Breast Cancer Staging
Tumor Size
Lymph Node Status
Tumor Grade



To assess prognosis and to guide treatment decision making, as well as research, breast cancer is generally assessed using a system called staging. Tumor stages range from Stage I to Stage IV, with Stage I having the best prognosis and Stage IV having the poorest. The staging system takes into account three major features of a woman's breast cancer:

• Tumor size
• Lymph node status
• Metastasis status

Tumor size can be an important indicator of how quickly a tumor is growing. However, a small tumor may be small because it is growing very slowly, or because it was growing quickly but was found early. Tumor size is only one of many factors used to indicate whether a woman's breast cancer is more or less aggressive.



Lymph node status indicates whether any breast cancer cells have moved from the original tumor into the lymph nodes. Lymph nodes are found throughout the body, and make up part of the lymphatic system, which is part of the body's immune system. If breast cancer does spread, it usually spreads first to the lymph nodes under the arm on the side of the breast cancer.

If lymph node status is positive, meaning the lymph nodes contain breast cancer cells, the cancer may be more likely to return or recur.

If the lymph node status is negative, meaning that the lymph nodes appear free of breast cancer cells, the cancer is less likely to recur.



Pathologists are doctors who are experts in diagnosing disease and who study both the overall and microscopic appearance of the tumors of women with breast cancer. In addition to the stage, pathologists classify tumors into one of three grades based on how similar in appearance the cancer cells are to normal cells, and on how many of those tumor cells are dividing. The greater the number of cells dividing, the higher the tumor grade. Tumor grade is one of many factors that, when used in combination, can indicate how aggressive someone's cancer is.

Grade 1: Tumor cells are more similar to normal cells and grow slowly (also called well-differentiated).

Grade 2: Tumor cells are somewhat abnormal and growing at moderate speed (also called moderately differentiated).

Grade 3: Tumor cells are abnormal and growing quickly (also called poorly differentiated).



Hormones are naturally occurring chemicals in the body that stimulate the growth of hormone-sensitive tissues, such as those in the breast. In some cases of breast cancer, the hormones estrogen and progesterone may stimulate tumor growth. To find out if your cancer is hormone-dependent, your doctor will likely have your tumor tissue tested for the presence of hormone receptors, which are proteins on the surfaces of cells to which hormones bind, thus activating tumor growth.

If your cancer is estrogen receptor-positive (ER+) or progesterone receptor-positive ( PR+), meaning it has receptors for those respective hormones, you may be a candidate for hormonal therapy.



Human epidermal growth factor receptor 2 (HER2/neu) is a protein that appears in the cancer cells of some women with breast cancer. Approximately 20%-40% of women show HER2 overexpression (gene amplification), which correlates with poor prognosis and is predictive of response to trastuzumab. ¹

A woman whose tumor has greater-than-normal levels of HER2/neu is considered HER2-positive. A woman whose tumor has normal levels of HER2/neu is considered HER2-negative.


Genomic tests look at groups of genes and how active they are within a tumor. This activity can influence how a cancer is likely to grow and respond to treatment. For example, the Oncotype DX^® test looks at a group of 21 genes and their activity in breast tumor tissue.

Recurrence is the return of the same cancer after initial treatment. Therapy for early-stage breast cancer aims to reduce the chance that cancer will return, or recur. It is valuable to know the chance that your particular cancer will return, because that can help you and your doctor determine whether additional treatment beyond surgery is appropriate.

There are two main types of recurrence:

Local recurrence is the return of cancer to the area where a woman originally had cancer and subsequent surgery. Signs of local recurrence of breast cancer usually become apparent during mammograms, physical examinations by a health professional or self-examinations. Local recurrence is often treated similarly to the way the original cancer was treated: with surgery, followed by radiation therapy (if it was not done initially), chemotherapy and/or hormonal therapy.

In distant recurrence, the cancer metastasizes, or spreads to parts of the body other than the original location (breast or lymph nodes located near the breast). Symptoms such as bone pain, weight loss, and shortness of breath may be signs of distant recurrence. If cancer does metastasize, it commonly spreads to the lungs, bones, liver or brain.