From a review of the records of 2,302 patients with retinoblastoma collated from CPMC and AFIP, it was found that retinoblastoma patients who survived their original eye cancer have a high incidence of second nonocular malignancies. The second neoplasms occur almost exclusively (97.5%) in patients who have had bilateral retinoblastoma, although retinoblastoma is much more commonly unilateral. The second neoplasms have appeared between 1 and 42 years after the successful treatment of retinoblastoma and have been fatal in approximately 85% of cases. Seventy-one percent of patients develop tumors in the field of the radiation beam; many of these were following treatment with low doses of radiation and after short latent periods. Nineteen percent of patients develop tumors clearly out of the field of radiation (eg, osteogenic sarcoma of the femur). Retinoblastoma patients appear to be unusually radio-sensitive to low doses of radiation and develop tumors in the field of radiation following treatment of 3,500 rads. They have a high incidence of nonocular tumors clearly distant from the radiation beam develop nonocular malignancies even if no radiation has been given. The incidence of multiple malignancies in patients successfully treated for retinoblastoma appears to be higher than for any other primary malignancy whether they receive radiation or not.
