Multiple myeloma - Causes of multiple myeloma

In multiple myeloma, it's not known what causes the plasma cells inside the bone marrow to become cancerous.

However, research has shown that some people who develop multiple myeloma have previosly had a rare condition called monoclonal gammopathy of unknown significance (MGUS).

MGUS

A person with MGUS has an excess number of protein molecules called immunoglobulins in their blood. The condition does not cause any symptoms and treatment is not required.

Some people with MGUS later develop myeloma, so if the results of routine blood tests show that you have MGUS, you will be referred to a specialist for regular check-ups.

Family history

Research has also shown that if you have a close relative (a parent, brother, sister or child) with myeloma or MGUS, you are two to three times more likely to develop myeloma or MGUS compared to someone with no family history of these conditions.

Lowered immunity

If you take medicines that lower your immunity, your risk of developing myeloma is thought to increase by up to three times compared to someone who does not take immunity-lowering medication.

Your risk of getting myeloma is also increased if you have a condition that lowers your immunity, such as HIV or AIDs.

Weight and diet

If you are overweight or obese, you may have a slightly increased risk of developing myeloma compared to someone with a healthy weight.

However, diet does not appear to have any bearing on myeloma risk, although the evidence in this area is limited.

Exposure to chemicals

Some studies have suggested that people who work in certain occupations may have an increased risk of developing myeloma as a result of being exposed to certain chemicals.

The occupations identified as possibly having an increased risk are:

• the petrol or oil industry
• farming
• wood working
• the leather industry
• painting and decorating
• hairdressing
• rubber manufacturing
• fire-fighting

However, the research in this area is limited and there is insufficient evidence to show that these occupations carry an increased risk of myeloma.

Radiation exposure

Studies have also suggested that people who are exposed to high levels of radiation may have an increased risk of developing myeloma (as is the case with other types of cancer).

Medicines

Small-scale studies have suggested that using paracetamol, insulin, or medicines used to treat gout may increase your myeloma risk.