What causes Ewing’s sarcoma?

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The cause of Ewing’s sarcoma is not currently known. However, as it commonly develops in adolescents it is thought that it may relate in some way to the rapid growth of bones.

There are no known inherited risk factors for developing Ewing’s sarcoma, but the disease is characterised by a specific genetic abnormality.

In approximately 85% of patients, a specific gene on chromosome 22 (called the Ewing’s Sarcoma RNA-Binding Protein 1 – EWSR1) translocates (moves to join) with a gene on chromosome 11 (called FLI1). This is called the EWSR1-FLI1 translocation and it is this genetic abnormality that causes Ewing’s sarcoma cells to grow and form tumours.

The EWSR1-FLI1 protein can be detected in tumour specimens and so helps to diagnose Ewing’s sarcoma. EWSR1 can be involved in other translocations with other chromosome locations, causing Ewing sarcoma, but these are much rarer.

There are no particular risk factors for developing Ewing’s sarcoma, although it does occur more frequently in males and with different incidence rates between ethnicities; so that it is almost exclusively a disease of Caucasians, while being extremely rare in those of African or Asian descent.

Some researchers believe that environmental triggers may contribute to the development of Ewing’s sarcoma.

Small studies have shown that incidence rates (the number of new cases of a disease per year) vary by geographical location. For example, within the UK, there are slightly higher rates of Ewing’s sarcoma in more rural populations. However, there are no known specific environmental factors that are known to contribute to the development of the disease.

Produced: November 2015

Published: February 2016

Review: November 2018

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