Arsenic methylation capacity is associated with breast cancer in Northern Mexico

Lizbeth López-Carrillo, Raúl Ulises Hernández-Ramírez, A. Jay Gandolfi, José Manuel Ornelas-Aguirre, Luisa Torres-Sánchez, Mariano E. Cebrian

Research output: Contribution to journalArticle

38 Scopus citations

Abstract

Exposure to environmental contaminants, dietary factors and lifestyles may explain worldwide different breast cancer (BC) incidence. Inorganic arsenic (iAs) in the drinking water is a concern in many regions, such as northern Mexico. Studies in several countries have associated the proportion of urinary monomethylarsenic (%MMA) with increased risks for many As-related diseases, including cancer. To investigate the potential relationships between the risk of BC and the capacity to methylate iAs, a hospital-based case-control study (1016 cases/1028 controls) was performed in northern Mexico. Women were directly interviewed about their reproductive histories. The profile of As metabolites in urine was determined by HPLC-ICP-MS and methylation capacity was assessed by metabolite percentages and indexes. Total urinary As, excluding arsenobetaine (TAs-AsB), ranged from 0.26 to 303.29μg/L. Most women (86%) had TAs-AsB levels below As biological exposure index (35μg/L). Women with higher %MMA and/or primary methylation index (PMI) had an increased BC risk (%MMA ORQ5vs.Q1=2.63; 95%CI 1.89,3.66; p for trend <0.001; PMI ORQ5vs.Q1=1.90; 95%CI 1.39,2.59, p for trend <0.001). In contrast, women with higher proportion of urinary dimethylarsenic (%DMA) and/or secondary methylation index (SMI) had a reduced BC risk (%DMA ORQ5vs.Q1=0.63; 95%CI 0.45,0.87, p for trend 0.006; SMI ORQ5vsQ1=0.42, 95%CI 0.31,0.59, p for trend <0.001). Neither %iAs nor total methylation index was associated to BC risk. Inter-individual variations in iAs metabolism may play a role in BC carcinogenesis. Women with higher capacity to methylate iAs to MMA and/or a lower capacity to further methylate MMA to DMA were at higher BC risk.

Original languageEnglish (US)
Pages (from-to)53-59
Number of pages7
JournalToxicology and Applied Pharmacology
Volume280
Issue number1
DOIs
StatePublished - Oct 1 2014

Keywords

  • Arsenic
  • Arsenic metabolism
  • Breast cancer
  • Case control
  • Mexico

ASJC Scopus subject areas

  • Toxicology
  • Pharmacology

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  • Cite this

    López-Carrillo, L., Hernández-Ramírez, R. U., Gandolfi, A. J., Ornelas-Aguirre, J. M., Torres-Sánchez, L., & Cebrian, M. E. (2014). Arsenic methylation capacity is associated with breast cancer in Northern Mexico. Toxicology and Applied Pharmacology, 280(1), 53-59. https://doi.org/10.1016/j.taap.2014.07.013