What is brain cancer?
Brain cancer is a disease of the brain in which cancer cells (malignant cells) arise in the brain tissue. Cancer cells grow to form a mass of cancer tissue (tumor) that interferes with brain functions such as muscle control, sensation, memory, and other normal body functions. Tumors composed of cancer cells are called malignant tumors, and those composed of mainly noncancerous cells are called benign tumors. Cancer cells that develop from brain tissue are called primary brain tumors while tumors that spread from other body sites to the brain are termed metastatic or secondary brain tumors. Statistics suggest that brain cancer occurs infrequently (1.4% of all new cancer patients per year), so it is not considered to be a common illness and is likely to develop in about 23,770 new people per year with about 16,050 deaths as estimated by the National Cancer Institute (NCI) and the American Cancer Society. Only about 5% of brain tumors may be due to hereditary genetic conditions such as neurofibromatosis, tuberous sclerosis, and a few others.