Abstract P2-13-03: Osteonecrosis of the Jaw: Dental Outcomes in Metastatic Breast Cancer Patients Treated with Bisphosphonates with/without Bevacizumab at Roswell Park Cancer Institute

Background: The etiology, optimal management, and long term outcome of osteonecrosis of the jaw (ONJ) is not well understood. Large trials have suggested that the combination of bevacizumab and bisphosphonates (BPs) does not significantly increase the incidence of ONJ. Because healing after mucosal trauma or dental surgery requires revascularization, it is possible that bevacizumab use could influence dental outcomes. Theoretically, the combination of bevacizumab and BPs may affect the time to development of ONJ and/or the response to dental therapy. Dental management of ONJ has not changed over time in our center, but increased recognition and screening may impact the dental outcome. Methods: We reviewed all cases of ONJ in metastatic breast cancer patients treated with BPs and with or without bevacizumab at Roswell Park Cancer Institute between October 2002 and April 2010. All patients diagnosed with ONJ discontinued BP therapy, while 3/7 (42%) continued bevacizumab until breast cancer progression. Type of BP, duration of treatment, total dose of BPs and bevacizumab dosing were recorded. All patients were treated in the department of dentistry with a combination of antibiotics, debridement, and chlorhexidine scrub. We evaluated the time to diagnosis of ONJ after the initiation of BP therapy, total dose of BP and dental treatment outcomes. Statistical analysis was performed using t-test and log-rank analysis. Results: See tables. 27 ONJ patients with a median age of 57 years (range 40-68) were analyzed. Patients were treated with zoledronic acid (95%), pamidronate (20%), or both (15%). 2 patients were excluded from dental response analysis due to lost follow up. Overall median time to ONJ treatment response was 5.0 months (range 1.3-67.5). Conclusions: The addition of bevacizumab to BP treatment did not significantly alter the time to the development of ONJ, the number of BP doses administered prior to diagnosis, or the response to dental treatment. However, ONJ response rates (complete and partial) to dental therapy have improved from 38% prior to 2007 to 58% after 2007, likely reflecting improved recognition and earlier treatment. Table.1 Time to ONJ and number of BP doses Table 2 ONJ response to dental treatments Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-13-03.