Multiple myeloma

Multiple myeloma is an uncommon bone marrow cancer that affects plasma cells, which are the cells found in bone marrow.

Plasma cells

Plasma cells are found in all bone marrow. They produce antibodies called immunoglobulin that the immune system uses to fight infection. 

In cases of multiple myeloma, the plasma cells become damaged and begin to release abnormal immunoglobulins called paraproteins.

The cancerous plasma cells also quickly reproduce and spread through affected bones, which damages the outer casing of the bone and leads to symptoms of bone pain and bone weakness.

The cancerous plasma cells also interfere with the production of blood cells in the bone marrow. There are three types of blood cell:

• red blood cells - which carry oxygen around the body,
• white blood cells - which help fight infection, and
• platelets - which help stop bleeding.

A lack of red blood cells means that the body is not getting enough oxygen and can cause a person to become very tired and out of breath. This is known as anaemia.

A lack of infection-fighting white blood cells makes a person more vulnerable to infection. A lack of platelets means that a person is at risk of excessive bleeding.

Myelomas usually affect multiple bones (hence the name multiple myeloma) where there is a high concentration of bone marrow. For example:

• the spine,
• skull,
• pelvis,
• rib cage,
• shoulder blades, and
• hip bones.

How common is multiple myeloma?

Multiple myeloma is an uncommon type of cancer that accounts for about 1% of all cases of cancer.

In the UK, it is estimated that there are 3,500 new cases of multiple myeloma diagnosed each year, and that there are currently 10,000-15,000 people living with multiple myeloma.

Multiple myeloma mostly affects people who are over 40 years of age, with the average age at diagnosis being 70.

For reasons that are unclear, rates of multiple myeloma are twice as high in black people than in white people.

The cause of multiple myeloma is unknown.

Outlook

Although there is no cure for multiple myeloma, treatment can be used to control the progression of cancer for several and, in some cases, many years. Treatments include chemotherapy and stem cell transplantation (also known as bone marrow transplantation).

A number of new and promising medications have recently been used to treat multiple myeloma and they work by encouraging the immune system to attack cancerous cells. These types of medication are known as immunomodulators.

The outlook for multiple myeloma can be significantly different for different individuals. For example, some people will die within several months of receiving a diagnosis, while other people can live up to 12 years.

After receiving a diagnosis of multiple myeloma, the average survival rate is three years.