Infections in cancer patients with medication-related osteonecrosis of the jaws

Abstract

Introduction: The association between bisphosphonates and osteonecrosis of the jaws has been widely reported in the literature. Despite the higher incidence and the poor prognosis in cancer patients, there is still little understanding of risk factors for infectious complications in these patients. Objective: Evaluate the factors associated with infectious events related to osteonecrosis induced by zoledronic acid (ZA) in oncological patients. Methods: It was a retrospective, longitudinal and observational study that included 21 patients and collected the following variables: age; oncological disease; classification of necrosis; affected bone; triggering factor; frequency of ZA use; the number of ZA doses at the time of necrosis; smoking; cancer activity at the time of necrosis; use of corticosteroids; previous or current treatment with chemotherapy, immunosuppressive and antiangiogenics drugs. The outcome of interest was the number of new infection episodes. Results: 33% of patients showed only one infectious event after MRONJ diagnosis, 28.6% of the cases had two, 19% - four, 9.5% - three, one patient had six and another seven infection episodes. Among all the studied variables only the classification of osteonecrosis, Class.2 + 3: 2.06 (±2.08) vs. Class. 1: 0.00 (±0.54)-p: 0.05 and the frequency of ZA use, Monthly: 2.09 (±1.64) vs. Quarterly: 0.25 (±0.46)-p: 0.002 showed highest incidence of infectious events. In the binary logistic regression, monthly use of bisphosphonate (OR:15; 1.34-16.64) and necrosis in the mandible (OR:10.8; 1.0-11.7) were associated with infection. Conclusion: MRONJ in cancer patients can be associated with recurrent infections and mandibular involvement, and monthly ZA use is potential risk factor for poor prognosis.