Retinoblastoma

Abstract Retinoblastoma is the commonest malignant eye tumor of childhood affecting 15 per 100,000 live births. Children predisposed to hereditary retinoblastoma as a result of carrying a mutant RB1 allele usually develop bilateral disease, but may be having only unilateral disease. However, only 10% of children have familial retinoblastoma, and most germline RB1 alleles are novel. Discussion here will center on prognostic risk factors for retinoblastoma at three levels: risk of developing retinoblastoma; risk of losing the eye with intraocular disease despite current therapies; and risk of death due to metastatic disease in spite of the best therapies. No multicenter clinical trials have been conducted to evaluate systematic therapy for intraocular or extraocular retinoblastoma. Such trials will require global collaboration. Since 1990, chemotherapy with focal (laser and cryo) therapy has replaced external beam radiation (EBRT) as primary therapy, to avoid the severe long‐term side effect of EBRT. However, EBRT remains a valuable tool to salvage eyes that fail chemotherapy/focal therapy. With full molecular analysis 93% of RB1 mutant alleles can be identified, supporting accurate identification of infants at risk, facilitating early diagnosis and intervention and vastly improving visual outcome and saving eyes in the long run. The 2002 TNM classification for metastatic retinoblastoma does not reflect differences in outcome for disease affecting the CNS versus bone marrow. Whereas, the newly proposed International Retinoblastoma Classification (IRC) addresses these issues. Current treatment of metastatic retinoblastoma offers hope. “Cure” with long‐term follow‐up is possible with chemotherapy, orbital and focal radiation, intrathecal chemotherapy, and bone marrow/stem cell transplant.