The incidence of retinoblastoma.

Data from the Third National Cancer Survey indicate that the annual incidence of retinoblastoma in the United States is 11.0 new cases per million children under the age of 5 years. In response to a reported excess of mortality among blacks, rates were computed by race. There was a rate of 10.8 cases per million children for the whites compared to 9.8 cases per million for the blacks. Among the total of 61 newly diagnosed cases reported among residents of the survey area, the 50 unilateral cases occurred in 24 boys and 26 girls, whereas the 11 bilateral cases occurred in nine girls and only two boys. The reasons for a female preponderance among the bilateral cases remain unclear.