Retinoblastoma (RB)

Clinical Features

Retinoblastoma (RB) is the most common intraocular cancer in childhood, with onset usually before 5 years of age. Incidence is one case per 15,000-20,000 livebirths worldwide. The most common presenting sign of RB is a white pupillary reflex (leukocoria), which reflects light (e.g. photographic flash) and blocks view of the red retina. Heritable retinoblastoma presents at a younger age than does non-heritable disease (Dimaras et al. Lancet. 2012; 379(9824): 1436-46). Approximately 40% of patients affected with RB are affected unilaterally and 60% of patients bilaterally. Children with germline RB1 mutations are also at a risk of pinealomas which occur in the pineal gland of the brain. Other cancers which typically occur later in adolescent or adult life are osteosarcomas, soft tissue sarcomas, or melanomas (Lohmann and Gallie; GeneReviews. 2013; ncbi.nlm.nih.gov/books).

Prevention

The overall survival rate for patients with early staged RB is 95% (Leal-Leal et al., Clinical Oncology. 2006; 8(1): 39-44). Cancers detected at advanced stages have a low survival rate making genetic testing crucial to begin chemotherapy, cryotherapy, and avoid radiation (Thompson and Thompson, Genetics in Medicine. 2007; 7: 302-303).

Chemotherapy

Chemotherapy has proven successful but only when treating tumors in early stages lacking extensive subretinal seeding and/or vitreous seeding (Villablanca et al., Archives of Opthalmology. 1996; 114(1): 1348-1356). A study done on patients with retinoblastoma showed that those with earlier staged cancer and treated with chemotherapy avoided enucleation and showed an 89% relapse-free rate. This study suggested early staged retinoblastomas could be cured by combining cyclosporine, laser, and cryo-therapies (Budning et al., Arch. of Ophthal. 1996; 114(11): 1321-1328).

Cryotherapy

Studies done on patients with RB treated initially with cryotherapy showed 20/21 patients were cured. Cryotherapy has also proven very successful as a secondary treatment option with an 85% success rate. However, cryotherapy fails once the disease has progressed to developing implantation seeds, making early diagnosis critical (Abramson et al., Archives of Ophthalmology. 1982; 100(8): 1253-1256).

Radiation Avoidance

Patients diagnosed with RB should avoid radiation as much as possible to prevent secondary tumors from arising (Lohmann and Gallie; GeneReviews. 2013; ncbi.nlm.nih.gov/books). A study done on patients with RB showed that the incidence of subsequent cancers was significantly elevated when treated with radiation treatment (Wong et al., JAMA. 1997; 278(15): 1262-1267).

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Disclaimer

This article is a summary of information that has been reported in the biomedical research literature. It is not medical advice for patients. All disease treatments should be under the direction of a qualified healthcare provider.

Last Updated: 4/10/2017