About Sarcoma
What Is
Sarcoma?
Sarcoma is a type of cancer that begins in the connective tissues of the body. These tissues include fat, blood vessels, nerves, bones, muscles, deep layers of the skin, tendons, and cartilage.
Sarcomas are grouped into two main categories: bone tumors and soft tissue tumors. Each category includes more specific subtypes based on the kind of cells that make up the tumor. There are more than 100+ known subtypes types of sarcoma, and many of them are considered rare.
1%
Of all new cancer diagnoses
in the U.S. are sarcoma
#5
Cancer among children
17K
Newly diagnosed patients each
year in the United State
Of the 1.7 million people who are diagnosed with cancer in the United States each year
- About 1% (17,000) will be diagnosed with sarcoma cancer.
- Some sarcomas are so rare that only a few people are diagnosed with that type each year.
- In children under age 18, where cancer is rare already, sarcomas are in the top 5 most diagnosed cancers, representing about 15-20% of childhood cancers.
Sometimes a cancer diagnosis is made quickly, especially when symptoms are clear and a person receives prompt medical attention. Diagnosing a new sarcoma can take longer, and this can be confusing or stressful for patients and families. A few reasons include:
- Symptoms may feel vague or familiar. Many early signs of sarcoma, such as a lump, bump, or ongoing pain in a joint, are common experiences that do not always point to cancer.
- Sarcoma can begin in many places. Because these tumors can form almost anywhere in the body, they may go unnoticed for some time before they cause concern.
- Sarcomas may be mistaken for more common conditions. Since noncancerous issues are far more likely, sarcomas are sometimes misdiagnosed as an injury, a pulled muscle, or a benign fatty tumor known as a lipoma.
If you or a loved one is seeking clarity, know that you are not alone. Many people reach a sarcoma diagnosis only after several steps, and support is available throughout the process.
Sarcomas are rare cancers, and because they occur in many different forms, researchers are still learning what causes them. Many studies group several types of sarcomas together so scientists can gather enough information to look for patterns. This approach helps advance research, even though each sarcoma subtype has its own unique characteristics. Here is what we do know:
Genetic Causes
Genes are like blueprints for the cells in your body. Changes in these genes are called mutations. There are many different types of mutations that can occur.
Some genetic variants may be present at birth, others may occur throughout a person’s lifetime. These mutations can be harmful, beneficial, or have no effect on the risk of developing cancer.
Sometimes, however, mutations in these genetic blueprints can cause cells to grow out of control and become cancerous. Most of the time gene mutations happen spontaneously. Sometimes they can be inherited from a parent and/or present at birth.
Genes associated with cancer predisposition are thought to contribute to about 5 to 10% of all cancers, and a small number are associated with sarcomas. Some of these risks can be detected by genetic testing of blood or saliva samples.
Environmental Causes
While most sarcomas cannot be linked to a specific cause, a few environmental factors are known to increase risk:
- A viral infection called Human Herpesvirus 8 (HHV-8) can lead to a type of sarcoma known as Kaposi sarcoma. This is more common in people with weakened immune systems, including those living with AIDS.
- Previous treatment with ionizing radiation or certain chemotherapy drugs may slightly increase the chance of developing a sarcoma later in life. This is rare, and the benefits of cancer treatment almost always outweigh this risk.
Other Changes in Cells
Even when no clear cause is identified, changes in DNA can still occur throughout life. The body works continuously to repair these changes, but sometimes a harmful mutation slips through and allows cells to grow out of control.
Learning about the specific genetic changes inside a sarcoma tumor can help guide treatment decisions and identify whether someone may be eligible for targeted therapies or clinical trials.
Tumor Mutation Burden
Sarcoma tumors vary widely in the number of genetic changes they carry. This is known as the tumor mutational burden. A tumor with more mutations may respond differently to certain treatments. Understanding a tumor’s mutation profile helps doctors consider newer therapies and evaluate clinical trial options.