What is a brain tumor?
A brain tumor is an abnormal growth of tissue in the brain. The tumor can either originate in the brain itself, or come from another part of the body and travel to the brain (metastasize). Brain tumors may be classified as either benign (non-cancerous) or malignant (cancerous), depending on their behavior.
A benign tumor does not contain cancer cells and usually, once removed, does not recur. Most benign brain tumors have clear borders, meaning they do not invade surrounding tissue. However, these tumors can cause symptoms similar to cancerous tumors because of their size and location in the brain.
Malignant brain tumors contain cancer cells. Malignant brain tumors are usually fast growing and invade surrounding tissue. Malignant brain tumors very rarely spread to other areas of the body, but may recur after treatment. Sometimes, brain tumors that are not cancer are called malignant because of their size and location, and the damage they can do to vital functions of the brain.
Metastatic brain tumors are tumors that begin to grow in another part of the body, then spread to the brain through the bloodstream. Common types of cancer that can travel to the brain include lung cancer, breast cancer, melanoma (a type of skin cancer), and colon cancer. All of these cancers are considered malignant once they have spread to the brain.
Facts about brain tumors:
Consider the following facts about brain tumors from the American Cancer Society:
More than 18,820 people in the US will be diagnosed with malignant tumors of the brain or spinal cord during 2006.
Cancer of the brain or spinal cord account for approximately 1.3 percent of all cancers and 2.2 percent of all cancer-related deaths.
What causes brain tumors?
The majority of brain tumors have abnormalities of genes involved in cell cycle control, causing uncontrolled cell growth. These abnormalities are caused by alterations directly in the genes, or by chromosome rearrangements which change the function of a gene.
Patients with certain genetic conditions (i.e., neurofibromatosis, von Hippel-Lindau disease, Li-Fraumeni syndrome, and retinoblastoma) also have an increased risk to develop tumors of the central nervous system. There have also been some reports of people in the same family developing brain tumors who do not have any of these genetic syndromes.
Research has been investigating parents of children with brain tumors and their past exposure to certain chemicals. Some chemicals may change the structure of a gene that protects the body from diseases and cancer. Workers in oil refining, rubber manufacturing, and chemists have a higher incidence of certain types of tumors. Which, if any, chemical toxin is related to this increase in tumors is unknown at this time.
Patients who have received radiation therapy to the head as part of prior treatment for other malignancies are also at an increased risk for new brain tumors.
What are the symptoms of a brain tumor?
The following are the most common symptoms of a brain tumor. However, each person may experience symptoms differently. Symptoms vary depending on the size and location of tumor. Many symptoms are related to an increase in pressure in or around the brain. There is no spare space in the skull for anything except the delicate tissues of the brain and its fluid. Any tumor, extra tissue, or fluid can cause pressure on the brain and result in increased intracranial pressure (ICP), which may result from one or more of the ventricles that drain cerebral spinal fluid (CSF, the fluid that surrounds the brain and spinal cord) becoming blocked and causing the fluid to be trapped in the brain. This increased ICP may cause the following:
- headache
- vomiting (usually in the morning)
- nausea
- personality changes
- irritability
- drowsiness
- depression
- decreased cardiac and respiratory function and, eventually, coma if not treated
Symptoms of brain tumors in the cerebrum (front of brain) may include:
- increased intracranial pressure (ICP)
- seizures
- visual changes
- slurred speech
- paralysis or weakness on half of the body or face
- drowsiness and/or confusion
- personality changes/impaired judgment
- short-term memory loss
- gait disturbances
- communication problems
Symptoms of brain tumors in the brainstem (middle of brain) may include:
- increased intracranial pressure (ICP)
- seizures
- endocrine problems (diabetes and/or hormone regulation)
- visual changes or double vision
- headaches
- paralysis of nerves/muscles of the face, or half of the body
- respiratory changes
- clumsy, uncoordinated walk
- hearing loss
- personality changes
Symptoms of brain tumors in the cerebellum (back of brain) may include:
- increased intracranial pressure (ICP)
- vomiting (usually occurs in the morning without nausea)
- headache
- uncoordinated muscle movements
- problems walking (ataxia)
The symptoms of a brain tumor may resemble other conditions or medical problems. Always consult your physician for a diagnosis.
Treatment for brain tumors:
Specific treatment for brain tumors will be determined by your physician based on:
- your age, overall health, and medical history
- type, location, and size of the tumor
- extent of the condition
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the condition
- your opinion or preference
Treatment may include (alone or in combination):
- surgery
Surgery is usually the first step in the treatment of brain tumors. The goal is to remove as much of the tumor as possible while maintaining neurological function. A biopsy is also done to examine the types of cells the tumor is made of for a diagnosis. This is frequently done if the tumor is in an area with sensitive structures around it that may be injured during removal. - chemotherapy
- radiation therapy
- steroids (to treat and prevent swelling especially in the brain)
- anti-seizure medication (to treat and prevent seizures associated with intracranial pressure)
- placement of a ventriculoperitoneal shunt (Also called a VP shunt.)
- This is a tube that is placed into the fluid filled spaces of the brain called ventricles. The other end of the tube is placed into the abdomen to help drain excess fluid that can build up in the brain and cause an increase in pressure in the brain.
- bone marrow transplantation
- supportive care (to minimize the side effects of the tumor or treatment)
- rehabilitation (to regain lost motor skills and muscle strength; speech, physical, and occupational therapists may be involved in the healthcare team)
- antibiotics (to treat and prevent infections)
- continuous follow-up care (to manage disease, detect recurrence of the tumor, and to manage late effects of treatment)
Newer therapies that may be used to treat brain cancer include the following:
- stereotactic radiosurgery – a new technique that focuses high doses of radiation at the tumor site, while sparing the surrounding normal tissue, with the use of photon beams from a linear accelerator or cobalt x-rays.
- gene therapy – a special gene is added to a virus that is injected into the brain tumor. An antivirus drug is then given which kills the cancer cells that have been infected with the altered virus.
Long-term outlook for a person with a brain tumor:
Prognosis greatly depends on all of the following:
- type of tumor
- extent of the disease
- size and location of the tumor
- presence or absence of metastasis
- the tumor’s response to therapy
- your age, overall health, and medical history
- your tolerance of specific medications, procedures, or therapies
- new developments in treatment
As with any cancer, prognosis and long-term survival can vary greatly from individual to individual. Prompt medical attention and aggressive therapy are important for the best prognosis. Continuous follow-up care is essential for a person diagnosed with a brain tumor. Side effects of radiation and chemotherapy, as well as second malignancies, can occur in survivors of brain tumors.
Rehabilitation for lost motor skill and muscle strength may be required for an extended amount of time. Speech therapists and physical and occupational therapists may be involved in some form of rehabilitation. More research is needed to improve treatment, decrease side effects of the treatment for this disease, and develop a cure. New methods are continually being discovered to improve treatment and to decrease side effects.