Breast Cancer (Facts, Stages) (cont.)

Medical Author:
Medical Editor:

In this Article

How is breast cancer staging determined?

Staging is the process of determining the extent of the cancer and its spread in the body. Together with the type of cancer, staging is used to determine the appropriate therapy and to predict chances for survival.

To determine if the cancer has spread, several different imaging techniques can be used.

Chest X-ray: It looks for spread of the cancer to the lung.

Mammograms: More detailed and additional mammograms provide more images of the breast and may locate other abnormalities.

Computerized tomography (CT scan): These specialized X-rays are used to look at different parts of your body to determine if the breast cancer has spread. It could include a CT of the brain, lungs, or any other area of concern.

Bone scan: A bone scan determines if the cancer has spread (metastasized) to the bones. Low level radioactive material is injected into the bloodstream, and over a few hours, images are taken to determine if there is uptake in certain bone areas, indicating metastasis.

Positron emission tomography (PET scan): A radioactive material is injected that is absorbed preferentially by rapidly growing cells (such as cancer cells). The PET scanner then locates these areas in your body.

Staging system

This system is used by a health-care team to summarize in a standard way the extent and spread of the cancer. This staging can then be used to determine the treatment most appropriate for the type of cancer.

The most widely used system in the U.S. is the American Joint Committee on Cancer TNM system.

Besides the information gained from the imaging tests, this system also uses the results from surgical procedures. After surgery, a pathologist looks at the cells from the breast cancer as well as from the lymph nodes. This information gained is incorporated into the staging as it tends to be more accurate than the physical exam and X-ray findings alone.

TNM staging. This system uses letters and numbers to describe certain tumor characteristics in a uniform manner. This allows health-care providers to stage the cancer (which helps determine the most appropriate therapy) and aids communication among health-care providers.

T: describes the size of the tumor. It is followed by a number from 0 to 4. Higher numbers indicate a larger tumor or greater spread:

TX: Primary tumor cannot be assessed
T0: No evidence of primary tumor
Tis: Carcinoma in situ
T1: Tumor is 2 cm or less across
T2: Tumor is 2 cm-5 cm
T3: Tumor is more than 5 cm
T4: Tumor of any size growing into the chest wall or skin.

N: describes the spread to lymph node near the breast. It is followed by a number from 0 to 3.

NX: Nearby lymph nodes cannot be assessed (for example if they have previously been removed).
N0: There has been no spread to nearby lymph nodes. In addition to the numbers, this part of the staging is modified by the designation "i+" if the cancer cells are only seen by immunohistochemistry (a special stain) and "mol+" if the cancer could only be found using PCR (special detection technique to detect cancer at the molecular level).
N1: Cancer has spread to one to three axillary lymph nodes (underarm lymph nodes) or tiny amounts of cancer are found in internal mammary lymph nodes (lymph nodes near breastbone).
N2: Cancer has spread to four to nine axillary lymph nodes or the cancer has enlarged the internal mammary lymph nodes.
N3: Any of the conditions below

  • Cancer has spread to 10 or more axillary lymph nodes with at least one cancer spread larger than 2 mm.
  • Cancer has spread to lymph nodes under the clavicle with at least area of cancer spread greater than 2 mm.

M: This letter is followed by a 0 or 1, indicating whether the cancer has spread to other organs.

MX: Metastasis cannot be assessed.
M0: No distant spread is found on imaging procedures or by physical exam.
M1: Spread to other organs is present.

Once the T, N, and M categories have been determined, they are combined into staging groups. There are five major staging groups, stage 0 to stage IV, which are subdivided into A and B, or A and B and C, depending on the underlying cancer and the T, N, and M scale.

Cancers with similar stages often require similar treatments.

What is the prognosis of breast cancer?

Survival rates are a way for health-care professionals to discuss the prognosis and outlook of a cancer diagnosis with their patients. Patients have to determine if they want to know this number or not and should let their health-care providers know.

The number most frequently discussed is five-year survival. It is the percentage of patients who live at least five years after they are diagnosed with cancer. Many of these patients live much longer, and some patients die earlier from causes other than breast cancer. With a constant change in therapies, these numbers also change. The current five-year survival statistic is based on patients who were diagnosed at least five years ago and may have received different therapies than are available today.

All of this needs to be taken into consideration when interpreting these numbers for oneself.

Below are the statistics from the National Cancer Institute's SEER database.

StageFive-year survival rate
0100%
I100%
II93%
III72%
IV22%

These statistics are for all patients diagnosed and reported. Several recent studies have looked at different racial survival statistics and have found a higher mortality (death rate) in African-American women compared to white women in the same geographic area.

Medically Reviewed by a Doctor on 6/5/2015

Patient Comments

Viewers share their comments

Breast Cancer - Symptoms Question: What symptoms did you experience when you developed breast cancer?
Breast Cancer - Stages Question: What stage was your breast cancer when you were diagnosed?
Breast Cancer - Type Question: What type of breast cancer do you have?
Breast Cancer - Treatment Question: What kind of treatment did you have for breast cancer?
Breast Cancer - Survival Rate Question: What is the prognosis for your breast cancer?
Breast Cancer - Diagnosis Question: How was your breast cancer detected?