In most cases, the cause is unknown. Several risk factors have been identified that increase the likelihood of developing a soft tissue sarcoma.
- External radiation therapy is the most well-established risk factor. Patients treated with radiation therapy for cancers of the breast, cervix, ovary, testes, retina, or lymphatic system have a much higher chance of developing a soft tissue sarcoma than the general population.
The risk appears to be related to the dose of radiation. To limit this risk, radiation treatment for cancer is planned to ensure that the greatest amount of radiation is delivered to diseased tissue while surrounding healthy tissue is protected as much as possible.
- Another risk factor for soft tissue sarcomas is exposure to certain chemicals in the workplace, including:
- vinyl chloride
- herbicides such as phenoxyacetic acids
- wood preservatives that contain chlorophenols
- A genetic disposition for the development of soft tissue sarcoma has been shown for several inherited diseases:
- Li-Fraumeni syndrome (associated with alterations in the p53 tumor suppressor gene)
- von Recklinghausen disease (also called neurofibromatosis type 1 and associated with alterations in the NF1 gene)
- hereditary leiomyomatosis and renal cell cancer syndrome (with alterations in the FH gene)
- hereditary retinoblastoma (with alterations in the RB1 gene)
Patients with these disorders are all at risk of developing soft tissue sarcomas.
- Chronic lymphedema following radiation to, or surgical removal of lymph nodes, is also a risk factor.