OSTEONECROSIS OF THE JAW (ONJ) IN BREAST CANCER PATIENTS: EFFECT OF PREVENTIVE MEASURES IN A MONOINSTITUTIONAL EXPERIENCE

Charts of all breast cancer patients affected by bone metastases observed at the Oncology Unit of Alessandria Hospital in years 2005-2020 have been reviewed.  Osteonecrosis of the Jaw (ONJ) frequency after antiresorptive treatment (bisphosphonates and/or denosumab) was investigated in breast cancer patients undergoing preventive (before start of treatment) and/or screening (during treatment) evaluations, including oral inspection and panoramic dental radiography. Patients received antiresorptive agents according to international guidelines, that partially recommended shorter and tailored duration of antiresorptive treatment (instead of indefinite prolonged administration, till to deterioration of Performance Status - as advised by older guidelines) only after 2008. We examined charts of 280 patients with bone metastases receiving bisphosphonates (mostly zoledronic acid or pamidronate) or denosumab or sequences of drugs, and evaluated for oral health, of which 196 treated after 2006, and undergoing pre-treatment evaluation. Out of 280 total patients, 24 cases of Osteonecrosis of the Jaw (ONJ) were registered among Alessandria Hospital breast cancer patients. However, 9 cases were detected among 84 cases starting antiresorptive treatment without preventive visit, and 15 cases were found among 169 cases receiving dental visit before treatment beginning (15/169, 8.8%). Our preliminary data do not show the decrease of the risk of ONJ in breast cancer patients treated in the latest decade, that we expected due to generally less intensive schedules of antiresorptive drugs and due to adoption of measure of pre-treatment visit. Further evaluations have been planned to investigate if higher ONJ risk was associated to single drug (denosumab versus zoledronic acid versus pamidronate) or sequences; prolonged treatment (> 2 years); pre-existing oral disease (periodontal disease, need for tooth extraction, ill fitting dentures); and other potential predictive factors