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A risk factor is anything that increases a person’s chance of getting a disease such as cancer. Different cancers have different risk factors.

Lifestyle-related risk factors such as body weight, physical activity, diet, and tobacco use play a major role in many adult cancers. But these factors usually take many years to influence cancer risk, and they are not thought to play much of a role in childhood cancers, including retinoblastomas.

There are very few known risk factors for retinoblastoma.

Age

Most children diagnosed with retinoblastoma are younger than 3 years old. Most congenital (heritable) retinoblastomas are found during the first year of life, while non-heritable retinoblastomas tend to be diagnosed in 1- and 2-year-olds. Retinoblastomas are rare after age 6.

Heredity

The risk of retinoblastoma is much higher in children with a parent who had the congenital (heritable) form of retinoblastoma. This form often results in tumors in both eyes (bilateral retinoblastoma).  

But for most children with retinoblastoma, there is no family history of the disease. This is true whether they have the heritable or non-heritable form of retinoblastoma.

On the other hand, children with the heritable form of retinoblastoma have a 1 in 2 chance of eventually passing on the RB1 gene change that causes the tumor to their children. Children with the non-heritable form do not pass on an increased risk.

To learn more about the causes of the heritable and non-heritable forms of retinoblastoma, see What Causes Retinoblastoma?

Unclear risk factors

Some studies have suggested some parental factors that might be linked to an increased risk of retinoblastoma, such as:

• Diets low in fruits and vegetables among mothers during pregnancy
• Exposure to chemicals in gasoline or diesel exhaust during pregnancy
• Exposure of fathers to radiation
• Older age among fathers

The possible link between these factors and retinoblastoma is still being studied.