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What Is Cancer?
Cancer develops when cells in a part of the body
begin to grow out of control. Although there are many kinds of cancer, they
all start because of out-of-control growth of abnormal cells.
Normal body cells grow, divide, and die in an orderly fashion. During the
early years of a person's life, normal cells divide more rapidly until the
person becomes an adult. After that, cells in most parts of the body divide
only to replace worn-out or dying cells and to repair injuries.
Because cancer cells continue to grow and divide, they are different from
normal cells. Instead of dying, they outlive normal cells and continue to
form new abnormal cells.
Cancer cells often travel to other parts of the body where they begin to
grow and replace normal tissue. This process, called metastasis, occurs as
the cancer cells get into the bloodstream or lymph vessels of our body. When
cells from a cancer like breast cancer spread to another organ like the
liver, the cancer is still called breast cancer, not liver cancer.
Cancer cells develop because of damage to DNA. This substance is in every
cell and directs all its activities. Most of the time when DNA becomes
damaged the body is able to repair it. In cancer cells, the damaged DNA is
not repaired. People can inherit damaged DNA, which accounts for inherited
cancers. Many times though, a person's DNA becomes damaged by exposure to
something in the environment, like smoking.
Cancer usually forms as a solid tumor. Some cancers, like leukemia, do not
form tumors. Instead, these cancer cells involve the blood and blood-forming
organs and circulate through other tissues where they grow.
Not all tumors are cancerous. Benign (noncancerous) tumors do not spread to
other parts of the body (metastasize) and, with very rare exceptions, are
not life threatening.
Different types of cancer can behave very differently. For example, lung
cancer and breast cancer are very different diseases. They grow at different
rates and respond to different treatments. That is why people with cancer
need treatment that is aimed at their particular kind of cancer.
Cancer is the second leading cause of death in the United States. Half of
all men and one-third of all women in the US will develop cancer during
their lifetimes. Today, millions of people are living with cancer or have
had cancer. The risk of developing most types of cancer can be reduced by
changes in a person's lifestyle, for example, by quitting smoking and eating
a better diet. The sooner a cancer is found and treatment begins, the better
are the chances for living for many years.
Thanks to the
American Cancer Society, Inc. for the Information above.
For more Information please visit
http://www.cancer.org/
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