McKesson Clinical Reference Systems: Women's Health Advisor 2002.2
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Breast Cancer

What is breast cancer?

When abnormal cells grow uncontrollably, they are called cancers. Cancer of the breast is one of the most common cancers in women.

Four out of five breast cancers occur in women over age 50. Very few breast cancers occur in men.

Breast cancer is a treatable and curable disease. Early detection is the key to a cure. The cancer usually starts as a small lump. However, with time the lump may grow and spread to nearby areas, such as the skin or the lymph nodes under the arm. In time, the tumor may spread to vital organs such as the liver, brain, lungs, and spine. If breast cancer is found early, before it spreads, it can often be cured.

How does it occur?

The cause of breast cancer is not known. Any woman can get breast cancer, but some women are more likely to develop it than others. Factors that increase your risk of having breast cancer include:

  • having a mother or sister with breast cancer
  • starting menstruation at a young age or going through menopause in your 50s
  • being over age 50
  • never having given birth or having your first child after age 30
  • a history of radiation exposure to the area of the breasts
  • hormone (estrogen) replacement therapy
  • excessive use of alcohol
  • obesity.

There is currently no definite evidence that taking birth control pills for a long time causes breast cancer.

What are the symptoms?

Most often the first sign of breast cancer is a lump in the breast. The lump is found most often in the upper, outer part of the breast. It is not usually painful. It may grow slowly or quickly.

Other signs of breast cancer include:

  • color change, dimpling, or puckering of the skin in an area of the breast
  • a change in the size or shape of the breast
  • fluid discharge from the nipple
  • lumps felt in the armpit.

How is it diagnosed?

Most women find their own breast cancers, either by accident or from a breast self-exam. Sometimes breast cancers are found at a health checkup or on a screening mammogram.

Mammograms can detect some cancers before a lump can be felt. They detect about 90% of cancerous lumps. Mammograms are also used to check lumps you or your health care provider may have found in a physical exam.

Most breast lumps are not cancer. Often they are fluid-filled cysts in the breast tissue that get larger and smaller with the menstrual cycle. But every lump must be checked. They will be checked with a mammogram and possibly also:

  • a breast exam by a health care provider
  • ultrasound scan
  • a needle or surgical biopsy.

These tests should be done even if the lump is not seen on the mammogram.

When you have a needle biopsy, you are given a local anesthetic to numb the area of your breast being tested. Then your health care provider inserts a needle into the breast lump and withdraws fluid or tissue from the lump. If fluid fills the needle, the lump is a cyst and not cancer. Removing the fluid also makes fluid-filled lumps go away. Tissue withdrawn by the needle will be examined in the lab.

If you have a surgical biopsy, your health care provider will give you an anesthetic, make a cut in the breast, and remove some or all of the lump. This breast tissue will be examined under a microscope. If the biopsy sample shows cancerous tissue, tests may be done to see if hormones make the cancerous cells grow more. The estrogen receptor (ER) test is one of these tests. You may have another procedure to remove lymph nodes from your armpit to see if cancer has spread beyond the breast. This procedure is called axillary node dissection.

How is it treated?

If a breast lump is cancerous, the decisions for treatment will be made by you and your health care provider. A surgeon or oncologist (cancer specialist) may also be consulted. Treatment decisions will take into account:

  • your age
  • the stage of development of the cancer
  • the type of cancer
  • whether the cancer has spread to lymph nodes or other parts of your body.

Possible surgical treatments are lumpectomy (removing the cancerous tissue only) or mastectomy (removing the entire breast). Lymph nodes in the armpit area may also be removed. Other possible treatments are radiation therapy, chemotherapy (anticancer drugs), and hormone therapy. These different treatments may be used singly or in combination.

If you are considering mastectomy, you should discuss the options for breast reconstruction surgery with your surgeon.

How can I take care of myself?

If you have been diagnosed with breast cancer:

  • Discuss your cancer and treatment options with your health care provider so that you understand them. Do not hesitate to get a second opinion.
  • Tell your health care provider if your treatment causes discomfort. Usually there are ways to relieve the discomfort.
  • Get regular checkups after your treatment is finished.
  • Continue monthly self-exams, even if both your breasts have been removed, to look for recurrence of the cancer.

There are many support services for women with breast cancer. You can find the names of groups and agencies from your health care provider or through your local American Cancer Society office.

Breast cancer survival continues to improve. As more women do regular self-exams, more cancers are found early. As mammograms and other screening methods improve, more cancers are being detected before they can even be felt. Finding and treating breast cancer early greatly increases your chances of survival and cure.

To help detect breast cancer early:

  • Do a breast self-exam every month.
  • Have a breast exam by your health care provider at least once a year.
  • Have a mammogram every year after age 50.
  • Never ignore a lump or change in the look or feel of your breast. Remember that a cancerous tumor is usually not painful.

Research suggests that regular exercise may help prevent breast cancer. Exercise regularly and stay fit.


Developed by McKesson Clinical Reference Systems
Published by McKesson Clinical Reference Systems.

This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.

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