Risks and causes of myeloma

We don’t know what causes most cases of myeloma. But there are some risks factors that can increase your risk of developing it. These include being older, being overweight and having certain medical conditions.

Anything that can increase your risk of getting a disease is called a risk factor.

Different cancers have different risk factors.­ Having one or more of these risk factors doesn't mean you will definitely get that cancer.

Being overweight or obese

The risk of myeloma is higher in people who are overweight Open a glossary item or obese Open a glossary item. This is compared to people with a healthy body weight. 

Age

As with most other cancers, the risk of myeloma increases as you get older. It is very rare in people under 40.

Monoclonal gammopathy of undetermined significance (MGUS)

Some people with myeloma already have a rare medical condition called MGUS. MGUS stands for monoclonal gammopathy of undetermined significance.

MGUS means there are too many large protein molecules (immunoglobulins) in the blood. Doctors often find MGUS by chance as it can show up in routine blood tests. 

In most people MGUS doesn't cause any symptoms or need treatment. 

MGUS does not usually need treatment. Some people with MGUS go on to develop myeloma, so your specialist or GP will see you regularly for check ups. About 1 out of 100 people with MGUS (1%) develop myeloma each year.

Family history

You have a higher risk of myeloma or MGUS if you have a close relative with myeloma or MGUS. A close relative means a parent, brother, sister or child. This is compared to people with no close family members with these illnesses. 

It is not clear as to why there is an increased risk. We need more research to fully understand how family history affects your risk of myeloma. Myeloma is rare. It is unusual for a family to have more than one member of a family with myeloma.

Some medical conditions

An autoimmune condition called pernicious anaemia appears to increase the risk of myeloma and MGUS. 

Gender

Myeloma is slightly more common in men than women. It's not clear why this is and there may be many factors involved including genetics and lifestyle.

Ethnicity

There is some evidence that myeloma is more common in Black people than in White people. It’s not clear why this is. 

Other possible causes

Stories about potential causes are often in the media and it isn’t always clear which ideas are supported by evidence. There might be things you have heard of that we haven’t included here. This is because either there is no evidence about them or it is less clear.

For detailed information on myeloma risks and causes

  • The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015
    K Brown and others
    British Journal of Cancer, 2018. Volume 118, Pages 1130-1141

  • The population impact of familial cancer, a major cause of cancer
    C Frank and others
    International Journal of  Cancer, 2014. Volume 134, Issue 8, Pages 1899-906

  • Risk of MGUS in relatives of multiple myeloma cases by clinical and tumor characteristics
    A Clay-Gilmour and others
    Leukaemia 2019. Volume 33, Issue 2, Pages 499-507

  • HIV Infection, Immunosuppression, and Age at Diagnosis of Non-AIDS-Defining Cancers
    M Shiels and others 
    Clinical Infectious Diseases, 2017. Volume 64, Issue 4, Pages 468-475

  • Anthropometric characteristics, physical activity and risk of hematological malignancies: A systematic review and meta‐analysis of cohort studies
    T Psaltopoulou, TN Sergentanis and others
    International Journal of Cancer, 2019. Volume 145, Issue 2, Pages 347-359 

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. If you need additional references for this information please contact patientinformation@cancer.org.uk with details of the particular risk or cause you are interested in.

Last reviewed: 
03 Nov 2023
Next review due: 
03 Nov 2026

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