Multiple myeloma is a type of cancer that affects the bone marrow, the body's blood-forming system. The plasma cells (a type of white blood cell) become abnormal and multiply rapidly, interfering with the production of normal blood cells. The overgrowth of malignant cells in the bone marrow can also weaken the bones, especially in the back and ribs, causing pain and bone fractures.
Multiple myeloma is uncommon, affecting about 20,000 people annually in the United States. Although the exact cause is unknown, multiple myeloma can be controlled in most patients, sometimes for many years. The development of new drugs has helped control multiple myeloma in a larger number of patients, and has resulted in longer survival.
People diagnosed with multiple myeloma often don't have any symptoms in the early stages of disease. Signs to look out for include:
Bone damage is the most serious concern at the time myeloma is diagnosed. Bone damage occurs because myeloma cells produce substances called cytokines, which can trigger bone cells (osteoclasts) to destroy surrounding bone. When more than 30 percent of the bone has been destroyed, X-rays will show either a thinning of the bone (osteoporosis) or the presence of dark holes (lytic lesions). The weakened area of bone can break, which is called a pathological fracture. To prevent bone destruction, your doctor may recommend giving you drugs that prevent osteoclasts from destroying bone (e.g., Zometa® or Aredia®).
This is especially common in the middle and/or lower back, rib cage or hips. The pain can be mild or severe depending on the size of the lesion, the speed with which it has developed and whether or not a fracture or nerve compression has occurred. Typically, movement makes the pain much worse.
Because the myeloma cells crowd out the other blood cells in the bone marrow, the number of red cells in the body decreases. This leads to symptoms of tiredness or fatigue
Because the myeloma cells crowd out normal white blood cells, which fight infection, there is a risk of infection. Symptoms of infection depend upon where the infection is located. Pneumonia, bladder or kidney infections, sinusitis and skin infections are common.
A high amount of calcium in the blood stream. When the bone is destroyed, calcium is released into the bloodstream. As the amount increases, the kidneys are unable to get rid of the calcium in the urine. Symptoms of hypercalcemia include thirst, nausea, constipation and mental confusion.
Having one or more of the symptoms listed above does not necessarily mean you have multiple myeloma. However, it is important to discuss any symptoms with your doctor, since they may indicate other health problems.
Blood and urine tests are needed to determine calcium levels and changes in the level of different abnormal proteins that myeloma produces. In the blood, these proteins are called “paraproteins” and in the urine, they are called “Bence-Jones proteins.” These paraproteins are measured in the blood by a test called serum protein electrophoresis (or SPEP). The Bence-Jones protein is measured in the urine by collecting a 24-hour urine sample and running a urine protein electrophoresis (or UPEP).
If these proteins cannot be detected by serum electrophoresis or by urine electrophoresis, an additional test, called immunofixation (or IFE), is performed to detect even small traces of these abnormal proteins.
Bone Marrow Aspiration
A bone marrow aspiration is used to determine the number of plasma cells present in the bone marrow. Normal bone marrow contains less than 5 percent plasma cells, whereas in myeloma, plasma cells account for more than 30 percent of cells being produced. However, it is important to know that multiple myeloma is considered a “spotty” disease, meaning that you can find a spot in your marrow that is packed with myeloma cells and move a few centimeters away and find a spot that is relative clean and free of myeloma cells.
Myeloma can be present as single or multiple tumors in the bone or soft tissue around the bone. These tumors are called plasmacytomas. Direct biopsy of one of these plasmacytomas usually shows 90-100 percent myeloma cells.
Bone X-rays or surveys will be done to look for lytic lesions or osteoporosis. Other more detailed tests may be required, such as a bone density scan, magnetic resonance imaging (MRI) or positron emission tomography (PET) scan. These tests may find very early or small lytic lesions missed by bone x-rays.
Once multiple myeloma is diagnosed, your doctor will determine the stage of the disease. Staging is a way of determining how much disease is in the body and where it is. The doctor needs this information to decide the best way to treat the cancer. Once staging is determined, it does not change regardless of response to chemotherapy or disease activity.
Multiple myeloma is staged using a system called Durie-Salmon Staging System. The system is based upon the number of bone lesions, the level of protein in the blood and/or urine and the blood calcium level.
Stage I: small amount of myeloma cells
Stage II: intermediate amount of myeloma cells
Stage III: large amount of myeloma cells
In addition, each stage is classified as “A” or "B" depending on kidney function. "A" means there is normal kidney function and “B” means abnormal kidney function. As you would expect, stage IIIB would require more urgent treatment to protect and/or recover kidney function.
Treatment generally depends on the stage of the disease, any previous treatments, and how well the patient has responded to previous treatment. Multiple myeloma is usually treated with chemotherapy, although radiation therapy may also be used to kill myeloma cells or to relieve pain in the spine and other areas. Some patients may require high-dose chemotherapy or radiation therapy followed by a stem cell transplant.
Chemotherapy destroys the myeloma cells directly. Chemotherapy may be given over a period of months. Most often chemotherapy may be received outside the hospital, but at times it may be necessary to receive it in the hospital. The drugs are given in cycles, giving the patient’s immune system and normal cells time to recover. By destroying the cancer cells, chemotherapy can also relieve many of the symptoms of the disease.
This is usually used to treat a specific area where there is bone destruction and pain. Radiation therapy can kill cancer cells more quickly than chemotherapy and has fewer side effects. For this reason, it is often used to get quicker pain relief and control severe bone loss.
New treatments are always being tested in clinical trials and some patients with cancer may want to consider participating in one of these research studies. These studies are meant to help improve current cancer treatments or obtain information on new treatments. Talk to your doctor about the clinical trials that may be right for you.