Multiple myeloma is a type of cancer that affects plasma cells. Plasma cells are the white blood cells that make antibodies. Multiple myeloma causes groups of abnormal plasma cells to accumulate in the bones. This can lead to the development of bone lesions.
Abnormal plasma cells can also congregate in the bone marrow. Since bone marrow is the source of your body’s blood cells, this interferes with production of blood cells.
Multiple myeloma can be categorized by its effect on the body. For example, some types are more likely to cause symptoms than others.
Indolent Myeloma has no discernible symptoms. It usually develops slowly and does not cause bone tumors. Only small increases in M protein and M plasma cells are seen. M protein is an abnormal type of antibody found in myeloma patients.
Solitary plasmocytoma involves only one tumor, typically located in a bone. It usually responds well to treatment but needs close monitoring.
The precise cause of this cancer is unknown. However, it starts with one abnormal plasma cell. That cell multiplies in the bone marrow, far more times than it should. Cancerous cells don’t have a normal life cycle. Instead of multiplying and dying out, they keep dividing indefinitely. This can overwhelm the body and impair the production of healthy cells.
Most people who develop multiple myeloma have no clear risk factors. However, some risk factors have been identified. These include being:
- over 50 (first diagnosis is usually in the early- to mid-60s)
- overweight or obese
- exposed to radiation
- employed in the petroleum industry
Having a history of monoclonal gammopathy of undetermined significance (MGUS) is also associated with myeloma risk. Each year, at least one percent of people with MGUS will also develop multiple myeloma.
Symptoms of multiple myeloma vary from person to person. Initially, symptoms may not be noticeable. However, as the disease progresses, most patients will experience at least one of four major types of symptoms. These symptoms are generally referred to using the acronym CRAB. CRAB stands for Calcium, Renal, Anemia, and Bone damage.
Kidney failure can be caused by high levels of M protein.
Anemia-related fatigue occurs when you have too few red blood cells. This happens when myeloma cells replace red cells in the bone marrow.
Bone injuries and fractures occur when myeloma cells invade the bone. Osteolytic bone fractures appear to be punched out areas on X-rays. They often cause bone pain--especially in the back, pelvis, ribs, and skull.
Additional signs of multiple myeloma may include:
- weakness or numbness, especially in the legs
- unintended weight loss
- repeated infections
Physicians often detect multiple myeloma before any signs are present. Routine physical exams, blood tests, and urine tests can uncover evidence of this cancer. If a doctor finds signs of myeloma when you don’t have symptoms, more tests will be needed. Using the following tests, your doctor can monitor the disease’s progression and determine if you need treatment.
Blood and Urine Tests
Blood and urine tests are used to detect M proteins. These proteins may be caused by multiple myeloma or other conditions. Myeloma cells also make a protein called beta-2-microglobulin. This too can be detected in blood. Finally, blood tests can be used to check the percentage of plasma cells in the bone marrow.
X-rays can be used to determine whether your bones have been damaged. PET scans, MRIs, and CT scans can also be used.
Physicians can examine bone marrow by removing a small amount using a needle. Once a sample is obtained, it can be checked for myeloma cells.
This test is also known as a visual field test. It measures your peripheral (side) and central vision. This tells your doctor if glaucoma is affecting your sight.
Staging and Risk Stratification
These types of tests are used to determine whether you have multiple myeloma or another condition. If multiple myeloma is found, the tests can show how far it has progressed. This is known as staging the cancer.
There’s no cure for multiple myeloma. However, there are treatments. These are only used if the disease is progressing. If no symptoms are present, your doctor is unlikely to suggest treatment
- Bortezomib is administered intravenously. It kills cancer cells by blocking proteasomes.
- Thalidomide is given orally to newly diagnosed patients.
- Lenalidomide is similar to thalidomide. However, it has fewer side effects. It also appears to be more potent.
- Chemotherapy is administered orally or intravenously to kill myeloma cells.
- Corticosteroids are often used to treat myeloma. This drug class includes prednisone and dexamethasone.
- Stem cell transplants can be used for treatment after high doses of radiation.
- Radiation therapy is used to kill myeloma cells.
Multiple myeloma can cause many complications. Fortunately, these are generally treatable.
Back pain can be treated with drugs or a back brace.
Infections can be treated with antibiotics.
Bone loss can be slowed or prevented with medication.
Anemia can be treated with erythropoietin. This drug stimulates the body to make red blood cells.
Many people respond well to treatment. However, issues can develop after years of successful treatment. An exact timetable for the disease is difficult to pinpoint. Those who have been diagnosed may not progress for long periods of time.
Progressive myeloma is ultimately fatal. Sufferers should discuss end-of-life care with doctors, and loved ones. Important topics include:
- pain relief
- the use of feeding tubes
- advance directives