Breast Cancer

What It Is

Breast cancer is a cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.

There are several types of cancer (uncontrolled cell growth) that can occur in the breast. Each is determined by its location within the breast tissue and whether or not the tumor has spread outside that location.

Tumors that form in the lobules are referred to as lobular breast cancer or carcinoma. Tumors that form in the ducts are referred to as ductal carcinoma.

A tumor can be an early stage of cancer that is confined to the place where it started, a term referred to as in situ or non-invasive. Alternatively, a tumor could be one that has spread to other parts of the breast, referred to as invasive or infiltrating. Therefore, there are 4 possible combinations:

• Lobular carcinoma in situ (LCIS), which is not considered a true cancer, but rather whose presence indicates an increased risk of developing cancer in the future
• Infiltrating (invasive) lobular carcinoma (ILC), which accounts for about 5% of all invasive breast cancers
• Ductal carcinoma in situ (DCIS), which is the most common type of noninvasive breast cancer—and the most curable
• Infiltrating (invasive) ductal carcinoma (IDC), which is the most common type of breast cancer and accounts for about 80% of invasive breast cancers

When breast cancer spreads, cancer cells may also be found in the lymph nodes in the armpit. These lymph nodes are called axillary lymph nodes. If the cancer reaches these nodes, it may have spread to other parts of the body. This is also an indicator of risk of recurrence. Breast cancer that has spread to other organs of the body is called metastatic breast cancer. When breast cancer spreads to other parts of the body, it most often goes to the bones, liver, or lungs.

 

Breast Cancer Stages

When a woman is diagnosed with breast cancer, her doctor needs to know what stage the cancer is in. This stage is based on the size of the tumor, the number of lymph nodes involved, and whether the cancer has spread. The following section describes the five stages of breast cancer and the treatments used for each stage.

The International Union Against Cancer and the American Joint Committee on Cancer have developed a standard system of describing the extent of a cancer's growth. This system is known as the TNM system.

In the TNM system, the 'T' indicates a tumor's size while the 'N' indicates whether the lymph nodes in the area of the original tumor have become cancerous. The 'M' indicates whether the cancer has spread, or metastasized, to other organs in the body, such as the lungs, bones, or liver. Once a person's T, N, and M stages have been determined, this information is put together in what is called stage grouping. This is used to determine a person's overall disease stage.

Stage grouping is expressed in Roman numerals from 0 (the earliest stage) to IV (the most advanced stage). Some stages also include letter designations.

• Stage 0 is sometimes called noninvasive carcinoma or carcinoma in situ. There are three types: lobular carcinoma in situ, ductal carcinoma in situ, and Paget's disease of the nipple.

Lobular carcinoma in situ, or LCIS, means abnormal cells exist in the lining of a lobule. These cells don't usually turn into invasive cancer. However, a woman who has these cells does have an increased risk of developing breast cancer in either breast. Some women with LCIS may want to take a medication that can help prevent breast cancer. These women may also want to take part in studies of other new treatments to prevent breast cancer. Others may choose not to have treatment, but they should see their doctor for regular checkups and mammograms. Some women may decide to have surgery to remove both breasts to try to prevent cancer.

Ductal carcinoma in situ, also called intraductal carcinoma or DCIS, means cancer cells exist in the lining of a duct. These cells have not invaded the surrounding breast tissue; however, if DCIS is not treated, cancer cells may become invasive breast cancer. Patients with DCIS may have a mastectomy or breast-sparing surgery followed by radiation therapy.

• Stage I and Stage II are considered early stages of breast cancer.
• Stage I is considered an early stage of breast cancer. Stage I means no cancer cells exist outside of the breast. It also means that the tumor is no more than an inch wide.
• Stage II (A or B) is also considered an early stage of breast cancer. This stage can mean that:
• If no tumor is found, but cancer is found in the lymph nodes under the arm; or
• The tumor is less than one inch wide and there is cancer in the lymph nodes under the arm; or
• The tumor is one to two inches wide and there may or may not be cancer in the lymph nodes; or
• The tumor is larger than two inches, but there is no cancer in the lymph nodes.

Women with early stage breast cancer may decide to have breast-sparing surgery followed by radiation therapy. They may also decide to have a mastectomy, with or without radiation therapy or breast reconstruction. The decision depends on the location and size of the tumor, the size of the woman's breast, and how the woman feels about other personal factors. Some of the lymph nodes under the arm are usually removed.

Many women who have Stage I breast cancer, and most women who have Stage II breast cancer, have chemotherapy and/or hormonal therapy in addition to surgery or surgery and radiation therapy. This added treatment is called adjuvant therapy. It is given to try to destroy any remaining cancer cells and stop the cancer from recurring.

• Stage III (A, B, or C) is also called locally advanced cancer. This may mean that the tumor in the breast is larger than in Stages I and II and that lymph nodes in the armpit or other areas around the breast are involved. Tissues around the breast (skin or chest wall) may also be involved. Inflammatory breast cancer is one type of locally advanced breast cancer.

Women who have Stage III breast cancer usually undergo local treatment to remove or destroy the cancer in the breast, and systemic treatment to lower the chances the disease will spread.

• Stage IV is metastatic cancer. This means that the cancer has spread to other parts of the body, most often the bones, lungs, liver, or brain.

Women who have Stage IV breast cancer will have chemotherapy and/or hormonal therapy to destroy cancer cells and control the cancer. They may also have surgery or radiation therapy to control the cancer in the breast if this has not already been done. Radiation may also be useful to control tumors in other parts of the body.

If a woman has been treated and the breast cancer has returned, it is called recurrent cancer. Cancer that returns only in the area of the surgery is called a local recurrence. If the disease returns in another part of the body, it is called metastatic breast cancer.

 

Who Is More At Risk

According to the American Cancer Society, 217,440 people will be diagnosed with breast cancer this year in the United States, most of whom will be women. Less than one percent of all breast cancer cases a year occur in men.

A woman's level of risk for developing breast cancer increases as she ages. It is unusual for a woman younger than age 35 to get the disease. Over her entire lifetime, a woman has a 1 in 8 chance of developing breast cancer.

The following factors have also been associated with an increased risk of breast cancer (in alphabetical order):

• Benign breast disease
• Children: never having them, or having a first child after the age of 30
• Estrogen replacements (hormone replacement therapy or HRT): having taken them for 5 or more years after menopause
• Family history of breast cancer
• Genetic alterations: changes in genes such as BRCA1 and BRCA2
• Lifestyle: drinking one or more alcoholic drinks per day
• Menstruation patterns: first period before the age of 12 or menopause after age 55
• Personal history of breast cancer
• Race: White women are slightly more likely to develop breast cancer than women of other races are.
• Radiation: previous exposure in the breast region, particularly during infancy or childhood

Keep in mind that a woman who has one or more risk factors will not necessarily get breast cancer. Experts believe that over half of all women with breast cancer have no known risk factors at all.

 

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