Brain Tumors

Depending on its type, a growing tumor may not cause any symptoms or can kill or displace healthy cells or disrupt their function. A tumor can move or press on sensitive tissue and block the flow of blood and other fluid, causing pain and inflammation. A tumor can also block the normal flow of activity in the brain or signaling to and from the brain. Some tumors don't cause any changes.

Tumors can be noncancerous (benign) or cancerous (malignant):

• Benign tumors can grow slowly or fast, don't spread to other parts of the body, and often can be removed surgically.
• Malignant tumors can invade surrounding tissue. Some cancerous brain tumors can be removed entirely through surgery. Some malignant tumors have edges that are hard to define, which makes it difficult for surgeons to remove the entire tumor.

Tumors can be primary or secondary:

• Primary tumors of the CNS are growths that begin in the brain or spinal cord. They can be either malignant or benign.  
• Metastatic tumors, or secondary tumors, of the CNS are caused by cancer cells that break away from a primary tumor somewhere else in the body and spread to the CNS. They are more common than primary tumors of the CNS and occur more often in adults than in children.

There are more than 120 types of brain tumors. Some are named by the type of normal cell they most closely resemble or by location. Brain tumors are not contagious, nor, at this time, are they preventable.

Anyone can develop a primary brain tumor, but the overall risk is very small. Brain tumors occur more often in males than in females and are most common in middle-aged to older persons. Although uncommon in children, brain tumors tend to occur more often in children under age nine, and some tumors tend to run in families. Most brain tumors in children are primary tumors.

Other risk factors for developing a primary brain tumor include race (caucasians are more likely to develop a central nervous system tumor) and occupation. Workers in jobs that require repeated contact with ionizing radiation or certain chemicals, including those materials used in building supplies or plastics and textiles, have a greater chance of developing a brain tumor.

Brain tumors release molecular information into the circulation. Biomarkers are molecules or other substances in the blood or tissue that can be used to diagnose or monitor a disorder. Liquid biopsies collect and analyze tumor components in body fluids, and there is an increasing interest in the investigation of liquid biopsies as a substitute for tumor tissue. Tumor-derived biomarkers include nucleic acids, proteins and tumor-derived extracellular vesicles that accumulate in blood or cerebrospinal fluid. Some CNS tumor biomarkers have been found, such as the epithelial growth factor receptor (EGFR) gene.

Researchers continue to search for additional clinical biomarkers of central nervous systems (CNS) tumors, to better assess risk from environmental toxins and other possible causes and monitor and predict the outcome of CNS tumor treatment. Identifying biomarkers may also lead to the development of new disease models and novel therapies for tumor treatment. Using biomarker tests, doctors may be able to predict how fast a tumor will grow and how you may potentially respond to chemotherapy, radiotherapy and other treatments.

Prevention for brain tumors involves reducing risk. Incidents of exposure-related brain tumors can be reduced by avoiding environmental conditions, such as excessive smoking or exposure to radiation. Early detection is also key to effective treatment, and discussing any family history of brain cancer or tumors with your providers is recommended, particularly in our parents—the source of our DNA.

Brain tumors cause many different symptoms, which can make detection tricky. Symptoms depend on tumor type, location, size and rate of growth. Certain symptoms are quite specific because they result from damage to particular areas of the brain. Symptoms generally develop slowly and worsen as the tumor grows.

In infants, the most obvious sign of a brain tumor is a rapidly widening head or bulging crown. Other more common symptoms of a pediatric brain tumor can include:

• Headaches that may become more frequent or severe
• Seizures
• Feelings of pressure inside the skull
• Nausea and vomiting
• Sudden onset of vision problems

In older children and adults, a tumor can cause a variety of symptoms, including headaches, seizures, balance problems and personality changes. Symptoms include:

• Headaches are the most common symptom of a brain tumor. Headaches may get worse over time, become more frequent or constant, and recur, often at irregular intervals. 
• Seizures that start in adulthood with no underlying cause are a key warning sign of a brain tumor.
• Nausea and vomiting.
• Vision or hearing problems.
• Personality, behavior and cognitive changes with psychotic episodes and problems with speech, language, thinking and memory.
• Motor problems, including weakness or paralysis, lack of coordination, or gradual loss of sensation or movement in an arm or leg.
• Balance problems, including dizziness, trouble walking, clumsiness or loss of equilibrium.
• Hydrocephalus and increased intracranial pressure, caused when a tumor blocks the flow of the cerebrospinal fluid (CSF) that bathes the brain and spinal cord. This can cause headaches, nausea and vomiting.

Other symptoms may include endocrine disorders or abnormal hormonal regulation, difficulty swallowing, facial paralysis and sagging eyelids, fatigue, weakened sense of smell, or disrupted sleep and changes in sleep patterns.

If you are suspected of having a brain tumor, your doctor (usually a neurologist, oncologist or neuro-oncologist) will perform a neurologic exam and may order a variety of tests based on your symptoms, personal and family medical history, and results of the physical exam. Once a tumor is found on diagnostic imaging studies, surgery to obtain tissue for a biopsy or removal is often recommended.

Diagnosing the type of brain cord tumor is often difficult. Some tumor types are rare, and the molecular and genetic alterations of some tumors are not well understood. You may want to ask your primary care doctor or oncologist for a second opinion from a comprehensive cancer center or neuro-oncologist with experience treating your diagnosis or tumor type. Even a second opinion that confirms the original diagnosis can be reassuring and help you better prepare for your care and treatment.
 

A neurological exam can be done in your doctor’s office. It assesses your movement and sensory skills, hearing and speech, reflexes, vision, coordination and balance, mental status, and changes in mood or behavior. Some advanced tests are performed and analyzed by a specialist.
 

Diagnostic imaging produces extremely detailed views of structures inside the body, including tissues, organs, bones and nerves. Such imaging can confirm the diagnosis and help doctors determine the tumor’s type, treatment options and, later, whether the treatment is working.

• Computed tomography (CT scan) is no longer the standard for evaluating a brain tumor. However, CT scans can detect the buildup of calcium, which causes tissue to harden and develop into a tumor and can often detect hemorrhage (blood) or the development of hydrocephalus. CT scans can be done in a few minutes, so they are often used in emergency situations.
• Magnetic resonance imaging (MRI) is the gold standard for diagnosing brain and spinal tumors and is more sensitive than a CT scan. In addition to higher resolution and better anatomic detail, MRI can provide information about blood flow (perfusion) and tumor cell density, as well as better pictures of tumors located near bone.

Usually a contrast agent (such as a dye) is injected into a vein before a CT or MRI. Many tumors become much easier to identify on the scan after the contrast is given.

• Functional MRI (fMRI) can help assess the distance between specific brain functions and tumors in particular areas of the brain. This is useful in planning surgery in areas of the brain that contain important function such as language.
• Magnetic resonance spectroscopy (MRS) can measure and analyze metabolic changes and the chemical makeup of a tissue sample.
• Positron emission tomography (PET) traces and measures the brain’s use of glucose (sugar, used by the brain for energy) that is attached to small amounts of radioactivity and injected into the bloodstream. Because malignant tissue uses more glucose than normal tissue, it usually shows up on the scan as brighter than surrounding tissue.
• Single-photon emission computed tomography (SPECT) studies blood flow to tissue. Certain tumors grow new blood vessels to increase their supply of blood and nutrients
• Angiography (or arteriogram) can distinguish certain types of tumors that have a characteristic pattern of blood vessels and blood flow. A dye is injected into a major blood vessel, and a series of X-rays is taken as the dye flows to the brain. Often, MRI can be used to evaluate blood vessels, a procedure called MR angiography.
   

• Testing blood, urine and other substances can provide clues about the tumor and monitor levels of therapeutic drugs.
• An electroencephalogram, or EEG, monitors brain activity through the skull (tumors can alter brain wave activity and cause seizures).
• A spinal tap (also called a lumbar puncture or CSF analysis) uses a special needle inserted into the spinal column to remove a small amount of the cerebrospinal fluid. The fluid is examined for abnormal cells or unusual levels of various molecules such as glucose and protein that suggest a brain or spinal cord tumor.
• Magnetoencephalography (MEG) studies brain function by measuring the magnetic field generated by nerve cells in the brain.

A specialized team of doctors advises and assists individuals throughout treatment and rehabilitation.

• A neuro-oncologist is a neurologist or oncologist who specializes in CNS tumors.
• An oncologist is a doctor who specializes in cancer.
• A neurologist is a doctor who specializes in CNS disorders.
• A neuroradiologist is a doctor who specializes in the CNS and is trained in reading diagnostic imaging results.
• A pathologist is a clinical doctor who diagnoses diseases of tissues or cells using a variety of laboratory tests.
• A neurosurgeon is a brain or spinal cord surgeon with specialized training in removal of central nervous system tumors.
• A radiation oncologist is a doctor who specializes in using radiation to treat cancer.

Your healthcare team will recommend a treatment plan based on the tumor’s location, type, size and aggressiveness, as well as your medical history, age and general health. Malignant tumors require some form of treatment, while some small benign tumors may need only monitoring. Treatment for a brain tumor can include surgery, radiation therapy, chemotherapy, targeted therapy or a combination of treatments.

Initial treatment for a CNS tumor may involve a variety of drugs to treat or ease symptoms, including:

• Anticonvulsants to treat or prevent seizures
• Pain medications
• Steroids or other anti-inflammatory drugs to reduce swelling and improve blood flow
• Antidepressants to treat anxiety or depression that might occur following a tumor diagnosis
• Anti-nausea drugs
   

Surgery is usually the first treatment to both obtain tissue for diagnosis and remove as much tumor as can be done safely. Surgery may be the only treatment you need if your tumor is considered benign or low grade. Based on the type and grade (low versus high), doctors often recommend follow-up treatment, including radiation and chemotherapy, or an experimental treatment. You will be referred to the specialists above to provide guidance on this treatment.

Surgery is usually the first step in treating an accessible tumor—one that can be removed without risk of neurological damage. Many low-grade tumors and secondary (metastatic) cancerous tumors can be removed entirely. Some tumors have a clearly defined shape and can be removed more easily. Your surgeon will try removing (called resecting or excising) all or as much tumor as possible.

An inaccessible or inoperable tumor is one that cannot be removed surgically because of the risk of severe nervous system damage during the operation. These tumors are frequently located deep within the brain or near vital structures such as the brain stem and may not have well-defined edges. In these cases, a biopsy may be performed.

A biopsy is sometimes performed to diagnose and help doctors determine how to treat a tumor. Biopsies can sometimes be performed by inserting a needle through a small hole in the body and taking a small piece of the tumor tissue. A pathologist will examine the tissue for certain changes that signal cancer and determine its stage or grade.

In some cases, a surgeon may need to insert a shunt into the skull to drain any dangerous buildup of CSF caused by the tumor. A shunt is a flexible plastic tube that is used to divert the flow of CSF from the central nervous system to another part of the body, where it can be absorbed as part of the normal circulatory process.

During surgery, some tools used in the operating room include a surgical microscope, the endoscope (a small viewing tube attached to a video camera), and miniature precision instruments that allow surgery to be performed through a small incision in the brain or spine. Other tools include:

• Intraoperative MRI, which uses a special type of MRI to provide real-time monitoring and evaluation of the surgery. Constantly updated images let doctors see how much of the tumor has been removed.
• Navigation equipment used in computer-guided, or stereotactic, neurosurgery, which gives doctors a precise, three-dimensional map of the spine or brain as the operation progresses. A computer uses preoperative diagnostic images to reduce the risk of damage to surrounding tissue.
• Intraoperative nerve monitoring tests, which use real-time recordings of nerve cell activity to determine the role of specific nerves and to monitor brain activity as the surgery progresses. Some surgeries may be done while the individual is awake under monitored anesthesia care, rather than under general anesthesia. This allows doctors to monitor the individual’s speech and motor functions as a tumor is being removed.
   

Radiation therapy usually involves repeated doses of high-energy beams such as X-rays or protons to kill cancer cells or keep them from multiplying. Radiation therapy can shrink the tumor mass. It can be used to treat surgically inaccessible tumors or tumor cells that may remain following surgery.

Radiation treatment can be delivered externally, using focused beams of energy or charged particles that are directed at the tumor, or from inside the body, using a surgically implanted device. The stronger the radiation, the deeper it can penetrate to the target site. Healthy cells may also be damaged by radiation therapy, but current radiation treatment is designed to minimize injury to normal tissue.

Treatment often begins soon after surgery and may continue for several weeks. Depending on the tumor type and location, a person may be able to receive a modified form of therapy to lessen damage to healthy cells and improve the overall treatment.

Externally delivered radiation therapy poses no risk of radioactivity to the person or family and friends. Types of external radiation therapy include:

• Whole brain radiation: generally used to shrink multiple cancerous tumors, rather than to target individual tumors. It may be given as the sole form of treatment or in advance of other forms of radiation therapy and microsurgery.
• Conventional external beam radiation: aims a uniform dose of high-energy radiation at the tumor and surrounding tissue. It is used to treat large tumors or those that may have spread into surrounding tissue.
• Three-dimensional conformal radiotherapy (3D-CRT): uses diagnostic imaging to prepare an accurate, computer-generated three-dimensional image of the tumor and surrounding tissue. The computer then coordinates and sends multiple beams of radiation to the tumor’s exact location, sparing nearby organs and surrounding tissue.
• Intensity modulated radiation therapy (IMRT): is similar to 3D-CRT but varies in the intensity of the hundreds of radiation beams to deliver more precise doses to the tumor or its specific areas, with less exposure to surrounding tissue.
• Hyperfractionation: involves giving two or more smaller amounts of radiation a day instead of a larger, single dose. It can deliver more radiation to certain tumors and reduce damage to normal cells.
• Proton beam therapy: directs a beam of high-energy protons directly at the tumor site, without spreading the radiation beyond the target. The dosing is similar to standard radiation (also called photon radiation), but proton beam radiation is best for treating tumors near important structures such as the brainstem and spinal cord. Proton beam therapy can be used as a standalone treatment or in combination with chemotherapy or as follow-up to surgery.
   

Radiosurgery is usually a one-time treatment using multiple, sharply focused radiation beams aimed at the brain tumor from multiple angles. It does not cut into the person but, like other forms of radiation therapy, harms a tumor cell’s ability to grow and divide. It is commonly used to treat surgically inaccessible tumors and may be used at the end of conventional radiation treatment.

• Linear-accelerated radiosurgery (LINAC) uses radar-like technology to prepare and fire a single beam of high-energy X-rays into the tumor. Also called high linear-energy transfer radiation, LINAC forms the beam to match the tumor’s shape, avoiding surrounding tissue. A special machine that rotates around the head then fires a uniform dose of radiation into the tumor.
• Radiosurgery can be given by a number of techniques, all designed to provide a precise dose of radiation to a small area. It has proven beneficial for tumors that do not spread into the surrounding brain, but radiosurgery is less beneficial for the common brain tumors that do spread into the brain. 

Side effects of radiation: Side effects of radiation therapy vary from person to person and are usually temporary. They typically begin about two weeks after treatment starts and may include fatigue, nausea, vomiting, reddened or sore skin in the treated area, headache, hearing loss, problems with sleep, and hair loss (although the hair usually grows back once the treatment has stopped). Radiation therapy in young children, particularly those aged three years or younger, can cause problems with learning, processing information, thinking and growing.

There are late side effects of radiation that may occur months to years after treatment that include shrinkage (atrophy) of the brain or spinal cord region that was treated.
 

Chemotherapy uses powerful drugs to kill cancer cells or stop them from growing or spreading. These drugs are usually given orally, intravenously or through a catheter or port and travel through the body to the cancerous cells. Your oncologist will recommend a treatment plan based on the type of cancer, drug(s) to be used, the frequency of administration, and the number of cycles needed. Chemotherapy is given in cycles to more effectively damage and kill cancer cells and give normal cells time to recover from any damage.

You might receive chemotherapy to shrink the tumor before surgery called neo-adjuvant therapy (a first step treatment to shrink a tumor before the primary treatment). Radiation therapy can also be given as neo-adjuvant therapy. After surgery, or radiation treatment if radiation is the primary treatment, chemotherapy could be called adjuvant therapy (treatment in addition to the primary treatment). Metronomic therapy involves continuous low-dose chemotherapy to block mechanisms that stimulate the growth of new blood vessels needed to feed the tumor.

Not all tumors are vulnerable to the same anticancer drugs, so your treatment may include a combination of drugs. Common CNS chemotherapies include temozolomide, carmustine (also called BCNU), lomustine (also called CCNU) and bevacizumab. Be sure to discuss all options with your medical team.

Side effects of chemotherapy may include hair loss, nausea, digestive problems, reduced bone marrow production and fatigue. The treatment can also harm normal cells that are growing or dividing at the same time, but these cells usually recover, and side effects often improve or stop once the treatment has ended.

Scientists at NIH and universities across the United States are exploring a variety of approaches to treat CNS tumors. These experimental approaches include boosting the immune system to better fight tumor cells, developing therapies that target the tumor cell while sparing normal cells, making improvements in radiation therapy, disabling the tumor using genes attached to viruses, and defining biomarkers that may predict the response of a CNS tumor to a particular treatment.
 

Targeted therapy is a cancer treatment that uses drugs to target specific genes and proteins that are involved in tumor cell growth. This helps slow uncontrolled growth and reduce the production of tumor cells. Targeted therapies include oncogenes, growth factors and molecules aimed at blocking gene activity.

Targeted therapy uses molecularly targeted drugs that seek out the cellular changes that convert normal cells into cancer. Targeted therapies include:

• Compounds that block blood vessel growth and the flow of nutrients and oxygen to the tumor. These compounds may also hamper cell signaling and stop tumor cells from spreading elsewhere in the body.
• Developing diagnostic and therapeutic screening tools for oncogenes—transformed genes that are involved in cell growth and cause normal cells to divide uncontrollably and become malignant.
• Kinase inhibitors—proteins that block growth-signaling enzymes without harming normal cells—that may make CNS tumors more sensitive to chemotherapy.
   

Biological therapy (also called immunotherapy) involves enhancing the body’s overall immune response to recognize and fight cancer cells. The immune system is designed to attack foreign substances in the body, but because cancer cells aren’t foreign, they usually do not generate much of an immune response. Researchers are using different methods to provoke a strong immune response to tumor cells, including:

• Proteins such as interleukin and interferon and other substances that slow tumor growth
• Antibodies (proteins that are normally produced by the body to ward off bacteria and viruses) that are linked to immunotoxin drugs that seek out tumor cells and deliver their toxin, with minimal damage to surrounding normal cells
• Gene therapy, which uses a virus that can pass through the brain’s protective blood-brain barrier to deliver a suicide gene to the tumor cell
• Vaccine therapy, which strengthens the immune response by inserting an antigen (a substance that triggers an immune system reaction) that the body will attack. Some vaccines attempt to target multiple antigens that the tumor may express.
   

Alternative and complementary approaches may help you or other individuals with a tumor better cope with the diagnosis and treatment. Some of these therapies, however, may be harmful if used during or after cancer treatment and should be discussed in advance with a doctor. Common approaches include nutritional and herbal supplements, vitamins, special diets, and mental or physical techniques to reduce stress.

Scientists continue to investigate ways to better understand, diagnose and treat CNS tumors. Several of today’s treatments were experimental therapies only a decade ago. Clinical studies are research studies that test or observe how well medical approaches work in people. Some clinical studies test new treatments such as a new drug or medical therapy. Treatment studies help researchers learn if a new treatment is effective or less harmful than standard treatments. Studies can be considered at any point, from the time of diagnosis through recurrence.

You may wonder how you or your loved one can help provide care for people with a brain tumor. Consider participating in a clinical trial so clinicians and scientists can learn more about brain tumors. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

Additionally, your doctor or clinic may have a case manager who can be assigned to you who will help navigate treatment, insurance, service providers and general education about your diagnosis. Your case manager may recommend you create a binder to help keep information and treatment organized. By remaining organized, you and your loved ones can feel empowered through your treatment journey, knowing just where to find a list of medications, allergies, emergency contacts, an ongoing list of questions, your medical history, copies of imaging films, reports, lab and pathology reports—all available upon request from your caregivers. You may also wish to keep a daily journal, documenting any reactions you’re having from medications or changes in your symptoms—start times and duration are important observations to share with your treatment team.

Many patients also find value in expanding their emotional support team—mental health practitioners, friends, family and neighbors. By maintaining contact and honest communication with others, you can avoid feeling isolated and reduce anxiety, fear and depression, which are natural responses to a diagnosis. 

For information about participating in clinical research, visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with brain tumors at Clinicaltrials.gov.