Breast Cancer Stages

Doctors use “stages” to talk about cancer, including breast cancer. Each stage describes how large a tumor is, and if the cancer has spread, how far. Stages are used to decide what treatment is best and to talk about survival rates.^1,2

Each stage is given a number of 0 through 4. The higher the number, the more advanced the cancer. Four is the most advanced stage of breast cancer.

Figure 1. Overview of breast cancer stages

Finding your stage

Information is gathered from many tests after you have been diagnosed with breast cancer. The tests may include a physical exam, biopsy, imaging tests, blood tests, and sometimes surgery.

You may hear your doctors talk about a pathological stage or a clinical-stage.³

• The pathological stage is also called the surgical stage. Before surgery, blood and imaging tests are done. Then, surgery to look at and remove the cancer is performed. The results of what the doctors saw during surgery, plus the test results, combine to give cancer a pathological stage.
• Sometimes surgery is not possible. When that happens, doctors set the cancer stage using only the physical exam, biopsy, blood tests, and imaging tests. This is called clinical staging. It may not be as precise as a pathological stage.

What do the stages mean?

Stage 0 is noninvasive. This means that cancer cells are there but have not spread to nearby tissue. Stage 0 cancer may also be called pre-cancer.¹

Stages 1, 2, and 3 are invasive. This means the cancer has begun to spread in the breast and possibly to nearby tissue.¹

Stage 1 is also called early-stage breast cancer

In stage 1, cancer has normally spread to a small area in the breast. Stage 1 can be a tumor about the size of a grape or smaller and nearby lymph nodes may have small amounts of cancer cells. Or, there can be no tumor in the breast but small groups of cancer cells are found in nearby lymph nodes.

Stage 2 is also called localized breast cancer

In stage 2, the cancer is larger and may or may not have spread to some nearby lymph nodes. Stage 2 may include:

• Breast tumors up to 2 inches in size (2 to 5 cm) and nearby lymph nodes may or may not have cancer cells
• No tumor, or breast tumors smaller than 1 inch (2 cm) in size, and have spread to nearby lymph nodes
• Tumors bigger than about 2 inches (5 cm) in size with no spread to nearby lymph nodes

Stage 3 is also called regional spread

In stage 3, the cancer is larger, has spread to more lymph nodes under the arm, and/or has spread to lymph nodes or other areas further away from the breast. It may have spread to the skin or chest wall and may involve lymph nodes near the collarbone or breastbone. The cancer may also cause swelling, inflammation, or an open wound on the breast or nearby.

Stage 4 is metastatic

Metastatic breast cancer is also called advanced breast cancer. This means cancer has spread beyond the breast to other parts of the body. The bones, brain, lungs, and liver are some of the places that breast cancer most often spreads. Stage 4 breast cancer may be a new diagnosis or earlier breast cancer that has returned.¹

There are oncologists (cancer doctors) who specialize in treating stage 4 breast cancer. While this stage of breast cancer is not curable, it is often treatable. Stage 4 breast cancer may respond to many treatments that can extend life by several years.⁴

Editor's note: For additional information about breast cancer staging, please check out our article, "What Do Those Breast Cancer Staging Letters and Numbers Mean"?