Aromatase inhibitors for breast cancer therapy: Analysis of real-world FAERS data.

Abstract

1051 Background: Aromatase inhibitors (AIs) are extremely effective adjuvant treatment in postmenopausal women with hormone receptor-positive breast cancer (HRPBC). We utilized the Food and Drug Administration Adverse Event Reporting System (FAERS) database to evaluate the musculoskeletal (MSK), fractures, and ischemic heart disease (IHD) adverse events (AEs) caused by AIs. Methods: We conducted a retrospective FAERS public database review to assess the MSK, fracture, and IHD AEs for the three AIs (anastrozole, letrozole, and exemestane) from 2001 through 2021. Chi-square was used to compare categorical variables. Results: A total of 31,683 AEs reports were identified, out of which, 15,140 (47.8%) were MSK, 13,311 (42.0%) were fracture, and 3,232 (10.2%) were IHD. The differences in AEs distributions among the three drug classes were statistically significant for MSK and fracture AEs (P < 0.001) but not reached statistical significance for IHD AEs (P = 0.140). MSK AEs were mostly reported with anastrozole, followed by exemestane, and letrozole in 35.23%, 33.97%, and 32.06%, respectively (P < 0.001). Compared to older individuals, younger adults (≤65 years) had higher rates of MSK AEs—mostly with anastrozole (38.43%, P < 0.001), followed by exemestane (36.37%, P = 0.006) and letrozole (34.28%, P < 0.001). Fracture AEs were mostly reported, in descending order, with letrozole, exemestane, and anastrozole in 12.07%, 11.41%, and 9.34% respectively (P < 0.001). Older adults (> 65 years) had higher rates of fracture AEs with letrozole (16.77%, P < 0.001) and anastrozole (10.37%, P < 0.001), while unable to demonstrate statistical significance with exemestane (13.48%, P = 0.108). Among older adults (> 65 years), IHD AEs were significantly reported with anastrozole (21.56%, P < 0.001) and exemestane (14.18%, P = 0.016) but no statistical significance reached for letrozole (14.12%, P = 0.528). Conclusions: The findings in this study highlight trends for selected AEs with various AI regimens, provide further insights, and help guide therapeutic decisions for patients with HRPBC.