Tumor DNA and MRI/CT Scan Findings in Patients With Grade III or Grade IV Malignant Glioma

RATIONALE: Studying levels of tumor DNA in the samples of blood from patients with cancer may help doctors find out whether the cancer has grown and how much. PURPOSE: This laboratory study is comparing levels of tumor DNA with MRI and CT scan findings to measure cancer growth in patients with grade III or grade IV malignant glioma.

OBJECTIVES: * Correlate changes in the level of serum tumor-specific DNA over time with changes in brain tumor size as measured by serial MRI or CT scans in patients with grade III-IV malignant gliomas. OUTLINE: This is a multicenter study. Blood samples are collected from patients at baseline and every 2 months thereafter. Tumor and nontumor plasma is extracted. Plasma samples are analyzed by polymerase chain reaction (PCR) to assess the p16\_ink4a, p73, and O \^6-MGMT gene promoter methylation profile. Quantitative realtime PCR is performed on samples with tumor-specific DNA to determine the plasma concentrations of each methylated tumor-specific gene and the total plasma tumor-specific DNA concentration. Patients also undergo MRI or CT scans every 2 months. PROJECTED ACCRUAL: A total of 60 patients will be accrued for this study.