Introduction to multiple myeloma (MM)
Myeloma is a form of cancer which affects plasma cells. These are a specialised type of lymphocyte, which in turn is one type of white blood cell. They are normally responsible for producing antibodies as part of the body’s reaction to infection.
Myeloma does not affect children and the condition becomes more common as you get older. Myeloma is treatable but is not generally considered curable.
People who have myeloma often have bone damage and, for this reason, myeloma is sometimes referred to as bone cancer. The condition is called multiple myeloma because there are commonly several separate areas of bone damage. It mainly affects the bone marrow, which is the tissue inside bones where blood cells are produced and is the reason why patients may have anaemia, bleeding and repeated infections.
Myeloma cells almost always produce an abnormal protein. High levels of this protein, which is called paraprotein, may cause kidney damage. The paraprotein level is often measured to assess how the condition is responding to treatment.
Myeloma is divided into two main groups:
- Smouldering or asymptomatic myeloma (where there are no symptoms or tissue damage caused by the myeloma)
- Symptomatic myeloma (where there are symptoms and/or tissue damage)
About 3 out of 10 patients with myeloma are diagnosed at a time when they have no symptoms. The most common symptom which you are likely to have experienced is back pain. Back pain is very common but there are some differences in back pain caused by myeloma. If you have myeloma, you are likely to have pain even after resting and to be worse at night and on moving which may cause you to wake up. Back pain associated with myeloma is often worse when lying on your back and the pain may not go away when you take standard painkillers.
You will usually have abnormal proteins called paraproteins in your blood and possibly in your urine. These proteins are similar to antibodies, which are molecules your body produces to fight infection. Unlike antibodies, which are a mixture of different kinds of molecules, a paraprotein is a protein produced by a single family of specialised cells that normally make an antibody against infections, but in myeloma these paraproteins have no useful function. If the levels of paraprotein are high there is a risk of damage to your kidneys and “thickening” of the blood, making patients tired and lethargic. Paraprotein levels may be measured to help assess how your condition is responding to treatment.
If you have been found to have myeloma but you have no symptoms (asymptomatic or smouldering myeloma) you are unlikely to receive treatment straight away. The main types of treatment for myeloma are the use of anti-cancer drugs (chemotherapy) and for patients who are otherwise fit and well, stem cell transplantation. You may also receive local radiation treatment (radiotherapy).
Within the last decade a number of new drugs have been introduced for treatment of myeloma; these are called novel agents, even though their use is now well established. Novel agents are thalidomide, bortezomib (Velcade™) or lenalidomide (Revlimid™). Standard practice for treating newly diagnosed patients is to include at least one novel agent.
The bone damage caused by myeloma can be improved or blocked by drugs called bisphosphonates. These are normally given to all patients from the time of diagnosis, even if you are having no other treatment.