Overview Osteosarcoma usually starts in osteoblasts, which are a type of bone cell that grows into new bone tissue. Osteosarcoma is most common in teenagers and young adults. It typically forms in the ends of the long bones of the body, which include bones of the arms and legs. In children and teenagers, it often develops around the knee. Rarely, osteosarcoma may be found in soft tissue or organs in the chest or abdomen.
Osteosarcoma is the most common type of bone cancer. Malignant fibrous histiocytoma (MFH) of bone is a rare tumor of the bone. It is treated like osteosarcoma.
These and other symptoms may be caused by osteosarcoma. Other conditions may cause the same symptoms. Consult a doctor if any of the following problems occur:
• Swelling over a bone or bony part of the body. • Pain in a bone or joint. • A bone that breaks for no known reason.
Treatment Different types of treatment are available for children with osteosarcoma or malignant fibrous histiocytoma (MFH) of bone. Some treatments are standard (the currently used treatment, often referred to as “standard of care”), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.
Because cancer in children is rare, taking part in a clinical trial should be considered. Some clinical trials are open only to patients who have not started treatment.
Four types of standard treatment are used:
Surgery Surgery to remove the entire tumor will be done when possible. Chemotherapy may be given first, to make the tumor smaller so less tissue and bone needs to be removed. This is called neoadjuvant chemotherapy.
The following types of surgery may be done:
• Wide local excision: Surgery to remove the cancer and some healthy tissue around it. • Limb-sparing surgery: Removal of the tumor in a limb (arm or leg) without amputation, so the use and appearance of the limb is saved. Most patients with osteosarcoma in a limb can be treated with limb-sparing surgery. The tumor is removed by wide local excision. Tissue and bone that are removed may be replaced with a graft using tissue and bone taken from another part of the patient's body, or with an implant such as artificial bone. If a fracture is found at diagnosis or during chemotherapy before surgery, limb-sparing surgery may still be possible in some cases. If the surgeon is not able to remove all of the tumor and enough healthy tissue around it, an amputation may be done. • Amputation: Surgery to remove part or all of an arm or leg. This may be done when it is not possible to remove all of the tumor in limb-sparing surgery. The patient may be fitted with a prosthesis (artificial limb) after amputation. • Rotationplasty: Surgery to remove the tumor and the knee joint. The part of the leg that remains below the knee is then attached to the part of the leg that remains above the knee, with the foot facing backward and the ankle acting as a knee. A prosthesis may then be attached to the foot.
Studies have shown that survival is the same whether the first surgery done is a limb-sparing surgery or an amputation.
Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.
Chemotherapy Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). Combination chemotherapy is the use of more than one anticancer drug. The way the chemotherapy is given depends on the type and stage of the cancer being treated.
Radiation therapy Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Osteosarcoma and MFH cells are not killed easily by radiation therapy. It may be used when a small amount of cancer is left after surgery or used together with other treatments.
Samarium Samarium is a radioactive drug that targets areas where bone cells are growing, such as tumor cells in bone. It helps relieve pain caused by cancer in the bone and it also kills blood cells in the bone marrow.
Treatment with samarium may be followed by stem cell transplant. Before treatment with samarium, stem cells (immature blood cells) are removed from the blood or bone marrow of the patient and are frozen and stored. After treatment with samarium is complete, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body's blood cells.
