What is Osteosarcoma and How Is It Treated?

Osteosarcoma is a type of cancer that starts in the bones—particularly in osteoblasts, immature bone cells that form bone tissue. Tumors usually form at the end of the long bones of the body, such as the arms and legs, where the bone grows quickly.

Osteosarcoma can develop at any age, but it occurs mostly in children and adolescents. It is a rare form of cancer with only about 600 people developing osteosarcoma each year in the United States. Symptoms include swelling over a bone, joint pain, and a bone that seemingly breaks for no reason.

Some people are at a higher risk of developing osteosarcoma, such those who have had past cancer treatment with radiation therapy and those with certain genetic conditions that increase the risk of cancer, such as Li-Fraumeni syndrome, hereditary retinoblastoma, and Rothmund-Thompson syndrome.

How is osteosarcoma treated?

Standard treatment includes surgery and chemotherapy. Chemotherapy is often given before surgery in order to decrease swelling around the tumor and in order to give the surgeon time to plan the proper operation. Specialized surgeons, orthopedic oncologists, surgically remove the entire tumor. Most patients can be treated with a limb-sparing surgery, during which the doctor removes the tumor and some of the surrounding healthy tissue from an arm or leg, and then replaces the removed bone and tissue with a graft of a donor bone or sometimes from the patient’s own body. Alternatively, a metal implant is used to replace the bone.

Osteosarcoma cells. Source: Dr. Lance Liotta Laboratory
Osteosarcoma cells. Source: Dr. Lance Liotta Laboratory

Sometimes it is not possible to remove the entire tumor and reconstruct the removed bone and soft tissue. This can happen when the tumor is very large or when it involves vital structures like major blood vessels or nerves, or when a patient is so young that the reconstruction would not be able to make up for all the remaining growth in the limb. When this is the case, an amputation or rotationplasty is performed and the patient is fitted with an external prosthesis after surgery. Less often, radiation therapy is used when a small amount of cancer cells remain after surgery.

Rotationplasty, a partial amputation that preserves a cancer-free lower leg and foot, is another option. This surgical option allows the child to maintain an active lifestyle, including high-impact sports, but often preserves a longer limb than with standard amputation.

All patients receive chemotherapy after surgery to kill any lingering cancer cells and to lower the risk of cancer recurring.

Researchers at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center are leading a number of studies in osteosarcoma. Research studies are underway to discover master regulators in osteosarcoma, which are key processes that the cancer cells rely on in order to survive. Additionally, several clinical trials of new drugs for patients who have had osteosarcoma come back or recur are being conducted. Finally, investigators are evaluating and comparing function and quality of life in patients who have had limb salvage surgery, amputation, or rotationplasty.

Learn more about osteosarcoma from Dana-Farber/Boston Children’s Cancer and Blood Disorders Center.