeq sequencing machines (Illumina; San Diego, CA, USA) were obtained from The Cancer Genome Atlas (TCGA) and the 1000 Genomes Project (1kGP). Analyzing the microsatellites from these sequences revealed that patients with various stages of glioma showed recognizable and consistent markers in their genomes for the disease. The investigators identified 48 GBM-specific loci, 42 lower-grade glioma specific loci and 29 loci that distinguish GBM from LGG.

This information indicates it is possible to develop a simple blood test that would help identify patients with different brain cancer grades, which could reduce invasive and inconclusive brain biopsies. These new, microsatellite-based diagnostics are applicable to many other cancers and diseases. It is hoped that with continued study, more markers and potential drug targets or therapies will be found.

Michael B. Waitzkin, JD, the CEO of Genomeon (Blacksburg, VA, USA) which holds an exclusive license in microsatellite technologies, said, “A blood test that can reliably differentiate between a malignant and benign brain tumor will have important clinical significance potentially preventing unnecessary brain biopsies which carry great risks to the patient and substantial costs to the health care system.” The study was published on June 5, 2014, in the journal Oncotarget.

Related Links:
Virginia Bioinformatics Institute
World Health Organization
Illumina