Multiple myeloma is a form of cancer that affects the bone marrow. The cancer is also called Kahler’s disease, named after an Austrian pathologist called Otto Kahler who first described the condition.
The bone marrow is the spongy soft tissue that lies within the hollow centre of some bones. The bone marrow contains stem cells that produce three forms of blood cells: the red blood cells (RBCs) that transport oxygen to cells in the body; the white blood cells (WBCs) involved in fighting infection; and platelets which are essential for blood clotting and healing processes.
In multiple myeloma, the plasma cells or plasmocytes which secrete antibodies become abnormal and are produced in large numbers. These abnormal plasma cells or myeloma cells produce large amounts of an abnormal antibody (immunoglobulin) called paraprotein or M protein. This abnormal immunoglobulin is not effective at fighting infection and also interferes with the production of normal immunoglobulins.
Myeloma does not form a lump or tumour as the myeloma cells proliferate and spread throughout the bone marrow. This eventually damages the bone and causes it to become thin, painful and prone to fracture.
The disease is called multiple myeloma because it effects various sites in the body. Some examples of the areas that may be affected include:
Areas around the hips and shoulders
The legs and arms
In the early stages of disease, few or no symptoms may be present and the condition is often only suspected or detected following routine blood or urine tests. As the condition progresses, however, symptoms such as fatigue, weight loss, bone pain and susceptibility to bone fracture eventually manifest.
Diagnosis is usually based on blood test results that indicate abnormally high levels of proteins and the presence of cancer cells. Urine is checked for the presence of the abnormal proteins produced by myeloma cells. These proteins can damage the kidneys and a urine test can indicate the level of the proteins present as well as showing how well the kidneys are working. A bone marrow biopsy is usually performed to confirm a diagnosis and usually involves a small bone sample being removed from a patient’s pelvis.
Multiple myeloma is not usually curable and treatment is therefore aimed at delaying the progression of the cancer for as long as possible. Treatment primarily involves anti-myeloma treatments to remove the abnormal cells from the bone marrow, relieving any symptoms such as anemia and bone pain, and minimizing the risk of fracture by using treatment to protect the bones.
Reviewed by Sally Robertson, BSc