Page 5 - Kids and Cancer

and when to stop growing. Cells are also chemically directed to
die if they are damaged or defective, which is a process called
apoptosis.
Cancer cells are rogue or renegade cells that do not follow the
orderly processes of normal cells. Cancer cells proliferate, or mul-
tiply, rapidly and never turn off or die through apoptosis. As the
American Association for Cancer Research explains, “Ignoring
the body’s signal to stop, malignant cells multiply to form tumors
in organs and tissues or, in the case of blood cancers, crowd
out normal cells in the blood stream and bone marrow.” Cancer
5
cells are called malignant because they can invade and destroy
nearby tissue and spread to other parts of the body. They steal
nutrition from normal cells and can even cause the body to grow
new blood vessels to bring oxygen and nutrients to the tumorous
mass. Blood cancer cells simply be-
come so abundant that there are not “Ignoring the body’s
enough normal blood cells left to carry signal to stop, malignant
oxygen and nutrients to the rest of the cells multiply to form
cells in the body. tumors in organs and
Although all cancers develop the tissues or, in the case of
same way, cancer is not just one blood cancers, crowd
disease—it is a collection of more than out normal cells in the
one hundred related diseases. Can- blood stream and bone
marrow.”
5
cers are usually named for the organ
or tissue in which they fi rst arise. For — American Association for Cancer
example, brain cancer starts in the Research
cells of the brain, and blood cancers
may start in the cells of the bone marrow, where blood cells are
produced. Even when the cancer cells travel to another part of the
body, the type of cancer is determined by the organ where the
disease fi rst started. For instance, a tumor that forms in the brain
may form its own blood vessels through which some cancer cells
can escape to other parts of the body and start to grow. No mat-
ter what other organ may be affected by these breakaway cancer
cells, the cancer is still considered a primary brain cancer. Some

9