Introduction
Cancer wreaks havoc in almost every part of the human body. Tumors strike the brain and the gut, muscles and bones. Some grow slowly; others are more aggressive and expand quickly. Their presence in human tissues signals chaos and a breakdown of normal function. Cancer brings unwelcome change to a biological machine that is perfect, marvelously beautiful, and complex beyond measure. Wherever tumors appear, they take on the appearance of alien life forms, invaders that enter the body through stealth and begin their programs of destruction from within. But appearances deceive: The truth is much more subtle and endlessly interesting.
There are two types of brain tumors: primary brain tumors that originate in the brain and metastatic (secondary) brain tumors that originate from cancer cells that have migrated from other parts of the body.
Primary brain cancer rarely spreads beyond the central nervous system, and death results from uncontrolled tumor growth within the limited space of the skull. Metastatic brain cancer indicates advanced disease and has a poor prognosis.
Primary brain tumors can be cancerous or noncancerous. Both types take up space in the brain and may cause serious symptoms (e.g., vision or hearing loss) and complications (e.g., stroke).
All cancerous brain tumors are life threatening (malignant) because they have an aggressive and invasive nature. A noncancerous primary brain tumor is life threatening when it compromises vital structures (e.g., an artery). http://www.oncologychannel.com/braincancer/
Tumors are not foreign invaders. They arise from the same material used by the body to construct its own tissues. Tumors use the same components -- human cells -- to form the jumbled masses that disrupt biological order and function and, if left unchecked, to bring the whole complex, lifesustaining edifice that is the human body crashing down..............
