If the biopsy shows that you have breast cancer, your doctor needs to learn the disease’s extent (stage) to choose the best breast cancer treatment options for you. The stage of your breast cancer is based on:
The information gained from the staging process will help your cancer care team provide customized cancer care for each patient’s specific needs. Staging may involve using some of the same test results gathered during the diagnostic process, in addition to other tests. These tests will also show if the breast cancer has spread and, if so, to what parts of your body.
One test, a sentinel lymph node biopsy, happens after surgery when nearby lymph nodes are collected and examined to see if cancer cells are present. The stage is typically unknown until after surgery to remove the tumor in your breast, along with one or more lymph nodes under your arm.
Breast cancer surgeons remove the lymph nodes that are most likely to have breast cancer cells. A blue dye, a radioactive substance, or both are injected near the breast tumor or under the nipple. Then, the surgeon uses a scanner to find the sentinel lymph node(s) containing the radioactive material or looks for the lymph node stained with the blue dye. These sentinel nodes are removed and checked for cancer cells. When breast cancer spreads, the cancer cells are often found in the axillary lymph nodes in the armpit.
Breast cancer can spread to almost any other part of the body, such as the bones, liver, lungs, and brain. When breast cancer spreads from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary (original) cancer tumor.
For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer. For that reason, it is treated as breast cancer, not bone cancer. Doctors call the new tumor “distant” or metastatic breast cancer.
The stage of breast cancer is based on several factors:
The location, size of the tumor and if the cancer has spread to the lymph nodes are noted using the TNM system. TNM stands for:
T followed by a number from 0 to 4 describes the primary tumor’s size and its spread to the skin or the chest wall under the breast. Higher T numbers mean a larger tumor or wider spread to tissues near the breast.
N followed by a number from 0 to 3 indicates whether cancer has spread to lymph nodes near the breast and, if so, how many lymph nodes are involved.
The following grouping by T, N, and M, according to the stage, is provided by the American Society of Clinical Oncology.
Stage 0 Also called non-invasive. Disease that is only in the ducts of the breast tissue and has not spread to the surrounding tissue of the breast. |
Tis Ta |
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 to the lymph nodes and the cancer in the lymph node 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 |
T1 or T2 |
N1 |
M0 |
Stage IIA Any 1 of these conditions:
|
T0 T1 T2 |
N1 N1 N0 |
M0 M0 M0 |
Stage IIB Either of these conditions:
|
T2 T3 |
N1 N0 |
M0 M0 |
Stage IIIA Either of these conditions:
|
T0, T1, T2 or T3 T3 |
N2 N1 |
M0 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 up to 9 axillary or internal mammary lymph nodes. 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 spread to 10 or more axillary lymph nodes, the internal mammary lymph nodes, and/or the lymph nodes under the collarbone. It has not spread to other parts of the body. |
Any T |
N3 |
M0 |
Stage IV Also called metastatic breast cancer. The tumor can be any size and has spread to other organs, such as the bones, lungs, brain, liver, distant lymph nodes, or chest wall |
Any T |
Any N |
M1 |
Recurrent Recurrent breast cancer is cancer that has come back after a time when it could not be detected following treatment. Even when the cancer seems to be destroyed, the disease sometimes returns because undetected cancer cells remained somewhere in your body after treatment. It may return in the breast or chest wall or return in any other part of the body, such as the bones, liver, lungs, or brain. The recurrent breast cancer may be described as local, regional, or distant. |
The tumor’s grade is a measurement of how much the cancer cells look like healthy cells. Tumor grading will give the oncologist a better idea of how quickly the cancer is likely to grow and spread.
To describe how abnormal the cancer cells and tissue are, the pathologist will assess the following three features:
For each feature, the pathologist assigns a score of 1 to 3; a score of “1” means the cells and tumor tissue look the most like healthy cells and tissue, and a score of “3” means the cells and tissue look the most abnormal. The scores for each feature are added together to get a total score between 3 and 9.
Three grades of breast cancer are possible:
The grade is determined after a biopsy.