Causes, Risk Factors, and Prevention of Soft Tissue Sarcomas

Radiation exposure accounts for less than 5% of sarcomas.

Patients might develop sarcomas from radiation given to treat other cancers, such as breast cancer or lymphoma. The sarcoma often starts in the part of the body that was treated with radiation. The average time between the radiation treatments and the diagnosis of a sarcoma is about 10 years.

Radiation therapy techniques have improved steadily over several decades. Treatments now target cancers more precisely and more is known about selecting radiation doses.

These advances are expected to reduce the number of cancers caused by radiation therapy. Because these cancers take so long to develop, the results of these changes might not be seen for a long time.

Still, radiation therapy is used only when its benefits (improved survival rate and relief of symptoms) outweigh its risks. To learn more, see Second Cancers in Adults.

Family cancer syndromes are disorders caused by gene changes that people are born with – often inherited from a parent. These changes are linked to a high risk of getting certain cancers. Some family cancer syndromes increase a person's risk of developing soft tissue sarcomas.

Neurofibromatosis

Neurofibromatosis is also known as von Recklinghausen disease. It's caused by a change in genes called NF1 and NF2.

It usually runs in families and causes many benign (non-cancerous) tumors that form in nerves under the skin and in other parts of the body. These are called neurofibromas.

About 5% of people with neurofibromatosis will develop a sarcoma in a neurofibroma.

Gardner syndrome

Gardner syndrome is a disease caused by changes in the APC gene. This syndrome is a type of familial adenomatous polyposis (FAP). People with Gardner syndrome get many polyps in the colon and have a high risk of getting colon cancer. It also causes problems outside the colon, including desmoid tumors, which are discussed in Soft Tissue Sarcoma.

Li-Fraumeni syndrome

Li-Fraumeni syndrome is caused by inherited defects in the TP53 gene. People affected by this syndrome have a high risk of getting cancer, such as breast cancer, brain tumors, leukemia , and sarcomas.

Only 10 to 20 out of 100 people with Li-Fraumeni syndrome will develop a soft tissue sarcoma. People with this syndrome are sensitive to the cancer-causing effects of radiation. So, if they have a cancer that's treated with radiation, they have a very high chance of developing a new cancer in the part of the body that was treated.

Hereditary Retinoblastoma

Hereditary retinoblastoma is an eye cancer in children that can be caused by changes in the RB1 gene. Children with this gene change also have a higher risk of developing bone or soft tissue sarcomas, especially if the retinoblastoma was treated with radiation.

Werner syndrome

Werner syndrome is caused by defects in the RECQL2 gene. Children with this syndrome have problems like those seen in the elderly. These include cataracts, skin changes, and clogged heart arteries (arteriosclerosis), which can lead to heart attacks. They also have an increased risk of cancers like soft tissue sarcomas.

Gorlin syndrome

Gorlin syndrome is also called nevoid basal cell carcinoma syndrome (NBCCS). It's caused by changes in the PTCH1 gene. People with this syndrome have a high risk of developing many basal cell skin cancers. They also have an increased risk of fibrosarcoma and rhabdomyosarcoma.

Tuberous sclerosis

Tuberous sclerosis can be caused by a change in the TSC1 and/or TSC2 gene. People with this syndrome often have seizures and learning problems. They get benign (non-cancerous) tumors in many different organs.

They also have kidney problems, often along with a kidney tumor called angiomyolipoma. People with tuberous sclerosis have an increased risk of rhabdomyosarcoma and perivascular epithelioid cell tumors (PEComas).

Lymph is a clear fluid containing immune system cells that's carried throughout the body by a series of lymph vessels. These vessels connect lymph nodes, which are small bean-shaped collections of immune system cells. When lymph nodes have been removed or damaged by radiation therapy, lymph fluid can build up and cause swelling. This is called lymphedema.

Lymphangiosarcoma, a cancer that develops in lymph vessels, is a very rare complication of chronic lymphedema.

Exposure to vinyl chloride, a chemical used in making plastics, is a risk factor for developing sarcomas of the liver, but it hasn't been proven to cause soft tissue sarcomas.

Arsenic has also been linked to a type of liver sarcoma but not soft tissue sarcoma.

Exposure to dioxin and to herbicides (weed killers) that contain phenoxyacetic acid at high doses, such as might occur in people who work on farms, might also be risk factors, but this isn't known for certain. There's no evidence that herbicides or insecticides, at levels encountered by the public, cause sarcomas.