Osteosarcoma is marked by:
- Pain in the bone that is sometimes worse at night or during exercise and isn't helped by pain relievers
- A lump or swelling in a child's arm or leg that develops up to several weeks after the pain. This usually occurs in the longer bones of the body
- An unexplained limp
- Unexplained bone fractures
- Weight loss
Causes and Risk Factors
Osteosarcoma is caused by genetic errors that occur during times of intense bone growth. It usually develops from osteoblasts, the cells that make bone grow. As a result, it usually affects teens who are having a growth spurt. People who develop osteosarcoma are typically between the ages of 10 and 25.
Most often, osteosarcoma involves the knee. It usually is found in the growing ends of the bones, the metaphysis.
Boys are more likely to develop osteosarcoma than girls. There is some evidence showing that teens who are taller than average have a greater risk of developing osteosarcoma.
Children who have inherited one of the rare cancer syndromes such as retinoblastoma or Li-Fraumeni also have a higher risk of developing osteosarcoma. Because radiation can trigger genetic mutations, children who have received radiation treatment for cancer have a greater risk of developing osteosarcoma.
There is no evidence that an injury can cause osteosarcoma to develop.