Second primary tumors in patients with retinoblastoma. A review of the literature.

PURPOSE The aim of this survey was to review the different studies regarding the occurrence of second primary tumours (SPT) among survivors of retinoblastoma. METHODS Ovid (Medline, Current contents life, Psychlit, Embase) was searched for the years 1966-1995 using the mesh headings: 'retinoblastoma', 'second primary neoplasms', and 'multiple primary neoplasms'. The inclusion criteria were: the study should involve 50 patients or more and should not be limited to one specific SPT. A checklist with criteria regarding the study design and the results was applied to each study. RESULTS Eleven studies were identified which met the inclusion criteria. Thirty-five different types of SPT (Ntotal = 243) were reported. Most of them were osteosarcomas (37.0%), followed by melanomas (7.4%), soft-tissue sarcomas (6.9%), brain tumors (4.5%), fibrosarcomas (3.3%), chondrosarcomas (3.3%), and sarcomas (3.3%). Less frequently reported were leukemias (2:4%), sebaceous cell carcinomas (1.6%), and non-Hodgkin lymphomas (1.6%). Pineoblastoma, which in fact is a trilateral retinoblastoma and not an SPT, was found in 2.4%. Despite the differences, all 11 studies showed a higher incidence of SPT compared to the general population. Only 4 studies were judged to be free from selection bias, reporting a cumulative incidence of SPT of 8.4% 18 years after diagnosis, 15.7% at the age of 20 years, 19% at the age of 35 years, and a relative risk of 15.4 for SPT, respectively. CONCLUSION SPT is a serious problem for the survivors of hereditary retinoblastoma and its importance should be recognized in (genetic) counseling of patients.