Myeloma is the final major category of blood cancer. Myeloma begins in the bone marrow and impacts certain white blood cells called plasma cells. Plasma cells produce antibodies, which are proteins that assist the body in ridding itself of harmful substances. Each plasma cell responds to one specific substance by producing one kind of antibody. The body has many types of plasma cells and, therefore, can respond to many types of substances. When cancer occurs, the body overproduces abnormal plasma cells, known as myeloma cells. Myeloma cells collect in the bone marrow and the outer layer of the bone.
Myeloma survivors in the United States are estimated to total more than 69,000, with over 21,700 new cases and 10,700 deaths a year. As we will discuss later, the blood and lymph systems play a central role in cancer development and eradication.
There are several forms of myeloma identified by the areas of the body impacted and the rate of progression. Most patients, about 90%, have multiple myeloma, meaning the disease is in multiple areas of the body by the time of diagnosis. The disease is most common in older individuals—the medium age at diagnosis is 70 years—but younger people can have myeloma too. Many times, it is a broken bone that leads a patient to seek treatment and that results in the diagnosis.
The most common sign of myeloma is bone fractures and bone pain without an apparent reason. Pain is most common in the back or ribs, but it can occur in other bones. The pain is usually made worse by movement. Other symptoms may include: weakness; fatigue; pale skin; recurring infections; neuropathy (numbness, tingling, burning or pain) in the hands or feet; increased thirst or urination; constipation; and kidney failure. Hyperviscosity syndrome is associated with myeloma. This may cause blurry vision, headaches, chest pain, abnormal bleeding, or shortness of breath.
There are various treatments for myeloma. Drugs include bortezomib (Velcade), thalidomide (Thalomid), dexamethasone (Decadron), lenalidomide (revlimid), Melphalan (Alkeran) which sometimes are used as single agents, but more often in various combinations. In addition, autologous stem cell transplants (sometimes tandem transplants) often are a component of treatment. There appears to be a role for maintenance therapy. There is no standard maintenance therapy at present, but research is ongoing and promising. Radiation therapy is used sometimes as a first-line treatment for patients whose myeloma is localized, in preparation for a stem cell transplant, or in carefully selected patients whose bone pain does not respond to chemotherapy. Carfilzomib (kyprolis) has been approved to treat refractory patients with multiple myeloma who have received at least two prior therapies.