Understanding Sarcomas
This information is displayed with permission of the University of Minnesota Cancer Center. For more information about this disease or to review active clinical trials, please visit the website of the Cancer Center.
Osteosarcoma (also called osteogenic sarcoma)
This is the most common type of primary malignant bone cancer. Osteosarcomas have subtypes, which include conventional osteosarcoma, parosteal, juxtacortical, Paget's or secondary-induced bone sarcomas (radiation-induced). Although it can occur at any age, osteosarcoma is typically found in teenagers and young adults and is slightly more common in males. Any bone in the body can be affected but the most common sites are the arms or legs, particularly around the knee and shoulder.
Osteosarcoma treatment includes chemotherapy for any tumor that has greater than 10% chance of spreading elsewhere in the body. After a course of chemotherapy called induction therapy, the local disease is then managed by surgical removal of the primary tumor and reconstruction. If the primary tumor cannot be completely removed, amputation is occasionally required.
After the management of the primary tumor, additional chemotherapy is focused on the possibility of microscopic disease in the bloodstream and lung that is undetectable. The principle behind the chemotherapy is to eradicate this disease before it begins growing. The course of treatment for osteosarcomas generally takes 10-12 months from the time of diagnosis, with chemotherapy followed by local control of the primary tumor, and then post-surgical control of any residual microscopic disease with additional chemotherapy for a total of 8-10 months.
Chondrosarcoma
This is a cancer of the cartilage although can also grow within a bone or on its surface. It is most typically found in middle-aged adults. Chondrosarcoma is usually a slow-growing tumor and the most common sites are the pelvis, shoulder and the upper part of the arms and legs.
The treatment for chondrosarcomas relies heavily on surgical removal, since there is limited response to radiation and/or chemotherapy. One of the reasons for aggressive treatment is that 10% of low-grade tumors have been reported to develop a much more aggressive biologic behavior, a process called dedifferentiation.
Ewing's sarcoma
This is a tumor that occurs primarily in younger patients between the ages of 5 and 30 years of age. Any bone can be affected, but the pelvis, thigh bone and shin bone are the most common sites. Like osteosarcoma, this cancer is slightly more common in males than females.
The prognosis for Ewing's sarcoma depends on the stage of the disease. If there is no evidence of disease outside of the local site, overall 60% of those patients will be cured. If the tumor is in a long bone such as the femur or humerus, is smaller than 8 centimeters in diameter and confined to the local site, the cure rate is 80+%. Even patients with metastatic disease to the lung may be cured.
Patients with Ewing's sarcoma usually respond dramatically to chemotherapy. A major difference between osteosarcoma and Ewing's sarcoma is treatment of the local disease may be done with radiation therapy rather than surgery alone. Our center believes that the complications of radiation therapy are sufficient that when we can use surgery with an acceptable result to the patient and family, we prefer surgical treatment over primary radiation in Ewing's sarcoma.
