Outcomes of integrating genetics in management of patients with retinoblastoma.

OBJECTIVE: To present the outcome of a comprehensive team approach to provide genetic evaluation and testing for a large cohort of children diagnosed with retinoblastoma.
METHODS: The multidisciplinary team included pediatric oncologists, an ophthalmologist, an ophthalmic pathologist, a geneticist, and genetic counselors. Retrospective data from 8 years included 90 initial evaluations, of which 81 probands were diagnosed with retinoblastoma (34 bilateral and 47 unilateral) and 9 were evaluated because of a positive family history.
RESULTS: Genetic testing was accomplished equivalently in bilateral and unilateral cases in 51 of 81 patients (63%). In 5 of 30 patients (17%), with unilateral disease an RB1 mutation was identified in peripheral blood samples. In another 7 of 30 patients (23%), mutation analysis confirmed the occurrence of sporadic retinoblastoma. Overall, genetic testing of 48 at-risk family members from 21 families revealed 6 individuals positive and 42 negative for the familial mutation.
CONCLUSIONS: Our study emphasizes that genetics can be incorporated into the management plan of all retinoblastoma patients using a team approach to ensure timely evaluations and appropriate counseling. Genetic evaluations improved risk prediction for patients and family members as well as prevented overutilization of clinical screening tests, which had potential morbidity for relatives documented to not carry an RB1 mutation.