Because the neurons within the brain cannot replicate, brain cancer is almost always caused by genetic mutations in the surrounding cells. These mutations cause the cells to grow rapidly and invade other tissues in the brain. The extent of the genetic mutations can determine how aggressive a type of brain cancer is.
Identification
Aggressive brain cancer describes brain cancers that grow rapidly and invade the surrounding tissue rapidly. Brain tumors, according to the Neurosurgery Department at Massachusetts General Hospital, are graded according to a scale that the World Health Organization developed. The higher the grade of the tumor, the more aggressive the brain cancer. Brain cancer of grades III and IV are the most aggressive, whereas those that are grades I and II grow more slowly and typically have a better prognosis.
Diagnosis
The grading of a tumor is based on the results of a biopsy, the Brain Tumor Center at Massachusetts General Hospital explains. This tissue sample allows a specialist (called a neuropathologist) to examine the cancer cells under a microscope. The neuropathologist will then determine from what kind of cell the cancer arose as well as if the cancerous cells have signs of fast growth and reproduction. Tumors are graded based on the appearance of the most malignant cells in the biopsy.
Types
There are many different kinds of high-grade brain tumors. Anaplastic astrocytomas, ependyomas, oligodendromas and oligoastrocytomas, for example, describe cases of brain cancer in which the cancerous cells appear to be very different than their healthy precursors. Other kinds of high grade brain cancer include glioblastoma multiforme, as well as cancers with unknown precursor cells (which include astroblastomas and polar spongioblastomas).
Symptoms
Aggressive cases of brain cancer can cause a variety of neurological symptoms. The most common symptoms, according to the American Brain Tumor Association, are a result of increased pressure on the brain. Common symptoms include a headache, behavioral changes, memory loss and seizures, though the exact symptoms depend on the location of the tumor and can vary from patient to patient.
Treatment
Because high grade brain tumors grow quickly, they require more aggressive treatment. The first course of therapy, according to the Brian Tumor Center at Massachusetts General Hospital, is (if possible) surgery. After two to four weeks (which gives the surgical site time to heal), patients are usually started on a regimen of chemotherapy and radiation treatments. Because aggressive brain cancers typically recur, patients will need careful observation and monitoring to see if the cancer has come back, even once the cancer is in remission.
