(050) Association Between Aromatase Inhibitors and Dry Eye Disease Among Women with Breast Cancer

Background: Estrogen-positive breast cancer (BC) makes up to 75% of BC patients; with aromatase inhibitors (AIs) and tamoxifen considered mainstay therapies. A number of case reports have found an association between AI use and ocular adverse events, including dry eye disease (DED), but to date, data on a head-to-head comparison between AIs and tamoxifen are not available.

Objectives: To quantify the risk of DED in women with BC taking AIs, compared to those taking tamoxifen.

Methods: The IQVIA health claims database was used as the main data source. This database captures medical diagnoses, procedures, prescriptions, and demographic data on approximately 150 million residents of the United States. Using a retrospective, new user, cohort design we identified all eligible users of AIs or tamoxifen, during a 10-year period (2010-2020). Cohort members were followed to the first mutually exclusive outcome of DED defined by the first ICD code 9th or 10th edition or the use of a drug that is exclusively used to treat DED. Cox regression was used to estimate hazard ratios (HR), adjusting for potential confounding variables and risk factors. Subsequent sensitivity analyses were conducted to test robustness of findings.

Results: Our study included 6,177 and 4,239 patients taking AIs and tamoxifen, respectively. AI users had a mean age of 61.5 (± 16.8 years), whereas tamoxifen users had a mean age of 54.6 (± 12.6). The mean follow-up time was 17.5 months. The crude HR for DED with AI use was 1.41 (95%CI: 1.07-1.86), compared to tamoxifen use. The adjusted HR for DED was 1.23 (95%CI: 0.92-1.64). Additionally, for participants > 55, the HR was 1.07 (95% CI: 0.74-1.54), while for participants ≤ 55, the HR was 1.43 (95% CI: 0.88-2.31).

Conclusions: Our study shows an increased risk of DED among AI users compared to tamoxifen users, when adjusting for confounders, although the estimate was not precise. Given that most women suffering from BC are either on AIs or tamoxifen, these findings need to be used for a more personalized risk-benefit assessment for each patient.