Exploiting the apoptotic actions of oestrogen to reverse antihormonal drug resistance in oestrogen receptor positive breast cancer patients

Breast. 2007 Dec;16 Suppl 2(Suppl 2):S105-13. doi: 10.1016/j.breast.2007.07.020. Epub 2007 Aug 24.


The ubiquitous application of selective oestrogen receptor modulators (SERMs) and aromatase inhibitors for the treatment and prevention of breast cancer has created a significant advance in patient care. However, the consequence of prolonged treatment with antihormonal therapy is the development of drug resistance. Nevertheless, the systematic description of models of drug resistance to SERMs and aromatase inhibitors has resulted in the discovery of a vulnerability in tumour homeostasis that can be exploited to improve patient care. Drug resistance to antihormones evolves, so that eventually the cells change to create novel signal transduction pathways for enhanced oestrogen (GPR30+OER) sensitivity, a reduction in progesterone receptor production and an increased metastatic potential. Most importantly, antihormone resistant breast cancer cells adapt with an ability to undergo apoptosis with low concentrations of oestrogen. The oestrogen destroys antihormone resistant cells and reactivates sensitivity to prolonged antihormonal therapy. We have initiated a major collaborative program of genomics and proteomics to use our laboratory models to map the mechanism of subcellular survival and apoptosis in breast cancer. The laboratory program is integrated with a clinical program that seeks to determine the minimum dose of oestrogen necessary to create objective responses in patients who have succeeded and failed two consecutive antihormonal therapies. Once our program is complete, the new knowledge will be available to translate to clinical care for the long-term maintenance of patients on antihormone therapy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Apoptosis
  • Aromatase Inhibitors / pharmacology*
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / physiopathology
  • Drug Resistance, Neoplasm
  • Estrogens / physiology*
  • Female
  • Humans
  • Receptors, Estrogen / drug effects*
  • Selective Estrogen Receptor Modulators / pharmacology*
  • Signal Transduction / drug effects


  • Aromatase Inhibitors
  • Estrogens
  • Receptors, Estrogen
  • Selective Estrogen Receptor Modulators