OBJECTIVES: Osteonecrosis of jaw is a chronic, severe bone disease that affects the maxilla and mandible. Aromatase inhibitors are a class of drugs used in postmenopausal women for the treatment of hormone receptor-positive breast cancer. This study aims to find the association of Aromatase Inhibitors by disproportionality analysis in FDA Adverse Event Reporting System (FAERS).

METHODS : Publicly available FAERS data was used in the study. Disproportionality analysis with Reporting Odds Ratio (ROR) and Proportional Reporting Ratio (PRR) with 95% confidence intervals (95% CI) were calculated. A value of ROR-1.96SE>1, PRR≥2, count of co-occurrences is 3 or more, with an associated χ2 value of 4 or more were considered as a positive signal.

RESULTS : FAERS database had a total of 15,178 reports for Osteonecrosis of jaw. Amongst which 1,061 (6.99%) reports were associated with aromatase inhibitors. The number of reports for Exemestane, Letrozole and Anastrozole were 362 (34.11%), 448 (42.22%) and 251 (23.65%) respectively. The aromatase inhibitor which had the highest risk was Exemestane with PRR 18.59 (95% CI 14.92-22.15) and ROR 18.73 (95% CI 15.14-22.60). Letrozole had a PRR of 13.37 (95% CI 8.47-25.92) and ROR 13.28 (95% CI 8.34-26.89) and Anastrozole had a PRR of 8.04 (95% CI 6.65-13.19) and ROR 8.01 (95% CI 6.64-13.37). The Likelihood ratio and Reporting rate were 536.13 and 8.02 respectively for Letrozole, 214.12 and 5.29 for Anastrozole, 523.79and 10.54 for Exemestane.

CONCLUSIONS : The present showed an association between aromatase inhibitors and osteonecrosis of jaw, while this adverse event is not listed in the clinical trial or post-marketing data. Although a causal relation cannot be definitively proved, the number of cases reported suggests that there might be an association. Increased awareness of this risk among both prescribers and patients may help mitigate the number and severity of these adverse events.