What is it?
Myeloma, also known as multiple myeloma, is a cancer of plasma cells. Plasma cells are mature lymphocytes, a type of white blood cell, that help fight infection by producing special proteins called antibodies or immunoglobulins. In myeloma, large numbers of abnormal plasma cells called myeloma cells are made in the bone marrow. These myeloma cells multiply abnormally, without any proper order, forming collections known as tumors that accumulate in different parts of the body, especially in the bone marrow and on the surfaces of different bones in the body. These tumours secrete chemicals that stimulate other bone marrow cells (osteoclasts) to remove calcium from the bone. As a result bones can become weaker, more brittle and prone to breakage. They also collect in the bone marrow preventing it from making normal red cells, white cells and platelets. Over time people with myeloma can become anaemic, more susceptible to infections and to bleeding and bruising more easily.
Myeloma cells typically produce an abnormal type of immunoglobulin called paraprotein or M protein, which can be detected in the blood and urine. Excessive amounts of paraprotein can cause problems in the body, such as kidney damage.
How common is it?
Each year in Australia around 1,500 people are diagnosed with myeloma.
Who gets it?
The risk of developing myeloma increases with age. Almost 80% of all new cases are diagnosed in people over the age of 60. Myeloma is uncommon in people under 40. It occurs more frequently in men than in women.
What causes myeloma?
The cause of myeloma remains unknown but it may result from damage to one or more of the genes that normally control blood cell development. In a small number of cases, exposure to high doses of radiation and ongoing exposure to certain industrial or environmental chemicals may increase the risk of myeloma. Some people with monoclonal gammopathy of undetermined significance (MGUS), a non-malignant (non-cancerous) condition, will eventually go on to develop myeloma.
What are the symptoms?
The most common symptom of myeloma is bone pain. This is usually felt in the back or ribs and may be made worse by movement. Other symptoms are caused by a lack of normal blood cells and include:
- anaemia, due to a lack of red cells; causing persistent tiredness, dizziness, paleness, or shortness of breath when physically active,
- frequent or repeated infections and slow healing, due to a lack of normal white blood cells, especially neutrophils,
- increased or unexplained bleeding or bruising due to a very low platelet count.
How is it diagnosed?
Myeloma is diagnosed using information gathered from a number of different tests. These include a physical examination, blood and urine tests, a bone marrow biopsy, x-rays and other more specialised bone imaging tests.
How is it treated?
The treatment for myeloma depends on a number of factors including the stage of your disease, your general health and your age. Although there is currently no cure for myeloma, treatment can be successful in controlling the disease, sometimes for several years.
People diagnosed with early stage disease, smouldering myeloma, don't have any symptoms and don't need treatment straight away. Treatment may be given at a later stage, when the disease progresses after some months or years. In these cases the doctor may recommend regular checkups, including blood and urine tests, to carefully monitor their health.
Chemotherapy, usually in combination with cortico-steroids, may be given to control the growth of myeloma. Treatment is given until the myeloma reaches a stable or plateau stage, where the amount of myeloma in the body is reduced to as low a level as possible. Once the myeloma is controlled more treatment is needed to prolong the remission for as long as possible. There are several treatments used, including cortico-steroids (prednisone / prednisolone), interferon and thalidomide. Thalidomide may also be used in the initial treatment of myeloma and to control myeloma that has come back (relapsed).
There are several options for treating relapsed myeloma. These include more chemotherapy, thalidomide and bortezomib (Velcade®).
Drugs called bisphosphonates are commonly used to prevent and treat complications due to bone damage. These drugs can help to re-strengthen the bone and reduce risk of fractures, therefore protecting them from the damaging effects of myeloma. By preventing bone destruction, these drugs also help to reduce bone pain, and hypercalcaemia (excess calcium in the blood), which can result from bone breakdown.
High dose chemotherapy followed by stem cell transplantation is used to treat some people with myeloma, who have no other serious illnesses. Promising new and experimental treatments are being developed all the time. Some of these treatments are currently being used in clinical trials in Australia and other parts of the world. Your doctor will be able to discuss with you all of the treatment options suitable for you.
Side-effects of treatment
All treatments can cause side-effects. The type and severity however will vary between individuals, depending on the type of treatment used and how an individual responds to it. In general, more intensive treatment is associated with more severe side-effects. It is important to report any symptoms you are having to your doctor or nurse. In most cases they can be treated and are reversible.
Your doctor and nurse will discuss with you the possible side-effects of any treatments you need and how they can be managed.