A team of Canadian and international cancer researchers led by Dr. Brenda Gallie at the Princess Margaret Cancer Centre, University Health Network (UHN), has discovered a new type of retinoblastoma, a rapidly developing eye cancer that affects very young babies- a finding that can immediately change clinical practice and optimize care for these children.
The finding, published online today in Lancet Oncology, is a breakthrough in recognizing that a single cancer gene (an oncogene) drives an aggressive retinoblastoma that starts long before birth in families with no history of the disease, says surgeon Dr. Gallie, an ophthalmologist who is also affiliated with The Hospital for Sick Children (SickKids) and a Professor in the Faculty of Medicine, University of Toronto.
"This research completely challenges conventional thinking and clinical practice," says Dr. Gallie. "The common type of retinoblastoma is initiated by damage to both copies of the RB1 tumor suppressor gene; the predisposition to this type of retinoblastoma can be inherited, so the other eye of the child and those of infant relatives are at risk to develop tumours. When we remove the eye with a large tumour in very young babies and show it is the new oncogene-driven type of retinoblastoma, there is believed to be zero risk for retinoblastoma developing in the other eye or in other infants in the family. This is a major advance in personalized cancer medicine for these children and families."
The oncogene-driven tumours are much larger than those anticipated in children with inherited retinoblastoma at the same age. "The earliest diagnosis comes when parents observe a white (instead of black) pupil of the eye, and the doctors listen to their observations and understand the urgency of referral. Sometimes Mom really does know best and clinicians should pay close attention."