American Journal of Cancer

, Volume 2, Supplement 1, pp 7–11 | Cite as

Letrozole versus Tamoxifen as First-Line Treatment for Metastatic Breast Cancer

A Survival Analysis
Review Article
  • 12 Downloads

Abstract

Third-generation aromatase inhibitors (AIs) have emerged as effective first-line treatment and after progression with tamoxifen for postmenopausal women with hormone receptor-positive metastatic breast cancer. In a recent multicenter, randomized, phase III trial of letrozole and tamoxifen, letrozole was significantly more effective than tamoxifen with respect to time to tumor progression (9.4 vs 6.0 months), objective response rate (32% vs 21%) and clinical benefit rate (50% vs 38%). Patients were more likely to remain on initial letrozole treatment and received significant survival benefits from 6 months to 2 years compared with those receiving tamoxifen. Letrozole is approved for first-line use and with improved efficacy over tamoxifen should be considered as a standard treatment option for patients with hormone-sensitive metastatic breast cancer. Additional studies comparing AIs as treatment for advanced disease are necessary to determine whether treatment advantages are class specific or relative to individual AIs.

Keywords

Tamoxifen Metastatic Breast Cancer Letrozole Anastrozole Exemestane 

Notes

Acknowledgements

The author has provided no information on sources of funding or on conflicts of interest directly relevant to the content of this review.

References

  1. 1.
    Dowsett M, Jones A, Johnston SR, et al. In vivo measurement of aromatase inhibition by letrozole (CGS 20267) in postmenopausal patients with breast cancer. Clin Cancer Res 1995; 1: 1511–5PubMedGoogle Scholar
  2. 2.
    Ingle JN, Johnson PA, Suman VJ, et al. A randomized phase II trial of two dosage levels of letrozole as third-line hormonal therapy for women with metastatic breast carcinoma. Cancer 1997; 80: 218–24PubMedCrossRefGoogle Scholar
  3. 3.
    Buzdar AU. A summary of second-line randomized studies of aromatase inhibitors. J Steroid Biochem Mol Biol 2001; 79: 109–14PubMedCrossRefGoogle Scholar
  4. 4.
    Dombernowsky P, Smith I, Falkson G, et al. Letrozole, a new oral aromatase inhibitor for advanced breast cancer: double-blind randomized trial showing a dose effect and improved efficacy and tolerability compared with megestrol acetate. J Clin Oncol 1998; 16: 453–61PubMedGoogle Scholar
  5. 5.
    Mouridsen H, Gershanovich M, Sun Y, et al. Superior efficacy of letrozole versus tamoxifen as first-line therapy in postmenopausal women with advanced breast cancer: results of a phase III study of the International Letrozole Breast Cancer Group. J Clin Oncol 2001; 19: 2596–606PubMedGoogle Scholar
  6. 6.
    Mouridsen H, Gershanovich M, Sun Y, et al. Phase III study of letrozole versus tamoxifen as first-line therapy of advanced breast cancer in postmenopausal women: analysis of survival and update of efficacy from the International Letrozole Breast Cancer Group. J Clin Oncol 2003; 21(11): 2101–9PubMedCrossRefGoogle Scholar
  7. 7.
    Bonneterre J, Thurlimann B, Robertson JF, et al. Anastrozole versus tamoxifen as first-line therapy for advanced breast cancer in 668 postmenopausal women: results of the Tamoxifen or Arimidex Randomized Group Efficacy and Tolerability study. J Clin Oncol 2000; 18: 3748–57PubMedGoogle Scholar
  8. 8.
    Nabholtz JM, Buzdar A, Pollak M, et al. Anastrozole is superior to tamoxifen as first-line therapy for advanced breast cancer in postmenopausal women: results of a North American multicenter randomized trial. Arimidex Study Group. J Clin Oncol 2000; 18: 3758–67PubMedGoogle Scholar
  9. 9.
    Bonneterre J, Buzdar A, Nabholtz JM, et al. Anastrozole is superior to tamoxifen as first-line therapy in hormone receptor positive advanced breast carcinoma. Cancer 2001; 92: 2247–58PubMedCrossRefGoogle Scholar
  10. 10.
    Thomas R, Makris A, Bloomfield D, et al. Empowering patients to make informed treatment decisions based on tolerability, quality of life, patient preference: a comparison of letrozole and anastrozole in a multicentre, randomised, single-blind cross over study [abstract 171]. Eur J Cancer 2002; 38Suppl. 3: S83CrossRefGoogle Scholar
  11. 11.
    Geisler J, Haynes B, Anker G, et al. Influence of letrozole and anastrozole on total body aromatization and plasma estrogen levels in postmenopausal breast cancer patients evaluated in a randomized, cross-over study. J Clin Oncol 2002; 20: 751–7PubMedCrossRefGoogle Scholar
  12. 12.
    Miller WR, Dixon JM. Local endocrine effects of aromatase inhibitors within the breast. J Steroid Biochem Mol Biol 2001; 79: 93–102PubMedCrossRefGoogle Scholar

Copyright information

© Adis International Limited 2003

Authors and Affiliations

  1. 1.Department of OncologyFinsen CenterCopenhagenDenmark

Personalised recommendations