Low grade gliomas, such as diffuse gliomas, are highly variable tumours whose disease courses are very difficult to predict. Whilst some low grade gliomas lie dormant, others rapidly progress to higher grade tumours, such as glioblastomas.
The evolution of gliomas from grade two to grade three or four is determined by changes in their genetics and lead to a considerable worsening of prognosis.
Due to the complex nature of these tumours, biomarkers (or indicators) are important in allowing better clinical management of patients. A biomarker could be a change in a gene in the tumour's DNA, or it could be a molecule produced by the tumours.
Many studies have been done to identify biomarkers that can be used to predict survival outcomes. For example, mutations to the gene IDH-1 are often linked with longer-term overall survival rates in patients with high grade glioma.
Professor Adi Gazdar and his team have identified that the expression or mutation of the SHOX2 gene is associated with poor survival prognosis and is a strong independent prognosis marker for diffuse gliomas.
They also identified that the combination of a low expression of SHOX2 in tumours with a non-mutated IDH1 gene had an overall better prognosis, despite being predicted to have a poor prognosis. They found that out of the tumours analysed, approximately a third of the non-mutated IDH-1 tumours with low SHOX2 expression were associated with an improved overall average survival of 9.6 years.
"Our findings are based on analysis of previously published studies. They will have to be confirmed in prospective studies, and their clinical contribution and method of use remain to be determined," says Professor Gazdar.
Further understanding of these molecular markers will benefit drug target identification and treatment selections for glioma patients.
As a charity, we understand that importance of biomarkers to bring us closer to an earlier and more accurate diagnosis of brain tumours.
Hence, we have launched a new funding scheme to support the validation of markers and their implementation into routine clinical use in the UK.
Read more about our clinical biomarkers awards (our scheme to identify and implement molecular testing for those affected by a brain tumour).
Read more about Professor Gazdar's research.