There are tremendous differences among brain tumors in children; some have a very poor outlook while others can be cured with surgery alone. These differences can make understanding pediatric brain tumors, and finding the right treatment for each one, confusing.
Fortunately, the specialists at the Jane and John Justin Neurosciences Center at Cook Children’s are among the nation’s finest when it comes to treating brain tumors. And they have access to some of the newest medicines and surgeries available.
What is a Brain tumor?
A tumor is any mass caused by abnormal or uncontrolled growth of cells. Tumors in the brain are categorized according to several factors, including where they're located, the type of cells involved, and how quickly they're growing. Some of the most common factors are:
- Low-grade vs. high-grade: Usually, low-grade tumors are slow-growing, while high-grade tumors are fast-growing and aggressive. High-grade tumors can invade nearby tissue or spread elsewhere in the body, and are more likely to recur after treatment. They are generally associated with a worse outlook.
- Localized vs. invasive: A localized tumor is confined to one area and is generally easier to remove, as long as it's in an accessible part of the brain. An invasive tumor has spread to surrounding areas and is more difficult or impossible to remove completely.
- Primary vs. secondary: Primary brain tumors originate in the brain. Secondary brain tumors are made up of cells that have spread (metastasized) to the brain from somewhere else in the body. In children, most brain tumors are primary.
There are many different types of pediatric brain tumors, ranging from those that can be cured with minimal therapy to those that cannot be cured even with aggressive therapy. Some of the most common include, but are in no way limited to:
Astrocytomas originate from star-shaped brain cells known as astrocytes. There are four major subtypes of astrocytomas:
- Juvenile pilocytic astrocytoma (grade 1)
- Fibrillary astrocytoma (grade 2)
- Anaplastic astrocytoma (grade 3)
- Glioblastoma multiforme (grade 4)
Low-grade astrocytomas (grades 1 and 2) in kids are highly curable because they usually grow slowly, don't spread, and usually are fairly easy to remove unless found in areas where surgery would be difficult (like the optic nerve). After surgery, there's a chance that chemotherapy or radiation won't be needed.
High-grade astrocytomas (grades 3 and 4) are more aggressive, more invasive, and more difficult to treat. Treatment usually includes surgery, chemotherapy, and radiation.
An important feature in determining the outlook for patients with astrocytomas is location, because this directly affects the chance for a cure. Tumors that can be completely removed surgically are much more likely to be cured, while those that can't be completely removed are, in general, less curable.
Brain stem glioma
The brain stem, located deep in the back of the brain, consists of the midbrain, pons, and medulla. These structures coordinate all of the brain's messages. They also control many of the body's autonomic functions (the autonomic nervous system is responsible for controlling many of the body processes we almost never need to think about, like breathing, digestion, sweating, and shivering).
A tumor that develops in any area of the brain stem is called a brain stem glioma. Tumors that occur in the pons (pontine gliomas) are the most common but are often the most difficult to treat. Tumors that occur in the midbrain and medulla are less common but usually more easily treated.
Symptoms of a pontine glioma may come on suddenly and worsen very quickly. These may include:
- Double vision
- Turning in of one eyeball
- Drooping of the eyelid or one side of the face
- Trouble swallowing
- Trouble speaking and walking
Midbrain tumors may cause similar eye symptoms, along with headaches and vomiting. This is due to increased pressure in the head caused by a blockage of cerebrospinal fluid, the fluid that surrounds and cushions the brain and spinal cord.
Tumors of the medulla are associated with swallowing problems and limb weakness. Because the brain stem is an area of the brain that generally can't tolerate surgery, brain stem gliomas are usually treated with radiation (high-energy X-rays that kill cancer cells) and chemotherapy.
Ependymoma tumors originate in brain cells that produce cerebrospinal fluid.
They mostly develop in children under age 5. Ependymomas are classified according to their location, and most do not spread (metastasize) to other areas of the body.
Those located in the top part of the head are called supratentorial. This type of tumor is associated with symptoms such as nausea, vomiting, and headaches from increased pressure within the brain, as well as weakness and vision problems.
Tumors found in the back of the head are more common. These are called infratentorial, and are also associated with nausea, vomiting, and headache, as well as trouble with coordination.
Supratentorial ependymomas often can be cured by surgery alone, while infratentorial ependymomas usually require much more aggressive treatment with surgery, chemotherapy, and radiation.
Ependymomas are treated primarily with surgery and radiation therapy. If the tumor can be completely removed, patients with ependymomas may need no additional treatments. However, some completely removed ependymomas and most incompletely removed ependymomas will require further treatment — usually radiation therapy and sometimes also chemotherapy.
Ependymomas can also be found in the spinal cord.
Primitive neuroectodermal tumors (PNETs)
Primitive Neuroectodermal Tumors (PNET) are a group of tumors that can occur anywhere in the brain, but whose cells look very similar under a microscope. Types of PNETs include
- Posterior fossa PNET
- Supratentorial PNET
All of these tumors are able to metastasize through the cerebrospinal fluid that surrounds the brain and the spinal cord. Medulloblastomas, by definition, can only occur in the posterior fossa or cerebellum (back part of the brain), while primitive neuroectodermal tumors can occur anywhere in the brain or spinal cord. These cancers are highly sensitive to chemotherapy and radiation therapy, so modern treatment regimens are usually curative. Although treatment regimens are effective, late side effects of therapy can be a significant problem.
PNET symptoms generally depend on their size and location, but common ones include:
- Headaches, nausea, and vomiting (especially in the morning) caused by increased pressure in the head
- Weakness in the arms and legs
- Vision problems
- Trouble with balance and coordination
Even though PNETs require aggressive treatment, including surgery, chemotherapy, and radiation therapy, recent medical advances have made a cure possible for the majority of children who have them.
Optic nerve gliomas
Optic nerve gliomas affect vision. The optic nerve sends signals to the brain about what the eye sees. A tumor that occurs along this pathway is called an optic nerve glioma. These tumors mostly affect kids under age 10; those with the genetic condition neurofibromatosis type 1 (which causes tumors to grow on nerve tissue) have an increased risk of developing them.
The most typical symptom is progressive vision loss. With slow-growing tumors, this may be hard to spot at first — especially in younger children who can't describe what they're seeing. With fast-growing tumors (or less aggressive ones that have reached a large size), vision problems will eventually become apparent.
Kids also may start tilting their heads or experiencing what appears to be developmental delays such as clumsiness during walking, speech difficulties, or behavior changes. A condition called nystagmus (when the eyeballs appear to "jitter" involuntarily) also might appear. Sometimes, if the tumor is pressing on the pituitary gland, growth problems can result.
Optic nerve gliomas are usually treated with chemotherapy, although radiation also can be used. Most kids do well with treatment, and further vision loss is usually prevented.
Craniopharyngiomas are low-grade tumors that arise in the middle of the brain near the pituitary gland. As a result of their location, many patients have endocrinologic (hormone) problems when the tumor is diagnosed and after it is treated.
While craniopharyngiomas can be cured with surgery alone, most pediatric centers do not attempt total removal of the tumor at diagnosis unless it can be accomplished without injury to the sensitive surrounding structures. Total removal of the tumor without consideration of these surrounding structures can cause permanent hormone deficiencies that can be difficult to manage.
Therefore, for most patients, only partial removal of the tumor is done at diagnosis, followed by radiation therapy for any remaining tumor. This approach usually results in effective treatment of the tumor without causing lifelong hormone deficiencies.
Germ Cell Tumors
These brain tumors usually arise from two special areas in the middle of the brain — the areas around the pituitary and pineal glands. Germ cell tumors include two main types, germinomas and nongerminomatous germ cell tumors.
Germinomas are sensitive to chemo and radiation therapy and both are usually used to help achieve an excellent cure rate. Nongerminomatous germ cell tumors include several different types of tumors which, in general, are not as curable as germinomas. Nongerminomatous germ cell tumors are treated with surgery, chemotherapy, and radiation therapy.
What causes a brain tumor?
Like all tumors, brain tumors originate when a normal cell begins to grow abnormally and multiply too quickly. Eventually these cells develop into a mass called a tumor. The exact cause of this abnormal growth is unknown, though research continues on possible genetic and environmental causes.
Some kids who have certain genetic conditions have a greater chance of developing brain tumors. Diseases such as neurofibromatosis, von Hippel-Lindau disease, and Li-Fraumeni syndrome are all associated with a higher risk of brain tumors.
Signs and symptoms
A brain tumor can cause symptoms by directly pressing on the surrounding brain, or by causing a buildup of spinal fluid and pressure throughout the brain (a condition known as hydrocephalus). A range of symptoms can develop as a result.
Signs or symptoms vary depending on a child's age and the location of the tumor and the type of tumor, but may include:
- Weakness of the face, trunk, arms, or legs
- Slurred speech
- Difficulty standing or walking
- Poor coordination
- In babies, a rapidly enlarging head
Because symptoms might develop gradually and can be like those of other common childhood conditions, brain tumors can be difficult to diagnose. So it's always wise to discuss any symptoms that concern you with your child's doctor.
If your doctor suspects that your child has a brain tumor, he or she will order imaging studies of your child’s brain: a CT scan, MRI, or possibly both. In some cases, additional testing will be requested to form a 3-D model of your child’s brain. Since no two tumors, even those of the same type, are exactly alike, thorough testing and diagnosis allows the neurologists and neurosurgeons to more accurately identify the type, extent and precise location of the tumor. This, in turn, enables them to determine the best possible treatment plan for your child’s specific needs. These procedures let our doctors see inside your child’s brain and identify any areas that look abnormal.
If imaging studies reveal a brain tumor, then surgery is likely to be the next step. Your pediatric neurosurgeon will try to remove the tumor; if complete removal is not possible, then partial removal — or at least a biopsy (removal of a sample for microscopic examination) — may be done to confirm the diagnosis.
Our pediatric pathologist (a doctor who helps diagnose diseases in children by looking at body tissues and cells under a microscope) will then review the tissue to classify and grade the tumor.
Special tests might be used to analyze the genetic makeup of the tumor cells. Using these tests to get specific information about cancer cells can help doctors identify the tumor and develop the best treatment plan for someone with a brain tumor.
The type or types of treatment your child undergoes will depend upon the type, size and location of their tumor. Because most pediatric brain tumor patients require some combination of surgery, radiation therapy, and chemotherapy, your child’s treatment team of will be made up of a variety of medical specialists, who have expertise in every area of care, and are renowned for their talent and compassion. Advancements in treatment areas in the last few decades have contributed to better outcomes and, here at Cook Children’s, we offer the very latest in technology, medicine and research.
The care of a child with a brain tumor is very complicated and requires close coordination between members of the medical team, which typically will include:
- A pediatric neuro-oncologist (a doctor who specializes in treating cancers of the brain or spine)
- A pediatric neurologist (a doctor who specializes in disorders of the nervous system)
- A pediatric neurosurgeon (a surgeon who operates on the brain or spine)
- A pediatric radiation therapist (a specialist who administers radiation therapy)
- Pediatric rehabilitation medicine specialists, including speech, physical, and occupational therapists
- Pediatric psychologists and social workers
- Child Life specialists
These experts will choose a child's therapy very carefully. Finding a treatment that will be effective and cure the child but not cause unacceptable side effects is probably one of the most difficult aspects of treating brain tumors.
Pediatric neurosurgeons are having more success than ever in helping to cure children with brain tumors, partly because of new technologies in the operating room and partly because it has been learned that an aggressive surgical approach at diagnosis can significantly increase the chance for cure.
Neurosurgeons may use stereotactic devices, which help target tumors by providing 3-D images of the brain during surgery. Staged surgeries are also being used more frequently. This means that instead of trying to remove a large tumor all at once, surgeons will take out only part of the tumor at diagnosis. The patient will then get chemotherapy and/or radiation therapy to shrink the tumor and then return to the operating room a second or even a third time to try to remove the rest of the tumor.
After surgery, some patients may not require any more treatment beyond observation (periodic checkups and imaging scans to watch for problems). Many, however, will require radiation therapy, chemotherapy, or a combination of both.
the use of high-energy light to kill rapidly multiplying cells is very effective in the treatment of many pediatric brain tumors. However, because the developing brain in children younger than 10 years old (and especially those younger than 5) is highly sensitive to its effects, radiation therapy can have serious long-term consequences. These may include seizures, stroke, developmental delays, learning problems, growth problems, and hormone problems. The decision to use radiation therapy is, therefore, an especially challenging one regarding young children.
The methods for giving radiation therapy have changed significantly over the last several decades. New computer-assisted technologies allow doctors to construct 3-D radiation fields that accurately target tumor tissue while avoiding injury to important brain structures like the hearing centers.
Chemotherapy (chemo) is the use of drugs to kill cancer cells. It is often given through a special long-lasting intravenous (IV) catheter called a central line, and may require frequent hospital stays.
Although chemotherapy has many short-term side effects (such as fatigue, nausea, vomiting, and hair loss), it has fewer long-term side effects than radiation therapy. Many children with brain tumors are treated with chemo in order to delay or avoid radiation treatment.
Unlike brain tumors in adults, many pediatric brain tumors are highly sensitive to the effects of chemo, so it is routinely used for many kids with brain tumors.
Late effects are problems that patients can develop after cancer treatments have ended. For survivors of pediatric brain tumors, late effects may include cognitive delay (problems with learning and thinking), seizures, growth abnormalities, hormone deficiencies, vision and hearing problems, and the possibility of developing a second cancer, including a second brain tumor.
Because these problems sometimes don't become apparent until years after treatment, careful observation and medical follow-up are needed to watch for these.
In some cases, short-term effects might improve with the help of physical, occupational, or speech therapy and may continue to improve as the brain heals.
In other cases, kids may experience side effects that are longer term, including learning disabilities; medical problems such as diabetes, growth delay, or delayed or early puberty; physical disabilities related to movement, speech, or swallowing; and emotional problems linked to the stresses of diagnosis and treatment. Some of these problems may become more severe with the passage of time.
Be aware of the potential for physical and psychological late effects, especially when the time comes for your child to return to school, activities, and friendships. Talk to teachers about the impact treatment has had on your child and discuss any necessary accommodations, including a limited schedule, additional rest time or bathroom visits, modifications in homework, testing or recess activities, and medication scheduling. Your doctor can offer advice on how to make the transition easier.
Caring for your child
Parents often struggle with how much to tell a child who is diagnosed with a brain tumor. Though there's no one-size-fits-all answer for this, experts do agree that it's best to be honest — but to tailor the details to your child's degree of understanding and emotional maturity.
Give as much information as your child requires, but not more. And when explaining treatment, try to break it down into steps. Addressing each part as it comes — visiting various doctors, having a special machine take pictures of the brain, needing an operation — can make the big picture less overwhelming. The members of the brain tumor care team are experts at helping families talk with the child and siblings if a family needs help with this.
Kids should be reassured that the brain tumor is not the result of anything they did, and that it's OK to be angry or sad. Really listen to your child's fears, and when you feel alone, seek support. Your social workers can put you in touch with support groups and other families of children with brain tumors who've been there and may have insights, and a shoulder, to share.
Also be aware that it's common for siblings to feel neglected, jealous, and angry when a child is seriously ill. Explain as much as they can understand, and enlist family members, teachers, and friends to help keep some sense of normalcy for them.
And finally, as hard as it may be, try to take care of yourself. Parents who get the support they need are better able to support their child. Please feel free to talk to your medical team about your concerns. Our social services, Child Life and pastoral teams are also here to help you find support for yourself and your family, especially if you have other children. These types of illnesses affect everyone. Dealing with feelings of pain, frustration, anger and loss, not to mention the extreme levels of stress is important for your health and the health of your family.
We also have an onsite concierge team who can help you arrange a night out, some family fun, and when you can, even help you with family vacation plans.