Day-care, early common infections and childhood acute leukaemia: a multicentre French case–control study

Abstract

We conducted a case -control study to investigate the role of early infections in the aetiology of childhood acute leukaemias. The study included 280 incident cases (240 acute lymphoblastic leukaemia and 40 acute non-lymphoblastic leukaemia) and 288 hospital controls, frequency matched by age, gender, hospital, catchment area of the hospital and ethnic origin. Data were obtained from standardised face-to-face interviews of the mothers. The interviews included questions on early common infections, day-care attendance, breast-feeding, birth order and infantile diseases. Odds ratios were estimated using an unconditional regression model including the stratification variables, parental socio-economic status and perinatal characteristics. Birth order was not associated with childhood leukaemia (acute lymphoblastic or acute non-lymphoblastic). A statistically-significant inverse association was observed between childhood leukaemia and day-care attendance (odds ratio=0.6, 95% Confidence Interval=(0.4 -1.0)), repeated early common infections (54 per year before age two, odds ratio=0.6 (0.4 -1.0)), surgical procedures for ear -nose -throat infections before age two (odds ratio=0.5 (0.2 -1.0)) and prolonged breast-feeding (56 months, odds ratio=0.5 (0.2 -1.0)). In the multivariate model including day-care attendance, early common infections and breast-feeding, results concerning breast-feeding remained unchanged. A statistically significant interaction between day-care attendance and repeated early common infections was observed. When the interaction was taken into account, the simple effects of day-care and early common infections disappeared (odds ratio=1.1 (0.5 -2.3) and odds ratio=0.8 (0.5 -1.3), respectively) while the joint effect of day-care attendance and early common infections was negatively associated with childhood leukaemia (odds ratio=0.3 (0.1 -0.8)). All the above associations were observed both for acute lymphoblastic leukaemia and acute non-lymphoblastic leukaemia. Our results support Greaves' hypothesis, even though they are not specific of common leukaemia.

Breastfeeding patterns and risk of childhood acute lymphoblastic leukaemia

“…Two of these previous studies restricted their analysis to children diagnosed between age 2 and 5 years and found no significant effect of breastfeeding on risk of leukaemia (Shu et al, 1995;UK Childhood Cancer Study Investigators, 2001). In contrast, five case -control studies (Shu et al, 1999;Smulevich et al, 1999;Infante-Rivard et al, 2000;Bener et al, 2001;Perrillat et al, 2002a, b) have reported a statistically significant protective association between breastfeeding and risk of either childhood ALL or overall leukaemia. One of these studies described a borderline statistically significant effect of breastfeeding on risk of ALL among children diagnosed less than 4 years of age (InfanteRivard et al, 2000).…”

“…For several decades, an infectious aetiology has been postulated as a cause of leukaemia in children (Heath and Hasterlik, 1963;Greaves, 1988;Kinlen, 1988;Severson et al, 1989;Doody et al, 1992), together with supporting evidence (Kinlen, 2000;Ma et al, 2002;Perrillat et al, 2002a, b;Jourdan-Da Silva et al, 2004).…”

Childhood and maternal infections and risk of acute leukaemia in children with Down syndrome: a report from the Children's Oncology Group

“…While a few studies have observed either positive or null associations between acute leukaemia and early common infections, (Dockerty et al, 1999;Schuz et al, 1999;Naumburg et al, 2002), most investigations have reported negative associations (van Steensel-Moll et al, 1986;McKinney et al, 1999;Schuz et al, 1999;Neglia et al, 2000;Perrillat et al, 2002;JourdanDa Silva et al, 2004) Van Steensel-Moll et al observed a significant negative association between ALL and common colds in the first year of life (van Steensel-Moll et al, 1986). Neglia et al observed a significant trend towards reduction in the risk of ALL with increasing frequency of ear infections in the first year of life and Perrillat et al reported a negative association between risk of ALL and a history of four or more ear infections in the first two years of life (Neglia et al, 2000;Perrillat et al, 2002). McKinney et al found a significantly reduced risk of ALL with neonatal infections, specifically skin infections, and recently Jourdan-Da Silva et al observed a slight negative association with early infections, particularly GI infections (McKinney et al, 1999;Jourdan-Da Silva et al, 2004).…”

“…Thus, the opportunity for and recognition of early-life infections has likely increased. Unfortunately, we did not collect data on day care experience, which has been shown in some studies to be a surrogate marker for exposure to infections (Ma et al, 2002;Perrillat et al, 2002).…”

Infections in early life and childhood leukaemia risk: a UK case–control study of general practitioner records

“…In support of this theory, various studies have demonstrated associations with various proxy measures of exposure to infection, such as day care attendance (Perrillat et al, 2002;Jourdan-Da Silva et al, 2004;Ma et al, 2005) and breastfeeding (UK Childhood Cancer Study Investigators, 2001). However, only one study has previously reported on ALL in relation to routinely recorded infections in early life .…”