Do We Know What Causes Soft Tissue Sarcomas?

Scientists still don't know exactly what causes most cases of soft tissue sarcoma, but they have found several risk factors that can make a person more likely to develop these cancers. And research has shown that some of these risk factors affect the DNA of cells in the soft tissues.

Researchers have made great progress in understanding how certain changes in DNA can cause normal cells to become cancerous. Our DNA carries the instructions for nearly everything our cells do. We usually look like our parents because they are the source of our DNA. However, DNA affects more than the way we look.

The DNA is divided into units called genes. Genes carry the recipes for making proteins, the molecules that determine all cell functions. Some genes contain instructions for proteins that control when our cells grow and divide.

Certain genes that promote cell division are called oncogenes. Others that slow down cell division or cause cells to die at the right time are called tumor suppressor genes. Cancers can be caused by DNA mutations (defects) that turn on oncogenes or turn off tumor suppressor genes.

Several family cancer syndromes have been found in which inherited DNA mutations cause a very high risk of developing breast, colon, kidney, eye, or other cancers. In some of these, there is also an increased risk of developing soft tissue sarcomas (these were noted in What Are the Risk Factors for Soft Tissue Sarcomas?) They are caused by defects (mutations) in genes that can be inherited from a parent. These gene defects can be found through testing. For more on this topic, see Family Cancer Syndromes and Genetics and Cancer.

DNA mutations in soft tissue sarcoma are common. They are usually acquired during life rather than having been inherited before birth. Acquired mutations may result from exposure to radiation or cancer-causing chemicals. In most sarcomas, they occur for no apparent reason.

Researchers still do not know why most soft tissue sarcomas develop in people who have no apparent risk factors.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: December 29, 2014 Last Revised: February 9, 2016

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