Myeloma, also known as multiple myeloma, is a type of bone marrow cancer arising from the plasma cells, which are normally found in the bone marrow. Plasma cells form part of your immune system.
Normal plasma cells produce antibodies (also called immunoglobulins) to help fight infection. In myeloma, the abnormal plasma cells release only one type of antibody known as paraprotien, which has no useful function. It is often through the measurement of this paraprotien that myeloma is diagnosed and monitored.
Bone marrow is the ‘spongy’ material found in the centre of larger bones in the body (see Figure 1). As well as being home to plasma cells, the bone marrow is the centre of blood cell production (red blood cells, white blood cells and platelets).
Myeloma affects multiple (hence multiple myeloma) places in the body where bone marrow is normally active in an adults, i.e. within the bones of the spine, skull, pelvis, the rib cage, and the areas around the shoulders and hips.
The areas usually not affected are the extremities: that is the hands, feet, and lower arm/leg regions. This is very important since the function of these critical areas is usually fully retained.
People affected by myeloma
Of the approximately 1,700 Australians who are diagnosed with myeloma each year, almost all are older than 40 years. Myeloma is most common in people aged 60 years and older, and men are affected more often than women.
Symptoms of myeloma
Most of the medical problems related to myeloma are caused by the build-up of myeloma cells in the bone marrow and the presence of the paraprotien in the blood or in the urine.
Common problems are bone pain, bone fractures, tiredness (due to anaemia), frequent or recurrent infections (such as bacterial pneumonia, urinary tract infections and shingles), kidney damage and a high level of calcium in the blood (hypercalcaemia).
Some people go on to develop myeloma after having being diagnosed with a benign (non-malignant) condition called MGUS which stands for Monoclonal Gammopathy of Undetermined Significance, This term describes the condition of the raised abnormal protein seen in myeloma (the paraprotien), but where there are no features of the disease (less than 10% plasma cells in bone marrow and no evidence of bone disease). The risk of transformation from MGUS to active myeloma is very low; only a 1% chance each year of follow-up. Even if the myeloma cells are at a higher level of 10-30% of the total bone marrow, the growth rate can be very slow and represent indolent/smouldering or asymptomatic myeloma.
Both these conditions can change very slowly over a period of years and do not require active treatment. It is very important to establish the correct diagnosis distinguishing MGUS and indolent myeloma from active or symptomatic myeloma, which does require treatment.
Causes of myeloma
Although a large amount of research has been done to investigate the potential causes of myeloma, nothing has been proven to date.
Exposure to certain chemicals, radiation, viruses and a weakened immune system are thought to be potential causal or trigger factors. It is likely that myeloma develops when a susceptible individual has been exposed to one or more of these factors. It is thought that susceptibility may increase with aging and the consequent reduction in immune function.
How myeloma is diagnosed
People suspected of having myeloma will usually need to have blood and urine tests, looking for evidence of paraprotien. X-rays or scans of the bones are also performed to determine if there are any areas of bone that have been weakened or eroded by the myeloma cells. A bone marrow biopsy – a test that involves taking a small sample of bone marrow, which is examined under a microscope to look for myeloma cells – is often required.
Treatment for myeloma
There have been many new developments in the treatment and management of myeloma over the last few years that have had a significant impact on the way myeloma is treated. Research is ongoing to develop new treatments and to use existing treatments in a better, more effective way.
Treatments for myeloma can be very effective at halting its progress, controlling the symptoms, and improving quality of life, but they are not able to cure it. Even after successful treatment, regular monitoring is needed in case the myeloma comes back.
In addition to the treatment you receive from your doctor, there are several things that you can do to make living with myeloma easier.
- There are in the region of 1,700 new cases per year in Australia
- About 10,000 people are living with myeloma at any one time
- Slightly more males than females will have myeloma
- Myeloma accounts for 15% of blood cancers and 1% of cancers generally
- Median age of onset is 70 and only 5-10% of patients are under 50