Information about the prevention of cancer and the science of screening appropriate individuals at high risk of developing cancer is gaining interest. Physicians and individuals alike recognize that the best “treatment” of cancer is preventing its occurrence in the first place or detecting it early when it may be most treatable.

The chance of an individual developing cancer depends on both genetic and non-genetic factors. A genetic factor is an inherited, unchangeable trait, while a non-genetic factor is a variable in a person’s environment, which can often be changed. Non-genetic factors may include diet, exercise, or exposure to other substances present in our surroundings. These non-genetic factors are often referred to as environmental factors. Some non-genetic factors play a role in facilitating the process of healthy cells turning cancerous (i.e. the correlation between smoking and lung cancer) while other cancers have no known environmental correlation but are known to have a genetic predisposition, meaning a person may be at higher risk for a certain cancer if a family member has that type of cancer.

Heredity or Genetic Factors in Ewing Sarcoma

At the present time, there is no known relationship between inherited genetic alterations and the majority of cases of Ewing’s sarcoma.  However, the majority of Ewing’s sarcomas are associated with a chromosomal rearrangement involving chromosome 11 and chromosome 22.[[1]]( "_ednref1") This rearrangement changes the position and function of genes, causing a fusion of genes referred to as a “fusion transcript.” Over 90 percent of individuals with Ewing’s sarcoma have an abnormal fusion transcript involving two genes known as EWS and FLI1. This important discovery has led to improvements in diagnosing Ewing’s sarcoma. Unfortunately, no one knows what is responsible for these chromosomal rearrangements or how to prevent them.

Environmental or Non-Genetic Factors

Some of the suggested risk factors for developing Ewing’s sarcoma are White race, parental occupation, parental smoking and surgery for inguinal hernia.[[2]]( "_ednref2") Ewing’s is very rare in children of African or Asian decent.  Hernias and Ewing’s sarcoma may share a common embryologic pathway; both conditions may be affected by genetic factors or in-utero (before birth) exposures to toxins. With regard to parental occupation, it has been suggested by several investigators that certain occupations, particularly farming, may increase the risk of Ewing’s sarcoma in the workers’ children. A study from Australia found that an increased incidence of Ewing’s sarcoma in children whose mothers worked on farms around the time of conception and during pregnancy.[[3]]( "_ednref3") The risk doubled when the mothers handled pesticides and insecticides. The same relationship was true for fathers, but was less significant.

Screening and Early Diagnosis of Ewing Sarcoma

For many types of cancer, progress in the areas of cancer screening and treatment has offered promise for earlier detection and higher cure rates. The term screening refers to the regular use of certain examinations or tests in individuals who do not have any symptoms of a cancer but are at high risk for that cancer. When individuals are at high risk for a type of cancer, this means that they have certain characteristics or exposures, called risk factors that make them more likely to develop that type of cancer than those who do not have these risk factors. The risk factors are different for different types of cancer. An awareness of these risk factors is important because 1) some risk factors can be changed (such as smoking or dietary intake), thus decreasing the risk for developing the associated cancer; and 2) persons who are at high risk for developing a cancer can often undergo regular screening measures that are recommended for that cancer type. Researchers continue to study which characteristics or exposures are associated with an increased risk for various cancers, allowing for the use of more effective prevention, early detection and treatment strategies.

In the case of Ewing’s sarcoma, the disease occurs rarely and risk factors are poorly understood. Currently, there are no effective screening tools available.


[[1]]( "_edn1") Dagher R, Pham TA, Sorbara L, et al, Molecular confirmation of Ewing sarcoma. J Pediatric Hematology Oncology. 2001;23:221-224.

[[2]]( "_edn2") Ferris, ITJ, Berbel TO, Ortega GJA, et al. Risk factors for pediatric malignant bone tumors. An Pediatr (Barc). 2005;63:537-547.

[[3]]( "_edn3") Valery PC, McWhirter W, Sleigh A, et al. Farm exposures, parental occupation, and risk of Ewing’s sarcoma in Australia: a national case-control study. Cancer Causes Control. 2002;13:263-270.