Multiple Myeloma Health Center
Multiple myeloma is a type of blood cancer (a hematologic cancer) that affects the plasma cells, a type of white blood cell that is responsible for making the antibodies for the immune system that mark bacteria, viruses, or other cancer cells for destruction and removal from the body. For reference, the different types of leukemia are also hematologic cancers that affect the white blood cells of the immune system.
In multiple myeloma, the cancerous plasma cells grow out of control and collect in the bone marrow, where they form tumors that interfere with the normal production of other blood cells and platelets. Most cases of multiple myeloma also produce a protein called paraprotein, which causes kidney disease as well.
The exact cause of multiple myeloma is unknown, but it likely begins like many other cancers, with one abnormal mutated plasma cell that then divides and produces other cancer cells in greater numbers. The uncontrolled growing plasma cells circulate around the rest of the body and damage multiple tissues. Research has shown an association with multiple myeloma and a genetic abnormality on chromosome 14 in about 50% of patients, and also an abnormality on chromosome 13 in about 50% of patients.
The disease is twice as common in African-Americans than in Caucasians, making it one of the top ten causes of cancer death in the African-American population. The peak age of onset is between age 60 and 70, and the disease is more common in men than in women. Additional risk factors include obesity, and having a history of another disease called monoclonal gammopathy of undetermined significance (MGUS, a benign disease where there are paraprotein antibodies in the blood, but they do not cause symptoms or problems).
Initial symptoms of multiple myeloma can vary and affect multiple parts of the body, but the most common symptoms will be anemia (low red blood cell counts, easy bruising and bleeding) and bone pain. The bone pain in multiple myeloma happens because a protein activates normal bone cells called osteoclasts, which act to resorb normal bone, causing a ‘punched out’ appearance on bone x-rays. These bones are then more susceptible to fracture, and the bone resorption also causes there to be too much calcium in the blood (hypercalcemia), which can cause weakness, confusion, fatigue, and most importantly kidney failure. Other symptoms include an increased susceptibility to infection and neurological symptoms such as nerve pain, loss of bowel and bladder control, headaches, and retinopathy.
Diagnosis will include blood tests to look for the presence of anemia, the presence of paraprotein, and evidence of kidney problems. A skeletal survey will also be done to look for the presence of bone lesions in the skull, vertebrae, hips and long bones of the extremities. This can be done with an X-ray, a CT, or an MRI. A bone marrow biopsy may be performed to help determine the stage of the disease.
Treatment for multiple myeloma depends on the stage of the disease and how aggressive it is. Some people have such slow growing asymptomatic disease that treatment may be delayed for years. Other patients will be treated with chemotherapies. In relatively healthy patients, chemotherapy may be followed by a bone marrow transplant, often from the patient’s own stem cells. Some people can get a bone marrow transplant from another donor, but this is rare. Older patients and sicker patients may not be able to tolerate bone marrow transplant, so these patients may be additionally treated with more chemotherapy.
It is the natural course of the disease for multiple myeloma to relapse after treatment, as chemotherapy and bone marrow transplants will rarely lead to a full cure. Your doctor may choose to try the same treatments again, or try something different to prevent treatment resistance.
Median survival (the midpoint of all patients, not the average) for patients after chemotherapy is 3.5 years, and 4.5 years if they’ve also had a bone marrow transplant. Average survival depends on the other diseases a patient might have, and how aggressive the disease is.