Multiple myeloma diagnosis and staging
We use these tests to properly diagnose multiple myeloma:
- Blood and urine tests. Myeloma cells often secrete an antibody called monoclonal immunoglobulin, or M protein. We measure the M protein levels in your blood and urine to determine the extent of the disease and to monitor treatment. Sometimes we measure a fragment of the M-protein called serum free light chain if the MM cells do not make intact immunoglobulin. Light chains in the urine is also called Bence Jones Protein.
- X-ray. Typically a first step in evaluating your bones. The radiologist is looking for areas of bone loss, called “lytic lesions” that indicate MM involvement.
- Magnetic resonance imaging (MRI). Can show if normal bone marrow has been replaced by myeloma cells or by a plasmacytoma (plasma cell tumor), especially in the skull, spine, and pelvis.
- Computed tomography scan (CT or CAT). Creates a detailed, cross-sectional view that shows any abnormalities or tumors in soft tissues.
- Positron emission tomography scan (PET or PET-CT). A way to create pictures of organs and tissues inside your body based on their metabolism. Cancer cells have more metabolic activity that stand out on the PET-CT scan wherever they may be in the body.
- Bone marrow aspiration and biopsy. Often done at the same time to examine the bone marrow. A bone marrow aspiration uses a needle to remove a sample of the liquid marrow. A bone marrow biopsy uses a needle to remove a small amount of solid marrow tissue using a needle.
- Fat pad aspirate. If amyloidosis is suspected, then we may take a sample of the collection of fat using a fine superficial needle around a person’s abdomen to be biopsied.
- Molecular testing of the tumor. Results of these tests can help determine your treatment options.
UCHealth uses the Revised International Staging System (RISS) to classify multiple myeloma, which is based on patients from around the world. It defines the factors that influence patient survival.
The system has three stages based on four factors:
- The amount of albumin in the blood.
- The amount of beta-2-microglobulin in the blood.
- The amount of a chemical called lactate dehydrogenase in the blood.
- The specific DNA abnormalities (cytogenetics) of the cancer.
Stage I. Serum beta-2 microglobulin is less than 3.5 (mg/L), albumin level is 3.5 (g/dL) or greater, cytogenetics are considered not high risk, and LDH levels are normal.
Stage II. Not stage I or stage III.
Stage III. Serum beta-2 microglobulin is 5.5 (mg/L) or greater, cytogenetics are considered high-risk, and/or LDH levels are high
Recent efforts have been made to further classify myeloma based on patterns of gene expression in myeloma cells.