Pediatric Retinoblastoma Statistics

Pediatric retinoblastoma is a rare form of children’s cancer; about four percent of all childhood cancer is retinoblastoma. Since cancer in children is rarer than in adults, retinoblastoma diagnoses make up only about one percent of all cancer diagnoses. Approximately one in 15,000 children is diagnosed with pediatric retinoblastoma per year. In the United States, about 250 to 300 cases are diagnosed per year; most patients are under the age of five.

Pediatric Retinoblastoma Statistics by Type

Pediatric retinoblastoma is either hereditary or non-hereditary. About 40 percent of all cases are hereditary retinoblastoma. Nearly all cases of non-hereditary retinoblastoma are unilateral, meaning that the tumor affects only one eye. While this is easier to treat, it is harder to diagnose, so the average age at which non-hereditary retinoblastoma is diagnosed 24 months compared to about 14 months for hereditary retinoblastoma.

Hereditary Retinoblastoma

Since those born with hereditary retinoblastoma have an abnormality in the retinoblastoma genes within all body cells, about eight percent of hereditary retinoblastoma patients develop a second cancer. Bilateral retinoblastoma, or cancer in both eyes, is also much more common. Only about 25 percent of those patients diagnosed with hereditary retinoblastoma have a family history of the disease. The gene abnormality does not display symptoms in all cases, and about 10 percent of patients that carry it do not develop retinoblastoma. Many parents are unaware of carrying the gene abnormality until children are born with retinoblastoma.

Non-hereditary Retinoblastoma

A gene abnormality also causes non-hereditary retinoblastoma, which encompass about 60 percent of retinoblastoma cases. However, this abnormality is only present in one cell of the retina, which greatly decreases the risk of developing a second cancer. The odds of having a second child with non-hereditary retinoblastoma are about one percent.

Pediatric Retinoblastoma Treatment Statistics

The cure rate for pediatric retinoblastoma is high, and about 90 percent of all patients that are diagnosed survive at least five years. However, studies are beginning to link radiation therapy and chemotherapy with an increased likelihood of developing secondary cancers in those that have the hereditary form of the disease. In studies, surgery to remove the eye was the treatment that carried the least like likelihood of developing secondary cancers, but vision cannot be saved in eyes that are removed so surgery is often reserved as a last resort.

In one study, about 30 percent of patients that had undergone radiation therapy developed secondary cancers, compared to about nine percent of non-irradiated patients. The patient’s age at the time of radiation therapy was a large factor in this study, with those under 12 months being at the highest risk. Chemotherapy has been shown to slightly increase this risk, but incidence rates were much less than with radiation therapy, and it is considered a safer alternative.