Definition
Multiple myeloma is cancer that starts in the plasma cells in bone marrow. Bone marrow is the soft, spongy tissue found inside most bones. It helps make blood cells.
Plasma cells help your body fight infection by producing proteins called antibodies. With multiple myeloma, plasma cells grow out of control in the bone marrow and form tumors in the areas of solid bone. The growth of these bone tumors weakens the solid bones and also makes it harder for the bone marrow to make healthy blood cells and platelets
Myeloma is the second most common blood cancer in the United States. In 2022, 7 percent of new myeloma cases were among Black people, according to the American Cancer Society.
Causes
The risk factors for multiple myeloma are not conclusive, because the cause of multiple myeloma is not known. Researchers believe that multiple myeloma is most likely the result of many risk factors acting together. There are, however, some factors that may be associated with an increased risk of developing multiple myeloma. These multiple myeloma risk factors include genetic factors, prevalence of MGUS, occupational exposure, age, race, and gender.
Age
The most significant risk factor for multiple myeloma is age, as 96% of cases are diagnosed in people older than 45 years, and more than 63% are diagnosed in people older than 65 years. Thus, it is thought that susceptibility to myeloma may increase with the aging process.
Gender
Men are slightly more likely to develop multiple myeloma than women.
Race
Multiple myeloma is more than twice as common in African Americans than in white Americans. The reason is not known.
Family History
Multiple myeloma seems to run in some families. Someone who has a sibling or parent with myeloma is 4 times more likely to get it than would be expected. Still, most patients have no affected relatives, so this accounts for only a small number of cases.
Workplace Exposures
The likelihood of multiple myeloma is higher than average among people in agricultural occupations, petroleum workers, workers in leather industries, and cosmetologists. Exposure to herbicides, insecticides, petroleum products, heavy metals, plastics, and various dusts including asbestos also appear to be risk factors for the disease. However, none of these associations is strong, and in most cases, multiple myeloma develops in individuals who have no known risk factors.
Obesity
A study by the American Cancer Society has found that being overweight or obese increases a person’s risk of developing myeloma.
Having Other Plasma Cell Diseases
Many people with monoclonal gammopathy of undetermined significance (MGUS) or solitary plasmacytoma will eventually develop multiple myeloma.
Symptoms
Multiple myeloma most commonly causes a low red blood cell count (anemia), which can lead to fatigue and shortness of breath. It can also cause low white blood cell count, which makes you more likely to get infections. Multiple myeloma can also cause low platelet count, which can lead to abnormal bleeding.
Common symptoms may include:
- Bone pain, often in the back or ribs
- Broken bones
- Weakness or fatigue
- Weight loss
- Frequent infections and fevers
- Feeling very thirsty
- Frequent urination
As the cancer cells grow in the bone marrow, you may have bone or back pain, most often in the ribs or back. The cancer cells can weaken bones. You may develop broken bones (bone fractures) just from doing normal activities. If cancer grows in the spine bones, pressure on the nerves may result. This can lead to numbness or weakness of the arms or legs.
Exams and Tests
Blood tests can help diagnose this disease. These tests include:
- Albumin level
- Calcium level
- Total protein level
- Kidney function blood tests
- Complete blood count (CBC)
- Blood and urine tests to identify proteins, or antibodies (immunofixation)
- Blood tests to quickly and accurately measure the specific level of certain proteins called immunoglobulins (nephelometry)
Bone x-rays may show fractures or hollowed out areas of bone. If your doctor suspects this type of cancer, abone marrow biopsy will be performed.
Bone density testing may show bone loss.
Treatments
Multiple myeloma is a treatable cancer, with early testing and diagnosis being key. There is no one standard multiple myeloma treatment. A patient’s individual treatment plan is based on a number of things, including:
- Age and general health
- Results of laboratory and cytogenetic (genomic) tests
- Symptoms and disease complications
- Prior myeloma treatment
- Patient’s lifestyle, goals, views on quality of life, and personal preferences
Treatment options include:
- Drugs – There are now 5 drug classes for the treatment of multiple myeloma: immunomodulatory drugs, proteasome inhibitors, chemotherapy, histone deacetylase inhibitor (HDAC inhibitor), and steroids. Click here for a list and description.
- Stem cell transplants – Allogeneic transplants involve transferring stem cells from a matched donor (usually a relative) to a myeloma patient following high-dose chemotherapy or radiation. An autologous stem cell transplant is when stem cells collected from the patient are transplanted to replenish stem cells.
- Bisphosphonates – Bisphosphonates are medicines that are used in the treatment of myeloma bone disease and are usually used in conjunction with other cancer therapy.
- Surgery – Multiple myeloma surgery may be required to help control pain or retain function or mobility. These may include physical therapy, splinting of bones to prevent or treat fractures, or surgical procedures (minor or major) to repair fractures.
- Alternative therapies – Alternative therapies like acupuncture, meditation, massage and aromatherapy may be helpful to manage MM treatments and side effects.
- Radiation therapy – Low dose radiation therapy is often used to treat bone tumors in multiple myeloma patients.
Click here to find a treatment center in your area.
Possible Complications
Kidney failure is a frequent complication. Others may include:
- Bone fractures
- High levels of calcium in the blood, which can be very dangerous
- Increased chances for infection, especially in the lungs
- Weakness or loss of movement due to tumor pressing on spinal cord
- Impaired immune system
- Anemia
When To Contact a Medical Professional
Call your doctor if you have multiple myeloma and you develop an infection, or numbness, loss of movement or loss of sensation.
Prevention
Multiple myeloma is not a preventable disease as very few cases are linked to avoidable risk factors. While many cancers have clear risk factors that influence the development of the disease, such as smoking and lung cancer, multiple myeloma’s risk factors are not fully understood. Unfortunately, this means nothing can be done to prevent the disease. Furthermore, while people with a history a plasma cell neoplasms, such as MGUS or a solitary plasmacytoma, are more likely to develop multiple myeloma, it is not clear what causes these diseases to progress on to myeloma.
Sources:
Multiple Myeloma Research Foundation
Reviewed by: Dr. Melvin Gaskins