Breast Cancer
What
is Breast Cancer?
Breast cancer is the commonest cancer among
women; it is estimated that one woman in every 11
will develop the disease during her lifetime. Normal breast development is
controlled by a number of
hormones, primarily oestrogens and progesterone, discovered decades ago
through fundamental
research on animals. Breast cancer happens when cells in the breast begin
to grow out of control
and can then invade nearby tissues or spread throughout the body. Large
collections of this out of
control tissue are called tumors. However, some tumors are not really
cancer because they cannot
spread or threaten someone's life. These are called benign tumors. The
tumors that can spread
throughout the body or invade nearby tissues are considered cancer and are
called malignant
tumors. Theoretically, any of the types of tissue in the breast can form a
cancer, but usually it
comes from either the ducts or the glands. Because it may take months to
years for a tumor to
get large enough to feel in the breast, we screen for tumors with
mammograms, which can
sometimes see disease before we can feel it. .
Types of
Breast Cancer :
The most
common type of breast cancer begins in the lining of the ducts and is
called ductal
carcinoma. Another type, called lobular carcinoma, arises in the lobules.
When breast cancer
spreads outside the breast, cancer cells are often found in the lymph
nodes under the arm (axillary
lymph nodes). If the cancer has reached these nodes, it may mean that
cancer cells have spread
to other parts of the body--other lymph nodes and other organs, such as
the bones, liver, or
lungs--via the lymphatic system or the bloodstream. Cancer that spreads is
the same disease and
has the same name as the original (primary) cancer. When breast cancer
spreads, it is called
metastatic breast cancer, even though the secondary tumor is in another
organ. Doctors
sometimes call this distant disease..
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