1585P - A Prospective Mono-Institutional Study on the Impact of a Systematic Prevention Program on the Incidence and Outcome of Osteonecrosis of the Jaw (ONJ) in Patients (PTS) Treated with Bisphosphonates (B) for Bone Metastases

Abstract

ABSTRACT Background B are commonly used to treat bone metastases in cancer pts, who have a higher risk of developing ONJ. The elective involvement of the jaw can have an anatomic rationale, since this region has a thin mucosa and microbiological contamination. The jaw is exposed to dental microtraumatisms and infections, so reparation mechanisms are essential. B inhibits bone turnover and since the increased demand for bone repair isn't satisfied, the bone is exposed to osteonecrosis. To reduce this risk we have developed a specific prevention program focused primarily on reducing its incidence and, wherever it develops, the need for demolitive surgery with permanent sequelae. Patients and methods All consecutive pts with bone lesions, that were eligible for treatment with B (either zoledronic or pamidronic acid) were prospectively evaluated. Before starting B, each patient was referred to an specialized odontoiatric team that performed: 1. dental examination; 2. orthopantomography; 3. professional dental hygiene. If the oral conditions weren't satisfactory (i.e., tooth decay, dental plaque, broken teeth), the dentist completed the necessary intervention before starting B. Results From April 2007 to April 2012 we collected data of 254 pts, 243 of which were treated with zoledronic acid and 9 with pamidronic acid. The median age was 74 years old (range 37-95), 92 male and 162 female. All pts had bone involvement: 74 pts had breast cancer, 39 lung cancer, 36 prostate cancer, 33 multiple myeloma and 72 others. On average the pts received 9.7 cycles (range 1-48). No case of ONJ was recorded. Conclusions Our study demonstrates that ONJ can be effectively prevented with a serious program that involves a multidisciplinary team. The odontoiatric basal evaluation is necessary to identify pts with oral pathologies or inadequate oral hygiene who must undergo preventive dental treatment. When reparative phaenomena are compromised by B, the healthy oral environment prevents infections and subsequent morbidity. In our opinion, this type of preventive program should be mandatory for all pts starting B. Disclosure All authors have declared no conflicts of interest.