Brain tumors occur mostly in children under 15 and in adults 65 and older, and are more common in white people than in black or Asian people.
Each year about 78,000 people learn that they have a primary brain tumor — a tumor that started out in the brain. Of those, about 53,000 are benign (not cancer) and 25,000 are malignant (cancer).
However, the vast majority of brain tumors diagnosed each year — about 150,000 — are secondary tumors, which start out elsewhere in the body and spread to the brain. Approximately one in every four adult cancer patients will develop secondary (metastatic) tumors in the brain. Cancers of the breast, lung, colon, kidney and skin (melanoma) are most likely to spread to the brain.
Brain Tumor Risk Factors
Because we don’t know why most brain tumors begin, we do not know how to prevent them, and right now there is no screening test for early detection.
Some brain tumors are caused by exposure to radiation— usually radiation therapy that was used to treat a previous cancer.
People with certain rare genetic disorders may be at risk for some brain tumors:
- Li-Fraumeni syndrome and neurofibromatosis type 1 increase the risk of glioma.
- Von Hippel-Lindau disease increases the risk of hemangioblastoma.
- Tuberous sclerosis increases the risk of astrocytoma.
- Neurofibromatosis type 2 increases the risk of acoustic neuroma and meningioma.
If you have been told you have one of these disorders, you may want to consider genetic counseling and testing. Roswell Park’s Clinical Genetics Service is the only center in Buffalo with formally trained genetic counselors who specialize exclusively in assessing inherited cancer risk.
Weakened Immune System
You may be at increased risk for a brain tumor if you have AIDS, take immune-suppressing drugs because you received an organ transplant, or have a weakened immune system for another reason — for example, because you were previously treated for cancer. This condition has been linked to greater risk of developing lymphomas of the brain or spine in particular.