Retinoblastoma screening
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Retinoblastoma Microchapters |
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Retinoblastoma screening On the Web |
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Risk calculators and risk factors for Retinoblastoma screening |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Simrat Sarai, M.D. [2]
Overview
According to the United States Preventive Services Task Force, screening for retinoblastoma is not recommended. There is no widely accepted screening protocol of retinoblastoma for the general population. However, children at increased risk of retinoblastoma based on known 13q deletion or family history should be evaluated by an ophthalmologist shortly after birth. In all offsprings and siblings of patients with retinoblastoma, screening dilated fundus examinations are recommended.[1]
Screening
There is no widely accepted screening protocol of retinoblastoma for the general population. However, children at increased risk of retinoblastoma based on known 13q deletion or family history should be evaluated by an ophthalmologist shortly after birth.
- Screening should then be conducted every 1 to two months during the first two years of life. After that screening should be conducted every three to four months until the child is three to four years of age, and every six months until five to six years of age unless genetic testing of the child reveals that he or she does not have the germline mutation identified in the affected relative, in which case screening examinations are not necessary. Retinoblastoma surveillance examinations are usually performed with the patient under general anesthesia to permit complete detailed examination of the ocular fundus.[2].
- There is 50 percent risk of passing the mutation on to their offspring in patients with bilateral retinoblastoma, unilateral retinoblastoma with a family history, or unilateral retinoblastoma with a proven RB1 somatic mutation. The risk of retinoblastoma may also be increased among siblings of a patient with retinoblastoma as one parent may have somatic mosaicism for the RB1 deletion or may be a silent carrier of RB1 mutation.[3] The magnitude of risk among offspring of the proband depends upon the tumor presentation in the proband (ie, unilateral or bilateral; unifocal or multifocal). The magnitude of increased risk among siblings of the proband depends upon the genetic status of the parents and the proband.
- Trilateral retinoblastoma is a well-recognized syndrome that occurs in 5% to 15% of patients with heritable retinoblastoma and is defined by the development of an intracranial midline neuroblastic tumor, which typically develops between the ages of 20 and 36 months.
- Given the poor prognosis of trilateral retinoblastoma and the short interval between the diagnosis of retinoblastoma and the occurrence of trilateral disease, routine neuroimaging could potentially detect most cases within 2 years of first diagnosis. Although it is not clear whether early diagnosis can impact survival, screening with MRI has been recommended as often as every 6 months for 5 years for those suspected of having heritable disease or those with unilateral disease and a positive family history. CT scans are generally avoided for routine screening in these children because of the perceived risk of exposure to ionizing radiation. At the time of diagnosis, patients who are asymptomatic of an intracranial tumor have a better outcome than do patients who are symptomatic.
- Approximately 5% to 10% of children with heritable retinoblastoma develop pineal gland cysts detected by MRI; these cyst abnormalities must be distinguished from the pineoblastoma that typically defines trilateral retinoblastoma.
- The American Academy of Pediatrics recommends red reflex testing infants, neonates, and children before discharge from the neonatal nursery and at all subsequent routine health clinic visits. Abnormal red reflex requires immediate referral to an ophthalmologist. As some children with retinoblastoma present with strabismus, all children with strabismus should be evaluated through a dilated eye exam for retinoblastoma. Screening dilated fundus examinations on all offspring and siblings of patients with retinoblastoma are recommended.
- Proposed fundus screening guidelines, based on the absolute risk, depending on the clinical context or genetic testing.[1]
| Clinical context or genetic testing | Risk to carry germinal RB1 mutation | Overall RB risk for the childa (%) | Fundus screening protocol recommendations |
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Abbreviations: RB, retinoblastoma; RB1, retinoblastoma gene.
a-The risk is computed assuming a 90% penetrance of the disease and a 50% risk to inherit the mutated allele from a parent. For unaffected parents of a bilaterally affected child, the risk to carry germinal mutation for each parent is 5%.
b-Or unilateral retinoblastoma with multifocal tumours.
References
- ↑ 1.0 1.1 Rothschild, P-R; Lévy, D; Savignoni, A; Lumbroso-Le Rouic, L; Aerts, I; Gauthier-Villars, M; Esteve, M; Bours, D; Desjardins, L; Doz, F; Lévy-Gabriel, C (2011). "Familial retinoblastoma: fundus screening schedule impact and guideline proposal. A retrospective study". Eye. 25 (12): 1555–1561. doi:10.1038/eye.2011.198. ISSN 0950-222X.
- ↑ Pizzo, Philip (2011). Principles and practice of pediatric oncology. Philadelphia, PA: Wolters Kluwer/Lippincott Williams & Wilkins Health. ISBN 160547682X.
- ↑ Rushlow D, Piovesan B, Zhang K, Prigoda-Lee NL, Marchong MN, Clark RD; et al. (2009). "Detection of mosaic RB1 mutations in families with retinoblastoma". Hum Mutat. 30 (5): 842–51. doi:10.1002/humu.20940. PMID 19280657.