Epidemiology

Neonatal infection increases childhood leukemia risk

Last Updated: 2007-03-12 12:51:14 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Infections in the first year of life increase the odds of acute lymphoblastic leukemia (ALL) being diagnosed between 2 and 5 years of age, research from the United Kingdom suggests.

Dr. Eve Roman from University of York and colleagues examined the relationship between clinically diagnosed infections in infancy and a diagnosis of ALL between ages 2 to 5 years among children in the United Kingdom Childhood Cancer Study.

Of the 455 children with leukemia diagnosed between 2 and 5 years, 425 had ALL.

According to the report in the March issue of the American Journal of Epidemiology, children diagnosed with ALL had significantly more infectious episodes in infancy than did controls; the average number of episodes was 3.6 for children with ALL versus 3.1 for controls.

The excess of clinically diagnosed infection in children who developed ALL was apparent from the first month of life (neonatal period). Overall, 18% of controls and 24% of ALL patients were diagnosed with at least one infection during the first month of life (odds ratio, 1.4). By the end of their first year of life, this figure had risen to 85% among controls and 88% among ALL patients (OR, 1.3).

Children with ALL "who had more than one neonatal infectious episode tended to be diagnosed with ALL at a comparatively young age; the mean age at ALL diagnosis was 37.7 months for (children) with two or more episodes versus 45.3 months for (children) with only one episode or none."

Dr. Roman and colleagues conclude that "early infection is positively associated with early-onset ALL." The findings "support the hypothesis that a dysregulated immune response to infection in the first few months of life promotes transition to overt ALL later in childhood."

Am J Epidemiol 2007;165:496-504.

http://www.reutershealth.com/archive/2007/03/12/professional/links/20070312epid001.html

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