Make genetic testing part of retinoblastoma care
Genetic evaluations performed by a multidisciplinary health care team improved risk prediction for children with retinoblastoma and their family members, and prevented overutilization of clinical screening tests.
Over an 8-year period, 51 youths with retinoblastoma being cared for at Texas Children's Cancer Center in Houston, a facility affiliated with Baylor College of Medicine, also in Houston, underwent genetic testing. A Baylor statement describing the study noted that retinoblastoma is the most common malignant tumor of the eye among children, and although often curable, the disease may cause the loss of an eye.
Some of the patients had bilateral retinoblastoma, a hereditary form of the disease that can affect one or both eyes and is often seen in infants and younger children. Others had unilateral retinoblastoma, which may or may not be hereditary, affects only one eye, and generally occurs in older children.
The testing was performed by a multidisciplinary team consisting of pediatric oncologists, an ophthalmologist, an ophthalmic pathologist, a geneticist, and genetic counselors. Overall, the genetic analysis demonstrated the causative mutation in 90% of patients with bilateral retinoblastoma and documented hereditary disease in 17% of the children with the unilateral form.
These results led to the testing of 48 at-risk relatives, mostly parents and siblings. Only six of those relatives were determined to have the familial mutation and required more extensive screening (Arch Ophthalmol. 2011;129:1428-1434).
Without genetic testing, most relatives of persons with retinoblastoma, particularly infant siblings, undergo eye examinations under anesthesia to screen for tumors, explained senior study author and Baylor professor of pediatric hematology/oncology Sharon E. Plon, MD, PhD, in the Baylor statement. “What we were able to show is that by systematically including genetic testing in the care of retinoblastoma patients, we could eliminate the need for such screening in the majority of relatives and save both health care costs and potential risks of the anesthesia.”