Blood is pumped around the body by the heart. It carries important nutrients and oxygen to the organs and tissues of the body. The blood is made of different types of cells.
- Red blood cells are filled with haemoglobin, which picks up oxygen from the lungs and carries it around the body.
- White blood cells kill bacteria and other invaders and help cure infection.
- Platelets are small cells that help stop bleeding if a person is injured.
- Plasma cells are made by lymphocytes-a type of white blood cell. Plasma cells make antibodies, which help to repair damaged cells and fight infection.
Blood cells and plasma cells are made in bone marrow (the spongy inside of bones). They all begin as stem cells. When cells mature, they enter the bloodstream.
Multiple myeloma is cancer of the plasma cells in bone marrow. Normally, the body makes as many plasma cells as it needs. When a person has multiple myeloma, too many plasma cells are made. This causes overcrowding in the bone marrow, which prevents adequate numbers of normal blood cells forming.
The abnormal plasma cells produce antibodies called M-protein (often called Bence-Jones protein or paraprotein). At the same time, the formation of normal antibodies is reduced making a person less able to fight infection.
Multiple myeloma spreads from the bone marrow into the bone. This can result in deposits in the bone called lytic lesions or can cause the bone to become thin, weak and more likely to break ( osteoporosis). The breakdown of the bone can cause an increase in the level of calcium in the blood ( hypercalcaemia). It can also affect the kidneys so that they cannot filter and clean the blood properly.
Causes of multiple myeloma
The cause or causes of multiple myeloma are not yet known.
Cancer is not contagious, so you cannot pass it on to other people.
How common is multiple myeloma?
Multiple myeloma is an uncommon cancer. It is rarely seen in people under 40 years of age. About 300 people are diagnosed with multiple myeloma in Victoria each year.
More information on multiple myeloma from the Leukaemia Foundation
Expert content reviewers:
Prof. Miles Prince MBBS (Hons) MD MRACMA FRACP FRCPA, Chair, Clinical Cancer Services; Professor, University of Melbourne; Director, Centre For Blood Cell Therapies, Peter Mac