In recent years, doctors have gained a better understanding of sarcoma growth patterns, the risks of sarcoma spreading and the most effective treatment options. As a result, survival following treatment for sarcoma has improved tremendously.
Fred Hutchinson Cancer Center offers comprehensive treatment from a team of experts who specialize in soft tissue sarcomas and bone cancers.
What is sarcoma?
Sarcomas are cancers that develop in connective tissues, including bones, cartilage, muscles, tendons, fibrous tissues, veins, arteries, nerves, skin and fatty tissues.
Cancer cells do not respond to regular cell growth, division and death signals like healthy cells do. They also don’t organize normally. Instead they grow into a tumor, which may invade surrounding layers of tissue and possibly spread to other organs.
- About half of sarcomas occur in the arms or legs.
- About half occur in the head and neck area, the internal organs or the back of the abdominal cavity (retroperitoneum).
- The term sarcoma comes from the Greek word sarkoma, meaning “fleshy growth.”
Sarcomas are divided into two main types: soft tissue sarcomas and bone cancers.
These are further classified into more than 70 sarcoma subtypes. Subtypes of sarcoma are named based on the surrounding tissue, the affected area of the bone or the type of cells creating the tumor.
These develop from soft tissues, such as muscles, fat, nerves, blood vessels, fibrous tissues or deep skin tissues. About 80 percent of sarcomas begin in soft tissues.
The most common soft tissue sarcomas in adults are:
- Gastrointestinal stromal tumor — is the most common sarcoma of the gastrointestinal tract.
- Leiomyosarcoma — develops from smooth muscle in abdominal and pelvic organs and blood vessels. (Unlike skeletal muscle, which you can control voluntarily, smooth muscle isn’t controlled consciously.)
- Liposarcoma — develops from fat tissue, most often in the back of the abdominal cavity but also in the soft tissues of the limbs.
- Pleomorphic sarcoma — usually occurs in the limbs (often the legs) and may also occur in the abdomen.
These cancers, also called osseous sarcomas, start in the bone. Bone cancers are much less common than benign (noncancerous) bone tumors or secondary cancers that spread to the bone from other locations (such as the lung or breast).
The most common bone cancer is osteosarcoma, which develops from cells that form bone.
Other common sarcoma subtypes include:
- Angiosarcoma — resemble blood or lymphatic vessels.
- Chondrosarcoma — develop from cartilage cells.
- Ewing’s sarcoma — arises from very primitive cells in the body. It can start in either soft tissue or bone.
- Fibrosarcoma — cancer of fibrous tissue.
- Malignant peripheral nerve sheath tumor — arises from nerves or related tissue outside of the brain and spinal cord.
- Rhabdomyosarcoma — resemble developing skeletal muscle. It most commonly grows in the arms or legs but can also develop in the head or neck or in the urinary or reproductive organs.
- Synovial sarcoma — can arise in any location in the body and often appears in young adults.
Sarcoma symptoms vary from person to person and depend on the type and location of the tumor and other factors, such as how far the tumor has spread.
In soft tissue sarcoma, you may develop a firm mass that you can see or feel. Usually these masses are painless, but some soft tissue sarcomas cause pain. A tumor in and around your joints may cause swelling and tenderness. A tumor in your abdomen may cause symptoms such as abdominal pain, blood in your stools or vomiting.
Pain in a bone is the most common symptom of bone cancer. At first the pain may come and go, but as the tumor grows, the pain eventually becomes constant. Bone tumors can weaken your bones, which can lead to fractures. Swelling may also occur, and you might be able to feel a lump, depending on where the tumor is located.
Conditions other than cancer may cause the same symptoms as sarcomas. If you have any symptoms that concern you, talk to your doctor.
When doctors suspect sarcoma, they may use several tools to gather more information about the tumor and determine whether it’s cancer.
For soft tissue sarcomas, doctors may use magnetic resonance imaging (MRI), computed tomography (CT) scans or positron emission tomography (PET) scans to create a picture of the inside of your body and see the tumor.
The only way to definitively diagnose soft tissue sarcoma is to perform a biopsy — to remove cells from the tumor and examine them under a microscope.
If your doctor thinks you might have sarcoma in a bone, they may use X-rays and other imaging tests, such as bone scans, MRIs and PET scans to find out more.
A biopsy is needed to confirm if cancer is present.
Adults over 40 who have a bone tumor or other bony abnormality that might be a tumor should be evaluated carefully to see whether they have primary lung cancer, kidney cancer, breast cancer or prostate cancer that may have spread to their bones. This means having a CT scan of the lungs and abdomen and a total body bone scan.
Testing the DNA of your cancer can give your doctor information about what caused your disease and which therapies will be most effective against it.
UW-OncoPlex is one diagnostic tool that uses genetic sequencing to look for mutations that cause cancer. These “genetic profiles” of cancer cells help doctors identify which mutations are driving tumors.
Some people carry an inherited risk of developing cancer, including sarcomas. Your Fred Hutch doctor may refer you to a genetic counselor who can talk with your about your genetic risk.
When doctors perform your biopsy, they evaluate how abnormal your cancer cells appear. This allows them to categorize your tumor as low grade or high grade.
Low-grade sarcomas, although cancerous, are less likely to spread to other parts of the body (though they may recur at the original site after treatment). High-grade sarcomas are more likely to spread.
Staging is the process of finding out how far cancer has spread within the tissue where it started or to other parts of the body. The treatment that your doctor recommends will be based, in large part, on the stage of your cancer when it is first diagnosed.
Sarcomas have their own specialized staging system. The stage depends on several factors, including:
- The size and location of the tumor or tumors (and for soft tissue sarcomas the depth too)
- The tumor grade
- Whether cancer is found in nearby lymph nodes
- Whether cancer is found in distant organs or tissues
Typically cancer is assigned an overall stage of I, II, III or IV, with IV being the most advanced. Some stages may be further subdivided into A and B, based on more precise features of the cancer.
How common is sarcoma?
Each year about 13,000 people in the United States are diagnosed with soft tissue sarcoma and about 3,500 are diagnosed with bone cancer. Together, all types of sarcoma represent just one percent of all new cancer cases.