Childhood acute lymphoblastic leukaemia and indicators of early immune stimulation: the Estelle study (SFCE)

R Ajrouche (1) , J Rudant (2) , L Orsi (2) , A Petit (3, 4) , A Baruchel (5) , A Lambilliotte (6) , M Gambart (7) , G Michel (8) , Y Bertrand (9) , S Ducassou (10) , V Gandemer (11, 12) , C Paillard (13) , L Saumet (14) , N Blin (15) , D Hémon (2) , Jacqueline Clavel (2)

1 UP11 - Université Paris-Sud - Paris 11
2 UPD5 - Université Paris Descartes - Paris 5
3 UPMC - Université Pierre et Marie Curie - Paris 6
4 CHU Trousseau [APHP]
5 Service d'hématologie et immunologie pédiatrique
6 Service d'hématologie pédiatrique-oncologie
7 CHU Toulouse - Centre Hospitalier Universitaire de Toulouse
8 APHM - Assistance Publique - Hôpitaux de Marseille
9 IHOPe - Institut d'hématologie et d'oncologie pédiatrique [CHU - HCL]
10 CHU de Bordeaux Pellegrin [Bordeaux]
11 CHU Pontchaillou [Rennes]
12 IGDR - Institut de Génétique et Développement de Rennes
13 Hôpital de Hautepierre [Strasbourg]
14 Hôpital Arnaud de Villeneuve [CHRU Montpellier]
15 Hôpital Mère-Enfant, CHU de Nantes

Background: Factors related to early stimulation of the immune system (breastfeeding, proxies for exposure to infectious agents, normal delivery, and exposure to animals in early life) have been suggested to decrease the risk of childhood acute lymphoblastic leukaemia (ALL). Methods: The national registry-based case-control study, ESTELLE, was carried out in France in 2010-2011. Population controls were frequency matched with cases on age and gender. The participation rates were 93% for cases and 86% for controls. Data were obtained from structured telephone questionnaires administered to mothers. Odds ratios (OR) were estimated using unconditional regression models adjusted for age, gender, and potential confounders. Results: In all, 617 ALL and 1225 controls aged >= 1 year were included. Inverse associations between ALL and early common infections (OR = 0.8, 95% confidence interval (CI): 0.6, 1.0), non-first born (>= 3 vs 1; OR = 0.7, 95% CI: 0.5, 1.0), attendance of a day-care centre before age 1 year (OR = 0.7, 95% CI: 0.5, 1.0), breastfeeding (OR = 0.8, 95% CI: 0.7, 1.0), and regular contact with pets (OR = 0.8, 95% CI: 0.7, 1.0) in infancy were observed. Conclusions: The results support the hypothesis that conditions promoting the maturation of the immune system in infancy have a protective role with respect to ALL.

Keywords: childhood leukaemia; infections; breast feeding; day-care; caesarean section; animals; pets

Domains: Life Sciences [q-bio]; Cancer

R Ajrouche, J Rudant, L Orsi, A Petit, A Baruchel, et al.. Childhood acute lymphoblastic leukaemia and indicators of early immune stimulation: the Estelle study (SFCE). British Journal of Cancer, 2015, 112 (6), pp.1017-1026. ⟨10.1038/bjc.2015.53⟩. ⟨hal-01143257⟩