Glioblastoma

Glioblastoma, or glioblastoma multiforme (GBM), is the most common and most aggressive malignant primary brain tumor in adults. It is a grade IV astrocytoma, characterized by rapid growth, diffuse invasion, and marked genetic and histologic heterogeneity.

GBM typically affects adults, with a median age in the mid-60s. Risk factors include prior ionizing radiation; most cases occur sporadically, and familial syndromes account for a small minority.

Symptoms arise over weeks and include headaches, seizures, focal weakness, speech or cognitive changes, and personality or memory changes. MRI usually shows a contrast-enhancing mass with irregular borders, central necrosis, and peritumoral edema, often crossing the corpus callosum.

Diagnosis requires tissue analysis. Histology shows necrosis with pseudopalisading tumor cells and microvascular proliferation. Molecular testing commonly includes MGMT promoter methylation and IDH mutation status, which help predict prognosis and treatment response.

Standard therapy follows the Stupp protocol: maximal safe surgical resection when possible, followed by radiotherapy with concurrent temozolomide, then adjuvant temozolomide. Supportive care may include corticosteroids; options for recurrence include reoperation, reirradiation, chemotherapy, or tumor treating fields in selected patients.

Prognosis remains poor, with median survival about 12–18 months; five-year survival is under 5%. Younger age, good performance status, and MGMT methylation are associated with longer survival. Research explores targeted therapies, immunotherapy, vaccines, and TTFields.