Multiple myeloma is the second most common blood cancer worldwide affecting approximately 150,000 people. About 74,000 new cases of multiple myeloma are diagnosed each year. The disease preferentially occurs in elderly people and affects more men than women.
Multiple myeloma is a cancer of plasma cells, a type of white blood cell in the bone marrow and peripheral blood which are key elements of the immune system and normally make proteins called antibodies to fight infections. In multiple myeloma, a group of abnormal plasma cells (myeloma cells) proliferates in an uncontrolled fashion, raising their numbers to a higher than normal level. These myeloma cells produce antibodies or part of antibodies (M protein, monoclonal protein, paraprotein) in large amounts which are excreted by the kidney and can be detected in the urine. Clinical symptoms of multiple myeloma result from this uncontrolled proliferation of plasma cells in the bone marrow and are:
- reduced red blood cell production (anemia) and fatigue
- destruction of the bone marrow resulting in bone pain and fractures and
- in a small proportion in kidney damage due to excretion of this abnormal protein.