Central Nervous System - ChildhoodLast Updated: February 08, 2012 This section has been reviewed and approved by the Cancer.Net Editorial Board, 02/11 Overview
A central nervous system (CNS) tumor begins when normal cells in the brain or the spinal cord change and grow uncontrollably, forming a mass. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body). A CNS tumor is especially problematic because a person’s thought processes and movements can be affected. This type of tumor also may be challenging to treat because the tissues surrounding the tumor may be vital to the body’s functioning. The brain is the center of thought, memory, and emotion. It controls the five senses (smell, touch, taste, hearing, and sight), movement, and other basic functions of the body, including heartbeat, circulation, and breathing. The spinal cord consists of nerves that carry information back and forth between the body and the brain. Anatomy of the brain The brain is made up of four major parts: the cerebrum, cerebellum, brain stem, and meninges. The cerebrum, the largest part of the brain, contains two cerebral hemispheres and is divided into four lobes where specific functions occur.
The cerebellum, or "little brain," is located beneath the cerebrum. The cerebellum controls coordination and balance. The brain stem, which is the lowest portion of the brain and connects to the spinal cord, controls involuntary functions essential for life, such as a person’s heartbeat and breathing. The meninges are the membranes that surround and protect the brain and spinal cord. There are three meningeal layers, called the dura mater, arachnoid, and pia arachnoid. Types of CNS tumors There are many different types of CNS tumors. Some are cancerous and very likely to grow and spread (called very aggressive or high grade), others are less aggressive (low grade), and others are noncancerous, which means they are not likely to grow and spread. The following types of CNS tumors are most common among children: This section covers CNS tumors diagnosed in children. Learn more about brain tumors in adults. Find out more about basic cancer terms used in this section. Looking for More of an Overview? If you would like additional introductory information, explore these related items on Cancer.Net:
Or, choose “Next” (below, right) to continue reading this detailed section. To select a specific topic within this section, use the icon panel located on the right side of your screen. Statistics
Approximately 4,000 CNS tumors are diagnosed each year in children younger than 20. About 1,000 of these are considered noncancerous tumors. CNS tumors are the second most common childhood cancer, after leukemia. The overall five-year survival rate (the percentage of children who survive at least five years after the tumor is detected, excluding those who die from other diseases) of children with CNS tumors is 71%. Survival statistics should be interpreted with caution. These estimates are based on data from thousands of children with this type of tumor, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with a CNS tumor. Because the survival statistics are measured in five-year intervals, they may not represent advances made in the treatment or diagnosis of this tumor. Learn more about understanding statistics. Statistics adapted from the American Cancer Society's publication, Cancer Facts and Figures 2012. Medical Illustrations
Risk Factors
A risk factor is anything that increases a person’s chance of developing a tumor. Although risk factors can influence the development of a tumor, most do not directly cause a tumor. Some people with several risk factors never develop a tumor, while others with no known risk factors do. The cause of most CNS tumors in children is not known. Researchers are studying a variety of possible causes of CNS tumors, including viruses. Different types of CNS tumors occur in different age groups. For example, some types of CNS tumors are more common in children younger than three. Head injury does not appear to cause a CNS tumor. A small number of CNS tumors occur in families. However, only a small percentage of children with a brain tumor have an identifiable genetic cause, usually in association with a familial disease called neurofibromatosis. Neurofibromatosis is an inherited disorder that causes neurofibromas (noncancerous tumors) to form on peripheral nerves in the body, brown spots on the skin, and deformities of tissues and bones. Neurofibromatosis is also called Recklinghausen’s disease or von Recklinghausen’s disease. Learn more about neurofibromatosis Type 1 and neurofibromatosis Type 2. Other, less common genetic conditions associated with a higher risk of a CNS tumor include Li-Fraumeni syndrome, tuberous sclerosis, nevoid basal cell syndrome, and Turcot syndrome. Symptoms and Signs
Children with a CNS tumor may experience the following symptoms or signs. Sometimes, children with a CNS tumor do not show any of these symptoms. Or, these symptoms may be caused by a medical condition that is not a tumor. If you are concerned about a symptom or sign on this list, please talk with your child’s doctor. The symptoms of a CNS tumor can affect any of the brain’s functions and depend on where the tumor is located. A CNS tumor may cause the following symptoms:
In a baby, the only symptom may be that the head is growing too fast. An infant’s skull can expand to make room for a growing tumor, so the baby may have a larger than normal head. Your child’s doctor will ask you questions about the symptoms your child is experiencing to help find out the cause of the problem, called a diagnosis. This may include how long your child has been experiencing symptom(s) and how often. If a tumor is diagnosed, relieving symptoms and side effects remains an important part of care and treatment. This may also be called symptom management, palliative care, or supportive care. Be sure to talk with the health care team about the symptoms your child experiences, including any new symptoms or a change in symptoms. Diagnosis
Doctors use many tests to diagnose a tumor, determine if it is cancerous, and find out if it has metastasized (spread). Some tests may also determine which treatments may be the most effective. For most types of tumors, a biopsy is the only way to make a definitive diagnosis. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the tumor has metastasized. Your child’s doctor may consider these factors when choosing a diagnostic test:
In addition to a physical examination, the following tests may be used to diagnose a CNS tumor: Computed tomography (CT or CAT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein to provide better detail. Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium may be injected into a patient’s vein to create a clearer picture. Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that a tumor is present, but only a biopsy can make a definite diagnosis. The sample removed during the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). The type of biopsy performed depends on the location of the tumor. Learn more about what to expect when having common tests, procedures, and scans. After these diagnostic tests are done, your child’s doctor will review all of the results with you. If the diagnosis is a tumor, these results also help the doctor describe the tumor; this is called staging. Learn more about the first steps to take after a diagnosis of a tumor. Staging
Staging is a way of describing a tumor, such as where it is located, if or where it has spread, and whether it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the tumor's stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient’s prognosis (chance of recovery). Several types of childhood CNS tumors can spread through the spinal fluid that surrounds the brain and the spine. For most types of CNS tumors, the tumor is described as either high-grade or low-grade, depending on how much of the tumor is left after surgery, the child’s age, and whether the tumor has spread. In general, a child with a low-grade tumor has a better prognosis. A recurrent tumor is a tumor that comes back after treatment. If there is a recurrence, the tumor may need to be staged and graded again. There are different stage descriptions for different types of tumors. Read more about staging for a specific type of CNS tumor. For example, review the staging section under astrocytoma if that is the specific diagnosis. Treatment
In general, tumors in children are uncommon, so it can be hard for doctors to plan treatments unless they know what has been most effective in other children. That’s why more than 60% of children are treated as part of a clinical trial. Clinical trials are research studies that compare standard treatments (the best proven treatments available) with newer treatments that may be more effective. Investigating new treatments involves careful monitoring using scientific methods, and all participants are followed closely to track their health and progress. To take advantage of these newer treatments, all children with a CNS tumor should be treated at a specialized cancer center. Doctors at these centers have extensive experience in treating children and have access to the latest research. A doctor who specializes in treating children with a tumor is called a pediatric oncologist. In many cases, a team of doctors treats a child with a tumor; this is called a multidisciplinary team. Pediatric cancer centers often have extra support services for children and their families, such as child life specialists, nutritionists, social workers, and counselors. Special activities and programs to help your child and family cope may also be available. Treatment overview Descriptions of the most common treatment options for a CNS tumor are listed below. Treatment options and recommendations depend on several factors, including the type of CNS tumor, whether it is cancerous, the stage and/or grade of the tumor, possible side effects, the family’s preferences, and the child’s age and overall health. Radiation therapy is often limited in children younger than three years old, because extensive radiation therapy can cause learning and memory problems later on in the child’s life.
Learn more about making treatment decisions. Surgery Surgery is the removal of the tumor and surrounding tissue during an operation. It is almost always used to determine the type of tumor, either through a biopsy or during treatment when the tumor can be removed without significant damage to the brain. A neurosurgeon is a doctor who specializes in treating a tumor in the brain or spine with surgery. Sometimes, a tumor spreads and grows between normal nerve cells, making surgery difficult. In certain cases, surgery can damage parts of the brain near the tumor, affecting arm and leg movement, breathing, swallowing, eye movement, or consciousness. Some tumors cannot be removed by surgery because of their location; these tumors are called inoperable; in these instances, the doctor will recommend other treatment options. Learn more about surgery. Radiation therapy Radiation therapy is the use of high-energy x-rays or other particles to kill tumor cells. A doctor who specializes in giving radiation therapy to treat a tumor is called a radiation oncologist. The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body. When radiation treatment is given using implants, it is called internal radiation therapy or brachytherapy. A radiation therapy regimen (schedule) usually consists of a specific number of treatments given over a set period of time. Stereotactic radiosurgery is a way to deliver high doses of radiation therapy directly to a tumor and not to healthy tissue. This technique makes detailed, three-dimensional maps of the brain and tumor, so doctors can pinpoint where to direct the radiation treatment. It works best for certain noncancerous tumors and a tumor that is only in one part of the brain. Learn more about radiation therapy. Side effects from radiation therapy may include fatigue, mild skin reactions, upset stomach, headaches, and loose bowel movements. Most side effects go away soon after treatment is finished. However, in the long term, radiation therapy can sometimes interfere with the growth and development of the child’s brain. Therefore, the doctor may choose to treat the tumor in another way. Chemotherapy Chemotherapy is the use of drugs to kill tumor cells, usually by stopping the tumor cells’ ability to grow and divide. Systemic chemotherapy is delivered through the bloodstream to reach tumor cells throughout the body. Chemotherapy is given by a medical oncologist, a doctor who specializes in treating a tumor with medication. A chemotherapy regimen usually consists of a specific number of cycles given over a set period time. A patient may receive one drug at a time or combinations of different drugs at the same time. Chemotherapy is effective for many cancerous types of brain tumors. Depending on the tumor type, chemotherapy may be given immediately after a biopsy or surgery or after radiation therapy. In some instances, chemotherapy is used at the same time as radiation therapy. Chemotherapy may also be given directly into the spinal canal, in a procedure called intrathecal chemotherapy, to treat tumor cells on the surface of the brain and spine. This procedure is still being researched in clinical trials and may not be available everywhere. The side effects of chemotherapy depend on the individual and the dose used, but they can include fatigue, risk of infection, nausea and vomiting, loss of appetite, and diarrhea. These side effects usually go away once treatment is finished. Learn more about chemotherapy and preparing for treatment. The medications used to treat a tumor are continually being evaluated. Talking with your child’s doctor is often the best way to learn about the medications prescribed for your child, their purpose, and their potential side effects or interactions with other medications. Learn more about your child’s prescriptions by using searchable drug databases. Recurrent CNS tumor Once your child’s treatment is complete and there is a remission (absence of symptoms; also called “no evidence of disease” or NED), talk with your child’s doctor about the possibility of the tumor returning. Many people feel worried or anxious that the tumor will come back. Learn more about coping with this fear. If the tumor does return after the original treatment, it is called a recurrent tumor. It may come back in the same place (called a local recurrence), nearby (regional recurrence), or in another place (distant recurrence). When this occurs, a cycle of testing will begin again to learn as much as possible about the recurrence. After testing is done, you and your child’s doctor will talk about the treatment options. Often the treatment plan will include the therapies described above (such as surgery, chemotherapy, and radiation therapy) but may be used in a different combination or given at a different pace. Your child’s doctor may also suggest clinical trials that are studying new ways to treat this type of recurrent tumor. For a recurrent CNS tumor, the next phase of treatment depends on three factors:
Depending on individual circumstances, the doctor may recommend surgery, radiation therapy, chemotherapy, and/or stem cell transplantation. Stem cell transplantation/bone marrow transplantation. Stem cell transplantation (SCT)/bone marrow transplantation may be used if a CNS tumor recurs. A stem cell transplant is a medical procedure in which diseased bone marrow is replaced by highly specialized cells, called hematopoietic stem cells. Hematopoietic stem cells are found both in the bloodstream and in the bone marrow. Today, this procedure is more commonly called a stem cell transplant, rather than bone marrow transplant, because it is the blood stem cells that are typically being transplanted, not the actual bone marrow tissue. Before recommending high-dose chemotherapy and transplantation, doctors will talk with the family about the risks of this treatment and consider several other factors, such as the type of tumor, results of any previous treatment, and the patient’s age and general health. In most stem cell transplants, the patient is treated with high doses of chemotherapy and/or radiation therapy to destroy as many tumor cells as possible. This also destroys the patient’s bone marrow tissue and suppresses the patient’s immune system. After the high-dose treatment is given, blood stem cells are infused into the patient’s vein to replace the bone marrow and restore normal blood counts. The replacement cells engraft (begin to make new blood cells) and turn into health, blood-producing tissue in 10 days to three weeks. Destroying the patient’s marrow reduces the body’s natural defenses, temporarily leaving the patient at an increased risk of infection. Until the patient’s immune system is back to normal, patients may need antibiotics and blood transfusions, and they need to follow certain safety restrictions provided by the health care team to help avoid infections. Learn more about bone marrow and stem cell transplantation. A recurrent tumor may bring up emotions such as disbelief or fear. You and your family are encouraged to talk with the health care team about these feelings and ask about support services to help you cope. Learn more about dealing with a tumor recurrence. If treatment fails Although treatment is successful for the majority of children with a tumor, sometimes it is not. If a child’s tumor cannot be cured or controlled, this is called an advanced or terminal tumor. This diagnosis is stressful, and it may be difficult to discuss. However, it is important to have open and honest conversations with your child’s doctor and health care team to express your family’s feelings, preferences, and concerns. The health care team is there to help, and many team members have special skills, experience, and knowledge to support patients and their families. Parents or guardians are encouraged to think about where the child would be most comfortable: at home, in a home-like setting elsewhere, in the hospital, or in a hospice environment. Nursing care and special equipment can make staying at home a workable alternative for many families. Some children may be happier if they can arrange to attend school part-time or keep up other activities and social connections. The child’s health care team can help parents or guardians decide on an appropriate level of activity. Making sure a child is physically comfortable and free from pain is extremely important as part of end-of-life care. Learn more about caring for a terminally ill child and advanced cancer care planning. The death of a child is an enormous tragedy, and families may need support to help them cope with the loss. Pediatric cancer centers often have professional staff and support groups to help with the process of grieving. Learn more on grieving the loss of a child. Find out more about common terms used during treatment. About Clinical Trials
Doctors and scientists are always looking for better ways to treat children with a CNS tumor. To make scientific advances, doctors create research studies involving people, called clinical trials. Many clinical trials are focused on new treatments, evaluating whether a new treatment is safe, effective, and possibly better than the current (standard) treatment. These types of studies evaluate new drugs, different combinations of existing treatments, new approaches to radiation therapy or surgery, and new methods of treatment. Children who participate in clinical trials are often among the first to receive new treatments before they are widely available. However, there is no guarantee that the new treatment will be safe, effective, or better than a standard treatment. There are also clinical trials that study new ways to ease symptoms and side effects during treatment and managing the late effects that may occur after treatment. Talk with your child’s doctor about clinical trials regarding side effects. In addition, there are ongoing studies about ways to prevent the disease. People decide to participate in clinical trials for many reasons. For some children, a clinical trial is the best treatment option available. Because standard treatments are not perfect, patients are often willing to face the added uncertainty of a clinical trial in the hope of a better result. Other people volunteer for clinical trials because they know that these studies are the only way to make progress in treating a childhood CNS tumor. Even if they do not benefit directly from the clinical trial, their participation may benefit future children with a CNS tumor. Sometimes people have concerns that, by participating in a clinical trial, they may receive no treatment by being given a placebo or a “sugar pill.” The use of placebos in cancer clinical trials is rare. When a placebo is used in a study, it is done with the full knowledge of the participants. Find out more about placebos in cancer clinical trials. To join a clinical trial, parents and children must participate in a process known as informed consent. During informed consent, the doctor should list all of the options, so that the person understands how the new treatment differs from the standard treatment. The doctor must also list all of the risks of the new treatment, which may or may not be different from the risks of standard treatment. Finally, the doctor must explain what will be required of each person in order to participate in the clinical trial, including the number of doctor visits, tests, and the schedule of treatment. Learn more about clinical trials, including patient safety, phases of a clinical trial, deciding to participate in a clinical trial, questions to ask the research team, and links to find clinical trials. For specific topics being studied for CNS tumors, learn more in the Current Research section. People who participate in a clinical trial may stop participating at any time for any personal or medical reason. This may include that the new treatment is not working or there are serious side effects. It is important that people participating in a clinical trial talk with the doctor and researchers about who will be providing their child’s treatment and care during the clinical trial, after the clinical trial ends, and/or if the person chooses to leave the clinical trials before it ends. Side Effects
A tumor and its treatment can cause a variety of side effects. However, doctors have made major strides in recent years in reducing pain, nausea and vomiting, and other physical side effects of treatments. Many treatments used today are less intensive but as effective as treatments used in the past. Doctors also have many ways to provide relief to patients when such side effects occur. Fear of treatment side effects is common after a diagnosis of a tumor, but it may be helpful to know that preventing and controlling side effects is a major focus of your child’s health care team. Before treatment begins, talk with your child’s doctor about possible side effects of the specific treatments your child will be receiving. The specific side effects that can occur depend on a variety of factors, including the type of tumor, its location, the individual treatment plan (including the length and dosage of treatment), and your child’s overall health. Common side effects for each treatment option are described in detail within the Treatment section. Ask your child’s doctor which side effects are most likely to happen (and which are not), when side effects are likely to occur, and how they will be addressed by the health care team. Also, be sure to communicate with the doctor about side effects your child experiences during and after treatment. Care of a patient’s symptoms and side effects is an important part of a child’s overall treatment plan; this is called palliative or supportive care. It helps children with a tumor at any stage of illness be as comfortable as possible. Learn more about the most common side effects of cancer and different treatments, along with ways to prevent or control them. Be sure to talk with your child’s doctor about the level of caregiving your child may need during treatment and recovery, as family members and friends often play an important role in the care of a child with a CNS tumor. Learn more about caregiving. In addition to physical side effects, there may be psychosocial (emotional and social) effects as well. For many families, a diagnosis of a CNS tumor is stressful and can bring difficult emotions. Patients and their families are encouraged to share their feelings with a member of the health care team, who can help with coping strategies. Learn more about the importance of addressing such needs, including concerns about managing the cost of your child's medical care. A side effect that occurs more than five years after treatment is called a late effect. Treatment of late effects is an important part of survivorship care. Learn more about late effects or long-term side effects by reading the After Treatment section or talking with your child’s doctor. After Treatment
After treatment for a CNS tumor ends, talk with your child’s doctor about developing a follow-up care plan. This plan may include regular physical examinations and/or medical tests to monitor your child’s recovery for the coming months and years. All children treated for a CNS tumor should have life-long, follow-up care. Based on the type of treatment the child received, the doctor will determine what examinations and tests are needed to check for long-term side effects and the possibility of secondary tumors. For example, craniospinal (head and spine) radiation therapy can cause cognitive (thought-process) and endocrine (hormonal) symptoms over time, although the severity can vary greatly depending on the dose given and the age of the child. Similarly, the risks and potential side effects of surgery vary widely, depending on the location of the tumor and how it grew. Likewise, the risks of chemotherapy and the likelihood of secondary tumors also strongly depend on the drugs and doses used. Your child’s doctor can recommend the necessary screening tests. Follow-up care should also address the child’s quality of life, including any developmental or emotional concerns. Learn more about childhood cancer survivorship. The child’s family is encouraged to organize and keep a record of the child’s medical information so that, as the child enters adulthood, he or she has a clear, written history of the diagnosis, the treatment given, and the doctor’s recommendations about the schedule for follow-up care. The doctor’s office can help you compile this. This information will be valuable to doctors who care for your child during his or her lifetime. ASCO offers treatment summary forms to help keep track of the treatment your child received and develop a survivorship care plan once treatment is completed. Children who have had a CNS tumor can also enhance the quality of their future by following established guidelines for good health into and through adulthood, including not smoking, maintaining a healthy weight, eating a balanced diet, and participating in regular physical activity. Talk with the doctor about developing a plan that is best for your child’s needs. Learn more about the next steps to take in survivorship. Find out more about common terms used after treatment of a CNS tumor is complete. Current Research
Doctors are working to learn more about CNS tumors, ways to prevent them, how to best treat them, and how to provide the best care to children diagnosed with this disease. The following areas of research may include new options for patients through clinical trials; Always talk with your child’s doctor about the diagnostic and treatment options best for your child. New medications. Doctors are examining new types of drugs that may better control tumor growth. Improved imaging techniques. Imaging techniques are being developed and refined that help surgeons pinpoint the tumor’s location, to reduce or prevent tissue damage to the healthy parts of the brain during treatment.
Improved methods of delivering radiation treatment. Doctors are experimenting with new techniques for delivering radiation therapy to certain types of tumors. These methods make detailed, three-dimensional maps of the brain and tumor, so doctors can focus the radiation on the tumor and avoid damage to the nearby healthy tissue. This can reduce a child’s exposure to radiation and lessen the long-term side effects. Finding specific tumor markers. Tumor markers are substances found at higher than normal levels in the blood, urine, or body tissues of some people with a tumor. Although tumor cells often make these markers, other cells in the body may also make them. Tumor markers are also called serum markers or biomarkers. Doctors are looking at various proteins and DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) markers in the blood samples and tumor tissue samples from children with CNS tumors to help predict how fast a tumor will grow and spread. This information may help doctors treat the tumor more effectively. Supportive care. Clinical trials are underway to find better ways of reducing symptoms and side effects of current CNS tumor treatments in order to improve patients’ comfort and quality of life. Learn more about common statistical terms used in cancer research. Looking for More about Current Research? If you would like additional information about the latest areas of research regarding CNS tumors, explore these related items:
Or, choose “Next” (below, right) to continue reading this detailed section. Questions to Ask the Doctor
Talking often with the doctor is important to make informed decisions about your child’s health care. These suggested questions are a starting point to help you learn more about your child’s care and treatment. You are also encouraged to ask additional questions that are important to you.
Patient Information Resources
In addition to Cancer.Net, there are other sources of information about this type of cancer available online. Cancer.Net maintains a list of national, not-for-profit organizations that may be helpful in finding additional information, services, and support. As always, be sure to talk with your doctor about questions you may have about information you find about this disease. View organizations that offer information on this specific type of cancer. |
