What you should know about sarcoma
Soft tissue sarcomas can appear in fat, muscle, blood vessels, deep skin tissues, cartilage, tendons, and ligaments.
Sarcoma is rare in adults. According to the American Society of Clinical Oncology (ASCO), it accounts for around 1% of all adult cancers. It is more common in children, accounting for around 15% of all childhood cancers.
The ASCO also say that around 60% of sarcomas start in an arm or leg, 30% begin in the abdomen or torso, and 10% start in the neck or head.
The National Cancer Institute predict that doctors in the United States will diagnose around 12,750 cases of soft tissue sarcoma in 2019, and they predict that 5,270 people will die from a sarcoma.
The symptoms will vary depending on the type of sarcoma and where in the body it develops:
Soft tissue sarcoma
In the early stages of soft tissue sarcoma, a person may not experience any symptoms.
People with soft tissue sarcomas often have no symptoms in the early stages.
When symptoms appear, a person may notice:
A tumor: In some cases, there may be a noticeable lump or swelling. This is usually painless.
Pain: If the tumor affects local tissues, nerves, or muscles, pain may be present in the area.
Specific symptoms may reflect the particular type of sarcoma.
For instance, tumors in the gastrointestinal system may bleed, so symptoms may include blood in the stool or stools with a black, tarry appearance.
In the case of bone sarcoma, the first sign may be pain, with or without a lump. It often affects the long bones in the arm or leg or the pelvis.
If it affects the pelvis, signs and symptoms may not appear until a later stage.
There are more than 50 types of sarcoma. They include the following types.
Soft tissue sarcoma
Types of soft tissue sarcoma depend on the specific tissue or location it affects.
Angiosarcoma: This type affects the blood or lymph vessels.
Gastrointestinal stromal tumor: This affects specialized neuromuscular cells of the gut.
Liposarcoma: This is a sarcoma of fat tissue. These often start in the thigh, behind the knee, or at the back of the abdomen.
Leiomyosarcoma: This affects smooth muscle in organ walls, often in the abdomen.
Synovial sarcoma: This may be a tumor of the stem cells. Cancerous tissue can develop around the joints.
Neurofibrosarcoma: This type affects the protective lining of the nerves.
Rhabdomyosarcoma: This forms in skeletal muscle.
Fibrosarcomas: These affect fibroblasts, which are cells in the connective tissue.
Myxofibrosarcoma: This affects the connective tissue and often develops in the arms and legs of older adults.
Mesenchymomas: These are rare and combine elements of other sarcomas. They can occur in any part of the body.
Vascular sarcoma: This type occurs in the blood vessels.
Schwannoma: This affects the tissues that cover the nerves.
Kaposi's sarcoma: This type mainly affects the skin but can occur in other tissues. It results from the human herpesvirus 8.
Sarcoma of the bone
Types of sarcoma of the bone include:
Osteosarcoma: This affects the bone.
Ewing sarcoma: This can occur in the bone or soft tissue.
Chondrosarcoma: This starts in the cartilage.
Fibrosarcoma: This occurs in fibrogenic tissue, which is a type of connective tissue.
For more information about bone cancer, click here.
A doctor will often not know the cause of sarcoma.
In many cases, doctors do not know what causes sarcoma. They tend to occur sporadically, with little or no family history.
However, researchers have identified some possible risk factors:
High doses of radiation: Having undergone previous radiation therapy for cancer increases the risk of developing a soft tissue sarcoma later on.
Genetic conditions: Genetic factors may play a role. People with syndromes such as neurofibromatosis and tuberous sclerosis appear to have a higher risk of sarcoma.
Exposure to chemicals: Exposure to vinyl chloride, dioxins, and phenoxyacetic herbicides may increase the risk, but more evidence is needed to confirm this.
Human herpesvirus 8: Kaposi's sarcoma is the only type of soft tissue sarcoma with a clearly defined cause.
Tests and diagnosis
A person should see their doctor if they notice a lump that is more than 2 inches across, if the lump is getting bigger, or if the person is experiencing pain.
The doctor will:
- ask the individual about their symptoms
- ask about their personal and family medical history
- conduct a medical examination
- suggest imaging scans, such as an X-ray, MRI, CT, or PET scan
- run laboratory tests
If the person has previously undergone treatment to remove a tumor, the presence of a new growth may indicate that it has returned.
What does a biopsy involve? Find out here.
A doctor may recommend one or more of the following treatment options for bone or soft tissue sarcoma:
Surgery: This is the most common treatment for sarcoma. It aims to remove the tumor and some of the normal surrounding tissue. The surgeon will usually take a tissue sample to carry out a biopsy at the same time. This can confirm the exact type of tumor.
Radiation therapy: A person may have this before or after surgery to destroy cancer cells.
In the case of soft tissue sarcoma, a doctor may prescribe olaratumab (Lartruvo) for those whose sarcoma has not responded to other treatments.
People with advanced soft tissue sarcoma who have already undergone chemotherapy may benefit from pazopanib (Votrient).
The choice and intensity of treatment depend on the stage and grade of cancer, the size of the tumor, and the extent of any spread.
How well does chemotherapy work for different types of cancer? Find out here.
New medical discoveries are improving the outlook for people with soft tissue sarcoma.
The outlook for a person with sarcoma will depend on factors such as the type, grade, and location. Health authorities use statistics to work out approximately how many people with cancer will survive for 5 years or more after a diagnosis.
For soft tissue sarcoma, the chance of surviving at least 5 more years after diagnosis is:
- 81% if the sarcoma is localized, meaning that it has not spread
- 58% if it is regional, meaning that it has spread to nearby tissues
- 16% if it is distant, meaning that it has reached other organs in the body
For bone sarcoma, the average 5-year survival rates are:
- 77% for localized cancer
- 65% for regional cancer
- 27% for distant cancer
It is worth noting that:
- Many people live for longer than 5 years after diagnosis.
- Thanks to new medical discoveries, these percentages continue to improve.
- Individual factors, such as age and overall health, will impact the chance of survival for each person.
As with other types of cancer, the outlook is better if a person receives a diagnosis and begins treatment in the early stages.
Unlike other types of cancer, lifestyle factors do not seem to play a role in the onset of sarcoma.
Although adopting a healthful lifestyle is a good idea for reducing the risk of many conditions, there does not seem to be a specific link with sarcoma.
It is not usually possible to prevent sarcoma, as doctors do not yet know what causes it.
Is a sarcoma always cancerous?
By definition, “sarcomas” are cancerous tumors of the connective tissues. When people use this word to name a disease, it means the tumor is malignant and cancerous.Christina Chun, MPH Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.