THE METASTATIC RISK IN RETINOBLASTOMA

580 patients with retinoblastoma were analysed retrospectively. Median follow up was 5.5 years. 41 patients developed metastases within 5 years. Clinical and histopathological risk factors were analysed by univariate tests with regard to the occurrence of metastases. Significant variables were then reevaluated using Cox proportional hazards method. Four factors correlated independently with the development of metastases: optic nerve invasion with involvement of the resection line, optic nerve invasion without involvement of the resection line, choroidal invasion and enucleation of an affected eye more than 120 days after initial diagnosis. The regression coefficient-beta of the Cox-model was used for a score classification with groups of high, medium and low metastatic risk. The 5-year incidence of metastases was 68%, 43% and 4% respectively.