What is a brain tumor?
Brain tumors are cancerous or noncancerous growths in the brain, which is part of the central nervous system (CNS). Most brain tumors are benign, meaning they are not cancerous. Less than 30% of brain tumors turn out to be brain cancer (malignant brain tumors). However, benign does not necessarily mean not dangerous. Noncancerous brain tumors can still cause symptoms and significant neurologic problems and damage to healthy brain tissue.
Brain tumors are either primary or secondary tumors. Primary tumors begin in the brain tissue itself. Secondary tumors are cancer that has spread, or metastasized, from other areas of the body. For example, breast cancer often spreads to the brain. There are well over 100 different types of primary brain tumors; however, the most common ones include:
Gliomas: Tumors that start in glial cells, which are supportive cells in the brain. They account for about 30% of brain tumors overall and 80% of cancerous brain tumors.
Meningiomas: Tumors that arise in the meninges, which is the membrane surrounding the brain. They are the most common type of brain tumor and are usually benign.
Pineal and pituitary tumors: Tumors that begin in the pineal or pituitary glands. They account for about 14% of brain tumors and most are benign.
Brain tumors are most common in children and older adults. However, they are relatively rare overall. In the United States, a person’s lifetime risk of developing a primary cancerous brain tumor is less than 1%. Contrast this with about 6% for lung cancer.
Brain tumor symptoms vary depending on the area of the brain it affects. They can be very general, such as headache, or very specific, such as vision changes. Still, even specific symptoms, such as fatigue or headaches from a brain tumor, can be common symptoms of other conditions. The only way to know for sure is to see your doctor for any unusual or persistent symptoms.
If your doctor diagnoses a brain tumor, a variety of effective treatments are available. The specific course of therapy will depend on whether or not it is cancerous, its location, and how aggressive it is.
What are the symptoms of a brain tumor?
A brain tumor can cause a wide variety of signs and symptoms. They vary depending on the tumor’s location, size, and how fast it is growing. Slow-growing tumors can cause gradual symptoms that you may not notice for some time. When tumors are growing quickly, symptoms can appear rather suddenly. Symptoms can also be very general or very specific.
Brain tumor symptoms can include:
Balance problems, weakness, or paralysis
Changes in vision, hearing, speech, touch, emotions, personality or judgment
Difficulty with fine motor skills, swallowing, or using facial muscles
Fatigue, headache, or head pressure
It’s important to see your doctor if you have any of these symptoms that persist or cause concern. Other conditions share many of these same symptoms. Getting a timely diagnosis offers the best chance of successfully treating the underlying cause.
If any of these symptoms appear suddenly, seek immediate medical attention (call 911). It may be a sign of a serious or potentially life-threatening condition, such as a stroke.
What causes brain tumors?
Doctors do not fully understand what causes brain tumors. Both cancerous and noncancerous brain tumors are the result of abnormal cell growth. Errors or mutations in a cell’s DNA cause this abnormal growth. However, it is not entirely clear how or why these errors occur and trigger tumors. It is likely that a combination of environmental and genetic factors play a role in their development.
What are the risk factors for brain tumor?
In most cases, the cause of a brain tumor is unknown. However, several factors increase a person’s risk of developing a brain tumor. Having risk factors does not mean you will get a brain tumor. And many people with brain tumors have no known risk factors. Even if you have risk factors and develop a brain tumor, doctors can rarely determine the exact or specific trigger of abnormal growth and tumor development.
Brain tumors tend to occur more often in children and older adults. Other risk factors for brain tumor include:
Exposure to ionizing radiation, which is the kind in X-rays
Family history of a brain tumor. About 5 to 10% of brain tumors are hereditary or genetically linked.
Male gender. However, some types of brain tumors are more common in women.
Reducing your risk of brain tumor
Reducing the risk of a particular disease involves controlling risk factors that you have the power to change. Unfortunately, the risk factors for a brain tumor are generally not modifiable. If you have a family history of a brain tumor, talk with your doctor about your risk or the risk for your child. Ask about specific monitoring recommendations to find early warning signs.
How is a brain tumor treated?
There is no one standard treatment for a brain tumor because each tumor and person is different. There are many factors that contribute to brain tumor treatment decisions. This includes the type of tumor, whether it is cancerous or not, its location, its size, and how fast it is growing. Your age and overall health are also considerations.
Possible brain tumor treatments include:
Chemotherapy to kill or stop the growth of tumor cells
Surgery to remove the tumor, or as much of it as possible
Targeted therapy to attack tumor cells using specific markers
Tumor treating fields (TTFs) or alternating electric field therapy, which is a treatment for glioblastoma
Talk with your doctor about the benefits and side effects of your treatment options. Consider getting a second opinion if you need help making a treatment decision. You may also want to ask your doctor about clinical trials. If you qualify to participate, a clinical trial can offer access to experimental and cutting-edge treatments.
A brain tumor can damage brain tissue and cause problems that may be permanent. Some tumors are more likely to cause problems than others due to their location. However, a common concern with any type of tumor is survival.
With brain tumors, doctors talk about survival in terms of the five-year relative survival rate. A relative survival rate looks at the percent of people with a disease who are still alive compared to people without the disease. A five-year relative survival rate makes this comparison for people five years after diagnosis. For example, a 65% five-year relative survival rate means someone with a disease is 65% as likely as someone without it to still be living five years after diagnosis.
The five-year relative survival rate for brain tumors varies greatly depending on the type of tumor and a person’s age. For meningiomas, the rate is fairly high, even for older adults. For people age 55 to 64, it is about 70%. For glioblastomas, the rate is low. For adults age 19 to 44, the rate is 19% and it decreases with older age.
It’s important to know that survival rates are only estimates. These rates can’t tell you how long you will survive with a brain tumor. Other factors, such as your overall health and the tumor’s response to treatment, play a role in your outlook. Your doctor is the best resource for information on your prognosis.