Stages of Breast Cancer

Executive Summary

The staging system of breast cancer depends upon the size of the tumor, its metastasis to lymph nodes and other body parts, and its biomarkers. The stages of breast cancer determine the extent of the disease condition that affects the patients. The location or suspect area of cancer growth is evaluated by assessing the stage of the disease. There are different stage descriptions for each type of cancer. The stages of breast cancer range from stage 0 to stage IV and the sub-stages include Stage 0, IA, IB, IIA, IIB, IIIB, IIIC, and IV.

What are the Stages of Breast Cancer?

There are various Stages of Breast Cancer ​1​. Staging is a way to explain the spread of breast cancer, including the size of the tumor, whether it has spread to lymph nodes, whether it has spread to distant parts of the body, and its biomarkers. Staging is classified before or after surgery on a patient. Doctors use diagnostic tests to determine the cancer stage. The stage does not complete because all the tests are not completed. Knowing the location helps doctors decide which treatment is best and can predict the patient’s prognosis or chance of recovery. There is a different stage description for each type of cancer.

Stage 0 of Breast Cancer

The cancer cells are confined to the ducts, leaves, or nipples in stage 0 known as carcinoma in situ. There are no cancer cells in adipose tissue or lymph nodes. This stage is sometimes referred to as “precancerous disease.” 

Stage IA of Breast Cancer

Cancer forms a tumor of fewer than 2 centimeters in stage IA. Cancer has not spread outside the breast. 

Stage IB of Breast Cancer

There are small clusters of breast cancer cells in the lymph nodes in stage IB.
In some cases, there are small tumors. In other cases, there is no tumor in the breast.

Stage IIA

There are two different types of issues classified as Stage IIA. In some cases, as in Stage IA, there is no tumor in the breast, or the tumor is less than 2 centimeters, but cancer cells are found in at least one to three or fewer lymph nodes. In other cases, the cancer is 2 to 5 centimeters in some other cases, but cancer has not spread to the lymph nodes.

Stage IIB

IIB Breast Cancer Stage is used when the tumor is 2 to 5 centimeters in size and has spread to the lymph nodes, but the lymph nodes have only small clusters of cancer cells that are less than 2 millimeters in length. This classification is also used for tumors larger than 5 centimeters, when cancer has not spread to the lymph nodes.


Stage IIIA

It is one of the stages of breast cancer where cancer cells are found in the lymph nodes. The tumor can be of any size. When lymph nodes are affected, there is an increased risk that cancer may spread or spread to other parts of the body. 

Stage IIIB 

In this stage of breast cancer, lymph nodes are usually involved, and cancer has spread to the chest wall and skin, causing ulcers. If the skin is affected, it is called inflammatory breast cancer, and the entire breast becomes painful, red, and enlarged.

Stage IIIC

The cancer spreads further at this stage of breast cancer and often affects the lymph nodes above or below the clavicle and the lymph nodes below the arm and near the sternum. The skin and chest wall are also affected. Some stage IIIC cancers are inoperable, and some can be treated with surgery.

Stage IV

Breast Cancer spread to other body parts through the lymph nodes and bloodstream. The brain, lungs, liver and bones are most commonly affected. The prognosis at this stage is inferior. One important aspect of this stage is that any stage can progress to stage IV without treatment. Therefore, early detection and early treatment are essential.


  1. 1.
    Koh J, Kim M. Introduction of a New Staging System of Breast Cancer for Radiologists: An Emphasis on the Prognostic Stage. Korean J Radiol. 2019;20(1):69-82. doi:10.3348/kjr.2018.0231