Astrocytomas, the most common type of glioma, are also the most common type of primary brain tumor. They develop from star-shaped glial cells called astrocytes. They may occur anywhere in the central nervous system (CNS), including the brain, the brain stem, or the spinal cord. Treatment usually includes surgery, radiation therapy and sometimes chemotherapy. Decisions about how to treat an astrocytoma are based mainly on the tumor's grade - the degree of anaplasia the pathologist sees when tissue from a biopsy specimen of the astrocytoma is examined under a microscope. Anaplasia is the term used to describe the characteristic pattern in which tumor cells grow without form, structure or orientation to one another. An astrocytoma is assigned a grade according to its degree of anaplasia. The degree of anaplasia reflects the tumor's potential for growth. The most rapidly growing astrocytomas have the greatest degree of anaplasia, are the most anaplastic and are therefore the most malignant. Within the United States and around the world there are several different systems for defining a tumor's grade, which is why different doctors may not use exactly the same terms to describe the same tumor. These different grading systems can make a confusing situation for patients when gathering information on their diagnosis. NBTF uses the World Health Organization (WHO) classification system, grading astrocytoma on a scale of 1 to 4, from the least aggressive to the fastest growing type of astrocytoma. If you have any questions about what your tumor grade is, ask your doctor for clarification.

Anaplastic (or high grade) astrocytomas

Also called mid-grade or grade III astrocytomas, anaplastic astrocytomas grow more rapidly than lower grade astrocytomas and contain cells with malignant traits. Surgery followed by radiation, and often chemotherapy, is used to treat anaplastic astrocytomas. There are many clinical trials looking into new treatments for anaplastic astrocytomas.

Glioblastoma multiforme (GBM)

These tumors sometimes called high-grade or grade IV astrocytomas, grow rapidly, invade nearby tissue and contain cells that are very malignant. Glioblastoma multiforme is among the most common and devastating primary brain tumor that affect adults, and in some cases children. Doctors usually treat glioblastomas with surgery followed by radiation therapy and often chemotherapy. As with other types of brain tumors, there are also many clinical trials that offer patients access to new experimental treatments.

Please visit the National Brain Tumor Foundation (www.braintumor.org) site for more information.