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Staging describes the extent or severity of an individual's cancer based on the extent of the original (primary) tumor and the extent of spread in the body.

  • Staging helps the doctor plan a person's treatment.
  • The stage can be used to estimate the person's prognosis (likely outcome or course of the disease).
  • Knowing the stage is important in identifying clinical trials (research studies) that may be suitable for a particular patient.

Staging helps researchers and health care providers exchange information about patients. It also gives them a common language for evaluating the results of clinical trials and comparing the results of different trials.

Staging is based on knowledge of the way cancer develops. Cancer cells divide and grow without control or order to form a mass of tissue, called a growth or tumor. As the tumor grows, it can invade nearby organs and tissues. Cancer cells can also break away from the tumor and enter the bloodstream or lymphatic system. By moving through the bloodstream or lymphatic system, cancer can spread from the primary site to form new tumors in other organs. The spread of cancer is called metastasis.

  • Stage 0: Carcinoma in situ (early cancer that is present only in the layer of cells in which it began).
  • Stage I, Stage II, and Stage III: Higher numbers indicate more extensive disease: greater tumor size, and/or spread of the cancer to nearby lymph nodes and/or organs adjacent to the primary tumor.
  • Stage IV: The cancer has spread to another organ.

Our Cancer Data Center uses summary staging. This system is used for all types of cancer. It groups cancer cases into five main categories:

  • In situ is early cancer that is present only in the layer of cells in which it began.
  • Localized is cancer that is limited to the organ in which it began, without evidence of spread.
  • Regional is cancer that has spread beyond the original (primary) site to nearby lymph nodes or organs and tissues.
  • Distant is cancer that has spread from the primary site to distant organs or distant lymph nodes.
  • Unknown is used to describe cases for which there is not enough information to indicate a stage.

Staging Workup

The breast cancer staging workup is the critical blueprint for your diagnosis and therefore directly affects your treatment plan. Staging is the combination of pieces of information that communicate to your treating physicians the size, growth and type of your tumor.

The majority of information for staging is obtained from pathology results of your lumpectomy or mastectomy, and in some cases biopsy. If there is concern that the cancer has spread beyond the breast and axillary lymph nodes, additional staging workup is needed to determine the true stage of the disease. In such cases, the concern is whether the cancer is actually Stage IV disease, meaning the cancer has spread to other organs in the body.

The following tests may be involved in a staging workup:

  • CT scan - CT scan (computerized tomography) uses X-rays that produce images of your body. The way the images are projected on screen gives your physicians more information than with a standard X-ray. This specific type of scan is used to examine the lungs and liver.
  • PET scan - Positron emission tomography (PET) scan is a non-invasive test that accurately images the cellular function of the human body. This allows your physicians to pinpoint the spread and growth of cancer. This test is not standard of care; some doctors use it and some do not. Its benefit for staging for breast cancer remains a gray area in medicine.
  • Bone scan - A bone scan is a nuclear scanning test that identifies new areas of bone growth or breakdown. Bone scans can find cancer that has spread (metastasized) to the bones.
  • Chest X-ray - A chest X-ray can help your physicians see how healthy your lungs are.
  • Blood Work - Blood work can be helpful for evaluating if cancer has spread. By monitoring different common measurements within the blood, your physicians can look for markers that predict cancer spread. Blood work is also done in preparation for surgery and periodically during chemotherapy.
  • MUGA - The Multiple Gated Acquisition scan (MUGA) is an extremely useful noninvasive tool for assessing the function of the heart. For women who may have specific chemotherapy drugs, this test is critical, as some chemotherapy drugs for breast cancer treatment can be toxic for your heart. The MUGA scan tells your physicians the health of your heart, so they can plan your chemotherapy accordingly.

It is important to note that there can be cancer cells in other organs that, due to their tiny size, are not yet visible on scans. Usually, cancer has to be at least one centimeter in diameter to be seen on scans.

Last Updated: 7/15/2013