Arsenic and breast cancer: A systematic review of epidemiologic studies

Arsenic is one of the heavy metals known to be a cause of cancer and many other serious human health problems. The International Agency for Research on Cancer (IARC), has classified arsenic as a Group 1 carcinogen. Studies were performed in different populations to investigate the association between arsenic and breast cancer and the present paper attempts to review these studies. Accessible electronic resources including, PubMed, Web of Knowledge, Science Direct and Scopus and Google Scholar were searched, with relevant phrases up to October 30, 2016. All articles were reviewed by two people separately and among them, original epidemiologic studies that investigated the association between breast cancer and exposure to arsenic were included. Eventually seven articles were selected from 126 retrieved articles. Although three studies (one case-control and two ecological) were not able to show a significant affect, others provide some evidence of a relation between arsenic and breast cancer in specific subgroups. Exposure to arsenic may increase the risk of breast cancer. The strength of this relation can vary due to regional and individual differences.