Risk Factors

A risk factor is anything that increases a person’s chance of developing cancer. Some risk factors can be controlled, such as smoking, and some cannot be controlled, such as age and family history. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do.

When retinoblastoma affects both eyes, it is always a genetic condition, even though only 10% to 15% of children with retinoblastoma have a family history of the disease. Rarely, the genetic form occurs in only one eye. The genetic form of the disease always occurs in very young children (rarely beyond one year old) and increases the child’s risk of developing another cancer later in life. About 60% of children with retinoblastoma do not have the genetic form. They develop a single tumor in only one eye, and there is no increased risk of additional tumors later in life.

Children who have had bilateral retinoblastoma or the hereditary form of unilateral retinoblastoma are at increased risk for developing other types of cancer; the risk of additional tumors is higher in those children who receive radiation therapy to the orbit (eye socket) to preserve vision or to other parts of the body where the tumor has spread.