Retinoblastoma in South Africa. A 20-year retrospective study at two tertiary academic hospital in Johannesburg

A dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Medicine in Ophthalmology Johannesburg, 2014Retinoblastoma is the most frequent malignant intraocular tumour of childhood, and in Africa it is the commonest and most important life threatening ocular neoplasm. In resource-rich countries such as the United States and Canada, survival rates for patients with retinoblastoma approach 100%. This is in stark contrast to developing countries where survival rates may be less that 20%. Despite the vast majority of affected patients living in less developed countries, there is little attention and published literature on disease characteristics in these populations. OBJECTIVES: To characterise retinoblastoma in the South African population through a 20-year retrospective analysis of patient records at two tertiary academic hospitals in Johannesburg. DESIGN AND METHOD: Retrospective clinical case series analysis of medical records of patients with retinoblastoma presenting to Charlotte Maxeke Johannesburg Academic Hospital and Chris Hani Baragwanath Academic Hospital between 01 January 1992 and 31 December 2011. RESULTS: The total number of retinoblastoma cases identified was 282, with 245 of these meeting the study inclusion criteria. Retinoblastoma comprised 6.9% of total paediatric oncology presentations. 65.3% were unilateral, 34.3% bilateral and 0.4% trilateral. The overall male to female ratio was 1.08. Mean age at presentation overall was 32.6 months (median 28.0 months), for unilateral 39.4 months (median 33.0 months) and for bilateral 19.7 months (median 17.0 months). The mean delay to presentation overall was 7.0 months (median 4.0 months), for unilateral 8.5 months (median 5.0 months) and for bilateral 4.4 months (median 3.0 months). The most frequent presenting symptoms were leukocoria (37.1%) and proptosis (34.7%). Distribution of disease stage at presentation (using the International Retinoblastoma Staging System) was 1.6% with Stage 0, 24.1% with Stage I, 27.8% Stage II, 16.3% Stage III and 25.3% Stage IV (data not available in 4.9%). 26.5% of patients defaulted care. The five-year survival rate was 57.7% in the overall study population, and according to disease stage at presentation: 95.3% - Stage I, 84.8% - Stage II, 49.7% - Stage III and 5.7% - Stage IV. CONCLUSION: The five-year survival rate for Stage I disease is similar to the overall five-year survival rates reported in the developed world. This suggests that treatment standards at the study hospitals are comparable with those of developed countries and that similar overall survival rates may be achieved if patients were to present as early. Delay to presentation, disease stage at presentation and defaulting care were identified as key factors contributing to the poor overall survival rate. This study provides information regarding patient demographics, social challenges in management, and patient outcomes in comparison to developed countries and to reports from other African populations. It also highlights the need for educational campaigns and screening initiatives to address poor survival outcomes as a result of late presentation and high rates of patients defaulting care. Finally, this report serves as a platform for comparison with future research in this area