Breast cancer - Types of breast cancer

Breast cancer

Types of breast cancer

Breast cancer is classified according to whether it has spread beyond the cells that line the thin tubes that carry the milk to the nipple (the ducts).

Doctors may also classify breast cancer based on how the cancer cells grow and the size and shape of the cancer cells. For example, a type of invasive breast cancer called medullary cancer has large cells. Also, the cells around the edges of the tumor look like cells from the

immune system
The immune system is made up of the parts of the body that are devoted to fighting infection. The body is constantly being threatened by infections from things like bacteria, viruses and parasites. The immune system fights these infections in different ways. At the microscopic level, the immune system uses antibodies and white blood cells, which travel in the blood and target infectious agents, such as bacteria. These microscopic parts of the immune system either kill the infectious agent directly, or take it to other parts of the body, like the spleen, where it can be dealt with. The lymph nodes are another important part of the immune system. Within them, white blood cells filter through the foreign material that has entered the blood, to see if there are any infections. When you have a swollen gland during a cold, this is actually a lymph node that is reacting to the infection. Unfortunately, it is possible for the immune system to become confused and to use its destructive powers to target healthy parts of the body. Diseases that result from this type of situation are called autoimmune diseases.

immune system.

Source:
American Joint Committee on Cancer Staging.
AJCC cancer staging manual: colon and rectum.
5th edition. Lippincott-Raven, Philadelphia; 1997.

Non-invasive breast cancer

Non-invasive breast cancer is contained within the ducts of the breast. This means it hasn't spread beyond the lining of the ducts, or into the surrounding fat or other breast tissue. This type of cancer is also called

in situ
Literally means "in position." The term can be used to describe a tumor that is in its natural or original position (for example, "carcinoma in situ").

in situ. (This means that it has stayed in the spot where it started growing and hasn't spread further.)

Some doctors divide non-invasive cancers into one of the following categories.

Lobular carcinoma in situ: This is not actually cancer. It means that you have abnormal cells in the lobules of your breast. And you have an increased risk of getting breast cancer in the future.
Ductal carcinoma in situ: This is cancer that started in the thin tubes that carry milk through the breast to the nipple (the ducts).

Because these cancers are so small that you can't feel them, they are usually found by chance during a

mammogram
A mammogram is a special kind of X-ray picture of the breast.

mammogram. On a mammogram they look like little white specks. These specks are actually tiny spots of calcium.

Source:
Julien JP, Bijker N, Fentiman IS, et al.
Radiotherapy in breast-conserving treatment for ductal carcinoma in situ: first results of the EORTC randomised phase III trial 10853.
Lancet. 2000; 355: 528-533.

Invasive breast cancer

Invasive breast cancer has broken through the walls of the ducts and spread into the fatty tissue in the breast. From there it can get into the

lymph vessels
Lymph vessels are part of your body's lymphatic system. This system moves lymph fluid through your body. This fluid carries proteins, white blood cells and other substances. Lymph vessels carry fluid between your lymph nodes.

lymph vessels or blood vessels. It can then spread to other parts of your body.

Invasive breast cancer is classified according to how far it has spread. It may be called:

Early breast cancer. This means that the cancer seems to be only in your breast or also in some of the

lymph nodes
Lymph nodes (also called glands) are small, bean-shaped lumps that you cannot usually see or easily feel. They are located in various parts of the body, such as the neck, armpit and groin. Lymph nodes filter the lymph fluid and remove unusual things, such as bacteria and cancer cells.

lymph nodes under your arm. This type of cancer can be removed by surgery. It's also called operable breast cancer. It's possible that some cancer cells may have spread outside the breast or armpit area but can't be detected
Locally advanced breast cancer. This means the cancer is bigger than 5 centimeters (around 2 inches), or has spread to your skin or to the front of your chest, or to both your skin and chest. The lymph nodes under your armpit might also have become matted together by the tumor.
Metastatic (or advanced) breast cancer. This means that the cancer has spread through the blood vessels or lymph vessels to other parts of your body, such as your bones, liver or lungs
Inflammatory breast cancer. This is a rare, invasive cancer that can block the lymph vessels in the skin over your breast. If you have this kind of breast cancer, your skin looks bumpy, like orange peel. Your skin may also feel warm and look red.

Most women with invasive cancer have early breast cancer that hasn't spread beyond the breast or nearby lymph nodes.

Invasive cancer is also called infiltrating breast cancer.

Sources for the information on this page:

American Joint Committee on Cancer Staging.AJCC cancer staging manual: colon and rectum.5th edition. Lippincott-Raven, Philadelphia; 1997.

Julien JP, Bijker N, Fentiman IS, et al.Radiotherapy in breast-conserving treatment for ductal carcinoma in situ: first results of the EORTC randomised phase III trial 10853.Lancet. 2000; 355: 528-533.

This information was last updated on May 11, 2009

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