English English French French Spanish Spanish
  This is a cross-sectional analysis including 4351 treatment-naive retinoblastoma patients from 153 countries. The goal of the study was to investigate whether sex predilection exists for this childhood eye cancer. For the entire sample, the mean retinoblastoma sex ratio, 1.20, was higher than the weighted global sex ratio at birth, 1.07 (p < 0.001). Analysis at economic grouping, continent, and country-level demonstrated differences in the sex ratio in the sample compared to the ratio at birth in lower-middle-income countries (n = 1940), 1.23 vs. 1.07 (p = 0.019); Asia (n = 2276), 1.28 vs. 1.06 (p < 0.001); and India (n = 558), 1.52 vs. 1.11 (p = 0.008). Sensitivity analysis, excluding data from India, showed that differences remained significant for the remaining sample (χ2 = 6.925, corrected p = 0.025) and for Asia (χ2 = 5.084, corrected p = 0.036). Excluding data from Asia, differences for the remaining sample were nonsignificant (χ2 = 2.205, p = 0.14). In conclusion, the study did not find any proof of sex predilection in retinoblastoma, which is estimated to include over half of new retinoblastoma patients worldwide in 2017. The high male to female ratio found in Asian countries, India in specific, which may have had an impact on global-level analysis, is likely due to gender discrimination in access to care in these countries, rather than a biological difference between sexes.