Resources and information for parents of children with cancer . . . by parents of children with cancer.

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Brain Cancers

Note: This section has health/medical information. It was not written by a health care professional. The main medical references are:

Recommended web site for all brain tumors: Brain cancers on the cancer.gov site and NCI PDQ for brain tumors
On this ped-onc site: Warning Signs of Childhood Cancer: Brain Cancers

Brain cancers account for 15% of pediatric cancers. Since the brain controls learning, memory, senses (hearing, visual, smell, taste, touch), emotions, muscles, organs, and blood vessels, the presentation of symptoms varies accordingly.

Treatment of pediatric brain cancers is more complex than is the treatment of some of the other cancers. Surgery to remove the tumor is not always possible because it may be inaccessible or because surgery would damage parts of the brain necessary for the functioning of the mind and/or body. Inoperable areas of the brain include: brain stem, thalamus, motor area, and deep areas of gray matter. Even a benign tumor in the brain can be life threatening. Another reason malignant brain tumors can be difficult to treat is because a blood-brain barrier exists which prevents some chemicals from entering the brain and reaching the tumor. Therefore, the prognosis depends not only on the type, grade, and size of the tumor, but on its location in the brain.

Reading about brain tumors can be particularly daunting for the parent of a recently diagnosed child. The nomenclature of brain cancers is difficult for the layman to master, since the tumors are described in terms with which most of us do not use in everyday conversation. Luckily, at least four sites (listed below) currently exist on the Internet that describe the many brain cancers. These sites use tables, diagrams, and pictures to depict the different pediatric cancers, as well as passages of detailed text. They are well written and are easy to understand because they fully explain each new medical term which they introduce.

The following is intended to be only a brief summary of the information presented in the above sources on brain tumors.

Types of Pediatric Brain Tumors

Most brain tumors are named for both type of cell from which the tumor originated and the location of the tumor in the brain.

examples of cell type

examples of location

general name

primitive neurectodermal, astrocytoma, medulloblastoma, ependymoma

cerebram, cerebellum, brain stem, optical nerve

glioma, adenoma, blastoma, carcinoma, sarcoma

Often the common name of a brain tumor reflects the cell type from which it arose: "astrocytoma" indicates that the tumor originated in astrocytes, star shaped cells that form part of the supportive tissue of the brain. More information about the tumor is included if you are told the name "cerebellar astrocytoma", indicating that it is located in the cerebellum in the brain.

Sometimes a general name is included in the name of a brain tumor, as in "brain stem glioma". Thus, the tumor is a glioma that is located in the brain stem. This name does not give any information about the type of glioma cell from which it arose. Glioma is a general term for tumors that arise from glial tissues, which are the supportive tissues of the brain. (Adenomas, usually benign, arise from a gland. Blastomas are malignant tumors whose cells have undeveloped or embryonic characteristics. A carcinoma is a malignant tumor that arises from skin or the lining of digestive, respiratory, or urogenital systems. Sarcomas are malignant tumors that arise from connective tissue, blood vessels, or the lymph system.) Brain tumors are usually either gliomas or blastomas. Often "glioma" or "blastoma" is included in the name of the tumor.

Certain types of brain tumors are more likely to occur in children because pediatric brain tumors usually arise from "young" cells, also known as immature or primitive cells. Common pediatric brain tumors are medulloblastoma, ependymoma, astrocytoma, brain stem and optical nerve gliomas, and gangliogliomas. However, any type of brain tumor can occur in children as well as adults.

Medulloblastoma. Medulloblastomas arise from primitive neuroectodermal tissue, or PNET. (PNET is a general term for a collection of many different brain tumors which arise from undeveloped brain cells.) Medulloblastomas are usually located in the cerebellum and are fast growing and highly malignant. They frequently spread, invading other parts of the central nervous system via the spinal fluid. Medulloblastomas account for the largest percentage of pediatric brain cancers. It is more common in boys than girls; it usually occurs between the ages of 2 and 6 (only 30% of medulloblastomas occur in adults); frequently spreads.

Ependymoma. Ependymomas arise from the cells that line the internal surfaces of the brain, thus, they are gliomas. The tumors arise from "ependyma", cells that line the fluid spaces of the brain and spinal cord. Ependymomas located in the cerebral hemispheres occur primarily in children and adolescents. Although these tumors are capable of malignant behavior, they are almost always benign.

Astrocytoma. Astrocytomas arise from brain cells which form part of the supportive system of the brain, in particular, cells called "astrocytes" for their star shaped appearance. This tumor are usually slow growing and many are considered "curable". Astrocytomas are often cystic, in which case they are particularly easy to remove completely.

Optical nerve glioma. These are slow growing tumors which form along the optic nerves. They usually occur children under the age of 10. The common cell type is pilocytic astrocytoma.

Brain stem glioma. These tumors, located in the brain stem, can be either slow or fast growing. Depending on the type of supporting tissue from which they arise, they can be either astrocytomas, anaplastic astrocytomas, glioblastoma multiforme, or a mixed tumor. In general, brain stem tumors are more common in children than they are in adults. Surgery is usually not possible in these tumors, and radiation and chemotherapy must be used instead.

Oligodendroglioma. Slow growing tumors which arise from cells which make the myelin that insulates nerve fibers. They are located in the hemispheres of the brain, especially the frontal and temporal lobes, and in children are more common in the thalamus.

Gangliogliomas. Usually slow growing, rarely malignant. these tumors can be located anywhere in brain, but are most often found in the temporal lobe. They arise from ganglia (a ganglion is a group of nerve cells). They occur most frequently in children and young adults.

Craniopharyngioma. Benign, congenital tumors. They are usually cystic and found primarily in children and adolescents.

Pineal Region Tumors. The pineal gland is located in the posterior portion of the third ventricle. The most common tumor of the pineal region is the germinoma. Germinomas (germ cell tumors) represent over one-third of the tumors in this region. Germinomas of the pineal region are most common in teen-agers. Additional tumors found in this area include other embryonal type tumors, teratomas, astrocytomas, pineocytomas, and pineoblastomas.

Treatment and Prognosis

Children with brain tumors should be seen at a multi-disciplinary medical center, staffed with the following: pediatric neurosurgeon, pediatric neuro-oncologist, pediatric hem-onc, pediatric neuro-radiolgoist, and a pediatric neuropsychologist. All too often children with brain tumor are not treated at centers that have the experience to handle all aspects of the disease.

The treatment and prognosis depends on the type, grade, and location of the tumor. Type and location are explained above paragraphs. The grade of the tumor indicates the degree of malignancy: its tendency to spread, its growth rate, and its similarity to normal cells when viewed under a microscope. Tumors with distinct borders are considered "grade I", are sometimes referred to as benign or mildly malignant. These tumors either do not grow or grow very slowly. Infiltrating tumors are those that tend to grow into surrounding tissue. Of the infiltrating tumors, the terms low-grade, mid-grade, and high-grade are frequently used. A "high grade" tumor is considered highly malignant. However, the exact system used to grade tumors varies with each specific family of tumors.

Brain tumors are treated with surgery, radiation, and chemotherapy. Depending on the type of tumor and the promptness of diagnosis, the 5 year survival rate is 40-80%.

Surgery. The purpose of surgery is to remove as much of the tumor as possible, to establish an exact diagnosis, to determine the extent of the tumor, and sometimes to provide access for other treatments, such as implants or radiation. As mentioned above, some tumors are inaccessible to the neurosurgeon.

Radiation. Conventional radiation therapy uses external beams of radiation aimed at the tumor, a therapy which is given over a period of several weeks. Other types of radiation are also available. Because the developing brain of a child is so very sensitive to radiation therapy, it is deliberately limited or delayed until the child has grown older and the brain has sufficiently matured.

Chemotherapy. Chemotherapy is required for the more aggressive or higher grade tumors. Many drugs will kill brain cells, but it is difficult to predict which tumors will respond to which chemotherapy agents. Therefore, treatment often consists of a combination of drugs.Certain classes of drugs will not pass the blood-brain barrier.

Shunting. Quite often childhood tumors the block the of the fluid spaces of the brain, creating pressure in the brain. In shunting, a thin silastic tube (the shunt) is placed into the fluid spaces of the brain, passed under the skin into the child's tummy where the fluid is absorbed.

Clinical Trials

Special mention needs to be made for the virtualtrials.com site, as well as the usual cancer.gov site:

Ped-Onc Resources for Brain Tumors

The following ped-onc resource lists have appropriate sections for parents of children with brain tumors:

Links to More Information

The following web sites provide good, general information on brain cancers and their treatment.

General Disclaimer

These pages are intended for informational purposes only and are not intended to render medical advice. The information provided on Ped Onc Resource Center should not be used for diagnosing or treating a health problem or a disease. It is not a substitute for professional care. If you suspect your child has a health problem, you should consult your health care provider.

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