A risk factor is something that increases the risk of developing cancer. It could be a behaviour, substance or condition. Most cancers are the result of many risk factors. But sometimes childhood bone cancer develops in children who don’t have any of the risk factors described below.
Osteosarcoma is the most common type of childhood bone cancer. The risk for this cancer is highest during the growth spurt in the teenage years. It occurs slightly more often in boys and in children of African ancestry.
Ewing sarcoma is the second most common bone tumour in children. It is slightly more common in boys than girls and usually develops in the teenage years. Ewing sarcoma is significantly less common in children of African ancestry.
There are no known risk factors for Ewing sarcoma. The following are risk factors for childhood osteosarcoma. All of the known risk factors for childhood osteosarcoma are not modifiable. This means that you can’t change them. Until we learn more about these risk factors, there are no specific ways to reduce the risk of childhood osteosarcoma.
Risk factors are generally listed in order from most to least important. But in most cases, it is impossible to rank them with absolute certainty.
There is convincing evidence that the following factors increase a child’s risk for osteosarcoma.
Genes are the basic biological unit of heredity passed from parents to a child. A genetic syndrome is a group of conditions or symptoms caused by a mutation (change) in one or more genes. Having any of the following genetic syndromes can raise the risk of developing childhood osteosarcoma.
Retinoblastoma is an eye cancer that occurs in children. It can be passed from parents to a child. Children with the inherited form of retinoblastoma have a higher risk of developing osteosarcoma and soft tissue sarcoma.
Li-Fraumeni syndrome is a rare inherited condition. It greatly increases the risk of developing several types of cancer in children and young adults, including osteosarcoma, rhabdomyosarcoma and other soft tissue sarcomas, breast cancer, brain tumours and leukemia.
Rothmund-Thompson syndrome is an inherited condition that affects a child’s growth and causes skeletal problems and skin rashes. Children with Rothmund-Thompson syndrome are more likely to develop osteosarcoma.
Werner syndrome is an inherited condition that causes children to age very rapidly after puberty. Werner syndrome increases the risk of developing osteosarcoma and other cancers.
Bloom syndrome is an inherited condition caused by a large number of abnormalities in the chromosomes. (A chromosomes is the part of a cell that contains genetic information.) A child with Bloom syndrome is usually smaller than average and has a high-pitched voice and characteristic facial appearance. Bloom syndrome increases the risk of developing osteosarcoma and other childhood cancers, including leukemia and Wilms’ tumour.
Children who recieved radiation therapy have a higher risk of developing osteosarcoma in the area that was treated with radiation. The risk is greater if higher doses of radiation therapy were used and if the child was treated at a young age. Osteosarcoma typically occurs 5–20 years after radiation therapy.
Children who received certain types of chemotherapy have a higher risk of developing osteosarcoma. The risk may be increased if the child also received radiation therapy.
Children with certain bone diseases, such as Paget disease of the bone, have a higher risk of developing osteosarcoma later in life (usually as an adult). Paget disease of the bone is a condition that affects the bone so that it breaks down and regrows faster than normal. It causes abnormal bone tissue to form, which makes bones heavier, thicker, weaker and more likely to break than normal bones.
It isn’t known whether or not fluoride in drinking water is linked with childhood osteosarcoma. It may be that researchers can’t show a definite link or that studies have had different results. Further study is needed to see if fluoride is a risk factor for osteosarcoma in children.
Ask your child’s healthcare team questions about risks.