Case control study of periconceptional folic acid intake and nervous system tumors in children.
ABSTRACT Since 1992, the Centers for Disease Control and Prevention recommends that women of childbearing age consume 400 µg of folic acid per day to reduce the risk of neural tube defects (NTD). It has been speculated that both NTD and nervous system tumors (NST) may share common mechanisms of altered development. It examines the association between folic acid supplementation and the risk for childhood NST.
Incident cases of children with cancer in Spain registered between 2004 and 2006 were identified through the MACAPE Network Group. Tumors were classified as tumors derived from the neuroectoderm (cases) and those with a mesoderm origin (controls). In a second analysis, NST were further divided into central nervous system tumors (CNST) and sympathetic nervous system tumors (SNST). We compared folic acid supplementation between the groups.
Overall, folic acid supplementation any time during pregnancy was similar between cases and controls (odds ratio (OR)=1.05; 95% confidence interval (CI) 0.92-1.20). However, supplementation before the 21st and 36th days of gestation resulted in significantly lower NST than in children with mesoderm tumors (OR=0.34; 95% CI 0.17-0.69 and OR=0.58; 95% CI 0.37-0.91, respectively). Preconceptional intakes of folic acid were also lower in NST although marginally nonsignificant (OR=0.44; 95% CI 0.10-1.02). When NST were divided into CNST and SNST, significant differences between tumors of mesoderm origin were only found for CNST.
Our results support the hypothesis that folate supplementation reduces the risk of childhood NST, especially CNST. The specific mechanism and cellular role that folate may play in the development of CNST have yet to be elucidated.
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ABSTRACT: BACKGROUND: Interest in a possible protective effect of maternal vitamin use before or during pregnancy against childhood brain tumors (CBT) and other childhood cancers has grown over the past decade. Our Australian study of CBTs, conducted between 2005 and 2011, investigated whether maternal use folic acid and other supplements was protective.METHODS: Case children were identified through the 10 Australian pediatric oncology centers and controls were recruited by national random digit dialing. Mothers of 327 cases and 867 control children provided information on supplement use before and during the index pregnancy, including brand name, dose, and timing. Data were analyzed using multivariable unconditional logistic regression.RESULTS: The OR for any maternal use of folic acid, use of folic acid without iron or vitamins B6, B12, C, or A, and any vitamin use before pregnancy, were: 0.68 [95% confidence interval (CI), 0.46-1.00; 0.55 (95% CI, 0.32-0.93) and 0.68 (95% CI, 0.46-1.01), respectively. The ORs for use of these supplements during pregnancy were also below unity, but generally closer to the null than those for the prepregnancy period. There was some evidence of an inverse dose-response during each time period.CONCLUSIONS: These results suggest that folic acid supplements before and possibly during pregnancy may protect against CBT. Such associations are biologically plausible through established mechanisms.Impact: This study provides evidence of a specific protective effect of prenatal folic acid supplementation against the risk of CBT that is not attributable to the actions of the other micronutrients investigated. Cancer Epidemiol Biomarkers Prev; 21(11); 1-9. ©2012 AACR.Cancer Epidemiology Biomarkers & Prevention 08/2012; · 4.12 Impact Factor