What are the risk factors for brain and spinal cord tumors?
A risk factor is anything that
affects your chance of getting a disease such as a brain or spinal cord tumor.
Different types of cancer have different risk factors. Some risk factors, like smoking,
you can change. Others, like your age or family history, can’t be changed.
Most brain tumors are not linked
with any known risk factors and have no obvious cause. But there are a few
factors that can raise the risk of brain tumors.
Radiation exposure
The best known environmental risk
factor for brain tumors is radiation exposure, most often from radiation
therapy to treat some other condition.
Family history
Most people with brain tumors do
not have a family history of the disease, but in rare cases brain and spinal
cord cancers run in families. In general, patients with familial cancer
syndromes tend to have many tumors that first occur when they are young.
Neurofibromatosis type 1 (NF1)
This genetic disorder, also known
as von Recklinghausen disease, is the most common syndrome
linked to brain or
spinal cord tumors. People with this condition have higher risks of
schwannomas, meningiomas, and certain types of gliomas, as well as
neurofibromas (benign tumors of peripheral nerves). Changes in the NF1 gene
cause this disorder. These changes are inherited from a parent in about half of
all cases. In the other half, the NF1 gene changes occur before birth in people
whose parents did not have this condition.
Neurofibromatosis type 2 (NF2)
This condition, which is much
less common than NF1, is associated with vestibular schwannomas (acoustic
neuromas), which almost always occur on both sides of the head. It is also
linked with an increased risk of meningiomas or spinal cord ependymomas.
Changes in the NF2 gene are responsible for neurofibromatosis type 2. Like NF1,
the gene changes are inherited in about half of cases or may occur before birth
in children without a family history.
Tuberous sclerosis
People with this condition may
have subependymal giant cell astrocytomas (SEGAs), which are low-grade
astrocytomas that develop beneath the ependymal cells of the ventricles). They
may also have other benign tumors of the brain, skin, heart, kidneys, and other
organs. This condition is caused by changes in either the TSC1 or theTSC2 gene.
These gene changes can be inherited from a parent, but most often they develop
in people without a family history.
Von Hippel-Lindau disease
People with this condition tend
to develop benign or cancerous tumors in different parts of the body, including
hemangioblastomas (blood vessel tumors) in the brain, spinal cord, or retina,
as well as tumors of the inner ear, kidney, adrenal gland, and pancreas. It is
caused by changes in the VHL gene. Most often the gene changes are inherited,
but in some cases the changes happen before birth in people whose parents don’t
have them.
Li-Fraumeni syndrome
People with this condition are at
higher risk for developing gliomas, along with breast cancer, soft tissue
sarcomas,leukemia, and adrenal gland cancer, and certain other types of cancer.
It is caused by changes in the TP53 gene.
Other syndromes
Other inherited conditions are
also linked with increased risks of certain types of brain and spinal cord
tumors, including:
·
Gorlin syndrome (basal cell
nevus syndrome)
·
Turcot syndrome
·
Cowden syndrome
Some families may have genetic
disorders that are not well recognized or that may even be unique to a
particular family.
Immune system disorders
People with impaired immune
systems have an increased risk of developing lymphomas of the brain or spinal
cord (known as primary CNS lymphomas). Lymphomas are cancers of lymphocytes, a
type of white blood cell that fights disease. Primary CNS lymphoma is less
common than lymphoma that develops outside the brain.
A weakened immune system can be
congenital (present at birth), or it can be caused by treatments for other
cancers, treatment to prevent rejection of transplanted organs, or diseases
such as the acquired immunodeficiency syndrome (AIDS).
Unproven effects on brain tumor risk
·
Cell phone use
·
microwave ovens
·
Radar
·
Satellite stations
·
Vinyl chloride (a chemical used to manufacture
plastics)
·
Petroleum products
·
Exposure to aspartame (a sugar substitute),
·
Exposure to electromagnetic fields
·
Infection with certain viruses