Soft tissue sarcoma can spread to more distant areas of the body, most commonly the lungs. The outlook for people with metastatic soft tissue sarcoma is typically poor.

Soft tissue sarcoma (STS) is a type of cancer that affects the body’s soft tissues. This can include soft tissues such as muscles, connective tissue, and blood vessels.

It’s possible for STS to start anywhere in the body. As STS advances, it may spread to more distant organs and tissues. This is called metastasis.

STS is when cancer forms in soft tissues. Soft tissues can include the following:

It’s possible for STS to form in any area of the body, including your:

  • arms and legs
  • torso
  • abdomen
  • head or neck

There are more than 50 different types of STS. Your outlook and treatment options can vary based on what type of STS diagnosis you’ve received.

Metastasis is when cancer spreads from its original site to more distant organs and tissues. You may also see it referred to as stage 4 cancer.

Cancer can spread when cancer cells move into your blood vessels or lymphatic vessels. They can then use the circulatory or lymphatic system, respectively, to travel to distant areas of your body.

Metastasis isn’t uncommon in STS. In fact, it’s estimated that about 40% to 50% of people with STS develop metastatic disease at some point.

General symptoms of metastatic cancer can include:

An older study from 2011 and a more recent 2020 study have found that the lungs are the most common site that STS metastasizes to. After the lungs, other metastatic sites are reported less commonly.

Below, we’ll explore a little more about each potential metastatic site and possible symptoms.

Lungs

The lungs are the most common metastatic site for STS. Lung metastases make up about 80% of first metastatic sites in people with STS. Specific symptoms of lung metastasis can include:

Liver

The liver has many vital functions in the body, including, but not limited to, making bile (a yellow or greenish fluid) for digestion and breaking down medications and other substances.

Symptoms of liver metastasis include:

Bones

STS that spreads to your bones can cause a variety of problems. These can be:

Peritoneum

The peritoneum is the lining of your abdominal cavity. Symptoms of the type of STS that metastasizes here can include:

Soft tissue

STS may also sometimes spread to other soft tissues. When this happens, you may notice a lump or bump on your body that gradually gets larger. It may or may not be tender or painful and can interfere with nearby tissues.

Lymph nodes

Your lymph nodes help to filter germs from your lymphatic system. Symptoms that STS may have spread to the lymph nodes include persistent lymph node swelling. Swollen lymph nodes may also be tender or painful.

It’s important to note that lymph nodes can also be swollen or tender due to other causes. These include infections or autoimmune diseases.

Brain

Metastatic STS in the brain may cause symptoms such as:

Anyone who has STS can develop a metastasis. But research has found that there are some factors that may increase your risk. These include:

  • the specific type of STS, because some types of STS are more aggressive than others
  • higher tumor grade, which means that cancer cells look more abnormal and are more likely to be aggressive
  • larger primary tumor size
  • a primary tumor that’s located deeper in your body
  • nearby lymph nodes that contain cancer cells

There are a few treatment options available for people with an STS metastasis. These include:

  • Surgery: In some situations, surgery can still be done to remove metastatic STS. According to the American Cancer Society (ACS), the outlook for people with metastatic STS that’s treated with surgery is best when the metastatic site is the lungs.
  • Chemotherapy: Chemotherapy uses drugs that affect the division of cancer cells. Doxorubicin, often with ifosfamide, is a common first-line treatment for metastatic STS.
  • Radiation therapy: Radiation therapy uses high energy radiation to kill cancer cells. It may also be used in combination with chemotherapy.
  • Targeted therapy: Targeted therapy drugs focus on specific markers in or on cancer cells. An example of a targeted therapy drug that may be used for STS is pazopanib (Votrient).
  • Immunotherapy: Immunotherapy helps your immune system respond to cancer, although its effectiveness for STS is still being studied. Immune checkpoint inhibitors such as pembrolizumab (Keytruda) are being studied in clinical trials of medications for the treatment of STS.

Remember that STS is a very diverse group of cancers. As such, the exact treatment that’s recommended for you will depend on the type of STS you have and other individual factors such as age and overall health.

Factors that can influence the outlook for people with metastatic STS include:

  • the type of STS
  • the location of the metastasis
  • how fast the STS is growing and spreading
  • how the STS responds to treatment
  • your age and overall health

Generally speaking, the outlook for people with metastatic STS is poor. A 2020 study of 212 individuals with metastatic STS found that the median overall survival time was 24 months.

The 5-year survival rate for people with metastatic STS is 15%.

A 5-year survival rate is the percentage of people with a certain type and stage of cancer who are alive 5 years after receiving a diagnosis.

It’s important to know that these statistics don’t account for individual differences or recent advances in treatment. If you’ve received a diagnosis of metastatic STS, speak with a healthcare professional about your specific outlook.

How common is soft tissue sarcoma?

STS isn’t common. The ACS estimates that about 13,400 people will receive a diagnosis of STS in the United States in 2023. STS also makes up a higher proportion of cancers (8%) in children than in adults (less than 1%).

Can soft tissue sarcoma be prevented?

One of the main risk factors for STS is having certain inherited disorders, which can’t be changed. As such, there’s currently no known way to prevent STS from developing.

The lungs are the most common site for STS to spread to. Less often, it can spread to other areas such as the liver, bones, or peritoneum. Factors such as type of STS, higher tumor grade, and larger tumor size increase the risk of metastasis.

The outlook for people with metastatic STS is typically poor. But every individual is different. A professional healthcare team can give you a better idea of your specific outlook.