What is Brain Tumor?
Not all brain tumors are cancer. Brain tumors are categorized into two groups: benign and malignant.
1. No cancerous cell is found in benign brain tumors:
- They are usually surgically removed and rarely recur.
- Margins and edges of benign brain tumors are clearly visualized.
- They do not invade surrounding healthy cells and do not spread to other body regions. However, all those characteristics do not imply that benign tumors are completely non-hazardous. Benign tumors may lead to severe health problems by compressing delicate zones of the brain.
- In contrast to benign tumors located in other body regions, benign tumors in brain may occasionally cause a life-threatening condition.
- Benign brain tumors very rarely progresses into malignant tumor over time.
2.Malignant tumors have cancerous cells:
- Malignant brain tumors are usually more hazardous and cause life-threatening conditions.
- Malignant tumors tend to grow rapidly and invade surrounding healthy tissues.
- Rarely, cancer cells detach from malignant brain tumors and spread to other regions of brain, the spine or even other regions of the body (metastasis).
In some cases, malignant tumors do not metastasize or invade to healthy tissues. Tumor may be confined to a tissue layer, scalp or any other structure in the cranium; this type of tumor is referred as “encapsulated tumor”.
Classification of Brain Tumors
Brain tumors are classified incrementally (from stage one to stage four). Stage of a tumor points out how cancer cells appear under microscope. Cells of high-stage tumors appear more unusual and multiply more rapidly than cells of low-stage tumors.
Primary Brain Tumors
Tumors originating from brain tissue are referred as primary brain tumor. Primary brain tumors are classified by the cells they originate from or the brain region.
Secondary Brain Tumors
Cells of a malignant tumor that is located in any tissue or organ of the body can spread to brain through the blood circulation, resulting in formation of a new tumor there. Such tumors are referred as secondary brain tumor or metastatic brain tumor.
Brain Tumors: Who are at risk?
Following factors are linked to increased risk of primary brain tumors:
- Male gender: Brain tumors are more common in men than women. However, meningioma, a tumor of central nervous system, is more frequently seen in women.
- Race: Brain tumors are more likely in white race than other races.
- Age: Although aging increases the risk of brain tumor, it is more common in people at and older than 70. On the other hand, it is the most common second type of cancer in children, following the leukemia. Brain tumors are more likely in children younger than 8 than children older than 8.
- Family: Positive family history for glioma, a central nervous system tumor, is linked to the risk of catching the same disease.
- Exposure to particular chemicals and/or radiation at the work place: Exposure to industrial radiation, formaldehyde, vinyl chloride and acrylonitrile is also a risk factor.
Symptoms of Brain Tumors
Symptoms of brain tumors vary depending on diameter, type and location of the tumor. Symptoms are manifested due to nerve ends compressed by the tumor, damaged brain tissue or accumulation of fluid in the scalp secondary to enlargement of the tumor. Most common symptoms of brain tumors are as follows:
- Headache getting worse in mornings,
- Nausea and/or vomiting,
- Altered speech, vision or hearing,
- Gait or standing imbalance,
- Extreme alterations in personality, mood or focusing attention,
- Memory problems,
- Twitching, spasms, abnormal contractions or seizures
- Numbness or tingling in arms and legs.
However, those symptoms are not specific to brain tumor or they may point out another health problem. Seeking medical attention immediately in the presence of those symptoms is very important for early diagnosis and treatment.
Diagnostic Methods of Brain Tumors
Following methods are used to diagnose tumor cells:
- Neurological examination
- Computed Tomography (CT)
- MRI (Magnetic Resonance Imaging)
- Cerebrospinal fluid (CSF) examination
Surgeons use three methods to examine tumor cells:
- Needle biopsy
- Stereotactic biopsy
- Treatment and concurrent biopsy
Surgery, radiotherapy or chemotherapy is chosen depending on type, stage and class of the tumor. A combination of those methods may be required for some patients.
In addition, patients may joint to special therapy programs at any stage of the disease in order to manage pain and symptoms of cancer and to cope with side effects and emotional burdens of the treatment. Such therapies are referred as “symptom management”, “supportive care” or “palliative care”.
Surgical treatment: Surgery is a treatment modality that is commonly used for brain tumors. Neurosurgeons open the skull with a procedure known as craniotomy.
Radiotherapy: Radiotherapy uses high-energy beams to damage cancer cells and to prevent multiplication thereof or destroy them. These rays include X-ray, gamma rays or protons. The tumor and the nearby tissues are irradiated. In some cases, whole brain or the spine can be irradiated.
Radiosurgery; radiosurgery is a medical procedure that utilizes a non-invasive method to treat benign and malignant tumors. If radiosurgery is used to treat brain lesions, it is also referred as stereotactic radiotherapy (SRT). Radiosurgery implies inactivating intracranial and extracranial tumors and lesions that are not appropriate for open surgery by delivering high-dose ionizing radiations to a focused target. Radiosurgery is reserved for patients, for whom conventional surgery is difficult or not recommended due to a tumor in close proximity to artery, nerve or other vital structures. Radiosurgery is usually applied in one session and its effects on the target can be as sharp as that of surgery. Exposure of healthy tissues to radiation is minimized by three dimensional computer-assisted planning and high immobilization.
Chemotherapy: Chemotherapy means killing cancer cells by medications. This method is occasionally used in treatment of brain tumors and medications can be administered by oral or intravenous routes. Whatsoever the administration route, the active substance is released to the blood circulation and circulates throughout the body. Medications are usually administered in cycles or courses and treatment periods are followed by recovery periods.
- Anti-convulsive medications
- Speech therapy