Brain cancer occurs when malignant cancer cells arise in the brain tissue. Cancer cells grow to form tumor that obstructs the proper functioning of the brain and other normal body functions. According to statistics, brain cancer is rare, with about 1.4% cases yearly. It is likely to develop in about 23,770 new people per year with about 16,050 deaths as projected by the National Cancer Institute (NCI) and the American Cancer Society. Only about 5% of brain tumors may be due to hereditary genetic conditions.
Grades of brain cancers
Even if brain cancer arise from the same type of brain tissue, not all brain tumors are alike. Tumors are assigned a grade depending on how the cells in the tumor appear microscopically. The four stages offer insight to the growth rate of the cell. NCI lists the following grades from benign to most aggressive
- Grade I: The tissue is benign and the cells look nearly like normal brain cells, and they grow slowly.
- Grade II: The tissue is malignant in this stage. The cells look less like normal cells.
- Grade III: In this stage, the malignant tissue has cells that look very different from normal cells. The abnormal cells are actively growing and have a distinctly abnormal appearance.
- Grade IV: The malignant tissue has cells that look most irregular and tend to grow rapidly.
Types of brain cancers
The most common primary brain tumors are usually named for the brain tissue type including brain stem cancers from which they developed.
- Pituitary adenomas
- Vestibular schwannomas
- Primitive neuroectodermal tumors
Gliomas is further divided into several subtypes, these include:
- Choroid plexus papillomas
Glioblastomas arise from astrocytes and are very aggressive malignant tumors. Senator John McCain was diagnosed with this form of brain tumor. These names all imitate different types of cells in the normal brain that can become cancer. Benign tumors can cause serious problems if they grow big enough to cause increased intracranial pressure or obstruct vascular structures or cerebrospinal fluid flow.
Stages of brain cancer
Brain cancers are classified according to their cell type and grade because they rarely spread to other organs like breast cancer. These cancer stages range from 0 to 4; with stage 4 indicating the cancer has spread to another organ.
Metastatic brain cancer
Cancer cells that develop in a body organ can spread through direct extension, or through the lymphatic system and through the bloodstream to other organs of the body organs. Tumors formed by such cancer cells that metastasize or spread to other organs are called metastatic tumors. Metastatic brain cancer is a mass of cells (tumor) that originated in another body organ and has spread into the brain tissue.
Causes of brain cancer
Primary brain tumors come from many types of brain tissue. Metastatic brain cancer is caused by the spread of cancer cells from a body organ to the brain. Scientists are yet to understand what causes normal cells to change to cancer cells in both metastatic and primary brain tumors. However, they suspect certain risk factors.
- People who work in an oil refinery, handlers of jet fuel or chemicals like benzene, chemists, embalmers, or rubber-industry workers.
- Heredity as a cause for brain tumors has not been proven.
- Radiation exposure, smoking, and viral infection (HIV), and other factors have not been proven to cause brain cancer. There is no good evidence that brain cancer is caused by head trauma, use of cell phones, or contagious.
Signs and symptoms of brain cancer
There may be a few early warning signs of brain cancer, but the most common signs and symptoms of brain cancer may:
Other common symptoms that can occur include:
- Nausea and/or vomiting
- Reduction in mental capacity
- Blurry vision
- Change in alertness
- Memory problems
- Changes in speech
- Personality changes
- weakness on one side of the body
- coordination problems,
These symptoms can also occur in people who do not have brain cancer. Cancer can occur in any part of the brain and a few brain cancers may produce few or no symptoms.
Tests doctors use to diagnose brain cancer
The preliminary test may include a medical history and physical examination. The results will determine if other specific tests need to be performed.
The most frequently used test to detect brain cancer is:
CT scan (computerized tomography): This test is a series of X-rays and is not painful, though a dye may need to be injected into a vein for better images of some internal brain structures.
MRI (magnetic resonance imaging): This test also shows the brain structures in detail better than CT. If the tests indicates tumors or abnormalities in the brain tissue, then other doctors such as neurosurgeons and neurologists that specialize in treating brain ailments will be consulted to help determine what should be done.
Tissue sample (biopsy): This may be gotten by surgery or insertion of a needle to help check the diagnosis.
Other tests such as white blood cell counts, electrolytes, or examination of cerebrospinal fluid to check abnormal cells or increased intracranial pressure.
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Treatment for brain cancer
The treatment plan is constructed by the brain cancer specialists, and treatments vary widely depending on the cancer type, brain location, tumor size, patient age, and the health status of the patient. Patients should discuss treatment options with their doctors.
The major treatment categories for most brain cancers are surgery, chemotherapy, and radiation therapy. Individual treatment plans often include a combination of these treatments.
Surgical therapy attempts to remove all of the tumor cells by cutting the tumor away from normal brain tissue. This surgery involves opening the skull, and it is often described as invasive surgery to differentiate it from noninvasive radiosurgery or radiation therapy. Some brain cancers are labelled inoperable by surgeons because trying to remove the cancer may cause further brain damage or even death. Patients with an inoperable brain tumor diagnosis should consider seeking a second opinion before surgical treatment is abandoned because it may be considered operable by another brain surgeon.
Radiation therapy destroy tumor cells by using high-energy radiation targeted onto the tumor to destroy the tumor cells’ ability to function and duplicate. Radiosurgery is a nonsurgical procedure that delivers a single high dose of precisely targeted radiation using highly focused gamma-ray or X-ray beams that join on the specific area or areas of the brain where the tumor or other abnormality is located.
Tomotherapy is a type of radiation therapy in which radiation is delivered in a highly precise manner that reduces radiation exposure to healthy tissue. It has also been used to treat brain cancer.
Chemotherapy: This destroy tumor cells by using chemicals or drugs that are specifically designed to destroy certain types of cancer cells.
Other treatment options may include:
- Hyperthermia (heat treatments)
- Immunotherapy (immune cells directed to kill certain cancer cell types)
- Steroids (to reduce inflammation and brain swelling). These may be added on to other treatment plans.
Side effects of brain cancer treatment
Side effects of brain cancer treatment vary with the treatment plan. Most treatment plans try to keep all side effects to a minimum. The side effects of brain cancer treatment can be severe for some persons. Treatment plans should include a discussion of potential side effects and the likelihood of them developing, so the patient and their caregivers can make appropriate treatment decisions.
Surgical side effects include an increase in current symptoms, damage to normal brain tissue, brain swelling, and seizures. Other symptoms of changes in brain function such as muscle weakness, mental changes, and decreases in any brain-controlled function can occur. Combinations of these side effects may happen. The side effects are most noticeable shortly after surgery but frequently decline over time. Occasionally, the side effects do not go away.
Chemotherapy usually damages rapidly growing cancer cells but also can affect normal tissue. Chemotherapy is usually given intravenously so the drugs can reach most body organs. Common side effects of chemotherapy are hair loss, nausea, loss of energy, vomiting.