The relation between the prevalence of anemia and incidence of childhood acute lymphoblastic leukemia was explored using international cross-sectional data as well as US time-series data.Methods
Lymphoid leukemia incidence rates for various countries from the International Agency for Research on Cancer were regressed on anemia prevalence rates from the World Health Organization in a cross-sectional analysis. Four decades of acute lymphoblastic leukemia incidence (from the Surveillance, Epidemiology, and End Results Program cancer registries) and anemia prevalence (from the National Health and Nutrition Examination Survey) also were examined in a time-series analysis.Results
There was a statistically significant inverse correlation between leukemia incidence and anemia prevalence in 53 countries, with leukemia incidence being highest in those countries where anemia prevalence was lowest. Examination of US leukemia incidence and anemia prevalence trends from 1973 through 2012 revealed similarly contrasting trends, with leukemia incidence increasing while anemia prevalence was decreasing. White children had half as much anemia but twice as much leukemia as black children.Conclusions
It is postulated that the iron-depleted state may be unfavorable to leukemogenesis, perhaps because lymphopoiesis is suppressed when erythropoiesis is stimulated. Conversely, the iron-replete state may be more favorable to leukemogenesis.