Brain Tumors: Primary - Diagnosis

(Page 4)

Biologic Markers. Elevated levels of certain cancer-associated molecules or compounds may be correlated with prognosis. For example, evidence of genetically mutated p53 indicates a poorer prognosis in younger patients with glioblastoma multiforme.

Elevations of epidermal growth factors (EGF) or vascular endothelial growth factors (VEGF) suggest aggressive tumors. High levels of the receptor for EGF (EGFR), in fact, are found in 70% of glioblastoma specimens.

Genetic Profiles of Cancer Cells. Analyses that identify genetic types may soon help clinicians determine if patients with specific brain tumor cells might respond better to one treatment than another. For example, specific genetic profiles of oligodendrogliomas can help predict how patients respond to nitrosourea alkylating drugs such as carmustine. Genetic variation tests are also being used to determine how patients may respond to epidermal growth factor receptor (EGFR) kinase inhibitors, such as erlotinib (Tarceva) and gefitinib (Iressa).

A genetic profile can also help give doctors a better idea of a patient’s prognosis and survival. In a 2006 study of patients with anaplastic oligodendroglioma, the status of specific chromosomal deletions within tumors was a better predictor of survival than which kind of treatment patients received. In fact, the researchers suggested that gliomas be classified according to chromosomal deletion status, and recommended that chromosomal testing be a regular part of diagnosis and treatment decisions.

Review Date: 10/19/2006
Reviewed By: Harvey Simon, M.D., Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.