Special Feature Breast cancer research from bench to bedside

Breast Cancer

, Volume 17, Issue 2, pp 86-91

Prediction of hormone sensitivity for breast cancers

  • Yasuo MiyoshiAffiliated withDivision of Breast and Endocrine Surgery, Department of Surgery, Hyogo College of Medicine Email author 
  • , Keiko MuraseAffiliated withDivision of Breast and Endocrine Surgery, Department of Surgery, Hyogo College of Medicine
  • , Masaru SaitoAffiliated withDivision of Breast and Endocrine Surgery, Department of Surgery, Hyogo College of Medicine
  • , Koushi OhAffiliated withDivision of Breast and Endocrine Surgery, Department of Surgery, Hyogo College of Medicine

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

The classic action that leads to transcriptional activation of estrogen response genes mediated through estrogen receptors (ER) and the estrogen complex plays a pivotal role in the development of ER-positive breast cancers. In addition to this pathway, non-classic action and non-genomic action, both estrogen-dependent and estrogen-independent genomic actions have also been found to contribute to ER-positive tumor growth. Although the details of these mechanisms are not well known, participation of the growth factor signaling pathway is likely to be the most significant factor for acquisition of resistance to hormonal therapy. This resistance is mediated not only directly through cell growth promotion by growth factor signaling, but also through enhancement of alternative ER signaling pathways in addition to classic action. The reason why tamoxifen-insensitive ER-positive breast cancers respond to aromatase inhibitors may be explained, at least in part, by the different estrogen-related signaling pathways in which aromatase inhibitors may block estrogen signaling. In this paper we discuss the molecular mechanisms for resistance to hormonal therapy based on an understanding of estrogen signaling pathways.

Keywords

Breast cancer Signaling pathway Hormonal therapy Growth factor