Mode of Delivery and Risk of Childhood Leukemia

Abstract

Background: Childhood infection and immune response have long been suspected in the etiology of childhood leukemia, specifically acute lymphoblastic leukemia (ALL). Normal primary inoculation of the core human microbiome is circumvented by cesarean section (CS) delivery, which is a proposed modulator of both immune response and early-life infection.Methods: In this study, we examined CS delivery and the risk of childhood leukemia using data from the California Childhood Leukemia Study (CCLS) case-control study and additive logistic regression models.Results: We observed no association between CS and acute myelogenous leukemia [OR, 0.96; 95% confidence interval (CI), 0.52-1.55]. We observed a suggestive association for ALL and CS (OR, 1.22; 95% CI, 0.97-1.54). When examining common ALL (cALL), defined as ALL with expression of CD10 and CD19 surface antigens and diagnosis occurring between 2 and 5.9 years of age, we found a significant association with CS (OR, 1.44; 95% CI, 1.0-2.06). ALL subjects that are not cALL showed a similar risk as ALL overall (OR, 1.15; 95% CI, 0.91-1.44). Because of previous findings suggesting effect modification, we stratified cALL subjects by Hispanic status. Although we observed no relationship for CS in non-Hispanics (OR, 1.14; 95% CI, 0.72-1.79), we did observe a strong association between cALL and CS in Hispanics (OR, 2.34; 95% CI, 1.23-4.46).Conclusion: Within the CCLS, CS delivery seems to be associated with cALL and Hispanic subjects may be driving the association.Impact: Further research combined with investigations into response to early infection and the microbiome is warranted. Cancer Epidemiol Biomarkers Prev; 23(5); 876-81. Ó2014 AACR.

Prelabor cesarean delivery and early-onset acute childhood leukemia risk

“…In contrast, the study by Reynolds et al (2002), using different age limits, did not provide evidence of an association with CD, and did not specifically examine the association with prelabor CD; the lower prevalence of CD among these study participants (22%) compared with more than 35% in the NARECHEM study and presumably the much lower prelabor CD rates might have also hindered the statistical power of that study to show an effect. In support of our findings of an association with specific ALL subtypes are the results of a recent study by Francis et al (2014) showing a positive association with the most frequent B-ALL subgroup, notably common ALL, whereas no statistically significant association was found in the all age onset ALL analyses. The authors sought to explore their hypothesis in the age range 2-6 years, without justifying the reasons, and a subcategory of B-ALL, notably common ALL, which comprises ∼ 60% of B-ALL.…”

Caesarean delivery and risk of childhood leukaemia: a pooled analysis from the Childhood Leukemia International Consortium (CLIC)

“…19 Separately, we stratified analyses by child's ethnic origin within ALL cases overall and then restricted analysis to children aged 2-5 years with ALL to replicate analyses from the California study. 20 For stratification by ethnic origin, we used data from the four US-based studies because these contained the most detailed data for ethnic origin. Because caesarean delivery is associated with lower rates of breastfeeding, 27 which is in turn associated with increased risk of childhood leukaemia, 28 we regarded breastfeeding as a potential mediator of the effect of caesarean delivery on leukaemia risk.…”

“…In what was, to our knowledge, the first study to investigate the role of prelabour caesarean delivery in childhood leukaemia, investigators showed an increased risk of overall ALL and precursor B-cell ALL in children aged 0–3 years after prelabour caesarean delivery, 19 whereas another study reported increased risk of common ALL (defined as ALL with expression of CD10 and CD19 surface antigens and diagnosis occurring between age 2 and 5.9 years), particularly in Hispanic people, after caesarean delivery. 20 …”

In utero cytomegalovirus infection and development of childhood acute lymphoblastic leukemia

“…15 (All data and samples have been approved for use by the The online version of this article contains a data supplement.…”