A Retrospective Observational Study of Risk Factors for Denosumab-Related Osteonecrosis of the Jaw in Patients with Bone Metastases from Solid Cancers

This single-center retrospective observational study aimed to identify risk factors for developing denosumab-related osteonecrosis of the jaw (DRONJ) in stage IV solid cancer patients with bone metastases. In total, 123 consecutive patients who had received 120 mg of denosumab every 4 weeks at least twice between July 2014 and October 2018 were included. We surveyed their demographics, medical history, blood test, underlying disease, and intraoral findings. Fourteen patients (11.4%) developed DRONJ within a mean denosumab administration period of 4 months (range: 2-52 months). Univariate analyses showed a statistically significant correlation between DRONJ and hormone therapy, chemotherapy/molecular target drug, apical periodontitis, periodontal disease, sex and body mass index. Multivariate analysis showed a statistically significant correlation between DRONJ and hormone therapy (odds ratio [OR], 22.07; 95% confidence interval [CI], 2.86-170.24), chemotherapy and/or molecular targeted therapy (OR, 18.61; 95% CI, 2.54-136.27), and apical periodontitis (OR, 22.75; 95% CI, 3.20-161.73). These findings imply that collaborative oral examinations by oral specialists may reduce the risk of development of DRONJ in patients treated with denosumab for bone metastases from solid cancers.