Background Retinoblastoma is the most common intraocular cancer worldwide. There is
some evidence to suggest that major differences exist in treatment outcomes for children
with retinoblastoma from different regions, but these differences have not been assessed
on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma
globally and to investigate factors associated with survival. Methods We did a prospective
cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed
between Jan 1,2017, and Dec 31,2017, then treated and followed up for 3 years. Patients
were recruited from 260 specialised treatment centres worldwide. Data were obtained
from participating centres on primary and additional treatments, duration of follow-up,
metastasis, eye globe salvage, and survival outcome. We analysed time to death and
time to enucleation with Cox regression models. Findings The cohort included 4064
children from 149 countries. The median age at diagnosis was 23.2 months (IQR 11.0-36.5).
Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported
in five (0.8%) of 636 children from high-income countries, 55 (5.4%) of 1027 children
from upper-middle-income countries, 342 (19. 7%) of 1738 children from lower-middle-income
countries, and 196 (42.9%) of 457 children from low-income countries. Enudeation surgery
was available for all children and intravenous chemotherapy was available for 4014
(98.8%) of 4064 children. The 3-year survival rate was 99.5% (95% CI 98.8-100.0) for
children from high-income countries, 91.2% (89.5-93.0) for children from upper-middle-income
countries, 80.3% (78.3-82.3) for children from lower-middle-income countries, and
57.3% (524-63-0) for children from low-income countries. On analysis, independent
factors for worse survival were residence in low-income countries compared to high-income
countries (hazard ratio 16.67; 95% CI 4.76-50.00), cT4 advanced tumour compared to
cT1 (8.98; 4.44-18.18), and older age at diagnosis in children up to 3 years (1.38
per year; 1.23-1.56). For children aged 3-7 years, the mortality risk decreased slightly
(p=0.0104 for the change in slope). Interpretation This study, estimated to include
approximately half of all new retinoblastoma cases worldwide in 2017, shows profound
inequity in survival of children depending on the national income level of their country
of residence. In high-income countries, death from retinoblastoma is rare, whereas
in low-income countries estimated 3-year survival is just over 50%. Although essential
treatments are available in nearly all countries, early diagnosis and treatment in
low-income countries are key to improving survival outcomes. Copyright (C) 2022 The
Author(s). Published by Elsevier Ltd.
