|Carolyn Vachani, RN, MSN, AOCN|
|The Abramson Cancer Center of the University of Pennsylvania|
| Last Modified: February 7, 2013
What is sarcoma?
Sarcoma is a cancer of the soft tissue (muscle, fat, nerve, or connective tissue) or bone. (This article will discuss sarcomas of the bone; soft tissue sarcomas will be discussed separately). Sarcomas encompass a group of over 40 different types of tumors. In general, sarcomas are considered quite rare, accounting for less than 1% of all adult cancer diagnoses, with approximately 10,000 new cases annually in the soft tissues and 2,400 new cases annually in the bone. Sarcomas are considered primary bone cancers (different from bone metastases from other cancers), and are named based on the site from which they arise. For example, chondrosarcomas arise from cartilage, osteosarcomas arise from bone, and fibrosarcomas arise from fibrogenic tissue.
Osteosarcoma is the most common type of bone sarcoma, accounting for approximately 35% of bone tumors. Chondrosarcoma is the second most common type in adults (accounting for 30% of bone sarcomas), and Ewing's sarcoma is the second most common type in children. All other types are extremely rare, each accounting for less than 1% of all bone sarcomas. (See list below for some types of sarcomas of the bone). Within these types, there are further subtypes -- for example, there are 11 different types of osteosarcomas.
Ewing’s sarcoma can occur in the bone or soft tissue (called extra-osseous), and this is important when treatment options are considered. The large majority of cases occur in the bones, and the diagnosis is most common in the teenage years. PNET (primitive neuroectodermal tumor) is a type of sarcoma closely related to Ewing’s. PNET can occur in the bone or the central nervous system. PNET of the bone is treated the same as Ewing’s sarcoma, but PNET in the brain or spinal cord is a genetically different tumor that is treated differently. Ewing’s, PNET, Askin’s tumors and neuroepithelioma all contain the same genetic abnormality, called an 11-22 chromosomal translocation (t11;22). Because of this similarity, these tumors are referred to as the Ewing’s sarcoma family of tumors and are treated similarly.
Am I at risk for sarcoma?
The cause of sarcoma of the bone (SB) is unknown in the large majority of cases. SB can develop from benign lesions in the bone or in areas that previously received radiation (these cases are rare and tend to occur many years after the radiation). In addition, a familial genetic syndrome called Li Fraumeni and a disease called Paget's are associated with sarcomas. For the most part, doctors do not know why SBs occur and therefore cannot determine who is at risk of developing the disease.
The rates of osteosarcoma and Ewing’s sarcoma are the same for boys and girls until 13 years of age, after which males are more commonly affected. Ewing’s is 10 times more common in Caucasians then in blacks (either American or African) or Asians.
What screening tests are available?
Unfortunately, there is no screening test for SB. Screening tests are developed for the early detection of common or very deadly diseases. Given how rare SBs are, they would be difficult to screen for in the general population. In addition, the number of different types of SB would make it very difficult to develop one single screening test that could detect all types.
What are the signs of sarcoma of the bone?
The primary sign of SB is pain, with or without a mass that can be felt. The area of pain depends on the area involved with tumor. SBs occur most commonly in the long bones (thigh or femur, upper arm or humerus) or the pelvis. Pelvic tumors may not cause symptoms until they are larger, or if they do cause symptoms, they may not be correctly diagnosed right away because of the rare nature of SB.
How are sarcomas of the bone diagnosed and staged?
Given how rare sarcomas are, many physicians have never seen or cared for a patient with sarcoma. When sarcoma is suspected, it is important to seek out a physician team familiar with sarcoma. A biopsy is critical for diagnosis and to determine the exact type of sarcoma. Successful biopsy requires knowledge of sarcomas and their treatment, and is best done by a surgeon familiar with sarcoma, followed by examination of the sample by a pathologist who has experience with sarcoma specimens. Biopsies can be performed as an open (surgical) procedure or a closed (percutaneous) procedure (using a large needle to remove the tissue). The biopsy must be performed properly to collect enough tissue to get a diagnosis, but not so much tissue that it would compromise the definitive surgical treatment of the tumor. In general, the preferred method is the least invasive technique that still allows the pathologist to give a definitive diagnosis.
Most tumor types are staged using a system, but this has been difficult, given the number of types of SB and the varying locations. The most widely used system was developed by the Musculoskeletal Tumor Society (MTS) in 1986. It incorporates size and histologic grade (how different the cells look under the microscope when compared to normal cells) in determining the stage. More recently, the American Joint Committee on Cancer (AJCC) and the International Union Against Cancer (UICC) developed a staging system that is beginning to take the place of the MTS system. It also incorporates size and histologic grade in determining the stage (see table below).
AJCC/UICC Staging System for Soft Tissue Sarcomas
Plain old x-rays are the most useful initial radiology study to evaluate the tumor. A bone scan may be performed to evaluate the entire skeleton for other lesions. CT scan of the chest is usually done to rule out any metastases (spread) to the lungs (this is the most common site of spread). MRI (magnetic resonance imaging) with or without CT scan will be done in preparation for surgery. In some cases, PET scan may be used to detect any tumor metastases.
How is sarcoma of the bone treated?
Given the rarity of SB, these patients are best served at a specialty treatment center. A Swedish study demonstrated that local recurrence rates were 2 and a half times higher in patients not referred to specialty centers. The study also found worse outcomes in patients who were referred to specialty centers after their initial surgery. Treatment of SB requires complex multimodality therapy (surgery, radiation and chemotherapy). Patients with suspected sarcomas should be referred to an orthopedic oncologist for biopsy and diagnosis.
Specific treatment is dependent upon the size and location of the tumor, the grade (aggressiveness) of the tumor, and whether or not it has spread. The following is a general review of current treatments, but specific cases should be discussed with the doctors on the team.
Surgery is the primary means of treatment in SB, with the goal of complete tumor removal. In patients with tumors in the arms or legs, this historically meant amputation. With the advances in orthopedic oncology, over 90% of patients with extremity tumors are now having limb-sparing surgery. In addition to the tumor, the surgeon typically removes a 2-cm area of normal tissue around the tumor whenever possible (to obtain "clear wide margins"). There is a low risk of spread to lymph nodes, therefore lymph node dissection is not routinely performed.
Radiation therapy can be performed before or after surgery, or even during surgery through the use of brachytherapy. Radiation therapy can be used to treat tumors when they are not resectable with surgery, when clear margins are not achieved with surgery, or when there is disease recurrence (at the site of the original tumor or other localized site). Radiation is used in the treatment of chondrosarcomas more often than other types of SBs.
Unlike soft tissue sarcomas, doctors have had success in treating bone sarcomas with chemotherapy. Chemotherapy can be given before surgery in order to shrink the tumor and allow for a better resection, or it can be given after surgery. Surgery and radiation can only act on a small area around the tumor site, whereas the main goal behind chemotherapy is to kill any cancer cells floating undetected elsewhere in the body. It is these cells that can plant themselves and start to grow in other organs, most commonly the lungs.
Of the available chemotherapies, different ones work better in the different types of SBs. For example, in Ewing's sarcoma, ifosfamide, cyclophosphamide, etoposide, doxorubicin and vincristine are the most effective medications. In osteosarcoma, doxorubicin, cisplatin, carboplatin, ifosfamide and methotrexate are more effective. These medications are generally used in combinations of several drugs that work in different ways.
SBs that metastasize generally spread to the lungs first. Researchers have learned that by surgically removing metastases limited to the lungs, they can greatly improve survival in what would otherwise be a dismal prognosis. This is not a small procedure, so patients have to be healthy enough to endure a surgical resection of the lung tumor(s).
Follow-up care varies depending on the type and grade of the tumor, yet another reason to have these patients managed at specialty centers. Below are some guidelines put forth by the National Comprehensive Cancer Network on various SBs.
Follow-up should include physical exam, chest x-ray and x-ray of the primary tumor site. This should be performed every 3 months for 2 years, then every 4 months for 1 year, then every 6 months for 2 years, then annually.
Follow-up should consist of physical exam, chest x-ray, and x-ray of primary tumor site.
Low grade: every 6 months for 2 years, then annually.
High grade: every 3-6 months for 5 years, then annually for a minimum of 10 years.
Follow-up should include physical exam and chest x-ray. Every 2-3 months for 2 years, gradually increase the time span between visits, and switch to annual visits after 5 years. MRI of the primary tumor site should also be performed every 6 months for 2 years.
Clinical trials have played and continue to play an important role in the treatment of sarcomas. In the past 20 years, considerable improvements have been made in sarcoma therapy, particularly surgery for sarcoma, with great improvements in rates of amputations and development of appropriate chemotherapy regimens. The treatments we have today were refined through clinical trials, and many new avenues continue to be explored. Talk with your physician about current clinical trials for sarcomas in your area or visit our clinical trials matching service.
This article is meant to give you a better understanding of soft tissue sarcomas. Use this knowledge when meeting with your physician, making treatment decisions, and continuing your search for information. You can learn more about sarcoma on OncoLink through the related links on the left.
Links to other resources
Sarcoma Foundation of America - The SFA raises money for sarcoma research and aims to raise awareness of sarcoma. The site has information for patients as well.
Sarcoma Alliance – This website, started by a sarcoma survivor, is based on the mantra "guidance, education, and support". They also maintain a list of specialty centers.
Bone Tumor.org – A site maintained by, Dr. Henry DeGroot, an orthopedic oncologist from the University of Massachusetts Medical School.
Types of Sarcoma of the Bone
(This list does not contain all types)
References & Further Reading
Abeloff, M., Armitage, J., Niederhuber, J., Kastan, M. & McKenna, G. (Eds.): Clinical Oncology (2004). Elsevier, Philadelphia, PA.
The American Cancer Society. Facts and Figures. www.cancer.org
Carvajal, R. & Meyers, P. (2005) "Ewing 's sarcoma and primitive neuroectodermal family of tumors" Hematol Oncol Clin North Am 19 (3): 501-525.
Gustafson, P., K. E. Dreinhofer, et al. (1994). "Soft tissue sarcoma should be treated at a tumor center. A comparison of quality of surgery in 375 patients." Acta Orthop Scand 65 (1): 47-50.
Hristov, B et al. The role of radiation treatment in the contemporary management of bone tumors. Journal of the National Comprehensive Cancer Network. 5(4):456-66, 2007 Apr.
Lenhard, RE, Osteen, RT & Gansler, T. (Eds): The American Cancer Society's Clinical Oncology (2001) The American Cancer Society, Atlanta, GA.
Lewis, VO. What's new in musculoskeletal oncology. Journal of Bone & Joint Surgery - American Volume. 89(6):1399-407, 2007 Jun.
Mankin, H. J., C. J. Mankin, et al. (1996). "The hazards of the biopsy, revisited. Members of the Musculoskeletal Tumor Society." J Bone Joint Surg Am 78 (5): 656-63.
National Comprehensive Cancer Network, Clinical Practice Guidelines - 2006, www.nccn.org
Schuetze, SM. Chemotherapy in the management of osteosarcoma and Ewing's sarcoma. Journal of the National Comprehensive Cancer Network. 5(4):449-55, 2007 Apr.