A Collection of Related Diseases
Cancer is the name given to a collection of related diseases. In all
types of cancer, some of the body’s cells begin to divide without
stopping and spread into surrounding tissues.
Cancer can start almost anywhere in the human body, which is made up
of trillions of cells. Normally, human cells grow and divide to form new
cells as the body needs them. When cells grow old or become damaged,
they die, and new cells take their place.
When cancer develops, however, this orderly process breaks down. As
cells become more and more abnormal, old or damaged cells survive when
they should die, and new cells form when they are not needed. These
extra cells can divide without stopping and may form growths called
tumors.
