Time to tumour detection in familial retinoblastoma patients: a retrospective study

Abstract

Background: Screening in familial retinoblastoma through regular fundus examination and molecular genetic testing, is recommended to improve prognosis in terms of vision, globe sparing and save life. At The Hospital for Sick Children (SickKids) fundus screening and genetic testing is done in all patients with familial retinoblastoma, while in Kenya there is no formalized screening protocol and genetic testing is not readily available. Objectives: To determine the mean time to first tumour detection, tumour characteristics and outcome in familial retinoblastoma patients seen at SickKids, Toronto, Canada and Kenyatta National Hospital (KNH), Nairobi, Kenya. Design: Retrospective descriptive study. Subjects: Familial retinoblastoma patients at SickKids from July 1, 1993 to September 30, 2013, for KNH, upto when all the medical files could be retrieved. Data collected included patient demographics, disease characteristics, treatment course and outcomes. Results: A total of 32 patients were reviewed; 20 (63%) were from SickKids and 12 (37%) from KNH. SickKids patients were all bilateral (20/20, 100%), compared to 7/12 (58%) of KNH. The mean time to detection of first tumour was 3.8 months from birth for SickKids and 25 months for KNH. Tumours were diagnosed at birth in 13/40 (33%) of eyes at SickKids while none at KNH. At SickKids most eyes were IIRC Group A (17/34, 43%) or Group B (15/34, 38%). None of the patients had extraocular disease. At KNH, affected eyes were at more advanced stage: IIRC Group D (8/24, 33%) and E (4/24, 17%) with 4/24 (17% eyes) having extraocular disease. All patients were treated using focal therapy at SickKids, (96% had laser photocoagulation). Only 2 (5%) patients had enucleation, while at KNH, all patients had enucleation, (unilateral or bilateral); with half of them receiving additional chemotherapy. At SickKids, 75% of salvaged eyes had vision between 20/20 and 20/60, with 8% having vision less than 20/200. In two eyes (5%) vision was assessed as central, steady and maintained. At KNH, 62.5% of the salvaged eyes had vision reported as fixing and following light, two eyes (25%) had vision better than 20/80. In one eye (12.5%), vision was perception of light. Conclusion: Early diagnosis and better outcomes were observed at SickKids familial retinoblastoma compared to KNH. Recommendation: Develop a screening protocol at KNH for familial retinoblastoma through fundus examination and genetic counseling and testing