Brain cancer is a disease of uncontrolled cell growth that starts in the brain tissue which is surrounded by meninges and protected by the cranium. Nervous system cancer is the disease of uncontrolled cell growth that starts in the spinal cord tissue also covered by meninges and protected by vertebrae. The brain is continuous with the spinal cord and together they form the central nervous system (CNS). 

Primary tumors of the central nervous system are formed by the uncontrolled growth of cells and may start in different regions of the brain or spinal cord. The primary tumors can be either benign (noncancerous) or malignant (cancerous):

• Benign tumors do not contain cancer cells and can sometimes be removed, depending on the location in the brain. They seldom grow back. Alternatively, benign tumors are sometimes treated by radiation therapy if they cannot be surgically removed without causing serious neurological damage. Although benign tumors do not invade tissues around them or spread to other parts of the body, they can press on sensitive areas of the brain and cause serious health problems. Unlike benign tumors in most other parts of the body, benign brain tumors are sometimes life threatening.
• Malignant tumors contain cancer cells and are generally more serious and can be life threatening. Malignant brain tumors are likely to grow rapidly and crowd or invade the surrounding healthy brain tissue.

By opposition to primary brain tumor, there are also metastatic brain tumors or brain metastases. Those tumors have started from a primary tumor located somewhere else in the body. Cells from this initial tumor have escaped the primary tumor and spread in the brain. The types of tumors that are more susceptible to spread to the brain are melanoma and cancer of the breast, colon and lung. The types of cancer that is more susceptible to spread to the spinal cord are lymphoma and cancer of the breast, prostate and lung. About fifty percent of the brain and spinal cord metastases are caused by lung cancer. The metastatic brain tumors are more common than primary brain tumors with an annual incidence more than four times greater than primary tumors.

It has been estimated that for the year 2011, 2,700 new brain cancer diagnoses would be made in Canada and that 1,800 Canadians would die from the disease, 58% men for 42% women. One in 126 Canadians is expected to develop brain cancer during his/her lifetime. Based on recent statistics, one in 166 Canadians will die of it.

The relative 5-year survival rate for brain cancer in Canada is estimated at 23%.

Types of brain and nervous system cancers

Causes – Risk factors

Signs and symptoms

Diagnosis

Treatment

Prognosis

References