ON THIS PAGE: You will find out more about what factors increase the chance of this type of cancer. To see other pages in this guide, use the colored boxes on the right side of your screen, or click “Next” at the bottom.
A risk factor is anything that increases a person’s chance of developing cancer. Although risk factors often 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.
Currently, the only known cause of retinoblastoma is a genetic mutation (change). This genetic form of retinoblastoma accounts for about 40% of cases and always occurs in very young children (rarely older than one year). When retinoblastoma affects both eyes, it is always a genetic condition. Despite the genetic link, only 10% to 15% of children with retinoblastoma have a family history of the disease. Rarely, the genetic form occurs in only one eye.
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 an additional tumor is higher for 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. If a newborn has a family history of retinoblastoma, the baby should be examined shortly after birth by an ophthalmologist (a medical doctor who specializes in eye care) who is experienced in treating cancers of the eye.
About 60% of children with retinoblastoma do not have the genetic form. They develop a single tumor in only one eye, and they have no increased risk of an additional tumor later in life.
Choose “Next” (below, right) to continue reading this guide to learn about what symptoms this type of cancer can cause. Or, use the colored boxes located on the right side of your screen to visit any section.