Senator Edward Kennedy dead at age 77 after a battle with brain cancer

Senator Edward Kennedy died last night from complications from a malignant glioma, a type of cancer of the brain. About 17,000 people in the United States are diagnosed with the disease. The word "cancer" is really a catch-all word for a number of conditions where cells multiply uncontrollably, affecting other cells and tissues nearby. In the case of the Senator's brain cancer, the glial cells, cells in the brain and spinal cord in charge of nutrition and homeostasis of the neurons, multiplied rapidly, affecting his brain tissue. Most neurons, the functional cells of the brain and nervous system, do not divide. Glial cells retain the ability to divide during our lives, hence their ability to multiply uncontrollably as well.
Other brain cancers occur when other cells in and around the brain also begin to divide uncontrollably. Still others occur when cancerous cells from other parts of the body travel to the brain and begin to multiply there. The causes for brain cancer are many, ranging from environmental exposures to known carcinogens to still-unknown genetic causes. The cause for the Senator's condition is not known at this time.
The best way to prevent any cancer is to maintain a healthy lifestyle that keeps the immune system working properly. This is because the immune system is able to recognize cells that have become cancerous and remove them from the body. This is not always possible, however, as immune systems are prone to become weaker with age, illness, or because of environmental factors. Of course, it is impossible to not have any contact with the environment or avoid certain conditions, like aging, that make the immune system weaker.