Full breastfeeding and paediatric cancer.

Aim: It has been suggested that there is an inverse association between breastfeeding and the risk of childhood cancer. We investigated the association between full breastfeeding and paediatric cancer (PC) in a case control study in Spain.

Methods: Maternal reports of full breastfeeding, collected through personal interviews using the Paediatric Environmental History, were compared among 187 children 6 months of age or older who had PC and 187 age-matched control siblings.

Results: The mean duration of full breastfeeding for cases were 8.43 and 11.25 weeks for controls. Cases had been significantly more often bottle-fed than controls (odds ratio (OR) 1.8; 95% confidence interval (CI) 1.1-2.8). Cases were significantly less breastfed for at least 2 months (OR 0.5; 95% CI 0.3-0.8), for at least 4 months (OR 0.5; 95% CI 0.3-0.8), and for 24 weeks or more (OR 0.5; 95% CI 0.2-0.9).

Conclusions: Breastfeeding was inversely associated with PC, the protection increasing with the duration of full breastfeeding. Additional research on possible mechanisms of this association may be warranted. Meanwhile, breastfeeding should be encouraged among mothers.