What is osteosarcoma?
A person with an osteosarcoma has abnormal cells in the bone that multiply out of control. These cancerous cells can form tumors and spread to other parts of the body. Osteosarcomas can weaken the bone, making them more prone to fractures. These tumors most commonly occur in the leg or upper arm, but also occur in the pelvis and skull. The cause for osteosarcoma is unknown, genetics may play a role in determining risk. Osteosarcoma is rare: only about 400 cases are reported each year in the US.

What are the symptoms of osteosarcoma?
Symptoms of osteosarcoma may include bone swelling and bone pain that worsens with exercise. Additional symptoms may include deformed bones, joint pains, and limping.

How does the doctor treat osteosarcoma?
Treatment for osteosarcoma may include chemotherapy and surgery to remove the tumor.