The human body is made up of billions of tiny cells that reproduce themselves by dividing. Through this normal process of cell division, the growth and repair of body tissue takes place. When a cell begins dividing irregularly, masses known as tumors can form. A malignant tumor, or cancer, can invade nearby tissues and organs. The rate of growth varies.
Some cancers are easily curable.
However, others are more difficult to cure by the time they are first diagnosed, particularly if the tumor has grown substantially. This depends largely on the organ of the body where cells first grow abnormally. Doctors customarily consider tumors originating from different organs as different diseases because of the variation in the causes, symptoms, course of disease and prognosis as well as approach to treatment. Cancer is a very common disease. One in three persons will be diagnosed with cancer some time in their life and it will eventually affect three out of every four families.