Blood levels of endocrine-disrupting metals and prevalent breast cancer among US women.

A growing body of evidence has pointed to a role of environmental chemical exposures in breast cancer etiology. This study was to examine the association between exposure to the endocrine-disrupting metals, including cadmium (Cd), lead (Pb), and mercury (Hg), and breast cancer in US women. A nationally representative subsample of 9260 women aged ≥ 20 years in the 2003-2012 National Health and Nutrition Examination Survey was analyzed for the association of blood levels of these metals with prevalent breast cancer using multivariate logistic regression models. Of the study participants, 284 women (weighted prevalence, 2.8%) were self-reported being diagnosed with breast cancer during 2003-2012. Breast cancer women showed significantly elevated blood levels of Cd and Pb, but not Hg. After adjusting for potential confounders, we found that women in all of the higher quartiles of blood lead levels (BLLs) had significantly increased odds ratio of prevalent breast cancer compared with those in the lowest quartile. However, a significant association with prevalent breast cancer was not seen with blood levels of either Cd or Hg. Our study demonstrates a potential relationship between lead exposure, measured as BLLs, and female breast cancer. Additional epidemiologic and mechanistic studies would further explore these interactions and elucidate the potential role of lead exposure in breast cancer etiology.