Once a diagnosis of breast cancer has been made, the next step is to identify the stage of the cancer. Staging is the process used to ascertain the size and location of a breast cancer. Depending on the results of patients' clinical breast examinations and biopsies, physicians may order imaging tests such as chest x-rays, mammograms of both breasts, bone scans, and MRI scans to aid in the staging process. Blood tests that evaluate patients' overall health and determine if the breast cancers have spread to other parts of their bodies also aid in determining breast cancer stages.

Identifying breast cancer stages is crucial for choosing the best treatment options for patients because staging enables patients' medical teams to understand how far the cancer has spread. The most common system for assessing breast cancer stages is the American Joint Committee on Cancer TNM System. This system classifies breast cancers based on the following stages:

•T describes the size of the tumor and how far it has spread within the breast or nearby organs.

•N indicates that lymph vessels within the breast have transported cancerous cells to the lymph nodes that are located under the arms. Lymph nodes are bean shaped groups of immune system cells that help fight infections and cancers.

•M means that the cancer is in metastasis - meaning it has spread to one or more distant organs.

This approach to staging is based on what a pathologist discovers after examining the breast mass and lymph nodes that were removed during surgery. Listed below is a summary of breast cancer stages.

1.Stage 0, the earliest stage of breast cancer, can take two forms: (1) Ductal carcinoma in situ (DCIS) is noninvasive because the cancer cells are located within the ducts and have not invaded the surrounding fatty breast tissue, lymph nodes, or distant organs. (2) Lobular carcinoma in situ (LCIS) is also noninvasive because abnormal cells grow only within the lobules or milk producing glands. Most oncologists do not consider LCIS to be a true cancer.

2.In Stage 1 cancer, the tumor is about 2 cm or 4/5 of an inch or less in diameter and has not spread beyond the breast to the lymph nodes or distant organs.

3.Stage IIA cancers have not spread to distant organs and are indicated in the following ways: (1) the tumor is found in 1 to 3 axillary (under arm) lymph nodes, but not in the breast; (2) the tumor is less than 2 cm and is also found in 1 to 3 axillary lymph nodes; or (3) the tumor is larger than 2 cm in diameter but less than 5 cm but is not found in the axillary nodes.

4.Stage IIB cancers have not spread to distant organs; however the: (1) tumor is larger than 2 cm in diameter but less than 5 cm but is not found in the 1 to 3 axillary lymph nodes; (2) the tumor is larger than 5 cm but has not grown into the chest wall nor spread to the lymph nodes.

5.In Stage IIIA the tumor is smaller than 5 cm in diameter and is found in 4 to 9 axillary nodes, or it is larger than 5 cm and is found in 1 to 9 axillary nodes or internal mammary nodes.

6.Stage IIB tumors have grown into the chest wall or skin, may be found in 0 to 9 axillary nodes, and may or may be found in the internal mammary nodes.

7.In Stage IIIC the tumor is any size and can be found in 10 or more axillary nodes, or 1 or more lymph nodes under or above the clavicle, or the internal mammary lymph nodes. However, it has not spread to distant organs.

8.Inflammatory breast cancer is a Stage III cancer. However, if it is discovered in distant organs or lymph nodes that are not near the breast, it is a Stage IV cancer.

9.Stage IV cancers, irrespective of size, have spread to distant organs such as bones, liver, lung, or lymph nodes that are far from the breast.

The best chance that breast cancer patients have of surviving the disease is to get the appropriate and best medical treatment, determining the breast cancer stages is the first step in developing comprehensive treatment plans.