NCCN Guidelines for Patients
Adolescents and Young Adults with Cancer, Version 1.2017
Cancer on the move
Normal cells typically stay where they are in the body.
But cancer cells can escape from where they started
and move to other parts of the body—a process
The ability to spread is what makes cancer so
dangerous. Once cancer cells get loose, they can
travel to distant parts of the body through the blood
or lymphatic system. The lymphatic system is made
up of lymph, lymph nodes, and lymph vessels. When
cancer cells settle into new places in the body they
can replace or damage healthy cells. In time, cancer
cells can damage other tissues or organs.
Cancer that has spread to a nearby body part
is called a
Cancer that has spread to a body part far from
the original area it started is called a
The cells that spread to other areas of the body are
still called by the name of the original place it started.
The original place the cancer started in the body is
also referred to as the primary tumor. For example,
when breast cancer cells spread to the lung it is not
called lung cancer; instead it is called metastatic
Causes of cancer
Doctors are not completely sure what causes cancer.
Many things can cause cancer or put someone at
risk for the disease. Doctors do know that cancer
gets its start when something goes wrong with the
genes—a process called mutation. Mutations can be
passed on from a parent and present before you are
born (inherited) or caused by later genetic damage
Inherited mutations are found in all of the body’s cells.
People with inherited genetic mutations have a higher
risk for certain cancers, but that doesn’t mean they
will definitely develop cancer. Only a small number of
cancers have an inherited mutation.
Acquired mutations, on the other hand, are found in
every person with cancer. Unlike inherited mutations,
which affect every cell in the body, acquired mutations
happen in specific cells or types of cells.
But I'm too young to have cancer!
What is cancer?