Which are the causes of Ewings sarcoma?

Ewing's sarcoma is a rare type of cancer that primarily affects children and young adults. It was first described by James Ewing, an American pathologist, in 1921. This aggressive tumor usually arises in the bones, but it can also develop in soft tissues. The exact cause of Ewing's sarcoma is not yet fully understood, but several factors have been identified as potential contributors to its development.

Genetic Factors:

Genetic abnormalities play a significant role in the development of Ewing's sarcoma. The majority of cases (about 85%) are characterized by a specific chromosomal translocation known as t(11;22)(q24;q12). This translocation involves the fusion of two genes: EWSR1 on chromosome 22 and FLI1 on chromosome 11. The resulting fusion gene, EWSR1-FLI1, produces an abnormal protein that disrupts normal cellular processes and promotes the growth of cancer cells. Other less common translocations involving related genes, such as EWSR1-ERG, have also been observed in a small percentage of cases.

Environmental Factors:

While genetic factors are important, environmental exposures may also contribute to the development of Ewing's sarcoma. However, specific causative agents have not been definitively identified. Some studies have suggested a potential link between exposure to ionizing radiation and an increased risk of developing Ewing's sarcoma. This is supported by the higher incidence of the disease among individuals who have undergone radiation therapy for other cancers. Additionally, certain chemicals and toxins, such as benzene and pesticides, have been implicated as potential risk factors, but further research is needed to establish a clear association.

Age and Gender:

Ewing's sarcoma primarily affects children and young adults, with the peak incidence occurring during the teenage years. It is relatively rare in adults over the age of 30. The reasons for this age distribution are not fully understood, but it may be related to the rapid growth and development of bones during childhood and adolescence. Furthermore, Ewing's sarcoma is slightly more common in males than females, although the reasons for this gender disparity remain unclear.

Family History:

There is evidence to suggest that a small percentage of Ewing's sarcoma cases may have a familial predisposition. Individuals with a first-degree relative (such as a sibling or parent) who has had Ewing's sarcoma may have a slightly higher risk of developing the disease themselves. However, the overall contribution of genetic factors to the development of Ewing's sarcoma is still being investigated, and most cases occur sporadically without a family history.

Other Factors:

Several other factors have been proposed as potential contributors to the development of Ewing's sarcoma, although their roles are not yet well understood. These include certain growth factors and signaling pathways that regulate cell growth and differentiation. Additionally, some studies have suggested a potential association between viral infections, such as Epstein-Barr virus (EBV) and human herpesvirus 8 (HHV-8), and the development of Ewing's sarcoma. However, more research is needed to establish a definitive link.

In conclusion, Ewing's sarcoma is a complex disease with multiple potential causes. Genetic factors, particularly chromosomal translocations involving the fusion of specific genes, play a significant role in its development. Environmental factors, age, gender, and family history may also contribute to the risk of developing this rare cancer. Further research is needed to better understand the interplay between these factors and to identify additional causes that may be involved.