Diagnostic delay and socio-demographic predictors of stage at diagnosis and mortality in unilateral and bilateral retinoblastoma
Menée par entretiens auprès de 179 parents mexicains d'enfants atteints d'un rétinoblastome unilatéral ou bilatéral, cette étude analyse l'association entre des facteurs socio-démographiques, le délai entre l'apparition des symptômes et le diagnostic, le stade au diagnostic et la mortalité
Background: More invasive retinoblastoma (Rb), characterized by increased morbidity and mortality, with lower rates of eye salvage and higher rates of extraocular dissemination, appears more prevalent in resource-poor countries. The relationship of diagnostic delay (lag time) and sociodemographic factors on the extent of disease at diagnosis has not been examined separately for unilateral and bilateral Rb. Methods: At diagnosis, consenting parents of 179 Mexican children with Rb were interviewed about initial symptoms and household demographic characteristics. Clinical presentation was classified using St. Jude's, International Staging System (ISS), and International Intraocular Retinoblastoma Classification (IIRC) criteria. Lag time (delay between noting symptoms and diagnosis), and sociodemographic factors were examined as predictors for higher stage at diagnosis and overall survival (OS). Results: In bilateral disease, lag time predicts stage at diagnosis using St. Jude's, and ISS criteria (p<0.005 in multivariate regression), and OS (p<.05,CoxHazards), but not extent of intraocular disease (by IIRC). In unilateral disease, lag time predicts neither extent of disease (using ISS, St Jude's and IIRC), nor OS. Indicators of prenatal poverty, including lower maternal education and the presence of dirt flooring in the home, predict more advanced disease by IIRC for bilateral Rb, and for unilateral by ISS, and St Jude's (p<0.001) as well as OS (p<0.05). Conclusion: These results suggest unilateral and bilateral retinoblastoma differ in factors governing progression and extra-retinal extension, possibly reflecting underlying biological heterogeneity. Impact: This demonstrates differing effect of social factors on extent of intra- and extraocular disease depending on laterality with implications for screening strategies.