Triple-negative breast cancer (TNBC)

Once your healthcare team diagnoses triple-negative breast cancer (TNBC), you may have other tests to figure out the extent of the cancer. This is called the cancer's stage. Your healthcare team uses your cancer's stage to understand your prognosis.

Complete information about the cancer's stage may not be available until after you have breast cancer surgery.

Tests and procedures used to stage breast cancer may include:

• Blood tests, such as a complete blood count and tests to show how well the kidneys and liver are working.
• Bone scan.
• CT scan.
• MRI.
• Positron emission tomography (PET) scan.

Not everyone needs all these tests. Your healthcare team picks the tests for you based on your situation.

First, healthcare professionals typically confirm if the cancer is triple negative by testing for the HER2 protein and the estrogen and progesterone receptors. Then they check to see how big the cancer is, its location and the distance it traveled from where it first started.

Types of staging

The process of breast cancer staging can take place at different times after diagnosis and around treatment. Your stage may change as your care team gets more information about your cancer.

Healthcare professionals use different types of stages at different times.

• Anatomic staging happens after a breast biopsy confirms cancer. It tells your care team about the size of the cancer and whether it has spread. It does not take cancer grade, hormone receptor status or HER2 status into account.
• Clinical prognostic staging happens after all tests on your biopsy sample are complete and your care team knows your cancer grade, hormone receptor status and HER2 status. The prognostic staging process tells your care team more about whether the cancer responds to medical treatment. It helps the team choose the first treatment.
• Pathological prognostic staging is used after surgery once the cancer is removed. This kind of staging looks at factors such as the size of the cancer removed during surgery and the number of lymph nodes removed that contain cancer.
• Postneoadjuvant therapy prognostic staging is used when you receive medicine as your first treatment for breast cancer. This staging process considers the status of the cancer after the medicine is given. It can help your care team decide what to do next. The healthcare team also might consider the residual cancer burden (RCB) score. This score tells the care team how much cancer remains after initial treatments.

Because there are several types of stages that consider different factors, the stages of breast cancer can be confusing and complicated. Ask your healthcare team to explain your stage and what it means for your treatment.

Anatomic stages

Anatomic staging is the simplest form of breast cancer staging. To decide on the anatomic stage, the healthcare team uses the size of the cancer and whether it has spread. Using this type of staging, the stages go from 0 to 4.

• Stage 0. Cancer cells have not grown beyond ducts. This cancer does not spread. Ductal carcinoma in situ is a stage 0 noninvasive cancer.
• Stage 1. The cancer in the breast is less than 1 inch (2.5 centimeters) in diameter. Cancer cells have spread beyond ducts into the breast tissue. There is little or no evidence of cancer in the lymph nodes. Cancer has not spread elsewhere in the body.
• Stage 2. The cancer in the breast is less than 2 inches (5 centimeters) in diameter and has spread to some underarm lymph nodes. Or the cancer is larger than 2 centimeters in diameter and has not spread to the underarm lymph nodes.
• Stage 3. The cancer in the breast is any size and has spread to many underarm lymph nodes. Or the cancer is larger than 2 inches (5 centimeters) in diameter and has spread to some underarm lymph nodes. This stage also includes cancers that spread to the skin, the chest beyond the muscle or the lymph nodes inside the chest wall. Inflammatory breast cancer is considered a stage 3 cancer.
• Stage 4. The cancer in the breast is any size and cancer cells have spread to sites away from the breast and nearby lymph nodes. These sites may include the brain, bones, lungs or liver.

The anatomic stage may be the first stage your healthcare team talks about after your diagnosis.