Birth weight, ethnicity, and occurrence of cancer in children: a population-based, incident case-control study in the State of Texas, USA

Objective: To investigate the relationship between birth weight and risk of early age childhood cancer and whether racial differences in birth weight distribution could explain differences in the incidence of cancer in white, Hispanic, and black children. Methods: We compared birth weights of 268 children younger than five years old and diagnosed with cancer in the State of Texas in 1995 to the birth weights of 2680 randomly selected, age-matched population-based controls. Birth weight, sex, race/ethnicity, maternal age, smoking status, parity, and gestational age information was ascertained from the birth certificates. Logistic regression analyses were performed to evaluate the association between high birth weight (> 4000 g) and occurrence of childhood cancer. Results: Increased odds ratios (OR) were found for "total cancer cases" (OR 1.4, 95% CI 0.9-2.1), "leukemia cases" (OR 1.7, 95% CI 0.9-3.0) and "acute lymphoblastic leukemia (ALL) cases" (OR 2.2, 95% CI 1.2-4.1). Increased ORs in the former two groups were shown to be due to ALL cases. Including the race/ethnicity variable in the regression model did not affect the ORs. Conclusion: Compared to newborns who weighed between 2500 and 4000 g at birth, children who weighed > 4000 g had an increased risk of developing childhood ALL during the first five years of life. Birth weight differences does not explain the sequence of childhood cancer incidence by race/ethnicity.