What is Breast Cancer?

Normal (left) versus cancerous (right) mammography image. Source: Wikipedia

Breast cancer (malignant breast neoplasm) is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas.

Worldwide, breast cancer comprises 10.4% of all cancer incidence among women, making it the most common type of non-skin cancer in women and the fifth most common cause of cancer death. In 2004, breast cancer caused 519,000 deaths worldwide (7% of cancer deaths; almost 1% of all deaths). Breast cancer is about 100 times more common in women than in men, although males tend to have poorer outcomes due to delays in diagnosis.

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 person's age, genetic factors, personal health history, and diet all contribute to breast cancer risk.

What Are the Symptoms of Breast Cancer?

The symptoms of breast cancer include:

  • 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 feel or appearance of the skin on the breast or nipple (dimpled, puckered, scaly, or inflamed).
  • Redness of the skin on the breast or nipple.
  • A change in shape or position of the nipple
  • An area that is distinctly different from any other area on either breast.
  • A marble-like hardened area under the skin.

What Are the Types of Breast Cancer?

The most common types of breast cancer are:

  • Invasive ductal carcinoma. This cancer starts in the milk ducts of the breast. Then it breaks through the wall of the duct and invades the fatty tissue of the breast. This is the most common form of breast cancer, accounting for 80% of invasive cases.
  • Ductal carcinoma in situ (DCIS) is ductal carcinoma in its earliest stage (Stage 0). In situ refers to the fact that the cancer hasn't spread beyond its point of origin. In this case, the disease is confined to the milk ducts and has not invaded nearby breast tissue. If untreated, ductal carcinoma in situ may become invasive cancer. It is almost always curable.
  • Infiltrating (invasive) lobular carcinoma. This cancer begins in the lobules of the breast where breast milk is produced, but has spread to surrounding tissues or the rest of the body. It accounts for about 10% of invasive breast cancers.
  • Lobular carcinoma in situ (LCIS) is cancer that is only in the lobules of the breast. It isn't a true cancer, but serves as a marker for the increased risk of developing breast cancer later, possibly in both breasts. Thus, it is important for women with lobular carcinoma in situ to have regular clinical breast exams and mammograms.

What are the Stages of Breast Cancer?

  • Early stage or stage 0 breast cancer is when the disease is localized to the breast with no evidence of spread to the lymph nodes (carcinoma in situ).
  • Stage I breast cancer: The cancer is two centimeters or less in size and it hasn't spread anywhere.
  • Stage IIA breast cancer is a tumor smaller than two centimeters across with lymph node involvement or a tumor that is larger than two but less than five centimeters across without underarm lymph node involvement.
  • Stage IIB is a tumor that is greater than five centimeters across without underarm lymph nodes testing positive for cancer or a tumor that is larger than two but less than five centimeters across with lymph node involvement.
  • Advanced breast cancer (metastatic) results after cancer cells spread to the lymph nodes and to other parts of the body.
  • Stage IIIA breast cancer is also called locally advanced breast cancer. The tumor is larger than five centimeters and has spread to the lymph nodes under the arm, or a tumor that is any size with cancerous lymph nodes that adhere to one another or surrounding tissue.
  • Stage IIIB breast cancer is a tumor of any size that has spread to the skin, chest wall or internal mammary lymph nodes (located beneath the breast and inside the chest).
  • Stage IIIC breast cancer is a tumor of any size that has spread more extensively and involves more lymph node invasion.
  • Stage IV breast cancer is defined as a tumor, regardless of size, that has spread to places far away from the breast, such as bones, lungs, liver, brain, or distant lymph nodes.

How Is Breast Cancer Diagnosed?

During your regular physical exam, your doctor will take a careful personal and family history and perform a breast exam and possibly one or more other tests:

  • Mammography
  • Ultrasonography

How is Breast Cancer treated?

  • Local treatments are used to remove, destroy, or control the cancer cells in a specific area, such as the breast. Surgery and radiation treatment are local treatments.
  • Systemic treatments are used to destroy or control cancer cells all over the body. Chemotherapy; hormone therapy such as tamoxifen; aromatase inhibitors such as Arimidex, Aromasin, Femara; and biologic therapies such as Herceptin are systemic treatments. A patient may have just one form of treatment or a combination, depending on her needs.

How can I protect myself from Breast Cancer?

Follow these three steps for early breast cancer detection:

  • Annual screening mammography starting at age 40 or 50. Breast cancer experts don't agree when women need to begin getting mammograms. Ask your doctor.
  • Women in high-risk categories should have screening mammograms every year and typically start at an earlier age. MRI or ultrasound screening can also be given in addition to mammograms. Discuss the best approach with your doctor.
  • Have your breast examined by a health care provider at least once every three years after age 20, and every year after age 40. Clinical breast exams can complement mammogram.
 

Sources: Wikipedia.com, WebMD.com