Birthweight and Acute Infant Leukemia: A Case-Control Study in Brazil

Abstract

ISEE-606 Objective: The relationship between high birth weight and pediatric malignancies has been associated as an important risk factor, including leukemia during childhood. However, the influence of birth weight in infant acute leukemia (IAL) has not so far been studied. This study aimed to ascertain the magnitude of association between birthweight and infant acute leukemia. Materials and Methods: An exploratory case-control aiming to evaluate the association of several environmental variables with this very rare form of leukemia has been carried out in a nationwide investigation in Brazil. This study enrolled a total of 230 IAL cases during 1999–2006 (170 children with acute lymphoblast leukemia (ALL) and 60 with acute myeloid leukemia (AML), all diagnosed under 21 months of age, and 464 age–frequency-matched hospital controls from the same centers wherein cases have been diagnosed. Results: A moderate increased risk for both ALL and AML was associated with birth weight 3500 g or more (OR=1.88, 95% CI, 1.29–2.15), and a higher birth weight distribution in all percentiles among leukemia cases was found comparatively to controls. Using the first quartile of birth weight as reference, increasing association in the second birth weight quartile (OR=1.46, 95% CI, 0.79–2.71), the third (OR=3.18, 95% CI, 1.83–5.53), and the fourth (OR =3.57, 95% CI, 2.07–6.18) were observed. Conclusions: As a whole, these results are consistent with an association pattern of high birth weight and an increased risk of acute leukemia in infants.