A new scientific study published in the American Chemical Society’s peer-reviewed journal Chemical Research in Toxicology shows how two known endocrine disrupting chemicals, triclosan and octylphenol, stimulate breast cancer cell growth (Lee et al. 2014). Triclosan (CAS 3380-34-5) is authorized in Europe for use in food contact plastics, while 4-octylphenol (CAS 1806-26-4) is listed in Europe as Substance of Very High Concern and has no known use in food contact materials. In their study, Korean researchers Hye-Rim Lee and colleagues exposed a human breast cancer cell line (MCF-7), as well as a special “xenograft” mouse model, to the two estrogenic substances. Xenografted animals have been implanted with foreign tissue, in this case human breast cancer tumors. In the present study the animals were exposed through injections only to the xenoestrogens of interest, not to naturally produced hormones. The new study shows that triclosan and octylphenol cause tumor growth in MCF-7 cells through an estrogen-receptor (ER) dependent pathway in vitro and in vivo; this growth effect could be inhibited by an ER-antagonist (ICI 182780).


Lee, HR. et al. (2014). “Progression of breast cancer cells was enhanced by endocrine disrupting chemicals, triclosand and octylphenol, via an estrogen receptor-dependent signaling pathway in cellular and mouse xenograft models.” Chemical Research in Toxicology (online March 31, 2014).