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Published on: August 13, 2019

Are all aromatase inhibitors the same? A review of the current evidence

Fritz Jänicke1

  • 1University Hospital Hamburg-Eppendorf, Hamburg, Germany. jaenicke@uke.uni-hamburg.de

Breast (Edinburgh, Scotland)
|December 9, 2004
PubMed

Insights

Third-generation aromatase inhibitors (AIs) show promise in treating hormone receptor-positive breast cancer. Letrozole demonstrates superior efficacy compared to anastrozole and tamoxifen across various treatment settings.

Area of Science:

  • Endocrinology
  • Oncology
  • Pharmacology

Background:

  • Third-generation aromatase inhibitors (AIs) like letrozole, anastrozole, and exemestane are emerging as alternatives to tamoxifen for postmenopausal women with hormone receptor-positive breast cancer.
  • AIs function by inhibiting the aromatase enzyme, thereby reducing estrogen biosynthesis, a key driver in hormone-sensitive breast cancers.

Purpose of the Study:

  • To review and summarize the evidence on the efficacy of third-generation AIs in managing breast cancer.
  • To compare the effectiveness of letrozole, anastrozole, and exemestane in different stages of breast cancer treatment.

Main Methods:

  • Systematic review of clinical studies and trials comparing AIs with tamoxifen and among themselves.
  • Analysis of data on estrogen suppression, clinical response rates, and safety profiles across neoadjuvant, adjuvant, and advanced disease settings.

Main Results:

  • Letrozole has shown superior estrogen suppression and clinical response compared to anastrozole in advanced metastatic breast cancer.
  • Letrozole is the only AI to consistently outperform tamoxifen in neoadjuvant and first-line advanced breast cancer settings.
  • All third-generation AIs demonstrate high efficacy and safety in treating advanced breast cancer.

Conclusions:

  • Third-generation AIs, particularly letrozole, represent a significant advancement in endocrine therapy for hormone receptor-positive breast cancer.
  • Evidence supports the use of letrozole over anastrozole and tamoxifen in specific clinical scenarios, warranting consideration in treatment guidelines.

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