Diagnostic scans are performed to find out if you have Metastatic Breast Cancer (MBC) and to measure response to treatment or progression of metastatic tumors. No matter how many times you have been through a scan, there is often anxiety involved in either the process itself or waiting for results. This is normal.
The most typical scans include:
- Bone Scans
- Chest X-Ray
- CT/CAT Scan (Computerized Tomography or Computerized Axial Tomography)
- Liver Scan
- MRI (Magnetic Resonance Imaging)
- PET Scan (Positron-Emission Tomography)
- PET CT Scan
- Blood Tests
Bone scans may reveal if cancer has spread to the bones. In a majority of metastatic-breast-cancer cases, metastases first occur in the bones. These scans look at the bones for “hot spots” that may reveal cancer. To conduct a bone scan, your healthcare provider injects dye and then waits a few hours for it to move through the bloodstream, so that it can be visible in the scan.
A chest x-ray may reveal if breast cancer has spread to the lungs. Metastases in the lungs rarely cause pain, but they can cause shortness of breath or a cough that won’t go away.
This scan provides a more-detailed x-ray of the body, usually in order to look for metastases in the brain, lungs and/or liver. Before the scan, you will either ingest a contrast dye and/or have it injected into a vein. The dye highlights specific areas of the body more clearly. A computer rotates around the body, creating a three-dimensional image.
A liver scan involves having a contrast dye injected into the vein. The dye will collect in areas where there is activity which could indicate cancer growth. A picture is then taken of the liver with a computer to pinpoint the size and location of the growth.
Before an MRI, patients receive an injection of a contrast dye, then lie down inside a tube-like machine that uses radio waves and a powerful magnet linked to a computer to take three-dimensional pictures of the body. The pictures show where cancer may be in the body. Because the MRI takes pictures all around the body, and can take 40 minutes or more, some people may feel claustrophobic while inside the machine. If this is a concern for you, talk to your healthcare team about how to make the test more comfortable for you.
This scan works by monitoring the use of glucose throughout the body. Cancer cells use more glucose, a source of energy, than normal cells do. Before the scan, you will have some radioactive glucose called a “tracer” injected into a vein. A computer then takes images and looks for the areas using the most glucose. The PET scan can sometimes find cancer that other tests miss.
A combination of the PET and CT Scans described above, performed at the same time, can present a more detailed image of the presence of extent of cancer in the body.
Different blood tests may be used to detect breast cancer:
- The CA 27.29 blood test measures the level of a protein called the CA 27.29 antigen, often found in the blood of women with breast cancer. In theory, the level rises as there is more breast cancer in the body. The test can, in some patients, help determine if cancer is growing in the body, and thus if treatments are working. Similar tests include the CA-15-3 and CEA.
- Circulating tumor cells (CTCs) may also be measured through a blood test. CTCs are extremely rare in healthy individuals and patients with nonmalignant diseases but are often present in people with metastatic cancer. Some clinical studies indicate the assessment of CTCs can assist doctors in monitoring and predicting cancer progression and in evaluating a patient’s response to therapy. However, CTC testing and use is still in the experimental stage.
A biopsy is the surgical removal of all or part of a suspected tumor/metastasis for examination under a microscope to check for cancer cells. Physical exam and imaging can show that something abnormal is present, but a biopsy is the only sure way to know whether the problem is cancer. Your doctor may want to biopsy, if possible, one or more of the suspected tumors in your body to determine their characteristics which will aid in making treatment decisions. While metastases often have the same characteristics of the initial breast cancer, they don’t always.