This Article Full Text Full Text (PDF) eLetters: Submit a response to this article Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services E-mail this article link to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints/Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Buzdar, A. U. Search for Related Content PubMed PubMed Citation Articles by Buzdar, A. U.

Advances in Endocrine Treatments for Postmenopausal Women with Metastatic and Early Breast Cancer

The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA

Correspondence: Aman U. Buzdar, M.D., Department of Breast Medical Oncology, Box 424, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, USA. Telephone: 713-792-2817; Fax: 713-794-4385; e-mail: abuzdar{at}mdanderson.org

For the past 25 years, the estrogen antagonist tamoxifen has been the hormonal treatment of choice for postmenopausal patients with hormone-sensitive metastatic and early breast cancer (EBC). However, tamoxifen is associated with certain tolerability and safety concerns. In addition, the hormonal options after progression are limited, and thus, alternative endocrine treatments have been developed. This review provides a synopsis of the newer alternatives in endocrine therapy of breast cancer: the aromatase inhibitors (AIs) and fulvestrant Faslodex^®, the estrogen receptor antagonist that downregulates estrogen and progesterone receptors and has no known agonist activity. The third-generation AIs, anastrozole and letrozole, have been shown to be as effective or more effective than megestrol acetate and tamoxifen as second- and first-line therapies for the treatment of postmenopausal patients with metastatic breast cancer, and exemestane has been approved for second-line use. Fulvestrant has been shown to be as effective as anastrozole as second-line therapy for metastatic breast cancer and has been approved in the U.S. for the treatment of postmenopausal women with hormone-receptor-positive metastatic breast cancer following progression on antiestrogen therapy. Anastrozole is the only AI with published clinical trial data and U.S. Food and Drug Administration approval for adjuvant therapy of postmenopausal women with EBC. The ‘Arimidex,’ Tamoxifen, Alone or in Combination (ATAC) trial, a double-blind, multicenter trial with 9,366 patients, compared tamoxifen with anastrozole, alone and in combination, as adjuvant endocrine treatment for postmenopausal patients with operable, invasive, EBC. The first analysis (at a median follow-up of 33.3 months) showed longer disease-free survival and, in general, better tolerability with anastrozole than with tamoxifen. This pattern was maintained at later analyses with a median follow-up of 47 months for efficacy and 37 months for safety and tolerability. Although longer follow-up is warranted, anastrozole appears to be a well-documented choice of endocrine adjuvant therapy for postmenopausal women with hormone-responsive breast cancer.

Key Words. Aromatase inhibitor • Adjuvant • Metastatic breast cancer • Breast cancer • Anastrozole • Fulvestrant

This article has been cited by other articles:

				S. Zhang, P. Lei, X. Liu, X. Li, K. Walker, L. Kotha, C. Rowlands, and S. Safe The aryl hydrocarbon receptor as a target for estrogen receptor-negative breast cancer chemotherapy Endocr. Relat. Cancer, September 1, 2009; 16(3): 835 - 844. [Abstract] [Full Text] [PDF]

				X. Liu, M. Abdelrahim, A. Abudayyeh, P. Lei, and S. Safe The nonsteroidal anti-inflammatory drug tolfenamic acid inhibits BT474 and SKBR3 breast cancer cell and tumor growth by repressing erbB2 expression Mol. Cancer Ther., May 1, 2009; 8(5): 1207 - 1217. [Abstract] [Full Text] [PDF]

				L. J Brandes N,N-diethyl-2-[4-(phenylmethyl) phenoxy] ethanamine (DPPE; tesmilifene), a chemopotentiating agent with hormetic effects on DNA synthesis in vitro, may improve survival in patients with metastatic breast cancer Human and Experimental Toxicology, February 1, 2008; 27(2): 143 - 147. [Abstract] [PDF]

				H. S. Rugo The breast cancer continuum in hormone-receptor positive breast cancer in postmenopausal women: evolving management options focusing on aromatase inhibitors Ann. Onc., January 1, 2008; 19(1): 16 - 27. [Abstract] [Full Text] [PDF]

				J. T. Jorgensen, K. V. Nielsen, and B. Ejlertsen Pharmacodiagnostics and Targeted Therapies--A Rational Approach for Individualizing Medical Anticancer Therapy in Breast Cancer Oncologist, April 1, 2007; 12(4): 397 - 405. [Abstract] [Full Text] [PDF]

				S. Massarweh and R. Schiff Resistance to endocrine therapy in breast cancer: exploiting estrogen receptor/growth factor signaling crosstalk Endocr. Relat. Cancer, December 1, 2006; 13(Supplement_1): S15 - S24. [Abstract] [Full Text] [PDF]

				R. Paulmurugan and S. S. Gambhir An intramolecular folding sensor for imaging estrogen receptor-ligand interactions PNAS, October 24, 2006; 103(43): 15883 - 15888. [Abstract] [Full Text] [PDF]

				H.-J. Kim, X. Cui, S. G. Hilsenbeck, and A. V. Lee Progesterone Receptor Loss Correlates with Human Epidermal Growth Factor Receptor 2 Overexpression in Estrogen Receptor-Positive Breast Cancer Clin. Cancer Res., February 1, 2006; 12(3): 1013s - 1018s. [Abstract] [Full Text] [PDF]

				L-A Martin, S Pancholi, C M W Chan, I Farmer, C Kimberley, M Dowsett, and S R D Johnston The anti-oestrogen ICI 182,780, but not tamoxifen, inhibits the growth of MCF-7 breast cancer cells refractory to long-term oestrogen deprivation through down-regulation of oestrogen receptor and IGF signalling Endocr. Relat. Cancer, December 1, 2005; 12(4): 1017 - 1036. [Abstract] [Full Text] [PDF]

				X. Cui, R. Schiff, G. Arpino, C. K. Osborne, and A. V. Lee Biology of Progesterone Receptor Loss in Breast Cancer and Its Implications for Endocrine Therapy J. Clin. Oncol., October 20, 2005; 23(30): 7721 - 7735. [Abstract] [Full Text] [PDF]

				R. W. Brueggemeier, J. C. Hackett, and E. S. Diaz-Cruz Aromatase Inhibitors in the Treatment of Breast Cancer Endocr. Rev., May 1, 2005; 26(3): 331 - 345. [Abstract] [Full Text] [PDF]

				N. P. Nunez, D. Jelovac, L. Macedo, D. Berrigan, S. N. Perkins, S. D. Hursting, J. C. Barrett, and A. Brodie Effects of the Antiestrogen Tamoxifen and the Aromatase Inhibitor Letrozole on Serum Hormones and Bone Characteristics in a Preclinical Tumor Model for Breast Cancer Clin. Cancer Res., August 15, 2004; 10(16): 5375 - 5380. [Abstract] [Full Text] [PDF]