Astrocytoma
Astrocytes, which can develop in any part of the brain or spinal cord, are star-shaped glial cells where the tumor originates. It can be any grade, but in adults, it most often arises in the cerebrum. Commonly astrocytomas are classified in four grades:
Grade I astrocytoma:
* Called low-grade glioma
* Slow growing
* Well-defined borders
* Rare and almost exclusively found in children or teens
Grade II astrocytoma:
* Rarely spreads to other parts of central nervous system
* Slow growing
* Borders not defined
* Common among men and women, 20s to 50s
Grade III astrocytoma:
* Sometimes called a high-grade or an anaplastic astrocytoma
* More aggressive than grade II astrocytoma
* Cells not uniform
* Invades other tissue
* More common in men than women
Grade IV astrocytoma:
* Called a glioblastoma or malignant astrocytic glioma
* Most invasive type of glial tumor
* Composed of several different cells, making it difficult to treat
* Grows rapidly and invades other tissue
* May have evolved from low-grade tumor
* Common in young adults and among men and women, 50s to 70s
* More common in men
Astrocytoma accounts for 3,000 new cases a year in the U.S. The annual U.S. incidence rate: three per 100,000.