Second Cancers After Retinoblastoma
Children with the hereditary form of retinoblastoma have a much higher risk for developing other types of cancer throughout their lives. This is because each cell in the body has an abnormal RB1 tumor suppressor gene, which would normally help stop some of these cancers from forming.
The risk for these cancers is even higher in any parts of the body that received radiation during treatment for retinoblastoma. Younger children treated with radiation therapy are more likely than older children to develop side effects such as second cancers or problems with bone growth in the irradiated area. Chemotherapy with certain drugs can also increase the risk of some cancers.
Most of these cancers are very treatable if detected early, which is why it is very important that these children are followed closely throughout life. The entire body must be examined carefully to avoid missing these second cancers.
The most common second cancers among retinoblastoma survivors include:
- Osteosarcoma (a type of bone cancer)
- Soft tissue sarcomas (cancers that develop in muscle, tendons and ligaments, and fatty tissue)
- Melanoma (a type of skin cancer)
- Lung cancer
- Bladder cancer
- Uterine cancer
- Breast cancer
- Brain tumors
- Cancers in the mouth or nose
Because of the increased risk these children face, it’s important that they’re taught about other factors that might increase their risk of cancer as they get older. For example, too much sun exposure can increase the risk of melanoma even further, and smoking can increase lung cancer risk, so avoiding these types of risk factors is very important. It’s also important to know what types of cancer screening tests these children might need as they get older. Of course, these children are also at risk of other cancers as they get older, just like children who did not have retinoblastoma.
Children with hereditary retinoblastoma also have a small risk of developing a tumor in the pineal gland within a few years. (This is known as trilateral retinoblastoma.) The pineal gland is a bean-sized structure lying under the middle of the brain. It can have cells similar to retina cells, which is why tumors can start there. This is why doctors often recommend that MRI scans of the head be done regularly for up to 5 years to try to detect such tumors as early as possible.
Non-hereditary (sporadic) retinoblastoma
Children who do not have the hereditary form of retinoblastoma don’t have the RB1 gene change in all of their cells, so they don’t have such a high risk of other cancers. Still, their risk of some cancers might be higher from getting chemotherapy and/or radiation therapy. These children are also at risk for other cancers as they get older, just like children who did not have retinoblastoma.
Last Medical Review: March 12, 2015 Last Revised: March 12, 2015