Stages of Breast Cancer

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“When you're in the midst of the diagnosis and staging process, and the tumor information is coming back in bits and pieces, at many different times, it is an extremely stressful time in your life. Uncertainty really stinks! But you will feel SO much better once you know what you're dealing with, when your treatment plan has been worked out, and you start your treatment. Only then does much of that dreadful uncertainty lift, and you finally feel that you are doing something to get rid of the problem. ”

Marisa Weiss, M.D., president and founder, breast radiation oncologist, Philadelphia, PA

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Is it stage II? Is it inflammatory breast cancer? Although learning where you fit in the scheme of breast cancer stages can feel like a jail term ("So now I guess I'm stuck at stage III"), this information is a key part of figuring out how you and your doctors will approach your treatment. The purpose of the staging system is to help organize the different factors and some of the personality features of the cancer into categories, in order to:

• best understand your prognosis (the most likely outcome of the disease)
• guide treatment decisions, since clinical studies of breast cancer treatments that you and your doctor will consider are partly organized by the staging system
• provide a common way to describe the extent of breast cancer for doctors and nurses all over the world, so that results of your treatment can be compared and understood

Stage 0

This stage is used to describe non-invasive breast cancer. There is no evidence of cancer cells breaking out of the part of the breast in which it started, or of getting through to or invading neighboring normal tissue. LCIS and DCIS are examples of stage 0.

Stage I

This stage describes invasive breast cancer (cancer cells are breaking through to or invading neighboring normal tissue) in which:

• The tumor measures up to 2 centimeters, AND
• No lymph nodes are involved.

Stage II

This stage describes invasive breast cancer in which:

• The tumor measures at least 2 centimeters, but not more than 5 centimeters, OR
• Cancer has spread to the lymph nodes under the arm on the same side as the breast cancer. Affected lymph nodes have not yet stuck to one another or to the surrounding tissues, a sign that the cancer has not yet advanced to stage III. (The tumor in the breast can be any size.)

Stage III

Stage III is divided into subcategories known as IIIA and IIIB.

Stage IIIA

Stage IIIA describes invasive breast cancer in which:

• The tumor measures larger than 5 centimeters, OR
• There is significant involvement of lymph nodes. The nodes clump together or stick to one another or surrounding tissue.

Stage IIIB

This stage describes invasive breast cancer in which a tumor of any size has spread to the breast skin, chest wall, or internal mammary lymph nodes (located beneath the breast right under the ribs, inside the middle of the chest).

Stage IIIB includes inflammatory breast cancer, a very uncommon but very serious, aggressive type of breast cancer. The most distinguishing feature of inflammatory breast cancer is redness involving part or all of the breast. The redness feels warm. You may see puffiness of the breast's skin that looks like the peel of a navel orange ("peau d'orange"), or even ridges, welts, or hives. And part or all of the breast may be enlarged and hard. A lump is present only half of the time. Inflammatory breast cancer is sometimes misdiagnosed as a simple infection.

Stage IV

This stage includes invasive breast cancer in which:

• A tumor has spread beyond the breast, underarm, and internal mammary lymph nodes, AND
• A tumor may have spread to the supraclavicular lymph nodes (nodes located at the base of the neck, above the collarbone), lungs, liver, bone, or brain.

"Metastatic at presentation" means that the breast cancer has spread beyond the breast and nearby lymph nodes, even though this is the first diagnosis of breast cancer. The reason for this is that the primary breast cancer was not found when it was only inside the breast. Metastatic cancer is considered stage IV.

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Additional staging information

You may also hear terms such as "early" or "earlier" stage, "later" or "advanced" stage breast cancer. Although these terms are not medically precise (they may be used differently by different doctors), here is a general idea of how they apply to the official staging system:

Early stage

• Stage 0
• Stage I
• Stage II

Later stage

• Stage II (if there are many lymph nodes involved)
• Stage III (IIIA, IIIB)

Advanced stage

• Stage IV

You may also hear the cancer described by 3 characteristics:

• size (T stands for tumor)
• node involvement (N stands for node)
• whether it has metastasized (M stands for metastasis)

The T category describes the original (primary) tumor:

• TX means the tumor can't be measured or found.
• T0 means there isn't any evidence of the primary tumor.
• Tis means the cancer is "in situ" (the tumor has not started growing into the breast tissue).
• The numbers T1-T4 describe the size and/or how much the cancer has grown into the breast tissue. The higher the T number, the larger the tumor and/or the more it may have grown into the breast tissue.

The N category describes whether or not the cancer has reached nearby lymph nodes:

• NX means the nearby lymph nodes can't be measured or found.
• N0 means nearby lymph nodes do not contain cancer.
• The numbers N1-N3 describe the size, location, and/or the number of lymph nodes involved. The higher the N number, the more the lymph nodes are involved.

The M category tells whether there are distant metastases (whether the cancer has spread to other parts of body):

• MX means metastasis can't be measured or found.
• M0 means there are no distant metastases.
• M1 means that distant metastases were found.

Once the pathologist knows your T, N, and M characteristics, they are combined, and an overall "stage" of 0, I, II, III, IIIA, IIIB, or IV is assigned.

For example, a T1, N0, M0 breast cancer would mean that the primary breast tumor:

• is less than 2 centimeters across (T1)
• does not have lymph node involvement (N0)
• has not spread to distant parts of the body (M0)

This cancer would be grouped as a stage I cancer.