Breast Cancer

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Definition | Causes | Risk Factors | Symptoms | Diagnosis | Treatment | Prevention | Organizations

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Definition

Breast cancer is a disease in which cancer cells grow in the breast tissue.

Cancer occurs when cells in the body (in this case breast cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissues and can spread to other parts of the body. A benign tumor does not invade or spread. Although most people think of breast cancer as affecting women, men can develop breast cancer as well.

Causes

The cause of breast cancer is unknown, but research shows that certain risk factors are associated with the disease.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

• Sex: Female
• Age: 50 or older
• Personal history of breast cancer
• Family members with breast cancer
• Changes in breast tissue, such as atypical hyperplasia or lobular carcinoma in situ (LCIS)
• Changes in certain genes (BRCA1, BRCA2, and others)
• Race: Caucasian
• Increased exposure to estrogen over a lifetime through:
  • Early onset of menstruation
  • Late onset of menopause
  • No childbearing or late childbearing
  • Taking hormone replacement therapy for long periods of time
• Increased breast density (more lobular and ductal tissue and less fatty tissue)
• Radiation therapy before the age of 30
• Alcohol

Note: Studies show that most women with known risk factors do not get breast cancer. And many women who get breast cancer have none of the risk factors listed above, other than the risk that comes with growing older.

Symptoms

When breast cancer first develops, there may be no symptoms at all. But as the cancer grows, it can cause the following changes:

• A lump or thickening in or near the breast or in the underarm area
• A change in the size or shape of the breast
• Nipple discharge or tenderness, or the nipple pulled back (inverted) into the breast
• Ridges or pitting of the breast skin (like the skin of an orange)
• A change in the way the skin of the breast, areola, or nipple looks or feels (for example, warm, swollen, red, or scaly)

Note: These symptoms may also be caused by other, less serious health conditions. Anyone experiencing these symptoms should see a doctor.

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam.

Tests may include:

ClinicalBreastExam – The doctor carefully feels the breast lump and the tissue around it. The doctor examines the size and texture of the lump and determines whether the lump moves easily.

Mammography – x-rays of the breast used to see lumps or other changes in breast tissue

Ultrasonography – the use of high-frequency sound waves to see whether a lump is a fluid-filled cyst (not cancer) or a solid mass (which may or may not be cancer)

Biopsy – removal of tumor tissue to be tested for cancer cells. Types of biopsies for breast cancer include:

• Fine-needle aspiration – removal of fluid and/or cells from a breast lump using a thin needle
• Needle biopsy – removal of tissue with a needle from an area that looks suspicious on a mammogram but cannot be felt
• Surgical biopsy –
  • Incisional biopsy – cutting out a sample of a lump or suspicious area
  • Excisional biopsy – cutting out all of a lump or suspicious area and an area of healthy tissue around the edges

Treatment

Once breast cancer is found, staging tests are performed to find out if the cancer has spread and, if so, to what extent.

Treatments include:

Surgery – removal of the cancerous tumor and nearby tissues, and possibly nearby lymph nodes. Surgeries to treat breast cancer include:

Lumpectomy –removal of the breast cancer and some normal tissue around it. Often, some of the lymph nodes under the arm are removed.

Segmental Mastectomy –removal of the cancer and a larger area of normal breast tissue around it. Occasionally, some of the lining over the chest muscles below the tumor is removed as well. Some lymph nodes under the arm may also be removed.

Mastectomy –removal of the breast, or as much of the breast as possible. Breast reconstruction is often performed at the same time as the mastectomy.

Radical Mastectomy –removal of the breast, both chest muscles, all of the lymph nodes under the arm, and some additional fat and skin. This procedure is only considered in rare cases if the cancer has spread to the chest muscles.

Modified Radical Mastectomy –removal of the whole breast, most of the lymph nodes under the arm, and, often, the lining over the chest muscles

Axillary Lymph Node Dissection –removal of the lymph nodes under the arm to help determine whether cancer cells have entered the lymphatic system

Radiation Therapy – the use of radiation to kill cancer cells and shrink tumors. Radiation may be:

External Radiation Therapy - radiation directed at the breast from a source outside the body.

Internal Radiation Therapy - radioactive materials placed into the breast in or near the cancer cells.

Chemotherapy – the use of drugs to kill cancer cells. Chemotherapy may be given in many forms including: pill, injection, and via a catheter. The drugs enter the bloodstream and travel through the body killing mostly cancer cells, but also some healthy cells.

Biological Therapy – the use of medications or substances made by the body to increase or restore the body's natural defenses against cancer. Also called biological response modifier (BRM) therapy.

Prevention

Because the cause of breast cancer is unknown, finding it early and treating it is the best way to prevent dying from the disease. And because it does not cause symptoms in the early stages, it is important to have screening tests to find the cancer before symptoms appear.

• Women age 40 and older should have a screening mammogram every year.
• Women between the ages of 20 and 39 should have a clinical breast examination by a health professional every 3 years.
• After age 40, women should have a breast exam by a health care professional every year.
• Women age 20 or older should perform a breast self-examination (BSE) every month.

Organizations

American Cancer Society
http://www.cancer.org

National Alliance of Breast Cancer Organizations
http://www.nabco.org/

CancerCare
http://www.cancercare.org/

SOURCES:

National Cancer Institute

American Cancer Society

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Last reviewed June 2001 by Medical Review Board