ON THIS PAGE: You will learn about how doctors describe a cancer’s growth or spread. This is called the stage. To see other pages, use the menu on the side of your screen.
Staging is a way of describing where the cancer is located, how much it has grown, and if or where it has spread. Doctors use diagnostic tests to find out the cancer's stage, so staging may not be complete until all the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis, which is the chance of recovery. There are different stage descriptions for different types of cancer.
The most commonly used tool that doctors use to describe tumor stage is the TNM system. TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:
- How large is the primary tumor and where is it located? (Tumor, T)
- Has the tumor spread to the lymph nodes? (Node, N)
- Has the cancer metastasized to other parts of the body? (Metastasis, M)
The results are combined to determine the stage of cancer for each person. There are five stages of breast cancer overall: stage 0 (zero), which is non-invasive ductal carcinoma in situ (DCIS), and stages I through IV (one through four), which represent invasive breast cancer.
There are two types of staging for breast cancer. First, the clinical stage is based on the results of tests done before surgery, such as a physical examination, x-rays, CT scans, and MRI tests. Then, the pathologic stage is assigned based on information found during surgery, plus the laboratory results of the breast tissue and any lymph nodes removed during surgery. In general, more importance is placed on the pathologic stage than the clinical stage. The stage provides a common way of describing the cancer so doctors can work together to plan the best treatments.
Cancer stage grouping
Doctors assign the stage of the cancer by combining the T, N, and M classifications. Read about specific T, N, and M classifications in the Guide to Breast Cancer. Inflammatory breast cancer is generally considered stage IIIB breast cancer at a minimum at the time of diagnosis.
Stage 0: Stage zero (0) describes disease that is only in the ducts and lobules of the breast tissue and has not spread to the surrounding tissue of the breast. It is also called noninvasive cancer (Tis, N0, M0).
Stage IA: The tumor is small, invasive, and has not spread to the lymph nodes (T1, N0, M0).
Stage IB: Cancer has spread only to the lymph nodes, and is larger than 0.2 mm but less than 2 mm in size. There is either no evidence of a tumor in the breast or the tumor in the breast is 20 mm or smaller (T0 or T1, N1mic, M0).
Stage IIA: Any one of these conditions:
- There is no evidence of a tumor in the breast, but the cancer has spread to the axillary or underarm lymph nodes but not to distant parts of the body. (T0, N1, M0).
- The tumor is 20 mm or smaller and has spread to the axillary lymph nodes (T1, N1, M0).
- The tumor is larger than 20 mm but not larger than 50 mm and has not spread to the axillary lymph nodes (T2, N0, M0).
Stage IIB: Either of these conditions:
- The tumor is larger than 20 mm but not larger than 50 mm and has spread to one to three axillary lymph nodes (T2, N1, M0).
- The tumor is larger than 50 mm but has not spread to the axillary lymph nodes (T3, N0, M0).
Stage IIIA: The cancer of any size has spread to four to nine axillary lymph nodes, but not to other parts of the body (T0, T1, T2 or T3, N2, M0). Stage IIIA may also be a tumor larger than 50 mm that has spread to one to three lymph nodes (T3, N1, M0).
Stage IIIB: The tumor has spread to the chest wall or caused swelling or ulceration of the breast or is diagnosed as inflammatory breast cancer. It may or may not have spread to the lymph nodes under the arm, but it has not spread to other parts of the body (T4; N0, N1 or N2; M0).
Stage IIIC: A tumor of any size that has not spread to distant parts of the body but has spread to 10 or more axillary lymph nodes or the lymph nodes in the N3 group (any T, N3, M0).
Stage IV (metastatic): The tumor can be any size and has spread to another organ (bones, lungs, brain, liver, distant lymph nodes, or chest wall (any T, any N, M1). Metastatic cancer spread is found when the cancer is first diagnosed about 5% to 6% of the time. Most commonly, metastatic breast cancer is found after a previous diagnosis of early-stage breast cancer.
Recurrent: Recurrent cancer is cancer that has come back after treatment. If there is a recurrence, the cancer may need to be staged again (called re-staging) using the system above.
Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual Seventh Edition (2010) published by Springer-Verlag New York, www.cancerstaging.net.
Information about the cancer’s stage will help the doctor recommend a treatment plan. The next section helps explain the treatment options for this type of cancer. Use the menu on the side of your screen to select Treatment Options, or you can select another section, to continue reading this guide.