Retinoblastoma-a clinical survey and its genetic implications

A clinical, pathological and genetic study was made of 50 patients with retinoblastoma in the Newcastle Hospital region over the period 1931-1970 inclusive. Twenty-seven patients were affected in one eye only; 23 had bilateral tumours. The incidence of the tumour was approximately 1:16,000 live births. Bilateral cases tended to present at a younger age, and were more likely to be familial. In bilateral cases the tumour in the second eye was often detected at an early stage by ophthalmoscopy. In a quarter of the cases there was a considerable interval (up to 10 years) before the second eye was found to be affected. A surprisingly large proportion of eyes with clinically advanced tumour proved to have the tumour histologically confined to the retina. This disparity between clinical and pathological severity emphasises the jusifiability of conservative treatment in the first instance in many cases. Twelve of the 50 patients developed a new tumour, local spread, or reactivation of a treated tumour, over a period ranging from 2 months to 10 years after primary treatment. This finding emphasizes the importance of frequent follow-up of all cases. Follow-up should include the patient's siblings and offspring, even in apparently "sporadic" cases. The of liability to develop retinoblastoma is suggested.