Primary and secondary prevention to effectively reduce the risk of bisphosphonate-related osteonecrosis of the jaw in patients with bone metastases .

Background Bone is one of the most frequent sites of metastasis in patients with advanced cancer. Nearly all patients with myeloma, 65–75% of patients with prostate or breast cancer, and 30–40% of patients with lung cancer or other solid tumors, eventually develop bone metastases. Bisphosphonates (BP), particularly zoledronic acid and denosumab, were demonstrated to effectively reduce skeletal complications in patients with bone metastases. However, bisphosphonate-related osteonecrosis of the jaw (BRONJ) can occur spontaneously, favored by dental extraction, dental implant surgery, or denture wearing. The purpose of this study was to underline the role of dental prevention as an effective tool to reduce the risk of BRONJ. Material and methods BRONJ was identified with the standardized query “osteonecrosis” among all data from patients treated at Modena Cancer Center from 2005 to 2016. For each case, demographic and medical information were analyzed, as well as data about notification (year of occurrence, outcome), type and duration of BP exposure, and associated risk factors (dento-alveolar surgery, chemotherapy, antiangiogenics). Data were differently analyzed taking into account the implementation of a Dental Prevention Service in patients who are candidates for BP therapy.Results Among 1663 patients treated with BP, 63 cases of BRONJ were identified (3.8%). 44 female and 19 men with a median age of 69 years (range 47-90 years), have been treated with BP for bone metastases from breast cancer (54%), hematologic malignancy (21%), prostate cancer (13%), renal cancer (5%), lung cancer (2%) and other tumors (5%). 15 maxillae and 48 mandibles were involved. The trigger event was a dental extraction in 29% of the cases, being spontaneously the other 71%. The median time to BRONJ was 28 months (range 1-89.1 months) from the first dose of BP, and 25 was the mean number of BP doses administered before BRONJ. Overall, a preliminary odontoiatric evaluation was performed in only 14 cases (22%). All but one of these dentistry opinions were obtained after 2010 when the Dental Prevention Service was created, which is a drop out of the risk of BRONJ from 4.1 to 1.9%. Conclusions. Prevention of the BRONJ is critical in in bone metastatic patients. The incidence of BRONJ over time can drop to 1.9% when primary and secondary prevention measures are implemented in routine clinical practice.