Definition and Overview
Brain and nervous system cancers primarily affect the brain and body parts that are connected to the nervous system. Research shows that these cancers are among the most common types that affect children, right after leukemia. These cancers are characterized by the presence of tumors in the brain and the spinal cord, which can then affect the entire nervous system.
Brain and nervous system cancers are usually treatable when they are discovered early. There are different types of these cancers, typically categorized according to the location of the tumors, the type of cancerous cells, and the speed of their growth. Malignant brain tumors often grow and spread at an alarming rate, quickly taking over the space of healthy brain cells and using up the blood and nutrients meant for them. These malignant tumors can also spread not only in the nervous system but also in other parts of the body that are quite far from the brain.
Contrary to popular belief that all tumors in the brain are cancerous, only malignant tumors can be labeled as such. However, non-cancerous growths or benign tumors can also pose serious health risks to the brain if left unchecked or untreated.
The World Health Organization (WHO) has developed a classification system to identify and categorize brain tumors. Malignant brain tumors that cause brain and nervous system cancers are assigned grades, with Grade I being the least malignant and Grade IV being the most malignant. Here are some of the brain cancer types listed in the WHO classification system:
Astrocytoma. These cancerous growths develop from astrocytes, which are star-shaped glial cells often located in the cerebrum. Astrocytomas can develop in patients of all ages, with the lower grade types often occurring in younger patients and the higher-grade types in adults. They can also develop in different parts of the brain and in the spinal cord, but they rarely metastasize to other parts of the body and do not affect the other organ systems.
Chordoma. A rare type of cancer, chordomas typically occur in the spine and the skull. Research shows that Chordomas grow slower than other types of brain and nervous system cancers, but are observed to be resistant to treatment and tend to recur after treatment.
CNS Lymphoma. In this type of brain and nervous system cancer, malignant tumors originate from the lymph tissues in the brain or the spinal cord. The risk of developing this condition is linked to having a weakened immune system.
Craniopharyngioma. This type of brain tumor develops from the embryonic tissue of the pituitary glands. Craniopharyngioma often develops in children, but can also occur in patients over 50 years old.
Glioma. Developing from glial cells in the brain or spine, gliomas are responsible for 80 percent of cases of malignant brain tumors. Gliomas do not metastasize through the bloodstream but can spread to other parts of the body and organ systems through the cerebrospinal fluid.
Medulloblastoma. This often originates in the bottom or back of the brain, or right on the floor of the skull and mostly affects children.
Meningioma. These tumors develop in the meninges and are rarely malignant. They also typically do not produce any observable symptoms in patients.
Metastatic brain tumor. These tumors do not originate from brain cells or tissues but from other parts of the body. Different types of cancer can spread to the brain, including germ cell tumors, sarcoma, leukemia, lymphoma, melanoma, and kidney, breast, lung, and bladder cancers.
Oligodendroglioma. A type of glioma, this type of brain and nervous system cancer originates from the oligodendrocytes and typically occur in adults. The average age at which oligodendroglioma is diagnosed is 35 years old.
Pituitary tumors. These tumors develop from the pituitary glands but are rarely cancerous.
Primitive neuroectodermal tumors. These highly malignant tumors develop from round neuroectodermal cells, which can affect the brain’s soft tissues and the bones of the spine and skull.
Cause of Condition
The exact causes of brain and nervous system cancers remain unknown, other than these conditions originate from the abnormal growth of cells in the brain, skull, or spine and spinal cord. However, several factors can increase an individual’s risk of these cancers, including the following:
- Genetic factors, as some serious brain and nervous system cancers run in the family
- Toxins found in the individual’s environment
- Heavy cigarette smoking
- Exposure to radiation, especially to the head
- HIV infection
- Having developed cancer as a child
- Taking hormone replacement therapy during post-menopause
- Living near power lines
- Having immune system issues
Symptoms of brain and nervous system cancers vary depending on the type of cancerous growths the patient has. However, there are some common symptoms, including the following:
- Severe headaches, which worsen with activity or become more painful in the early mornings
- Seizures or convulsions, which can be accompanied by loss of consciousness, loss of body tone, and an inability to control body functions
- Sensory issues, including problems with touch and sensation, vision, smell, and hearing
- Loss of awareness
- Partial or total loss of consciousness
- Changes in personality
- Memory issues
- Loss of balance
- Muscle weakness
- Altered perception of touch or pressure
- Partial or complete vision loss
- Comprehension issues
- Pain or pressure in certain spots of the head or spine
Who to See and Types of Treatment Available
Upon observing the symptoms described above, the patient must immediately see his or her doctor, who can then refer him or her to a team of medical professionals who can treat the condition.
Several factors need to be considered when treating brain and nervous system cancers, including the patient’s age, medical history, overall health, the type of tumor, its location and size, as well as the possibility of spread or recurrence, and the patient’s tolerance for certain types of therapy, medication, and surgical procedures.
Patients may be prescribed anti-epileptic or anti-seizure medication and steroids to manage the symptoms. However, in cases where surgery does not pose a serious risk or if the patient will greatly benefit from the removal of the tumor, the patient should immediately undergo surgical tumor removal.
- National Brain Tumor Society
- 2007 WHO Classification of Tumors of the Central Nervous System
- Cancer Research UK
- National Cancer Institute