Osteonecrosis of the jaw in patients with multiple myeloma

Osteonecrosis of the jaw (ONJ) has been associated with the use of pamidronate and zoledronic acid. ONJ was assessed prospectively since July 2003 in 202 patients with multiple myeloma who received bisphosphonates since April 1995. Fifteen patients (7.4%) developed ONJ. The median time of exposure to bisphosphonates was 39 months for patients with ONJ compared to 28 months (p=0.048) for patients with no ONJ. The cumulative hazard of developing ONJ was significantly higher in patients treated with zoledronic acid alone than in those treated with pamidronate alone / pamidronate+zoledronic acid / zoledronic acid+ibandronate sequentially (1% at 1 year and 15% at 4 years vs. 0% and 5%, p=0.003). In conclusion, the risk of ONJ is increased with time of exposure and probably with the use of zoledronic acid.

Bisphosphonates are used for the treatment of bone involvement by multiple myeloma and solid tumors. Recently, avascular osteonecrosis of the jaw (ONJ) has been associated with their use. Osteonecrosis refers to the death of bone as a result of impaired blood supply. ONJ has been described in association with the use of zoledronic acid and pamidronate in various malignancies and it has been suggested that its development requires a long period of exposure. The diagnosis of osteonecrosis, in most cases, has been made retrospectively, based on the review of medical records rather than by a specialist. Furthermore, a denominator for the patients who were diagnosed with OJN was not established. In order to define the incidence of ONJ as well possible risk factors we have been prospectively studying the development of ONJ since 2003, while all patients who received bisphosphonates in our department over an 8-year period have been entered into a database. A first analysis, including all patients with malignant bone disease, has already been reported. Nevertheless, such an analysis may not be representative of the problem in each malignancy, since there are differences associated with the duration of treatment. Additionally, biological differences associated with the development of ONJ in different tumors cannot be excluded. That initial report included 111 patients with MM. In our current report, another 91 patients have been included. We, therefore, studied the incidence and possible risk factors associated with bisphosphonate treatment separately in patients with MM.

Source: http://www.haematologica.org/preprint/20060601/03906078_9641.pdf