About Sarcoma of the Bone
Sarcoma is extremely rare – representing about 1 percent of all cancers or 20,000 to 30,000 cases in the United States each year. It is not a single disease but rather a group of cancers that develop in the bone or connective tissue.
Cancer occurs when cells mutate (change abnormally) and begin growing out of control. These cells form tumors that can often be seen on imaging like an X-ray, computed tomography (CT) scan, or magnetic resonance imaging (MRI) scan.
A biopsy is required to determine the diagnosis of a tumor that appears suspicious on imaging.
Many patients wonder why they developed sarcoma or if they are at a high risk for the disease. In general, cancer develops after the genetic material in cells changes abnormally and the cells begin growing out of control. When there are enough of these abnormal cells, they can form a tumor.
People who have had sarcoma before are at higher risk of recurrence.
Symptoms vary according to where the tumor is located.
For sarcomas of the bone, symptoms include:
- A lump or bump under the skin
- Bone pain
For soft-tissue sarcomas, symptoms include:
- A painless lump that grows rapidly
- A lump usually on an extremity
Risk factors for sarcoma
Having one or more of these factors does not necessarily mean that you will develop sarcoma. Some people without major risk factors can also develop the disease.
Sarcoma risk factors include:
- Inherited conditions like Li-Fraumeni syndrome or retinoblastoma
- Prior radiation therapy
- Chronic exposure to workplace chemicals such as herbicides, arsenic, or dioxin
Types of sarcoma
The most common subtypes of the sarcomas of the bone are:
- Ewing’s sarcoma
Sarcomas of the bone are somewhat more common in children and adolescents.
There are more than 50 types of soft-tissue sarcomas. The most common include:
- Vascular sarcoma
This is more common in adults and affects the lining of blood vessels and lymphatic channels.
- Smooth muscle sarcoma
This can develop anywhere in the body but is more common in the uterus and abdomen.
- Fibrohistiocytic sarcoma
This is more common in children and usually develops on the arms, legs, and torso.
This is more common in adults and develops in fatty tissue.
Other factors in diagnosis and treatment planning
There are additional considerations beyond type and subtype that affect recommendations your care team may make for treatment.
- Tumor size offers clues about how quickly the tumor may have developed and how likely it is to spread. Larger cancers are more likely to progress to the lymph nodes.
- Grade assigns a numeric value to describe how abnormal the cancer cells appear under the microscope. The higher the number, the more aggressive the cancer. Lower numbers are usually associated with slower growth.
Diagnostic tests for sarcoma
If a doctor or facility outside Stanford has already given you a diagnosis, we will have your results sent to our pathologists (doctors specializing in cancer diagnosis). They will review your test results and confirm or correct your diagnosis.
At Stanford, we tailor the diagnostic phase of cancer care to each individual patient. If you need further testing to complete your diagnosis, your doctor and care team will work with you to determine which tests you need. Tests may include:
- Imaging (radiology)
To obtain the most precise understanding of your cancer, your doctor may schedule you for different types of imaging that diagnose cancer. If you have been screened elsewhere and received abnormal results, we may perform additional imaging, if needed.
- Biopsy (pathology)
If your imaging or other screening tests show that you may have cancer, you will need a biopsy. This test takes a tiny sample of cells from abnormal areas of tissue.
- Genetic tests
Genetic testing is a medical test that identifies changes in genes, chromosomes, or proteins. For sarcomas, genetic testing can show whether you have inherited mutations that heighten your family’s risk of developing sarcoma.
- Lab tests (blood draws)
Before and during treatment, your doctor will ask you to have your blood drawn and tested at a lab. Blood tests can provide a variety of information, helping to establish your diagnosis and plan your course of cancer treatment.
Stages of sarcoma
When your care team determines your diagnosis, they also assess what stage of cancer you have. Staging describes:
- Size of the tumor
- Location of the cancer
- Whether the cancer has spread and, if so, to where
A cancer diagnosis and its staging help you and your doctor make decisions about your treatment plan. This information is also helpful in determining your prognosis (probable outcome based on the experience of others).
The stages of sarcoma are:
Stage IA: The tumor is 5 cm or smaller and either superficial or deep. It has not spread to the lymph nodes or to other parts of the body.
Stage IB: The tumor is larger than 5 cm and either superficial or deep. It has not spread to the lymph nodes or to other parts of the body.
Stage IIA: The tumor is 5 cm or smaller and either superficial or deep. It has not spread to the lymph nodes or to other parts of the body. The grade is higher than the grade for stage IA.
Stage IIB: The tumor is larger than 5 cm and either superficial or deep. It has not spread to the lymph nodes or to other parts of the body. The grade is higher than the grade for stage IB.
Stage III: This stage can be described by either of the following:
- The tumor is larger than 5 cm and either superficial or deep. It has not spread to the lymph nodes or to other parts of the body. The grade is higher than the grade for stage IIB.
- The tumor is any size, either superficial or deep, or any grade. However, it has spread to the regional lymph nodes but not to other parts of the body.
Stage IV: The tumor is any size, either superficial or deep, any grade, and may or may not have spread to the regional lymph nodes. However, it has spread to other parts of the body).
Recurrent: Recurrent sarcoma is sarcoma that has come back after treatment.
Current as of: 1/2020