Multiple myeloma is a cancer of antibody producing cells, called plasma cells, which are located in the bone marrow. Healthy plasma cells do not grow and divide but have learned to make antibodies that protect us from infections. Cancerous plasma cells (= myeloma cells) can grow and multiply, “blindly” produce useless and sometimes incomplete antibodies (called light chains) and release molecules (called cytokines) that can affect healthy cells around them. Sometimes myeloma is found before it causes problems and then it is called smoldering myeloma. When it causes problems or when the risk is high that it causes problems within 1-2 years, treatment is indicated. The problems it can cause are summarized with the abbreviation “CRAB”.
- C stands for high blood Calcium. This is caused by stimulation of bone eating cells (called osteoclasts) by cytokines released from myeloma cells. Osteoclasts release calcium from bones into the blood. This weakens the bones and high blood calcium can impair the kidneys ability to conserve water. Since calcium is electrically charged, high levels can also affect organs that are regulated electrically, like the gastrointestinal tract, heart and brain.
- R stands for Renal, meaning kidney problems. This can be caused by three main mechanisms. One is dehydration related to high blood calcium. If myeloma produces incomplete antibodies called light chains, they are small enough to be filtered by the kidneys and if they reach high concentrations in the kidneys they can fall out of solution, form casts, and trigger an inflammatory reaction that results in kidney failure. If myeloma causes bone pain due to fractures or tumors, patients who have not yet been diagnosed and advised often take over the counter pain medications of the NSAID (nonsteroidal anti-inflammatory drug) class like ibuprofen, and these medications can also be the cause of kidney problems since myeloma kidneys are more susceptible to their side effects on the kidneys.
- A stands for Anemia, meaning low red blood cells and low hemoglobin. This can be caused by myeloma cells leaving little space for healthy bone marrow cells responsible for production of red blood cells or by myeloma cells releasing cytokines that suppress these cells.
- B stands for Bone disease or bone lesions. This can be with or without bone pain. The mechanisms are stimulation of osteoclasts as mentioned above or the development of myeloma tumors in bones.
In addition to these “CRAB” problems, myeloma cells can weaken the immune system and increase the risk for infections.
Multiple myeloma screening is not routinely performed, mainly because it is rare, currently not considered curable although treatment has improved dramatically, and a value to early detection has not been proven. If multiple myeloma is suspected in an individual who is experiencing frequent infections, fatigue, anemia, bone pain or has laboratory findings such as low kidney function, high calcium or high total protein (excess useless antibodies released by myeloma increase the total protein value), testing may be recommended.
What tests are available for multiple myeloma?
There are several baseline tests that can be used for multiple myeloma screening, including:
- Blood and urine tests for monoclonal proteins — These are the useless antibodies or antibody fragments called light chains that come from the clone of myeloma cells. Monoclonal proteins can usually be detected in the blood and/or urine of multiple myeloma patients. The monoclonal protein serves no useful function and sometimes has negative effects, such as blood thickening, kidney damage and abnormal bleeding. Because the monoclonal protein is sometimes found in patients who do not have multiple myeloma, further testing will be required if it is identified in order to reach a definitive diagnosis.
- Imaging — In the many patients with multiple myeloma, routine X-rays show distinct areas of bone erosion, general bone thinning and/or fractures, usually in the vertebrae, ribs, pelvic bones and thigh and upper arm bones. Other imaging tests, including magnetic resonance imaging (MRI), computerized tomography (CT) and positron emission tomography (PET), can also be helpful for diagnostic purposes.
- Bone marrow aspiration and biopsy — A small sample of bone marrow is collected from a patient’s pelvis in the back for laboratory analysis to determine whether the bone marrow cells are comprised of an excessive amount of plasma cells (generally more than 10 percent).
- Genetic and chromosomal tests — Specialized tests can reveal genetic or chromosomal abnormalities of the plasma cells that are usually associated with multiple myeloma. In addition, the unique mutations in antibody genes of myeloma cells are identified. Results are useful for tracking minimal residual disease, predicting a patient’s prognosis and response to treatment.
The physicians and researchers in the Malignant Hematology Program at Moffitt Cancer Center are working to develop new and better multiple myeloma screening techniques and treatments in order to detect and address the condition as early and effectively as possible. Our multispecialty team includes surgeons, medical oncologists and radiation oncologists, all of whom have years of experience focused specifically on diagnosing and treating multiple myeloma. By working together, these experts are continually gaining ground in further understanding the condition, with a goal of one day defeating it.
Medically reviewed by Frederic Reu, MD. Malignant Hematology.
If you have questions or would like to learn more about multiple myeloma screening tests, contact Moffitt by calling 1-888-663-3488 or using our convenient new patient registration form. No referrals are necessary.