Determinants of Breast Cancer Stage

Breast cancer stage

Breast cancer stage describes the extent of the cancer within your body. Knowing 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.

Breast cancer staging

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.

When needed, results from a health care provider’s physical exam and/or tests like mammography may be used in addition to pathologic staging.

TNM system of staging

Although there are a few ways to classify stage, the most widely used is the TNM system.

TNM stands for:

  • T = Tumor size
  • N = Lymph Node status (the number and location of lymph nodes with cancer)
  • M = Metastases (whether or not the cancer has spread to other areas of the body)

Learn more about tumor size (T) and staging.

Learn more about lymph node status (N) and staging.

Learn more about metastases (M) and staging

Stages of breast cancer

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).

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.