Sarcoma is the name given to a variety of cancers that that arise from the bones and soft tissues, including fat, muscle, blood vessels, and nerves. Bone sarcomas typically occur in children and adolescents, whereas soft tissue sarcomas are more common in adults. Sarcomas are very rare in comparison to carcinomas, which develop in the glands and organs of the body such as lung, breast, and prostate. It is estimated that 10,000 new sarcomas occur annually in the U.S. out of a total of over 1 million new cancer cases per year.
There are more than 70 types of soft tissue sarcoma. Some of the more common types are:
- Liposarcoma – fat
- Leiomyosarcoma – smooth muscle
- Rhabdomyosarcoma – skeletal muscle
- Angiosarcoma – blood vessel
- Malignant peripheral nerve sheath tumor – covering around nerves
- Synovial sarcoma – unknown tissue of origin
- Undifferentiated pleomorphic sarcoma – unknown tissue origin
- Desmoid tumor – unknown tissue origin
- Dermatofibrosarcoma protuberans – unknown tissue origin
All of the different types of sarcoma are considered cancer. However, some types of sarcoma are very slow growing and are almost benign; whereas other types of sarcoma grow rapidly and are very aggressive.
Symptoms of sarcoma can be, but are not limited to, a new lump and pain. Sometimes sarcomas do not cause any symptoms and are detected when a patient sees a doctor for other issues.
Sarcoma can occur anywhere in the body. The most common location is in the legs and arms. About 20% of sarcomas appear in the back of the abdomen, which is also known as the retroperitoneum. Sarcomas in this location can frequently grow to a very large size before they are detected.
How can I tell if I have sarcoma?
If you suspect you have a soft tissue sarcoma, your doctor may have you undergo a CT scan or MRI, followed by a biopsy. The type of biopsy will be based on the size and location of the tumor:
- Core biopsy: The removal of tissue using a wide needle. This can be done as a minor procedure in the clinic or by a radiologist (sometimes guided by ultrasound or CT/MRI).
- Incisional biopsy: The removal of part of a lump or a sample of tissue through a minor surgery.
A pathologist looks at the biopsy tissue under a microscope to look for cancer cells to make the diagnosis (including the specific type of sarcoma) and determine the grade of the tumor. The grade of a tumor depends on how abnormal the cancer cells look under a microscope and how quickly the cells are dividing. High-grade tumors usually grow and spread more quickly than low-grade tumors.
Because sarcoma can be hard to diagnose, patients should ask to have their biopsy reviewed by a trained sarcoma pathologist. The correct diagnosis is critical to determine the appropriate treatment.
What is the treatment for sarcoma?
For sarcomas that have not spread, surgery is the main treatment. Surgery may be challenging and in some cases, chemotherapy and/or radiation therapy may be given either before or after the operation. Patients with sarcomas that have already spread or that cannot be removed by surgery usually undergo chemotherapy. In the last few years, newer drugs have become available for sarcoma, including better “targeted” therapies.
Because it is so rare, the treatment of sarcoma should be done at a specialized center with physicians who have experience and expertise in this specific disease. The treatment plan can be complicated, so the best approach is through a multidisciplinary team discussion that involves sarcoma experts from surgery, medical oncology, and radiation oncology. Surgery for sarcoma is also best performed by a surgical oncologist (cancer surgeon) trained to manage this frequently challenging disease. This avoids inappropriate treatment such as incomplete or overly-aggressive surgery.