Parental medication use and risk of childhood acute lymphoblastic leukemia

BACKGROUND. Few studies have examined the risk of childhood acute lymphoblastic leukemia (ALL) associated with parental medication use. As part of a large case-control study conducted by the Children's Cancer Group, we evaluated the association between maternal and paternal medication use and the risk of ALL in offspring. METHODS. Information on selected medication use in the year before and during the index pregnancy was obtained by telephone interview. Participants included 1842 children of 14 years or younger with newly diagnosed and immunophenotypically defined ALL and 1986 individually matched controls. Data were analyzed using logistic regression models and stratified by immunophenotypes of ALL and age at diagnosis of cases. RESULTS. After adjusting for potential confounders and other medication use, we found that maternal use of vitamins (odds ratio [OR] = 0.7, 99% confidence interval [CI]: 0.5-1.0) and iron supplements (OR = 0.8, 99% CI: 0.7-1.0) only during the index pregnancy was associated with a decreased risk of ALL. Parental use of amphetamines or diet pills and mind-altering drugs before and during the index pregnancy was related to an increased risk of childhood ALL, particularly among children where both parents reported using these drugs (OR = 2.8, 99% CI: 0.5-15.6 for amphetamines or diet pills, OR = 1.8, 99% CI: 1.1-3.0 for mind-altering drugs). Stratified analyses showed that maternal use of antihistamines or allergic remedies and parental use of mind-altering drugs were strongly associated with infant ALL, whereas patterns of association between childhood ALL and parental medication use did not influence markedly the immunophenotypic subgroup of ALL. CONCLUSIONS. The findings of this study suggest that certain parental medication use immediately before and (luring the index pregnancy may influence risk of ALL in offspring. (C) 2002 American Cancer Society.