Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) in urological malignancies: a multi-center retrospective study

Introduction We evaluated the incidence and risk factors for antiresorptive agent-related osteonecrosis of the jaw (ARONJ) in prostate and kidney cancer patients. Materials and methods We retrospectively reviewed the clinical data of 547 patients from 13 hospitals. Prostate and kidney cancer patients with bone metastases who were treated with a bone-modifying agent (BMA) between January 2012 and February 2019 were enrolled. Exclusion criteria were BMA use for hypercalcemia, a lack of clinical data, a follow-up period of less than 28 days and a lack of evaluation by dentists before BMA administration. The diagnosis and staging of ARONJ were done by dentists. Results Two-hundred eighteen patients were finally enrolled in the study, including 168 prostate cancer patients and 50 kidney cancer patients. Of them, 49 (29%) prostate cancer patients and 18 (36%) kidney cancer patients needed tooth extraction prior to BMA initiation. The mean follow-up period after BMA initiation was 552.9 ± 424.7 days (mean ± SD). In the cohort, 23% of the patients were diagnosed with ARONJ in the follow-up period. The 1-year cumulative incidences of ARONJ were 9.4% and 15.4% in prostate and kidney cancer patients, respectively. Multivariate analysis indicated that kidney cancer, tooth extraction before BMA and a body mass index (BMI) ≥ 25 kg/m 2 were significant predictors for ARONJ. Conclusion ARONJ is not a rare adverse event in urological malignancies. Especially, kidney cancer, high BMI patients and who needed tooth extraction before BMA were high risk for developing ARONJ.