Brain cancer is a disease characterized by the presence of malignant (cancerous) cells in the brain tissue. Cancer cells usually impact bodily and cognitive functions, including muscle control, memory, respiration, and others.
Tumors made up of cancerous cells are called malignant tumors. Non-cancerous tumors are called benign tumors. Malignant tumors effectively subdue healthy cells, taking their blood, nutrients, and space in the body.
Brain cancer, while serious, is quite rare. Studies estimate that the illness accounts for less than 1.5 percent of all new cancer cases. Per the National Cancer Institute, there are approximately 23,770 new cases and 16,050 deaths from brain cancer each year.
BRAIN CANCER “GRADES”
Brain tumors are assigned a ‘grade’ (I through IV, or 1-4) denoting their microscopic appearance and level of severity. Grades are as follows:
I: Benign cell tissue; cells grow slowly and look nearly identical to normal brain cells.
II: Malignant cells; cells appear more different than usual in comparison to grade I cells.
III: Malignant cells look quite different compared to normal brain cells (‘anaplastic’). They spread to malignant cells faster than grade I and II.
IV: Malignant cells appear highly anaplastic. Cells grow quickly.
Benign cells grow at a slower rate than malignant cells; however, benign cells located in vulnerable areas may be life-threatening and still require treatment. Some malignant tumors – though not all – respond promisingly to treatment (more on this later).
BRAIN CANCER TYPES AND STAGES
Brain cancer types receive classification according to the originating area. For example, “brain stem cancer” tends to develop around the medulla oblongata, pons, and midbrain near the spinal cord. Primary types of brain cancer include glioblastoma, glioma, meningioma, medulloblastoma, pituitary adenoma, and vestibular schwannoma.
Metastatic brain tumors originate in other areas of the body, such as the lung or lymphatic system. They are formed by cells that spread (metastasize) from other organs or areas of the body. Metastatic brain cancers are more common than the primary types listed above…
WHAT CAUSES BRAIN CANCER?
As mentioned, primary brain cancer originates in the neurological regions of the body. More specifically, brain tumors arise from multiple kinds of brain tissue, e.g. astrocytes and glial cells. Metastatic tumors form from cancerous cells that spread (metastasize) from other areas of the body.
Despite this knowledge, as with nearly every other type of cancer, scientists can’t pinpoint the catalysts of brain cancer. Scientific data do show that certain demographics are more at risk for developing brain cancer than others.
The following factors may increase the risk of someone developing brain cancer:
Children and older adults (ages 55 and up) develop brain tumors more than middle-aged adults and teenagers. However, anyone of any age can get a brain tumor.
There is scant evidence, but there could be a possible link between increased risk of cancer and exposure to some substances, such as solvents, pesticides, and rubber.
Men are more likely than women to develop a brain tumor, but women are more prone to meningioma.
It’s estimated that around 5 percent of brain tumors are attributable to a family history of conditions, including neurofibromatosis, nevoid basal cell carcinoma syndrome, tuberous sclerosis, Turcot syndrome, and von-Hippel-Lindau disease.
RACE AND ETHNICITY:
White adults are at a higher risk of developing brain tumors than adults of other races, sans certain types such as meningioma. Some of the ethnic differences in risk are striking; for example, northern Europeans are twice as likely to develop a brain tumor as the Japanese.
Exposure to ionizing radiation in a clinical setting (such as via x-rays) is a risk factor for developing brain cancer.
Studies show a link between head trauma and meningioma. Predisposition to seizures also appears to be a risk factor for brain cancer.
The Epstein-Barr virus, typically associated with causing mononucleosis (mono), is now thought to be a risk factor for CNS lymphoma. High concentrations of cytomegalovirus (CMV) have been discovered in brain tumor tissue. However, scientists caution that more research is needed concerning the potential link between virus exposure and the development of brain cancer.