Brain Tumors & Treatment
Malignant Brain Tumors
Malignant brain tumors represent the single most common type of brain tumor, constituting approximately half of all newly diagnosed tumors. Malignant brain tumors are generally derived from supporting brain tissue known as glia (Gliomas).
Gliomas account for about half of all primary brain tumors and nearly one-fifth of all primary spinal cord tumors. They originate from nerve cells called glial cells. Gliomas occur most often in the cerebral hemispheres, but also are found in the optic nerve, the brain stem, and especially among children, the cerebellum. There are many types of gliomas, including:
Most gliomas are astrocytomas, which develop from star-shaped glial cells called astrocytes. These tumors can occur in different parts of the brain, and thus, produce varying symptoms ( balance and coordination may be affected). The result of increased intracranial pressure may be headache, vomiting, and visual problems.
Glioma tumors are categorized by grades. Grading occurs after biopsy, when a pathologist examines the brain tissue for breakdown of cell structure. While there are different systems used to assign grades, in general, they are as follows:
- Grade I tumors are slow growing; their cells are near-normal in appearance; and are not malignant.
- Grade II tumors have cells that are slightly abnormal in appearance and can spread to surrounding tissue.
- Grade III tumors grow quickly, contain abnormal cells, and spread to surrounding tissue.
- Grade IV tumors contain aggressive, abnormal cells that reproduce quickly. These are the most malignant of brain tumors.
The types of graded astrocytomas include:
These Grade I and II, or low-grade, astrocytomas contain relatively normal cells and are less malignant than the other two grades. While well-differentiated astrocytomas often can be completely removed through surgery, those that are inaccessible to the surgeon may be life-threatening.
These Grade III astrocytomas contain cells with some malignant traits.
Treatment: Surgery followed by radiation, and some chemotherapy, is used to treat anaplastic astrocytomas.
These tumors, sometimes called high-grade or grade IV astrocytomas, grow rapidly, invade nearby tissue, and contain cells that are very malignant. Glioblastoma multiforme is among the most common and devastating primary brain tumors that strike adults. Doctors usually treat glioblastomas with surgery followed by radiation therapy. Chemotherapy may be used before, during or after radiation (link to Cancer Center webpage).
Treatment: For both anaplastic gliomas and glioblastomas , surgery is usually performed to remove the tumor.
A rarely occurring and slow-growing form of glioma, gangliogliomas can be found in the brain or spinal cord.
Treatment: These tumors are usually treated with surgery. Functional image-guided surgery may optimize the safety and completeness of surgical resection.
Brain Stem Gliomas
Like their name suggests, brain stem gliomas are located at the base of the brain. They occur more frequently in children than in adults. Brain stem gliomas can range in grade, from slow growing and benign to fast-growing and malignant.
Treatment: Brain stem gliomas occur in a vulnerable location, so surgery is rarely performed to remove them. Radiation therapy can reduce symptoms and improve the patient’s chance of survival by slowing tumor growth.
Mixed gliomas contain more than one type of glial cell; one of them usually being astrocytes. For reasons that are not known, mixed gliomas most commonly occur in young men.
Mixed gliomas often produce symptoms common to many brain tumors–headache, vomiting, and visual problems. Depending on the tumor’s location, there may be paralysis on one side of the body, memory difficulties, and personality changes.
Treatment: Treatment focuses on the most malignant cell type found within the tumor and often involves surgical resection. Radiation therapy is another possibility.
Optic Nerve Gliomas
Optic nerve gliomas can interfere with vision, causing "crossed" eyes, or strabismus; bulging eyeballs, or loss of sight. People with neurofibromatosis, a condition where fiber-like growths affect the nerves, may be susceptible to these types of tumors.
Treatment: Treatment may include surgery, radiation or chemotherapy.
Pituitary tumors arise from cells in the pituitary gland, a structure located at the base of the brain, critical for normal hormonal functioning. Some of these tumors secrete hormones that may cause changes such as abnormal growth, skin changes, loss of sexual potency or drive, or alteration in menstruation and infertility in women. As these tumors enlarge, they can press on surrounding structures, particularly the visual nerves. Pituitary tumors that secrete hormones can often be suppressed by therapy, stabilized and shrunk. Tumors that are not responsive to hormonal therapy are usually surgically removed.
Meningioma is the most common benign brain tumor occurring in as many as 30 to 40 percent of all brain tumor incidences.
Acoustic neuroma, also known as vestibular schwannoma, is a benign tumor arising from the eighth cranial nerve. Symptoms of acoustic neuroma often include dizziness, hearing loss or imbalance. This type of tumor is extremely common and can grow to a very large size.
Metastatic Brain Tumors
Metastatic or “secondary” brain tumors occur when cancer cells break away from a primary tumor elsewhere in the body, and spread to the brain via the bloodstream. Metastastic brain tumors are more common than primary brain tumors, which originate in the brain.
Cancers that metastasize to the brain include lung, breast, colon, melanoma, and kidney cancer, and others that are less common. The Providence Regional Cancer Partnership is one of the most comprehensive cancer programs in the region, ensuring that the best care is closest to home.