By Christopher McPherson, MD
After a brain tumor has been diagnosed and the shock has been absorbed, one of the first questions my patients ask is, Why did this happen? What caused the tumor to appear?
In most cases, the answer is that we really don’t know. Despite years of research, medical scientists do not understand the causes of most tumors that begin growing in the brain. The vast majority of these tumors – called primary brain tumors — start from a malfunctioning gene within a brain cell, and there is nothing the patient could have done to prevent it.
Nevertheless, we do have information about a few risk factors and why some brain tumors begin.
Radiation
Researchers have long known that exposure to radiation can damage DNA, causing mutations that can lead to cancer. The radiation necessary to cause this type of damage can come from a catastrophic exposure during, say, a nuclear event, or from radiation used to treat an earlier cancer or a tumor of the head.
Cell phones
Researchers have worried about long-term exposure to very low doses radiation emitted by mobile phones. But thus far, there is no conclusive evidence that cell phones can lead to brain tumors.
Exposure to pesticides, industrial solvents or other chemicals
Although there is no conclusive evidence that exposures to these potent substances cause brain tumors, you should always follow commercial, state, or federal guidelines when working with them.
High intake of cured meats
Some studies have suggested that brain tumors may be caused by compounds that result from nitrates and nitrites that are often added to cured meats.
Inherited diseases, such as neurofibromatosis
About 5 percent of brain tumors can be linked to genetic factors. Neurofibromatosis type 2 (NF-2), for example, is a rare disease that predisposes individuals to the development of vestibular schwannomas, also known as acoustic neuromas. These tumors grow from the Schwann cells that form the covering of the vestibulocochlear nerve, which is located near the inner ear. They are benign (not cancerous) but can lead to deafness if they develop on both sides.
Demographics
Some tumors are more common in certain groups of people. Brain tumors are more common in men than women, for example. Meningioma tumors, which are benign, are more common in women than men, and more common in blacks than whites. Caucasians are more likely to develop brain cancer (gliomas) than African Americans. Brain tumors occur in children and adults of all ages.
Cancer elsewhere in the body
There is no mystery about the cause of metastatic brain tumors, also known as secondary brain tumors. These tumors form when cancer cells from an existing tumor in the body spread through the bloodstream to the brain. Cancers of the breast, lung, colon, kidneys, and skin (melanoma) are most likely to metastasize to the brain.
What can you do to protect yourself from the threat of a primary brain tumor?
- Eat a nutritious, balanced diet, with plenty of fruits, vegetables, and leafy greens.
- Minimize your intake of processed meats that contain nitrates and nitrites.
- Take sensible, recommended precautions when working with pesticides, industrial solvents, and other potent chemicals.
- Because the verdict on cell phones is still out, keep your phone away from your head as much as possible, and keep cell phones away from your body and bed at night.
- Have regular checkups, and visit your doctor if you develop unusual symptoms such as chronic headaches, blurry vision, dizziness, or loss of balance.
Remember that primary brain tumors are relatively rare. The risk of a brain tumor should not keep you awake at night!
Christopher McPherson, MD, is a neurosurgeon with Mayfield Brain & Spine and a member of the TriHealth Neuroscience Institute. For more information about brain tumors, visit http://www.mayfieldclinic.com/PE-BrainTumor.htm