Risk factors and causes of soft tissue sarcomas

Although the causes of soft tissue sarcomas are unknown, research is going on to try to find out more. Sarcomas, like other cancers, are not infectious and can’t be passed on to other people.


Sarcomas can occur at any age but are more common as people get older. About 4 out of 10 people (40%) that are diagnosed with a soft tissue sarcoma are over 65.

Genetic conditions

Most sarcomas are not caused by an inherited faulty gene that can be passed on to other family members. Members of your family are not likely to have an increased risk of developing a soft tissue sarcoma because you have one.

However, people who have some rare inherited genetic conditions are more at risk of developing a sarcoma. These conditions include:

  • neurofibromatosis
  • Gardner’s syndrome
  • Li-Fraumeni syndrome
  • retinoblastoma.

You would normally know if you had one of these conditions and your doctor would check you regularly for any sign of a sarcoma.

Previous radiotherapy treatment

Very rarely, a soft tissue sarcoma will occur in a part of the body that has previously been treated with radiotherapy for another type of cancer. The sarcoma will not usually develop until at least 5–10 years after the radiotherapy treatment. To reduce the risk, radiotherapy is very carefully planned. Improvements in the way radiotherapy is given mean that the risk of developing a sarcoma is very small.

Exposure to chemicals

The development of some sarcomas may be linked to exposure to some types of chemicals. These include:

  • vinyl chloride, which is used for making plastics
  • some types of herbicides (weedkillers)
  • dioxins, which are a waste product made during the manufacture of chemicals and fertilisers.


There is no evidence that an injury can cause a soft tissue sarcoma to develop. It is possible that an injury may draw attention to a sarcoma that was already there and not causing any symptoms, but the sarcoma will have taken many years to develop.

Back to Diagnosing

How cancers are diagnosed

You might notice changes in your body. There are lots of possible causes for different symptoms, so it’s important to know what to look out for. If your doctor wants to find out more they might organise different tests or scans.