Brain Cancer

Reviewed by Dr. Clement J. Cheng

Primary brain cancer is a relatively rare disease, accounting for only 1 percent of all cancers and 2.5 percent of all cancer deaths. Primary brain cancer is cancer that originates in the brain and should be distinguished from metastatic, or secondary, brain cancer. One in four patients with cancer originating elsewhere in the body will develop metastatic brain cancer; only 10 to 12 people of 100,000 are diagnosed with primary brain cancer every year.

Several types of primary brain tumors exist:

• Meningiomas: These are the most common brain tumors, accounting for approximately 24 percent of cases. Most tumors of this type are benign (85 percent) and curable with surgery. However, some of these tumors are located close to vital parts of the brain and cannot be cured with surgery alone.

• Glioblastoma: This is the most common malignant primary brain tumor. It grows rapidly and accounts for 23 percent of primary brain tumors. Patients usually must undergo a combination of surgery, chemotherapy, and radiation to treat glioblastoma. Less than 9 percent of glioblastoma patients survive two years, 3.4 percent survive five years, and 2.3 percent survive 10 years. Long-term survival is impossible.

• Astrocytoma and pituitary tumors: These tumors account for 8 percent of primary brain tumors. These tumors come in four grades, spanning from one to 4 on a scale of least to most malignant. Most astrocytomas cannot be cured. Pilocytic astrocytomas and subependymal giant cell astrocytomas are two types that have good prognosis. Patients with these brain tumors usually undergo a combination of surgery, chemotherapy, and radiation therapy. About 43 to 63 percent of these patients live two years, 30 to 48 percent live five years, and 21 to 36 percent survive 10 years. Generally, the less malignant the cancer, the better the survival rate.

• Schwannomas: Schwannomas, also called nerve sheath tumors or acoustic neurons, are usually benign. They form in the part of the cranial nerve responsible for balance and hearing. They account for approximately 6 percent of primary brain tumors.

• Anaplastic astrocytoma: Anaplastic astrocytomas account for approximately 4 percent of primary brain tumors. Patients with these tumors usually undergo surgery, chemotherapy, and radiation therapy to treat them. Two-year survival is at 45 percent. Five-year survival is at 30 percent. Ten-year survival is at 21 percent.

• Oligodendrogliomas: Three percent of brain tumors are of this type. Generally, they cannot be removed with surgery alone. Seventy-seven percent of people diagnosed with this type of cancer live two years, 61 percent live five years, and 44 percent live 10 years.
  

Symptoms of a brain tumor include:

• Headache with coughing
  
• Headache that wakes a person at night
  
• Headaches with different characteristics from previous headaches
  
• Neurological changes, such as changes in vision or paralysis
  

Brain cancer is diagnosed with MRI scan and biopsy. If cancer is suspected elsewhere in the body, X-rays and CT scans can determine the location.

Brain cancer was once an inoperable disease. Recent advances in computer-assisted surgery allow surgeons to treat cancers that once were untreatable. The location of the brain tumor is the key to recovery—if it is in an accessible location and can be removed, the patient may recovery fully and permanently. However, some tumors are located too deep in the brain to be removed even partially without resulting in severe neurological damage. In this case, chemotherapy and radiation therapy may be prescribed. A new treatment, chemotherapy-impregnated wafers (gliadel wafers) may be an option.

Traditional surgery to remove a brain tumor may be performed under sedation and local anesthesia if the tumor is located close to important functional areas of the brain. A PET scan can identify the avoidable areas of the brain prior to surgery. Following surgery, steroids can control swelling in the brain, which used to account for high mortality rates.