Frequently Asked Questions About Brain Cancer
Q. What is brain cancer?
A. Benign brain tumors do not contain cancer cells, but they can press on sensitive areas in the brain and cause symptoms. They are usually a collection of extra cells that cause a mass of tissue called a "tumor." They typically have clear borders and do not invade surrounding areas. They usually can be removed by surgery and are not likely to grow back.
Malignant brain tumors contain cancer cells that can grow like a plant and put out "roots" that grow into healthy brain tissue and interfere with vital functions. They are often life threatening. They may not have roots and then are called encapsulated. Malignant tumors are likely to grow rapidly. Doctors refer to brain tumors by grade, depending on what the cells look like under the microscope. Grades are from low grade (I) to high grade (IV) that tell how abnormal the cells look and how fast they may grow.
Q. What is the central nervous system?
A. The brain and the spinal cord form the central nervous system. It controls walking, talking, breathing and digesting food. It is also involved with our senses – seeing, hearing, touching, tasting and smelling – as well as our emotions, thoughts and memory.
Q. What are the symptoms of brain tumors?
A. The symptoms depend on the size of the tumor and the location. Symptoms are caused by damage to vital tissue and by pressure from the tumor or swelling, which may happen if the tumor blocks the flow of cerebrospinal fluid.
§ Headaches that tend to be worse in the morning
§ Nausea and vomiting
§ Weakness or loss of feeling in arms and legs
§ Stumbling or lack of coordination in walking
§ Abnormal eye movements or changes in vision
§ Changes in personality or memory
§ Changes in speech
Q. What are the causes of brain tumors?
A. The causes of brain tumors are not known. Brain tumors are not contagious. They can occur at any age, although they are most common in children 3-12 years old and adults 40-70 years old. Risk factors include working in industries such as oil refining, rubber manufacturing and drug manufacturing; other studies show chemists and embalmers have higher incidence of brain tumors. Researchers also are looking at exposure to viruses as a possible cause. Brain tumors sometimes occur in several members of the same family, so researchers are studying families to see whether heredity is a cause. Scientists do not believe that head injuries cause brain tumors to develop.
Q. How is a brain tumor diagnosed?
A. The doctor does a complete physical exam with special attention to neurological examination. This includes checks for alertness, muscle strength, coordination, reflexes and response to pain. The doctor also examines the eyes for swelling caused by a tumor pressing on the nerve that connects the eye and the brain.
The doctor may request a CT (or CAT) scan or an MRI. A CT scan is a series of detailed pictures of the brain. The pictures are created by a computer linked to an X-ray machine. Sometimes dyes are injected into to help show differences in the tissue of the brain.
An MRI (magnetic resonance imaging) gives pictures using a powerful magnet linked to a computer. An MRI is helpful in diagnosing brain tumors because it can "see" through the bone of the skull to the tissue underneath. A dye may also be used to enhance the likelihood of detecting the tumor.
An MRS (magnetic resonance spectroscopic) is a non-invasive method that can be used with MRI to provide information about cellular activity and degree of malignancy.
A PET (positron emission tomography) scan is a computerized imaging procedure that can help find cancer cells in the body.
Other possible tests:
§ Skull X-ray – can show changes in bone or calcium deposits which are sometimes present in brain tumors.
§ Brain scan – reveals and records abnormal areas on special film. A small amount of radioactive material is injected into the vein. This dye is absorbed by the tumor and shows up on the film. The radiation leaves the body within six hours and is not dangerous.
§ Angiogram or ateriogram – a series of X-rays after a dye is injected into an artery. These X-rays can show the tumor and blood vessels that lead to it.
§ Myelogram – an X-ray of the spine. A special dye is injected into the cerebrospinal fluid in the spine, and the patient is tilted to allow the dye to mix with the fluid. This test may be done if a doctor suspects a tumor in the spinal cord.
Q. What are the types of brain tumors?
A. There are primary and secondary brain tumors. Tumors that begin in brain tissue are known as primary tumors. Secondary tumors are when cancer spreads from another site to the brain, which is called metastasis. Brain tumors are classified by the type of tissue in which they begin. The most common brain tumors are gliomas.
Types of gliomas:
§ Astrocytomas arise from small, star-shaped cells called astrocytes. They may grow anywhere in the brain or spinal cord. In adults, astrocytomas most often arise in the cerebrum. In children, they occur in the brain stem, the cerebrum and the cerebellum. A grade III astrocytoma is sometimes called anaplastic astrocytoma. A grade IV astrocytoma is usually called glioblastoma multiforme.
§ Brain stem gliomas occur in the lowest, stem-like part of the brain. The brain stem controls many vital functions. Tumors in this area generally cannot be removed. Most brain stem gliomas are high-grade astrocytomas.
§ Ependymomas usually develop in the lining of the ventricles. They also may occur in the spinal cord. Although these can develop at any age, they are most common in childhood and adolescence.
§ Oligodendrogliomas arise in the cells that produce myelin, the fatty covering that protects nerves. These tumors usually arise in the cerebrum. They grow slowly and usually do not spread into surrounding brain tissue. Oligodendrogliomas are rare. They occur most often in middle-aged adults but have been found in people of all ages.
There are other types of brain tumors that do not begin in glial tissue. Some of the most common are:
§ Medulloblastomas were once thought to develop from glial cells. However, recent research suggests that these tumors develop from primitive nerve cells that normally do not remain in the body after birth. For this reason, medulloblastomas are sometimes called primitive neuroectodermal tumors (PNET). Most medulloblastomas arise in the cerebellum; however, they may occur in other areas as well. These tumors occur most often in children and are more common in boys than in girls.
§ Meningiomas grow from the meninges. They are usually benign. Because these tumors grow very slowly, the brain may be able to adjust to their presence; meningiomas often grow quite large before they cause symptoms. They occur most often in women between 30 and 50 years of age.
§ Schwannomas are benign tumors that begin in Schwann cells, which produce the myelin that protects the acoustic nerve (the nerve of hearing). Acoustic neuromas are a type of schwannoma. They occur mainly in adults. These tumors affect women twice as often as men.
§ Craniopharyngiomas develop in the region of the pituitary gland near the hypothalamus. They are usually benign; however, they are sometimes considered malignant because they can press on or damage the hypothalamus and affect vital functions. These tumors occur most often in children and adolescents.
§ Germ cell tumors arise from primitive sex cells, or germ cells. The most frequent type of germ cell in the brain is the germinoma.
§ Pineal region tumors occur in or around the pineal gland, a tiny organ near the center of the brain. The tumor can be slow growing (pineocytoma) or fast growing (pineoblastoma). The pineal region is very difficult to reach, and these tumors often cannot be removed.
Q. What are the treatments for brain tumors?
A. The doctor develops a treatment plan to fit each patient, depending on the patient’s age and general health and the type, location and size of the tumor. Brain tumors are treated with surgery, radiation therapy and chemotherapy. Before treatment most patients are given steroids to reduce swelling. They may also be given anticonvulsant medications to prevent seizures.
§ Surgery is the usual treatment for most brain tumors. To remove the tumor, the neurosurgeon makes an opening in the skull. This is called a craniotomy. Whenever possible, the surgeon removes all of the brain tumor, but sometimes only part can be removed if removing would cause damage to vital brain tissue. Some tumors cannot be removed, and a biopsy is done to help decide treatment. Sometimes the biopsy can be done with a CT scan or MRI to pinpoint the tumor’s exact location, and only a small hole is needed in the skull. This is called stereotaxis.
§ Radiation therapy uses high-powered rays to damage cancer cells and stop them from growing. It is often used when surgery is not possible or not all of the tumor was removed. Radiation may be given in two ways.
External radiation treatments are given five days a week for several weeks. The treatment depends on the type and size of the tumor and age of the patient.
Radiation can also be placed directly into the tumor. Depending on material used, the implant may be left in the brain for a short time or permanently.
§ Stereotactic radiosurgery is another way to treat brain tumors. An MRI or CT scan is used to pinpoint the location of the tumor, and the treatment is given in one session. High-energy rays are aimed at the tumor from many angles. A high dose of radiation reaches the tumor without damaging other brain tissue. This may be referred to as the gamma knife.
§ Chemotherapy is the use of drugs to kill cancer cells. The doctor may use one drug or a combination. The medications may be given by mouth or by injection into a muscle or vein. Sometimes chemotherapy is given intrathecal, which is into cerebrospinal fluid. Chemotherapy is often given on an outpatient basis and is given in cycles – a treatment period followed by a rest period then another treatment – for several cycles.
Clinical trials are designed to determine whether a new approach is both safe and effective. Treatments that may be studied include:
§ Radiation twice daily
§ Hyperthermia, in which a tumor is heated to increase the effect of radiation
§ Drugs injected into the artery leading to the brain or directly into the brain
§ High-dose chemotherapy followed by bone marrow transplant
§ Biological therapy, which is a treatment to improve the body's immune system to fight the cancer
§ Molecular chemotherapy, or anticancer drugs based on newly discovered signaling pathways in brain tumor cells
§ Gene therapy and viral therapy, or the use of viruses or vectors (carriers) to deliver cancer-killing genes or agents to disease sites
Q. What are the side effects of treatment?
A. Surgery may damage normal brain tissue, and edema may occur. Seizures, weakness, coordination problems, personality changes and difficulty in speaking or thinking may result. Most side effects of surgery lessen or disappear with time.
Radiation may cause fatigue and hair loss, which may be temporary or permanent. Skin reaction in the treated area is common. The scalp and ears may be red, itchy or dark; these areas may feel and look sunburned. Patients should not use lotions without doctor advice. Sometimes radiation may cause headache, memory loss or seizures because the brain cells killed by radiation may form a mass that causes pressure. Doctors may suggest surgery or steroids to relieve these problems. Patients may have fatigue and lose their appetite four to eight weeks after radiation; this may last for several weeks, but it will usually go away. Children who have radiation treatments may have learning problems and partial loss of eyesight, or they may not grow or develop normally.
Chemotherapy side effects depend on the drugs used. Patients may experience lower resistance to infection, loss of appetite, nausea, vomiting, mouth sores, less energy and hair loss. These side effects usually go away after treatment. Some chemotherapy causes sterility. Some chemotherapy can cause kidney damage, so patients may be given large amounts of fluid while taking these drugs. Patients may also have tingling in fingers, ringing in ears or difficulty hearing. These problems may not clear up after treatment.
Steroids reduce swelling in the brain and may cause increased appetite, weight gain or swelling of the face and feet. Steroids can also cause restlessness, mood swings, burning indigestion, acne and elevated glucose. The steroid treatment must be gradually stopped so the body can adjust.
Q. What questions should I ask the doctor?
A. Here are some suggestions:
§ What treatment do you recommend?
§ Are there other methods of treatment?
§ What are the benefits of the various treatment options?
§ What are the risks?
§ What are you prescribing, and what is it supposed to do?
§ How should I expect to feel during treatment?
§ What side effects, if any, can I expect from treatment?
§ Should I bring someone with me for my treatments?
§ Will the treatment or disease affect my ability to work, drive or care for my family?
§ How often are the treatments and checkups?