Denosumab-associated jaw bone necrosis in cancer patients: retrospective descriptive case series study.

Background: Denosumab (DMB) is a bone antiresorptive agent used to treat osteoporosis or metastatic cancer of the bones. However, denosumab-associated osteonecrosis of the jaw (DRONJ) has become a common complication in cancer patients. The prevalence of osteonecrosis of the jaw (ONJ) in cancer patients is estimated to be similar for both bisphosphonate-related cases (1.1 to 1.4%) and denosumab-related cases (0.8 to 2%), with the addition of adjunctive therapy with anti-angiogenic agents reportedly increasing its prevalence to 3%. (Spec Care Dentist 36(4):231-236, 2016). The aim of this study is to report on DRONJ in cancer patients treated with DMB (Xgeva®, 120mg).

Case presentation: In this study, we identified four cases of ONJ among 74 patients receiving DMB therapy for metastatic cancer. Of the four patients, three had prostate cancer and one had breast cancer. Preceding tooth extraction within 2 months of the last DMB injection was found to be a risk factor for DRONJ. Pathological examination revealed that three patients had acute and chronic inflammation, including actinomycosis colonies. Among the four patients with DRONJ referred to us, three were successfully treated without complications and had no recurrence following surgical treatment, while one did not follow up. After healing, one patient experienced a recurrence at a different site. Sequestrectomy in conjunction with antibiotic therapy and cessation of DMB use proved to be effective in managing the condition, and the ONJ site healed after an average 5-month follow-up period.

Conclusion: Conservative surgery, along with antibiotic therapy and discontinuation of DMB, was found to be effective in managing the condition. Additional studies are needed to investigate the contribution of steroids and anticancer drugs to jaw bone necrosis, the prevalence of multicenter cases, and whether there is any drug interaction with DMB.