Background: Estrogens are essential for the growth of breast cancer in the case of premenopausal as
well as in postmenopausal women. However, most of the breast cancer incidences are reported in postmenopausal
women and the concurrent risk surges with an increase in age. Since the enzyme aromatase catalyses
essential steps in estrogen biosynthesis, Aromatase Inhibitors (AIs) are effective targeted therapy in patients
with Estrogen Receptor positive (ER+) breast cancer. AIs are more effective than Selective Estrogen Receptor
Modulators (SERMs) because they block both the genomic and nongenomic activities of ER. Till date, first,
second and third-generation AIs have been approved by the FDA. The third-generation AIs, viz. Letrozole,
Anastrozole, Exemestane, are currently used in the standard treatment for postmenopausal breast cancer.
Methods: Data were collected from Medline, PubMed, Google Scholar, Science Direct through searching of
keywords: ‘aromatase’, ‘aromatase inhibitors’, ‘breast cancer’, ‘steroidal aromatase inhibitors’, ‘non-steroidal
inhibitors’ and ‘generations of aromatase inhibitors’.
Results: In the current scenario of breast cancer chemotherapy, AIs are the most widely used agents which reveal
optimum efficacy along with the least side effects. Keeping in view the prominence of AIs in breast cancer
therapy, this review covered the detailed description of aromatase including its role in the biosynthesis of estrogen,
biochemistry, gene expression, 3D-structure, and information of reported AIs along with their role in breast
Conclusion: AIs are the mainstream solution of the ER+ breast cancer treatment regimen with the continuous
improvement of human understanding of the importance of a healthy life of women suffering from breast cancer.