Osteonecrosis of the jaw and bisphophonates in oncology

Bisphosphonates are potent osteoclastic inhibitors that are indicated in the prevention of bone complications. They could also be of interest in the prevention of bone metastases. Several recent international publications have highlighted the onset of osteonecrosis of the jaw (ONJ) in patients treated with bisphosphonates. These osteonecroses manifest in the form of bone exposure, recent tooth mobility, swelling and inflammation and, occasionally, localised pain but they can remain asymptomatic for weeks or even months. The prevalence of these osteonecroses in cancer patients treated with bisphosphonates could range from 1 to 10%. In most cases (60 to 80%), ONJ develops after alveolo-dental surgery (e.g. tooth extraction). Length of exposure to bisphosphonate probably increases the risk. Our recommendations regarding the diagnosis, classification, prevention and treatment of cases of ONJ observed during bisphosphonate administration are based on published studies and our experience. It is obvious that the use of bisphosphonates is undoubtedly beneficial in the treatment of bone complications but the incidence of ONJ during long-term treatments and at high doses warrants preventive measures. These measures are straightforward : bucco-dental repair prior to treatment, good hygiene and regular monitoring during treatment. Current, non-invasive procedures are still permitted. In other cases, the suspension of treatment is indicated until healing is complete. The increase in the incidence of ONJs, serious adverse events, raises the issue regarding duration and administration of bisphosphonate treatment in the management of bone metastases. Studies are currently underway in an attempt to answer this issue.     

Osteonecrosis of the jaw related to the use of bisphosphonates

PURPOSE OF REVIEW: Osteonecrosis of the jaw associated with the use of potent nitrogen containing bisphosphonates is a new and challenging clinical entity with a high impact on quality of life. This review attempts to consolidate the rapidly expanding literature into practical guidelines and provides expert consensus for areas of uncertainty. RECENT FINDINGS: Diagnostic criteria and a staging system for osteonecrosis of the jaw have been proposed, and histomorphologic analysis has confirmed osteonecrosis of the jaw as a proper disease, distinctively different from osteoradionecrosis. Various guidelines for the management of osteonecrosis of the jaw have been suggested and further retrospective research has provided new insights into its epidemiology. SUMMARY: Osteonecrosis of the jaw is a distinct entity of uncertain origin that is increasingly being observed in patients treated with potent aminobisphosphonates, although the etiology is probably multifactorial. Recent data confirm the predisposition of multiple myeloma patients to develop osteonecrosis of the jaw. Although various treatment strategies have been reported, conservative management remains the mainstay of therapy.     

Osteonecrosis of the jaw and bisphosphonate use in breast cancer patients

It is renowned that breast cancer patients suffer from a number of cancer-related skeletal events, while drugs recently added to the practitioners’ quiver, such as aromatase inhibitors, intensify the need to preserve bone mass in this group of patients. Bisphosphonates are potent inhibitors of both normal and pathologic bone resorption. Besides their apoptotic and antiproliferative activity on osteoclasts, bisphosphonates can also exert various effects on macrophages, keratinocytes and fibroblasts. Bisphosphonate-related osteonecrosis of the jaw is a complication that emerged after broad clinical use of bisphosphonates, and which has not yet been adequately described in a clinical trial setting. The purpose of this review is to critically reflect the incidence, etiopathogenesis, prevention and treatment of osteonecrosis of the jaw. Succinct suggestions are provided to ensure clinicians prevent and detect the complications early.     

Osteonecrosis of the jaw in cancer patients receiving IV bisphosphonates

Cases of osteonecrosis of the jaw (ONJ) have been reported with an increasing frequency over the past few years. ONJ is most often identified in patients with cancer who are receiving intravenous bisphosphonate therapy but it has also been diagnosed in patients receiving oral bisphosphonates for nonmalignant conditions. The condition involves exposed bone of the maxilla or mandible. Although it is often associated with a recent dental surgical procedure, spontaneous ONJ can also occur. Patients commonly present with symptoms. Through case reporting and clinical experience, there is a suggestion that the incidence of ONJ in patients with cancer receiving intravenous bisphosphonates ranges between 1% and 10%. Management of ONJ focuses on maximizing oral health, conservative actions with mouth rinses, antibiotics, and avoidance of unnecessary invasive dental procedures. The currently available data on ONJ are reviewed here.     

Osteonecrosis of the jaw and use of bisphosphonates in adjuvant breast cancer treatment: a metanalysis

To estimate the cumulative randomized evidence for the overall incidence of bisphosphonates induced jaw osteonecrosis in adjuvant treatment of breast cancer. Systematic review and meta-analysis of randomized clinical trials. Trials were located through PubMed, ISI, Cochrane Library, and major cancer scientific meetings searches. We identified 15 studies reporting data on osteonecrosis of the jaw. A total of 10,694 randomized women were included, of whom 5,312 received bisphosphonates and 5,382 received either placebo or no treatment. Osteonecrosis of the jaw was a rare event, occurring in 13 (0.24%) of the 5,312 patients receiving bisphosphonates, and in one of the 5,382 patients in the control group. All the 13 events of osteonecrosis of the jaw reported among bisphosphonates arms occur in patients undergoing treatment with zoledronic acid (13/3,987, 0.33%). No events of osteonecrosis of the jaw were reported among patients randomized to receive clodronate (n = 669), pamidronate (n = 460), risedronate (n = 171), and ibandronate (n = 25); however, these samples were too small to be able to rule out the condition. Treatment with zoledronic acid was significantly associated to the occurrence of osteonecrosis of the jaw (OR = 3.23, 95% CI = 1.7–8) compared with no use. No significant between-study heterogeneity was observed. Despite use of zoledronic acid is associated to a higher number of events compared with no use, the osteonecrosis of the jaw during the adjuvant treatment of breast cancer is a rare event. At current dosage, adjuvant use of bisphosphonates in breast cancer treatment is safe. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Osteonecrosis of the jaw in cancer after treatment with bisphosphonates: incidence and risk factors.

PURPOSE: Osteonecrosis of the jaw (ONJ) has been associated recently with the use of pamidronate and zoledronic acid. We studied the incidence, characteristics, and risk factors for the development of ONJ among patients treated with bisphosphonates for bone metastases. PATIENTS AND METHODS: ONJ was assessed prospectively since July 2003. The first bisphosphonate treatment among patients with ONJ was administered in 1997. Two hundred fifty-two patients who received bisphosphonates since January 1997 were included in this analysis. RESULTS: Seventeen patients (6.7%) developed ONJ: 11 of 111 (9.9%) with multiple myeloma, two of 70 (2.9%) with breast cancer, three of 46 (6.5%) with prostate cancer, and one of 25 (4%) with other neoplasms (P = .289). The median number of treatment cycles and time of exposure to bisphosphonates were 35 infusions and 39.3 months for patients with ONJ compared with 15 infusions (P < .001) and 19 months (P = .001), respectively, for patients with no ONJ. The incidence of ONJ increased with time to exposure from 1.5% among patients treated for 4 to 12 months to 7.7% for treatment of 37 to 48 months. The cumulative hazard was significantly higher with zoledronic acid compared with pamidronate alone or pamidronate and zoledronic acid sequentially (P < .001). All but two patients with ONJ had a history of dental procedures within the last year or use of dentures. CONCLUSION: The use of bisphosphonates seems to be associated with the development of ONJ. Length of exposure seems to be the most important risk factor for this complication. The type of bisphosphonate may play a role and previous dental procedures may be a precipitating factor.     

Osteonecrosis of the jaw in patients with bone metastases treated with bisphosphonates: a retrospective study

OBJECTIVE: Bone metastases are a major cause of morbidity in cancer patients. Treatment includes bisphosphonates, which are also associated with avascular osteonecrosis of the jaw (ONJ). Our aim was to evaluate the correlation between bisphosphonates and ONJ. PATIENTS AND METHODS: Of the 539 patients with bone metastases treated in our department from June 2002 to December 2006 with i.v. bisphosphonates, eight (1.5%) developed ONJ. RESULTS: The eight patients with ONJ had all been given zoledronic acid, and two had also been treated with pamidronic acid. In four of the patients, ONJ was diagnosed during treatment, while in the remaining four it was diagnosed several months after therapy with bisphosphonates had ended. Six of these patients received local noninvasive treatment, of whom five progressed. Two showed apparent autolimitation of the disease. The remaining two patients underwent surgical resection and currently show no signs of relapse. All eight ONJ patients presented with various concomitant risk factors such as paradontopathy, dental extraction, or spontaneous avulsion. CONCLUSIONS: Our results show that ONJ can appear months after interruption of treatment and that a surgical approach can be used in suitable cases. Closer cooperation is needed among specialists to define guidelines for the prevention of ONJ in patients with bone metastases.     

Osteonecrosis of the jaw in prostate cancer patients with bone metastases treated with zoledronate: a retrospective analysis

Osteonecrosis of the jaw (ONJ) has recently been reported as a potentially serious complication of prolonged treatment with intravenous bisphosphonates. We studied its frequency in prostate cancer patients receiving intravenous zoledronate. The medical and dental records of 52 consecutive patients with prostate cancer and bone metastases treated at our institute between January 2002 and October 2005 were reviewed. All patients received intravenous zoledronate 4 mg every 3 or 4 weeks and concomitant conventional prostate cancer treatments. We analysed the association of ONJ with the number of administrations of zoledronate and exposure to chemotherapy. At a median follow-up of 7 months (range 1-41) after the initiation of zoledronate, ONJ occurred in six patients (12%, 95% C.I. 5.4-23.0%). All six ONJ cases occurred after the 9^th administration of zoledronate. The median number of zoledronate administrations was 17 (range 9-24) and 8 (range 1-32) for patient developing and not developing ONJ, respectively (p =0.02). Chemotherapy with docetaxel was also associated with a strong, but not statistically significant, trend towards increased risk of ONJ (OR 3.8, 95% C.I. 0.4-35.6, p =0.24). The length of exposure to zoledronate was associated with an increased frequency of ONJ in prostate cancer patients. A possible role of chemotherapy with docetaxel as a cofactor for ONJ merits further evaluation.     

Osteonecrosis of the jaw: dental outcomes in metastatic breast cancer patients treated with bisphosphonates with/without bevacizumab

The etiology, optimal management, and outcome of osteonecrosis of the jaw (ONJ) are not well understood. Because healing after mucosal trauma requires revascularization, theoretically, the combination of bevacizumab (bev) and a bisphosphonate (BP) could affect the time to development of ONJ and/or the response to dental therapy. We reviewed all cases of ONJ in metastatic breast cancer patients treated at our institution with bev+BPs and BPs alone between October 2002 and April 2010. We identified 27 ONJ patients with a median age of 57 years (range, 40 to 68 years). Seven patients received bev+BPs; 20 patients received BPs alone. Patients received intravenous zolendronate (95%), pamidronate (20%), or both (15%). Patients were treated with antibiotics (93%), alveoplasty/debridement (67%), and chlorhexidine scrub (81%). There was no difference in dental treatment between the groups or by the year of diagnosis (before 2007 versus 2007-2010). Complete resolution (CR) was achieved in 24% of all patients; 33% treated with bev+BPs, and 21% treated with BPs alone. Rates of CR improved from 15% to 33% after 2007. The median time to response was 5.6 months (range, 1.3 to 67.5 months). The addition of bev to BPs did not appear to alter the time to development of ONJ (32.6 months versus 34.6 months, respectively). The number of BP treatments administered before the diagnosis of ONJ between bev+BPs and BPs (32 doses versus 36.5 doses) was similar. However, our sample size was too small to characterize the difference statistically. Because dental management of ONJ has not changed over time at our institute, early recognition and screening may account for the improvement in dental outcomes.     

Osteonecrosis of the jaw in patients with multiple myeloma treated with bisphosphonates: definition and management of the risk related to zoledronic acid

PurposeBisphosphonates (BPs) are currently used to treat bone lesions in patients with multiple myeloma (MM). Osteonecrosis of the jaw (ONJ) has been reported as an adverse event of such treatment, especially after treatment with zoledronic acid (ZA). The aim of this study was to evaluate incidence, risk factors, management, and prevention strategies of ONJ in order to optimize the current standard use of BPs in MM.Patients and MethodsWe reviewed the medical records of 105 patients with MM treated in 2 hematology departments with monthly pamidronate 90 mg and/or ZA 4 mg and evaluated for ≥ 12 months. Because they are risk factors for ONJ development, we analyzed patient and disease features, previous MM treatments, type and number of BP infusions, and previous history of dental procedures.ResultsSeventeen patients (16%) with MM treated with BPs developed ONJ after a median number of 43 BP infusions (vs. 28 in patients without ONJ; P = .035). In 11 of 17 patients, ONJ arose after a tooth extraction. Among risk factors, the administered doses of ZA were significantly associated with ONJ, and 12 consecutive doses of ZA proved to double the risk of developing this complication. Regular hard- and soft-tissue oral assessment was of benefit in the prevention of further ONJ occurrence.ConclusionThe most important risk factor for ONJ is represented by the number of ZA infusions. Tooth extractions and invasive procedures should be avoided. A multidisciplinary approach including oncohematologists and dental teams proved critical to better identify, prevent, and manage ONJ.     

Ameloblastoma of the jaw. A reappraisal of the role of megavoltage irradiation

Ten patients with ameloblastoma of the jaw were treated with megavoltage irradiation between 1958 and 1982. Seven cases were treated with radiation alone and six responded initially. One patient subsequently recurred and was successfully salvaged surgically. Three patients were treated with combined radiation therapy and surgery. Carefully applied megavoltage irradiation has a useful role in the management of ameloblastoma, particularly in large maxillary tumors with associated destruction of the infrastructure of the maxillary antrum. It is apparent from this series, and from the literature, that the ameloblastoma is not an inherently radioresistant tumor.     

Genomewide pharmacogenetics of bisphosphonate-induced osteonecrosis of the jaw: the role of RBMS3

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious adverse drug reaction. We conducted a genomewide association study to search for genetic variants with a large effect size that increase the risk for BRONJ.

Methods.

We ascertained BRONJ cases according to the diagnostic criteria of the American Association of Oral and Maxillofacial Surgeons. We genotyped cases and a set of treatment-matched controls using Illumina Human Omni Express 12v1 chip (733,202 markers). To maximize the power of the study, we expanded the initial control set by including population and treatment-tolerant controls from publicly available sources. Imputation at the whole-genome level was performed to increase the number of single nucleotide polymorphisms (SNPs) investigated. Tests of association were carried out by logistic regression, adjusting for population structure. We also examined a list of candidate genes comprising genes potentially involved in the pathogenesis of BRONJ and genes related to drug absorption, distribution, metabolism, and excretion.

Results.

Based on principal component analysis, we initially analyzed 30 white cases and 17 treatment-tolerant controls. We subsequently expanded the control set to include 60 genetically matched controls per case. Association testing identified a significant marker in the RBMS3 gene, rs17024608 (p-value < 7 × 10⁻⁸); individuals positive for the SNP were 5.8× more likely to develop BRONJ (odds ratio, 5.8; 95% confidence interval, 3.1–11.1). Candidate gene analysis further identified SNPs in IGFBP7 and ABCC4 as potentially implicated in BRONJ risk.

Conclusion.

Our findings suggest that genetic susceptibility plays a role in the pathophysiology of BRONJ, with RBMS3 having a significant effect in the risk.     

The role of macrophages in asbestos-induced carcinogenesis

Data available on the pathways of asbestos (fibrous) carcinogenesis still leaves much to be desired. Asbestos is regarded as a non-genotoxic substance by most researchers. There is insufficient evidence on the interaction of fibres, target-cells and macrophages. Macrophages secreted proteins (ca. 450 kD) to inhibit proliferation of intact mesothelium and cytoxine (3-5 kD) which stimulated the cellular sensitivity of intact mesothelium and mesotheliomas to the toxic influence of asbestos. It was suggested that the effect was due to the triggering of intrinsic causation of cell death. Like any other fibres, carcinogenic effect of asbestos could be accounted for by such significant factor as active oxygen radicals. When exposed to asbestos, both intact mesothelial and mesothelioma cells and macrophages synthesized those substances. Free radical-like substances in conjunction with macrophage-conditioned media produced toxic effect on mesothelial cells. The role of active oxygen radicals in fibre-induced carcinogenesis is discussed.     

Distinct role of macrophages in different tumor microenvironments

Macrophages are prominent in the stromal compartment of virtually all types of malignancy. These highly versatile cells respond to the presence of stimuli in different parts of tumors with the release of a distinct repertoire of growth factors, cytokines, chemokines, and enzymes that regulate tumor growth, angiogenesis, invasion, and/or metastasis. The distinct microenvironments where tumor-associated macrophages (TAM) act include areas of invasion where TAMs promote cancer cell motility, stromal and perivascular areas where TAMs promote metastasis, and avascular and perinecrotic areas where hypoxic TAMs stimulate angiogenesis. This review will discuss the evidence for differential regulation of TAMs in these microenvironments and provide an overview of current attempts to target or use TAMs for therapeutic purposes.     

The role of photosensitized macrophages in photodynamic therapy

Cancer stimulates macrophage infiltration and encourages angiogenesis, which is necessary for tumor growth and invasion. It seems, that the influence of photodynamic therapy (PDT) on immune cells and immune regulators plays a crucial role in this process. In order to study this effect, the influence of δ-aminolevulinic acid (ALA) PDT on the activity of the murine macrophage J-774A.1 cell line was assessed. J-774A.1 cells were incubated with different concentrations of ALA and irradiated with a VIS light source (400-750 nm) at 5, 10 and 30?J/cm2. The effects of ALA-PDT were evaluated on the basis of cell viability and the secretory activity of macrophages (nitric oxide, NO; reactive oxygen intermediates, ROI; tumor necrosis factor α, TNF-α; interleukin-1β, IL-1β; and nuclear factor κB, NF-κB; proteins, p50 and p65). Experiments showed that at the higher energy doses, there was a large increase in ROI and TNF-α release and decreased levels of NF-κB p50 and p65, IL-1β production and NO release. The increased levels of ROI and TNF-α release after PDT could be an additional factor for the complete eradication of tumors. The decrease in NF-κB p50 and p65 and IL-1β levels could inhibit tumor progression.