Cancer is a general term for a group of diseases characterized by uncontrolled cell division and growth. Cells begin to divide in an uncontrolled fashion when the protective mechanisms of the body no longer can fix the damage to the genetic material which normally occur in cells.
Cancers may be grouped by their location and growth pattern.
Cancer in children differs from those in adults because of their biological background is often different. This also explains why there are clear differences in the occurrence of cancers in children and adults.