Retinoblastoma

Retinoblastoma (Rb) is a rare malignant tumor of the retina and the most common primary intraocular cancer of childhood. It arises from immature retinal cells (retinoblasts) and is caused by biallelic inactivation of the RB1 tumor suppressor gene located on chromosome 13q14. The disease can present in heritable (approximately 40% of cases) or non-heritable (approximately 60%) forms. Heritable retinoblastoma typically presents earlier, is often bilateral or multifocal, and carries an increased lifetime risk of secondary non-ocular malignancies, particularly osteosarcoma and soft tissue sarcomas. Non-heritable retinoblastoma is usually unilateral and unifocal. The hallmark presenting sign is leukocoria (a white pupillary reflex), often noticed in photographs. Other common signs include strabismus (misalignment of the eyes), eye redness, eye pain, poor vision, and in advanced cases, proptosis (bulging of the eye) or signs of orbital or metastatic disease. The tumor can grow inward toward the vitreous cavity (endophytic), outward toward the choroid (exophytic), or diffusely within the retina. If untreated, retinoblastoma can spread along the optic nerve to the brain, or metastasize hematogenously to the bone, bone marrow, and other organs, which can be fatal. Treatment depends on the laterality, stage, and extent of disease, and aims to preserve life, then the eye, and then vision whenever possible. Current treatment options include systemic intravenous chemotherapy (chemoreduction), intra-arterial chemotherapy (delivered directly to the ophthalmic artery), intravitreal chemotherapy, focal therapies such as laser photocoagulation, cryotherapy, and thermotherapy, external beam radiation therapy (now used less frequently due to secondary cancer risk in heritable cases), and enucleation (surgical removal of the eye) for advanced unilateral disease. With early diagnosis and modern multimodal treatment, survival rates in developed countries exceed 95%. Genetic counseling and surveillance of at-risk family members are essential components of management.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Retinoblastoma