Breast Cancer Diagnosis and Breast Cancer Staging

At Siteman, we strongly emphasize the diagnosis and staging process. There are many different types of breast cancer, and each type can require a different approach to treatment, especially when the stage of the cancer is also taken into account.

Because each Siteman patient receives a personalized treatment plan, our Washington University Physicians take great care to deliver accurate information about cancer type and stage. They use innovative tests and the latest technology to make sure they get it right.

Breast cancer diagnosis

Imaging tests

Patients often learn that they may have breast cancer after undergoing a screening mammogram or other imaging procedure. The Joanne Knight Breast Health Center at Barnes-Jewish Hospital and Washington University School of Medicine offers a full array of all-digital breast imaging services, including screening and diagnostic mammography, breast ultrasound, and breast MRI.

Not all patients will need advanced techniques such as breast ultrasound or breast MRI. Physicians use these methods when they need to get a closer look at a mass or suspicious area. Women at an increased risk of breast cancer sometimes need to be screened using ultrasound or MRI for an extra level of detail.


A biopsy is a procedure to remove a sample of tissue from a tumor or other, abnormal area of the breast. A physician will then use a microscope to search the sample for breast cancer cells. If cancer cells are present, the physician will conduct further tests to learn which type of breast cancer it is.

Patients will be given numbing medication or, in some cases, sedation to help keep them comfortable during procedure. Biopsies are conducted on an out-patient basis.

Types of biopsy include:

Fine needle aspiration

This is the least invasive method of biopsy. The surgeon or radiologist uses a thin needle with a hollow center to remove a sample of cells from the suspicious area. In cases where the lump cannot be felt, physicians use imaging to guide the needle to the right location.

Image-guided core needle biopsy

Core needle biopsy uses a larger hollow needle than fine needle aspiration. The surgeon or radiologist removes several cylinder-shaped samples of tissue while using an imaging technique, such as ultrasound, for guidance.

Surgical biopsy

Even if less invasive biopsy techniques don’t show cancer, some may indicate certain benign conditions that should be removed. These areas can be completely taken out with surgery through a small incision in the breast. Only a small proportion of women need surgical biopsies.

Hormone and genetic tests

If a biopsy shows that a patient has cancer, physicians will study the hormones and genes present in her biopsied tissue. This testing can reveal the type of cancer, how quickly it may grow, how likely it will spread, how well certain treatments might work and how likely the cancer is to recur.

Types of hormone and genetic tests include:

Estrogen and progesterone receptor test

Some cancers are fed by the hormones estrogen and progesterone.  This test determines how much estrogen and progesterone feed the tumor and cause it to grow.  When tumors are driven by these hormones, treatment to block estrogen and progesterone may stop the cancer from growing. This test measures the amount of estrogen and progesterone (hormones) receptors in cancer tissue.

Human epidermal growth factor type 2 (HER2/neu) receptor test

HER2 is a gene in some breast cancer cells.  This laboratory test measures how much HER2 a cell has. Cancers with HER2 may grow more quickly and are more likely to spread to other parts of the body.  There are specific drugs that target HER2 to help shut these tumors down.

Multigene tests

These tests study samples of tissue to look at the activity of many genes at the same time, and may help predict whether cancer will spread to other parts of the body or recur.

Some multigene tests help predict whether stage I or stage II breast cancer that is estrogen receptor positive will spread to other parts of the body. If the risk of the cancer spreading is high, chemotherapy may be given to lower the risk.

Breast cancer staging

How is breast cancer staged?

After a patient has been diagnosed with breast cancer, physicians conduct tests to find out if the cancer has spread within the breast or metastasized to other parts of the body. The cancer will be assigned a “stage” based on whether or how far the cancer has spread.

There are three ways that cancer spreads in the body:

  1. Through tissue
  2. Via the lymph system
  3. In the bloodstream

When cancer surfaces in another part of the body, the new tumor, or metastatic tumor, is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bone, the cancer cells in the bone are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

Tests and procedures that may be used in the staging process include:

Sentinel lymph node biopsy

The sentinel lymph node is the first lymph node the cancer is likely to spread to from the main tumor. To determine which lymph node is the sentinel lymph node, a radioactive substance and/or blue dye is injected near the tumor. The substance or dye flows through the lymph ducts to the lymph nodes. The first lymph node (or nodes) to receive the substance or dye is removed, and a pathologist views the tissue under a microscope to look for cancer cells.

Additional staging scans

Some patients with later-stage breast cancer will be given CT scans, bone scans, or a PET scan in an effort to find out how far the cancer cells have spread. However, only a minority of patients require these tests.

Stages of breast cancer

After the appropriate tests are complete, the cancer can be assigned a stage from 0 to IV. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

Stage 0 (carcinoma in situ)

There are 2 types of breast cancer in situ: ductal carcinoma in situ (where abnormal cells are found in the lining of a breast duct) and Paget’s disease of the nipple (abnormal cells are found in the nipple only).

Stage I

Stage I is usually diagnosed when the tumor is smaller than 2 centimeters, although this can vary according to other characteristics of the cancer. Some cancer cells may have spread to the closest lymph nodes to the breast, which are located in the armpits.

Stage I is divided into stages IA and IB. Stage IB is more advanced.

Stage II

Stage II breast cancers are typically those in which the tumor is still smaller in size – between 2 and 5 centimeters – but the cancer has spread to farther lymph nodes, such as those near the breastbone. Some tumors that are larger than 5 centimeters will be diagnosed as stage II if the cancer has not spread to any lymph nodes.

Stage II is divided into stages IIA and IIB. Stage IIB is more advanced.

Stage III

In patients with stage III breast cancer, the tumor is often larger than 5 centimeters. The cancer may have spread to 4 to 9 lymph nodes in the armpits, to lymph nodes near the breast bone, and to lymph nodes above and below the collarbone. Stage III breast cancer can also spread to the chest wall and/or to the skin of the breast. Cancer that spreads to the skin may be inflammatory breast cancer.

Stage III is divided into stages IIIA, IIIB, and IIIC. Stage IIIC is the most advanced.

Stage IV

The cancer has spread to other parts of the body, most often the bones, lungs, liver, or brain. This is also known as metastatic breast cancer.

Inflammatory Breast Cancer

In inflammatory breast cancer, cancer has spread to the skin of the breast, and the breast looks red and swollen and feels warm. The redness and warmth occur because the cancer cells block the lymph vessels in the skin. The skin of the breast may appear dimpled, like the skin of an orange. There may not be any lumps in the breast that can be felt.

Inflammatory breast cancer may be stage IIIB, stage IIIC, or stage IV.