Genetic susceptibility to breast cancer risk associated with inorganic arsenic exposure

Abstract

ObjectiveTo evaluate whether the association between breast cancer (BC) and inorganic arsenic (iAs) exposure is modulated by selected polymorphisms in iAs metabolism. MethodsA population based case-control (1016/1028) study was conducted in Northern Mexico. Urinary arsenic metabolites were measured by High Performance Liquid Chromatography. Metabolites percentages and methylation ratios, were estimated. Genotypes of selected polymorphisms were determined by allelic discrimination. The interaction between polymorphisms and iAs metabolites percentages and methylation ratios on BC was assessed with unconditional logistic regression models. ResultsA significant interaction (p=0.002) between MTR c.2756A>G polymorphism and percentage dimethylarsinic acid (DMA) on BC was found; BC risk related with %DMA was lower in AG+GG carriers than in AA carriers. No other significant interactions were found. ConclusionMTR c.2756A>G polymorphism may confer protection for BC associated with iAs exposure. Further research is warranted to elucidate the potential involvement of other polymorphisms in iAs-related BC.