Tests

After you find out that you have breast cancer, you may need other tests to help choose the best treatment for you.

Lab Tests with Breast Tissue

The breast tissue that was removed during your biopsy can be used in special lab tests:

• Hormone receptor tests: Some breast cancers need hormones to grow. These cancers have hormone receptors for the hormones estrogen, progesterone, or both. If the hormone receptor tests show that the breast cancer has these receptors, then hormone therapy is often recommended as part of the treatment plan. (See the Hormone Therapy section.)
• HER2 test: Some breast cancers have large amounts of a protein called HER2, which helps them to grow. The HER2 test shows whether a woman's breast cancer has a large amount of HER2. If so, then targeted therapy against HER2 may be a treatment option. (See the Targeted Therapy section.)

It may take several weeks to get the results of these tests. The test results help your doctor decide which cancer treatments may be options for you.

Staging Tests

Staging tests can show whether cancer cells have spread to other parts of the body.

When breast cancer spreads, cancer cells are often found in the underarm lymph nodes (axillary lymph nodes). Breast cancer cells can spread from the breast to almost any other part of the body, such as the lungs, liver, bones, or brain.

Your doctor needs to learn the stage (extent) of the breast cancer to help you choose the best treatment. Staging tests may include…

• Lymph node biopsy: If cancer cells are found in a lymph node, then cancer may have spread to other lymph nodes and other places in the body. Surgeons use a method called sentinel lymph node biopsy to remove the lymph node most likely to have breast cancer cells. The NCI fact sheet Sentinel Lymph Node Biopsy has more information, including pictures of the method.
  
  If cancer cells are not found in the sentinel node, the woman may be able to avoid having more lymph nodes removed. The method of removing more lymph nodes to check for cancer cells is called axillary dissection.
• CT scan: An x-ray machine linked to a computer takes a series of detailed pictures of your chest or abdomen. You may receive contrast material by mouth and by injection into a blood vessel in your arm or hand. The contrast material makes abnormal areas easier to see. The pictures from a CT scan can show cancer that has spread to the lungs or liver.
• MRI: A strong magnet linked to a computer is used to make detailed pictures of your chest, abdomen, or brain. An MRI can show whether cancer has spread to these areas. Sometimes contrast material makes abnormal areas show up more clearly on the picture.
• Bone scan: The doctor injects a small amount of a radioactive substance into a blood vessel. It travels through the bloodstream and collects in the bones. A machine called a scanner detects and measures the radiation. The scanner makes pictures of the bones. Because higher amounts of the substance collect in areas where there is cancer, the pictures can show cancer that has spread to the bones.
• PET scan: You'll receive an injection of a small amount of radioactive sugar. The radioactive sugar gives off signals that the PET scanner picks up. The PET scanner makes a picture of the places in your body where the sugar is being taken up. Cancer cells show up brighter in the picture because they take up sugar faster than normal cells do. A PET scan can show cancer that has spread to other parts of the body.