1. ¹UMDNJ-Robert Wood Johnson Medical School, The Cancer Institute of New Jersey, New Brunswick, NJ, 170 Frelinghuysen Road, Piscataway, NJ 08854, USA
2. ²Rutgers University, The State University of New Jersey, The Cancer Institute of New Jersey, 33 Livingston Avenue, Suite 100, New Brunswick, NJ 08901-1958, USA
3. ³College of Public Health, University of Arizona, Tucson, AZ, USA

Correspondence: D Wartenberg, E-mail: Dan.Wartenberg@umdnj.edu

Received 21 June 2003; Revised 24 November 2003; Accepted 23 January 2004; Published online 30 March 2004.

Abstract

We evaluated the infectious aetiology hypothesis of childhood leukaemia that rapid population influx into rural areas is associated with increased risk. Using data from the US SEER program, we found that in changes in rural county population sizes from 1980 to 1989 were associated with incidence rates for childhood acute lymphocytic leukaemia (ALL). The observed associations were strongest among children 0–4 years of age, born in the same state as diagnosis, in extremely rural counties, and when counties adjacent to nonrural counties were excluded. Similar analyses for brain and central nervous system (CNS) cancer in children, a disease less linked to this infectious hypothesis, provide evidence against methodologic bias. Similar evaluations for other decades were not meaningful due to limited sample sizes and, perhaps, increased population mobility.