econd nonocular tumor in urvivor of heritable retinoblatoma and prior radiation therapy Original Reearch Article

PURPOE: The principal objective of thi tudy were to etimate the incidence of econd tumor among children treated for heritable retinoblatoma during a 50-year period and to invetigate the relationhip between thee tumor and previou radiation therapy. METHOD: The record of all retinoblatoma patient examined at the Mayo Clinic from 1941 through 1990 were retropectively reviewed. The therapeutic modality ued to manage the tumor, the occurrence of any econd malignancy, and current follow-up on all patient were evaluated. REULT: Eighty-two (46%) of 180 children with retinoblatoma had bilateral tumor (76 patient) or unilateral dieae and a poitive family hitory (ix patient) and were followed for an average of 21.8 year (range, 1 month to 53 year). The Kaplan-Meier etimate of econd nonocular tumor among the 82 patient with heritable retinoblatoma were 12% at 10 year, 16% at 25 year, and 30% at 40 year. Although 14 of the 15 patient who developed econd malignancie had received radiation therapy, only four of the malignancie occurred within the field of irradiation. CONCLUION: The relatively low incidence of econd tumor among long-term urvivor of heritable retinoblatoma in thi erie of patient occurred predominantly outide the field of irradiation. The variable incidence of econd nonocular malignancie in previou report may reflect variation in radiation technique and doage.