An integrated evaluation of socioeconomic and clinical factors in the survival from childhood acute lymphoblastic leukaemia: a study in Greece.

An evaluation of the role of socioeconomic factors in the survival of children with leukaemia, controlling for major clinical prognostic indicators, has been attempted in very few studies and the role of these factors may be different in various cultural settings. Our investigation aims to study the independent role of socioeconomic factors on the prognosis of childhood acute lymphoblastic leukaemia (ALL) in Greece. During a 7-year period (1996-2002) 293 cases of incident ALL were diagnosed and followed up in four Childhood Haematology-Oncology Units, which covered over half of all childhood ALL cases nationwide. At the time of diagnosis, information concerning age, gender, maternal schooling, maternal marital status, sibship size, distance of residence from the treating centre, attendance of day care centre and clinical information was recorded. The influence of these factors on survival was studied by modelling the data through Cox's proportional-hazards regression. After adjustment for clinical prognostic factors, children of mothers who were not currently married, were of low educational level or were living far from the treating centre tended to have lower survival (P-values 0.02, 0.14 and 0.08, respectively). There was also evidence that two factors that are predictive of disease occurrence, that is sibship size and attendance of day care centre, may also predict survival (P-values 0.04 and 0.26, respectively). In conclusion, socioeconomic factors are likely to influence survival from ALL at least in some sociocultural contexts. Moreover, there is evidence that factors that could affect incidence of ALL through modulation of herd immunity may also have prognostic implications for this disease.