Conventional osteogenic sarcoma (also called osteosarcoma)
Osteogenic sarcoma is the most common tumor of bone. Approximately 800-1000 cases of osteogenic sarcoma are seen in the United States each year. A second peak of incidence of osteosarcoma occurs in the 8th decade of life, typically associated with Paget disease of bone. Osteosarcoma typically affects adolescents, and generally affects bones around the knee joint, though any bone of the body can be affected. Treatment typically involves chemotherapy and surgery to try to achieve the best cure rate. Standard drugs that are used include doxorubicin and cisplatin in adults, and the same two drugs with high-dose methotrexate in children, adolescents, or young adults. The use of ifosfamide remains controversial. Recurrences typically occur in the lungs. This is one situation where surgery can be curative; resection of lung metastases from a primary osteosarcoma is a standard of care when there is a small number of lung nodules that can be removed safely, and can be associated with a 30-35% cure rate. Osteosarcomas occur commonly in familial syndromes associated with sarcoma, such as Li-Fraumeni syndrome (involving a mutation in the p53 gene), retinoblastoma (involving a mutation in the Rb gene), and Rothmund-Thomson syndrome.
Conventional chondrosarcoma
Conventional chondrosarcoma can be a difficult tumor to treat. It often arises in older patients, and often in the pelvis. As a result, people with multiple medical diagnoses are put in the position of requiring a very large operation with a high risk of post-operative complications, with subsequent loss of function. For chondrosarcomas that arise in other sites, surgery can be less morbid and represents the standard of care. People with metastatic disease often times do not respond well to chemotherapy. Grade 1 chondrosarcomas nearly never metastasize, Grade 2 chondrosarcomas have only a 10-15% risk of metastasis, and grade 3 chondrosarcomas have a two-thirds or higher risk of metastasis. As a result, some people with grade 3 chondrosarcomas will be given adjuvant chemotherapy. A version of chondrosarcoma called clear cell chondrosarcoma has an intermediate risk of metastasis, but treatment is typically surgery alone.
Ewing sarcoma
This is the third most common sarcoma of bone, and second most common in children. The same tumor occurs in the soft tissue of adults more than it occurs in bone. We estimate there are fewer than 500 cases a year in the United States. Without chemotherapy the cure rate is at best 10%, but with chemotherapy a cure rate of up to 75% in children and 50-60% in adults is seen. Surgery and radiation are also commonly used as treatment for the primary tumor in order to try to achieve the highest cure rate possible. Ewing sarcomas can appear in any site of the body. Then they recur, it is most commonly in the lungs and bones.
Dedifferentiated chondrosarcoma
This is a more aggressive version of chondrosarcoma, typically occurring in adolescence and in people over age 60. It shows features of both chondrosarcoma and of elements of a less differentiated tumor, such as MFH (malignant fibrous histiocytoma), which does not show even a hint of relatedness to the chondrosarcoma. This version of chondrosarcoma has a high risk of recurrence, even greater than that of grade 3 conventional chondrosarcoma (described above).
Less common bone and cartilage sarcoma subtypes
Parosteal osteogenic sarcoma
Parosteal osteosarcoma is a low grade osteosarcoma of bone that grows from the surface of the bone without lifting off the surface connective tissue of bone, called periosteum. It occurs by far most commonly along the posterior, distal femur in the 3rd decade of life. Treatment for this rare form of osteosarcoma is usually surgery alone, although if there are aggressive features such as dedifferentiation or a high grade component seen, chemotherapy is also often given.
Periosteal osteogenic sarcoma
Parosteal osteosarcoma is a low grade osteosarcoma of bone that grows from the surface of the bone and lifts off the surface connective tissue of bone, called periosteum, and is also associated with new bone formation in the area of the lifted periosteum. It typically occurs between ages of 10 and 30. Treatment for this rare form of osteosarcoma is usually surgery alone. It is not clear if chemotherapy is helpful for this type of osteosarcoma, though it is often given if the tumor appears more aggressive than usual.
Mesenchymal chondrosarcoma
This is a rare bone tumor which shows a mixture of aggressive small round blue cells mixed with more typical lower grande chondrosarcoma. They usually affect people between ages of 15 and 30, and have a high risk of recurrence. The benefit of chemotherapy is not known, though chemotherapy is often used. The typical chemotherapy drugs that are used in the adjuvant setting (or metastatic setting, for that matter) are the drugs used for Ewing sarcoma and similar sarcomas.
Giant cell tumor of bone
Giant cell tumor of bone is a tumor of bone that typically occurs between ages 20 and 40, and has a unique appearance under the microscope. It occurs in the area of the knee and lower spine, typically. It is treated by scraping out the tumor and treating the tumor cavity with cement (which heats up and also destroys tumor as a result) or with liquid nitrogen (freezing and thawing the tumor in place, often killing remaining cells). A bone graft is often used to try to reconstruct the area as well. In some cases, the tumor can be removed as one piece without damaging other tissues, and in these cases a bone graft may be performed as well. Conventional giant cell tumors have a risk of recurrence where they start, and have a low but real chance of metastasis to the lungs. Giant cell tumors must be differentiated from aneurysmal bone cysts,
Adamantinoma
This is a very rare tumor of cells that are associated with bone formation that are may be similar to the cells responsible for forming teeth. The latter cells can form cancers of the lower jaw more than the upper jaw, termed ameloblastoma. Adamantinoma nearly always affects the tibia, and is treated with surgery. Rare cases can travel elsewhere in the body, at which point chemotherapy is used to try and increase lifespan.
Chordoma
Chordoma is a tumor that appears very similar to the cells that fetal cells that formed the spine during development, the notochord. The relationship to development of the bone while the fetus is growing in the uterus is hard to understand, since tumors of this sort typically only arise in people over age 50. It typically occurs at the base of the skull, or in the sacrum (the very base of the spine in the pelvis). Given these locations, surgical removal is often times not possible. This is one tumor that can respond to radiation, with an intent to cure even tumors that are not surgically removable, and is an ideal type of tumor with which to try proton beam radiation. For tumors that recur, there are hints that imatinib (Gleevec) may be of some use, and only infrequently are responses seen to other chemotherapy drugs.
Sarcomas of bone that arise more commonly in soft tissue:
Other sarcomas that typically occur in soft tissue in adults that can also occur in bone. These include malignant fibrous histiocytoma (MFH [also termed high grade undifferentiated pleomorphic sarcoma or HGUPS]), fibrosarcoma, leiomyosarcoma, and angiosarcoma, among others. Please see the similar section under "Soft Tissue Sarcomas" for details. While leiomyosarcoma of bone is typically treated with surgery alone, many physicians treat MFH of bone like other osteogenic sarcomas, using chemotherapy and surgery as the mainstay of treatment.