Breast cancer staging
Once your health care team knows you have breast cancer, they will do more tests to stage it. Staging is a tool the team uses to find out how advanced the cancer is. The stage of the cancer depends on the size and location of a tumor, whether it has spread, and how far the cancer has spread.
Your health care team uses staging to help:
- Decide the best treatment
- Know what kind of follow-up will be needed
- Determine your chance of recovery (prognosis)
- Find clinical trials you may be able to join
Of all the different types of cancers, breast cancer is one of the most talked about, and with good reason. One out of every eight women will develop breast cancer sometime in their life. That's why every woman should be thinking about how to protect herself from this disease. Breast cancer is cancer that forms in the breast. Usually, it begins in the tubes that transport milk from the breast to the nipple. If the cancer spreads to other parts of the breast or body, it's called invasive breast cancer. Some breast cancers are more aggressive, growing more quickly than others. Although women are 100 times more likely to develop breast cancer, men can also get the disease because they do have breast tissue. You're more likely to get breast cancer if you're over 50, you started your periods before age 12, or you have a close family member with the disease. Drinking more than a couple of glasses of alcohol a day and using hormone replacement therapy for several years also may increase your risk. The telltale sign of breast cancer is a lump in your breast or armpit. You may also notice a change in the shape, size, or texture of your breast, or have fluid coming from your nipple when you're not breastfeeding. If you notice any changes in your breasts, call your doctor. You'll probably need to have an imaging scan, such as a mammogram, MRI, or ultrasound. A piece of tissue may be removed from your breast, called a biopsy. With these tests, your doctor can tell whether you have breast cancer, and if so, determine whether or not it has spread. So, how do we treat breast cancer? That really depends on the type of cancer, and how quickly it's spreading. Your doctor may recommend that you have the cancer removed with surgery. Sometimes it's enough just to remove the lump. That's called a lumpectomy. In other cases, the doctor will need to remove the entire breast to get rid of all the cancer or prevent it from coming back. That's called a mastectomy. Other treatments for breast cancer include chemotherapy, medicines that kill cancer cells, and radiation therapy, which uses energy to destroy cancer. Women whose cancer is fueled by the hormone estrogen may receive hormone therapy to block the effects of estrogen on their cancer. Today's breast cancer treatments are better than ever. Many women who have breast cancer go on to live long, healthy lives. The outlook really depends on how fast the tumor is growing, and how far it has spread. That's why it's so important to report any changes in your breasts to your doctor as soon as you notice them. Women who are at an especially high risk for breast cancer because of their family history can talk to their doctor about taking medicine or even having surgery to reduce their risk.
Two Types of Staging
There are two types of staging for breast cancer.
Clinical staging is based on tests done before surgery. These may include:
- Physical exam
- Breast MRI
- Breast Ultrasound
- Breast Biopsy, either ultrasound or stereotactic
- Chest x-ray
- CT scan
- Bone scan
- PET Scan
Pathological staging uses the results from lab tests done on breast tissue and lymph nodes removed during surgery. This type of staging will help determine additional treatment and help predict what to expect after treatment ends.
How Stages are Determined
Stages of breast cancer are defined by a system called TNM:
- T stands for tumor. It describes the size and location of the main tumor.
- N stands forlymph nodes. It describes whether cancer has spread to the nodes. It also tells how many nodes have cancer cells.
- M stands formetastasis. It tells whether the cancer has spread to parts of the body away from the breast.
What the Stages Mean
Doctors use seven main stages to describe breast cancer.
- Stage 0, also called carcinoma in situ. This is cancer that is confined to the lobules or ducts in the breast. It has not spread to surrounding tissue. Lobules are parts of the breast that produce milk. Ducts carry the milk to the nipple. Stage 0 cancer is called noninvasive. This means it has not spread. Some stage 0 cancers become invasive later. But doctors cannot tell which ones will and which will not.
- Stage I. The tumor is small (or may be too small to see) and invasive. It may or may not have spread to the lymph nodes close to the breast.
- Stage II. There may be no tumor found in the breast, but cancer can be found that has spread to axillary lymph nodes or nodes close to the breastbone. Axillary nodes are nodes found in a chain from under the arm to above the collarbone. There might also be a tumor between 2 and 5 centimeters in the breast with small cancers in some of the lymph nodes. Or, the tumor could be larger than 5 centimeters with no cancer in the nodes.
- Stage IIIA. Cancer has spread to 4 to 9 axillary nodes or to nodes near the breastbone but not to other parts of the body. Or, there could be a tumor larger than 5 centimeters and cancer that has spread to 3 axillary nodes or to nodes near the breastbone.
- Stage IIIB. The tumor has spread to the chest wall or to the skin of the breast causing an ulcer or swelling. It may also have spread to axillary nodes but not to other parts of the body.
- Stage IIIC. Cancer of any size has spread to at least 10 axillary nodes. It may also have spread to the skin of the breast or breast wall, but not to distant parts of the body.
- Stage IV. The cancer is metastatic, which means it has spread to other organs such as the bones, lungs, brain, or liver.
How Staging Guides Treatment
The type of cancer you have, along with the stage, will help determine your treatment. With stage I, II, or III breast cancer, the main goal is to cure the cancer by treating it and keeping it from coming back. With stage IV, the goal is to improve symptoms and prolong life. In almost all cases, stage IV breast cancer cannot be cured.
Cancer can come back after treatment ends. If it does, it can occur in the breast, in distant parts of the body, or in both places. If it does return, it may need to be restaged.
National Cancer Institute website. Breast cancer treatment (adult) (PDQ) - health professional version.
Neumayer L, Viscusi RK. Assessment and designation of breast cancer stage. In: Bland KI, Copeland EM, Klimberg VS, Gradishar WJ, eds. The Breast: Comprehensive Management of Benign and Malignant Diseases. 5th ed. Philadelphia, PA: Elsevier; 2018:chap 37.
Last reviewed on: 10/28/2021
Reviewed by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.