The present invention relates to biomarkers for neoplasias such as high grade gliomas. The inventors have discovered that the overexpression of senescence associated genes (SAG) is associated with a poor prognosis in subjects with high grade gliomas. The present invention provides SAG biomarkers for predicting response to therapy for subjects having high grade glioma based on dividing the samples into high and low risk groups diagnosing high grade glioma monitoring progression of high grade glioma from one biological state to another and determining efficacy of treatment for high grade gliomas.