Retinoblastoma in Great Britain 1963-2002

Abstract
Aim: This paper describes the epidemiology and family history status of 1601 children with retinoblastoma in Great Britain diagnosed 1963–2002 and summarises the practical consequences for diagnosis and counselling of developments in molecular genetics. Methods: Incidence rates were analysed according to year of diagnosis and tumour laterality. Cases were classified as heritable or non-heritable on the basis of laterality and family history of the disease. Results: There were 998 unilateral cases, 581 bilateral and 22 of unknown laterality. Bilateral cases tended to be diagnosed at a younger age than unilateral. All bilateral cases are regarded as heritable, and 35% had a family history of the disease. 7% of the unilateral cases had a family history and are therefore heritable. Thus, at least (41%) of our cases are heritable. This is an underestimate, since these data on family history are incomplete. For unilateral cases aged below 1 year, the reported incidence rate increased significantly (p<0.0001) by about 2.5% per year; for the age group 1–4 years, the average increase was about 0.5% per year (not significant).