What is breast cancer?
Cells in the body normally divide (reproduce) only
when new cells are needed. Sometimes, cells in a part of the body grow and
divide out of control, which creates a mass of tissue called a tumor. If the
cells that are growing out of control are normal cells, the tumor is called
benign (not cancerous). If, however, the cells that are growing out of control
are abnormal and don't function like the body's normal cells, the tumor is
called malignant (cancerous).
Cancers are named after the part of the body from
which they originate. Breast cancer originates in the breast tissue. Like other
cancers, breast cancer can invade and grow into the tissue surrounding the
breast. It can also travel to other parts of the body and form new tumors, a
process called metastasis.
What causes breast cancer?
We do not know what causes breast cancer, although we
do know that certain risk factors may put you at higher risk of developing it. A
woman's age, genetic factors, family history, personal health history, and diet
all contribute to breast cancer risk.
Who gets breast cancer?
Breast cancer is the most common cancer among women
other than skin cancer.
In the US, breast cancer is the second-leading cause
of cancer death in women after lung cancer, and it's the leading cause of cancer
death among women ages 35 to 54. Only 5% to 10% of breast cancers occur in women
with a clearly defined genetic predisposition for the disease. The majority of
breast cancer cases are "sporadic," meaning there is no direct family history of
the disease. Increasing age is another risk factor for developing breast cancer.
What are the warning signs of breast cancer?
- A lump or thickening in or near the breast or in the underarm that
persists through the menstrual cycle
- A mass or lump, which may feel as small as a pea
- A change in the size, shape, or contour of the breast
- A blood-stained or clear fluid discharge from the nipple
- A change in the look or feel of the skin on the breast or nipple
(dimpled, puckered, scaly, or inflamed)
- Redness of the skin on the breast or nipple
- An area that is distinctly different from any other area on either breast
- A marble-like hardened area under the skin
These changes may be found when performing monthly
breast self-exams. By performing breast self-exams, you can become familiar with
the normal monthly changes in your breasts.