Article
Incidence of bisphosphonate related osteonecrosis of the jaw (BRONJ) in consideration of primary diseases and concomitant therapies. A retrospective cohort study
Search Medline for
Authors
Published: | December 7, 2011 |
---|
Outline
Text
Background: The problem of bisphosphonate related osteonecrosis of the jaw (BRONJ) is a subject of scientific discussions to oral and maxillofacial surgeons since its first description by Marx in 2003. Many retrospective studies on the etiology and pathogenesis have been carried out to understand the pathological mechanism, most concerned to issues of dosage and application. Recently, co-factors have been tried to identify, which could promote the development of BRONJ. However, in this subject only individual factors have been considered in retrospective studies.
Methods: The present study is based on data of 169 patients with osseous metastatic malignancies. All patients received intravenous bisphosphonate therapy. On the basis of medical history, malignancy, and primary treatment, the modality of bisphosphonate therapy, and existing co-morbidities and medication, correlated features have been analyzed. The role of immunosuppressive drugs, influence of underlying diseases, general factors such as age and gender were examined. The predictability of necrotic involvement, influenced by the underlying malignancy and its specific therapy, e.g. radiation and cytostatic therapy were analyzed and statistical evaluated.
Results: 8.9% (n=15) of patients developed a BRONJ. Average time between primary diagnosis of malignancy and BRONJ was 80 months. Nine patients had breast cancer, five prostate cancer and one renal cancer. Separation into stages and histological subtype did not show any significant correlation, as well as age and gender are not associated to the occurrence of BRONJ. Statistical analysis showed a significant correlation concerning monocytostatic therapy (p=0.0215) and triple cytostatic therapy (p= 0.0137). The majority of BRONJ-patients (60%) were treated by bisphosphonate therapy including zoledronate. Median number of single bisphosphonate applications was 28, in combined therapy 44. Concomitant medications, does not suggest possible correlation, and so do accompanying diseases, arterial hypertension (33.33%) and arterial microcirculatory disturbances (20%).
Conclusion: The final consideration after evaluation displays on which subjects research should be done more intensively. The influence on the pathogenesis of BRONJ by cytostatics and combined therapies of cytotoxic drugs has been demonstrated statistically. Concerning bisphosphonate therapy we found a drug- and dose-dependent occurrence of BRONJ. Furthermore, accompanying diseases have been determined which are connected to the occurrence of a BRONJ. Regarding to pathophysiological coherencies, further retrospective and prospective studies should be performed to consider the role of tissue perfusion and oxygen saturation, the influence of immunosuppressive drugs in relation to the occurrence of BRONJ, and influence on wound healing after initial lesions.