TY - JOUR
T1 - Childhood acute lymphoblastic leukemia and indicators of early immune stimulation: A childhood leukemia international consortium study
AU - Rudant, J.
AU - Lightfoot, T.J.
AU - Urayama, K.Y.
AU - Petridou, E.T.H.
AU - Dockerty, J.D.
AU - Magnani, C.
AU - Milne, Elizabeth
AU - Spector, L.G.
AU - Ashton, L.J.
AU - Dessypris, N.
AU - Kang, A.Y.
AU - Miller, M.R.
AU - Rondelli, R.
AU - Simpson, J.M.
AU - Stiakaki, E.
AU - Orsi, L.
AU - Roman, E.A.
AU - Métayer, C.
AU - Infante-Rivard, C.
AU - Clavel, J.
PY - 2015/4/8
Y1 - 2015/4/8
N2 - The associations between childhood acute lymphoblastic leukemia (ALL) and several proxies of early stimulation of the immune system, that is, day-care center attendance, birth order, maternally reported common infections in infancy, and breastfeeding, were investigated by using data from 11 case-control studies participating in the Childhood Leukemia International Consortium (enrollment period: 1980-2010). The sample included 7,399 ALL cases and 11,181 controls aged 2-14 years. The data were collected by questionnaires administered to the parents. Pooled odds ratios and 95% confidence intervals were estimated by unconditional logistic regression adjusted for age, sex, study, maternal education, and maternal age. Day-care center attendance in the first year of life was associated with a reduced risk of ALL (odds ratio = 0.77, 95% confidence interval: 0.71, 0.84), with a marked inverse trend with earlier age at start (P <0.0001). An inverse association was also observed with breastfeeding duration of 6 months or more (odds ratio = 0.86, 95% confidence interval: 0.79, 0.94). No significant relationship with a history of common infections in infancy was observed even though the odds ratio was less than 1 for more than 3 infections. The findings of this large pooled analysis reinforce the hypothesis that day-care center attendance in infancy and prolonged breastfeeding are associated with a decreased risk of ALL.
AB - The associations between childhood acute lymphoblastic leukemia (ALL) and several proxies of early stimulation of the immune system, that is, day-care center attendance, birth order, maternally reported common infections in infancy, and breastfeeding, were investigated by using data from 11 case-control studies participating in the Childhood Leukemia International Consortium (enrollment period: 1980-2010). The sample included 7,399 ALL cases and 11,181 controls aged 2-14 years. The data were collected by questionnaires administered to the parents. Pooled odds ratios and 95% confidence intervals were estimated by unconditional logistic regression adjusted for age, sex, study, maternal education, and maternal age. Day-care center attendance in the first year of life was associated with a reduced risk of ALL (odds ratio = 0.77, 95% confidence interval: 0.71, 0.84), with a marked inverse trend with earlier age at start (P <0.0001). An inverse association was also observed with breastfeeding duration of 6 months or more (odds ratio = 0.86, 95% confidence interval: 0.79, 0.94). No significant relationship with a history of common infections in infancy was observed even though the odds ratio was less than 1 for more than 3 infections. The findings of this large pooled analysis reinforce the hypothesis that day-care center attendance in infancy and prolonged breastfeeding are associated with a decreased risk of ALL.
U2 - 10.1093/aje/kwu298
DO - 10.1093/aje/kwu298
M3 - Article
C2 - 25731888
SN - 0002-9262
VL - 181
SP - 549
EP - 562
JO - American Journal of Epidemiology
JF - American Journal of Epidemiology
IS - 8
ER -