Breast cancer stage describes the extent of the cancer within your body.
The stage of your breast cancer helps plan your treatment.
Breast cancer stage is the most important factor for prognosis. In general, the earlier the stage, the better the prognosis will be.
Pathologic staging (the standard way to stage breast cancer) is based on a pathologist’s study of the tumor tissue and any lymph nodes removed during surgery.
Sometimes, results from a health care provider’s physical exam and/or tests such as mammography may help with staging.
Although there are a few ways to classify stage, the most widely used is the TNM system.
TNM stands for:
Learn more about tumor size (T) and staging.
Learn more about lymph node status (N) and staging.
Learn more about metastases (M) and staging.
The stages of breast cancer range from 0 to IV (0 to 4).
Stage depends on the combination of tumor size (T), lymph node status (N) and metastases (M). In 2018, the current system of staging breast cancers will be updated and will include more information such as the hormone receptor status of the tumor.
For example, a cancer with a T1 tumor (less than 2 cm), no lymph nodes with cancer (N0) and no metastases (M0) is classified as stage I (T1N0M0).
The highest stage (stage IV) is any cancer with metastases (M1), no matter the size of the tumor or the lymph node status.
Most often, the higher the stage of the cancer, the poorer the prognosis will be.
The table below lists the TNM classifications for each stage of breast cancer.
Stages of Breast Cancer
Ductal carcinoma in situ
Early breast cancer
Locally advanced breast cancer
Any T, N3M0
Metastatic breast cancer
Any T, any N, M1
Facts for Life: Breast Cancer Prognosis
Breast Cancer 101 - Types and Staging
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