Childhood brain tumors and maternal cured meat consumption in pregnancy: differential effect by glutathione S-transferases.

Abstract

Some epidemiologic studies suggest that maternal consumption of cured meat during pregnancy may increase risk of brain tumors in offspring. We explored whether this possible association was modified by fetal genetic polymorphisms in genes coding for glutathione S-transferases (GSTs) that may inactivate nitroso compounds. We assessed six GST variants: GSTM1 null, GSTT1 null, GSTP1(I105V) (rs1695), GSTP1(A114V) (rs1138272), GSTM3*B (3-bp deletion), and GSTM3(A-63C) (rs1332018) within a population-based case-control study with data on maternal prenatal cured meat consumption (202 cases and 286 controls born in California or Washington, 1978-1990). Risk of childhood brain tumor increased with increasing cured meat intake by the mother during pregnancy among children without GSTT1 [OR = 1.29; 95% confidence interval (95% CI), 1.07-1.57 for each increase in the frequency of consumption per week] or with potentially reduced GSTM3 (any -63C allele; OR = 1.14; 95% CI, 1.03-1.26), whereas no increased risk was observed among those with GSTT1 or presumably normal GSTM3 levels (interaction P = 0.01 for each). Fetal ability to deactivate nitrosoureas may modify the association between childhood brain tumors and maternal prenatal consumption of cured meats. These results support the hypothesis that maternal avoidance during pregnancy of sources of some nitroso compounds or their precursors may reduce risk of brain tumors in some children.