Serum N-Telopeptide and Bone-Specific Alkaline Phosphatase Levels in Patients With Osteonecrosis of the Jaw Receiving Bisphosphonates for Bone Metastases

Therapeutic approach and management algorithms in medication-related osteonecrosis of the jaw (MONJ): recommendations of a multidisciplinary group of experts

BACKGROUND

The justification for this consensus is the absence of local protocols on Medication-Related Osteonecrosis of the Jaws (MONJ), for prevention, evaluation, and treatment, involving physicians and dentists, leading to suspension of antiresorptive treatments, despite their benefit in the prevention of fragility fractures (40-70%). These fractures cause disability and mortality (80% and 20-30%, respectively), as opposed to the low risk associated with MONJ in osteoporotic (0.01-0.03%) and oncological patients (1.3-1.8%).

PURPOSE

To provide management recommendations through algorithms that guide health professionals to prevent, diagnose, and treat MONJ in different clinical scenarios.

METHOD

A technical multidisciplinary team composed of specialists with extensive experience in osteoporosis or osteonecrosis of the jaw from Fundación Santa Fé (Bogotá, Colombia) and the Asociación Colombiana de Osteoporosis y Metabolismo Mineral was selected. Three rounds were carried out: definition of questions, answers using Delphi methodology, and the discussion of questions in order to have an agreement. The whole group participated in two phases, and the developer group in the total number of rounds. A literature review was conducted to obtain academic support to design questions with clinical relevance.

RESULTS AND CONCLUSIONS

The consensus group generated definitions and recommendations useful for doctors and dentists, following clinical algorithms involving four scenarios: osteoporosis patient who requires dental procedures and has not received antiresorptives, osteoporosis patient who are under treatment with antiresorptives, cancer patients, and MONJ-instituted patients. The therapeutic approach in osteoporosis and cancer patients, in invasive dental procedures, must be relied on the risk-benefit treatment.

Medication-Related Osteonecrosis of the Jaw: MASCC/ISOO/ASCO Clinical Practice Guideline

PURPOSE

To provide guidance regarding best practices in the prevention and management of medication-related osteonecrosis of the jaw (MRONJ) in patients with cancer.

METHODS

Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. Guideline development involved a systematic review of the literature and a formal consensus process. PubMed and EMBASE were searched for studies of the prevention and management of MRONJ related to bone-modifying agents (BMAs) for oncologic indications published between January 2009 and December 2017. Results from an earlier systematic review (2003 to 2008) were also included.

RESULTS

The systematic review identified 132 publications, only 10 of which were randomized controlled trials. Recommendations underwent two rounds of consensus voting.

RECOMMENDATIONS

Currently, MRONJ is defined by (1) current or previous treatment with a BMA or angiogenic inhibitor, (2) exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region and that has persisted for longer than 8 weeks, and (3) no history of radiation therapy to the jaws or metastatic disease to the jaws. In patients who initiate a BMA, preventive care includes comprehensive dental assessments, discussion of modifiable risk factors, and avoidance of elective dentoalveolar surgery (ie, surgery that involves the teeth or contiguous alveolar bone) during BMA treatment. It remains uncertain whether BMAs should be discontinued before dentoalveolar surgery. Staging of MRONJ should be performed by a clinician with experience in the management of MRONJ. Conservative measures comprise the initial approach to MRONJ treatment. Ongoing collaboration among the dentist, dental specialist, and oncologist is essential to optimal patient care.

Association between biomarkers and medication-related osteonecrosis of the jaws: a systematic review

OBJECTIVES

Our aim was to conduct a systematic review (SR) of the literature assessing the role of human biomarkers in the diagnosis or prognostication of medication-related osteonecrosis of the jaws (MRONJ).

STUDY DESIGN

An electronic search without date or language restriction was carried out in PubMed/MEDLINE, the Cochrane Central Register of Controlled Trials, Web of Science, and LILACS for publications until March 2018. In addition, a manual search in the gray literature was conducted. The search process was performed by 2 independent reviewing authors. Eligibility criteria included randomized and nonrandomized clinical trials, prospective or retrospective cohorts, case controls, and case series evaluating the association between biomarkers and MRONJ. The protocol of this SR was registered in PROSPERO under number CRD42018095886.

RESULTS

The search and selection process yielded 19 studies (2 case series, 6 case-control studies, 9 prospective cohort studies, and 2 retrospective studies) published between 2008 and 2018. Twenty-four biomarkers collected from serum, saliva, and urine were investigated by these studies. Eleven biomarkers were possibly related to MRONJ; however, no consensus is observed in the literature with regard to the sensitivity and clinical effectiveness of these biomarkers.

CONCLUSIONS

Although many biomarkers have been associated with MRONJ, the present SR found scarce clinical evidence supporting the use of these biomarkers for the diagnosis and prognosis of MRONJ.

Serum Markers of Bone Turnover and Angiogenesis in Patients With Bisphosphonate-Related Osteonecrosis of the Jaw After Discontinuation of Long-Term Intravenous Bisphosphonate Therapy

PURPOSE

To analyze serum markers of bone turnover, angiogenesis, endocrine function, and inflammation in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) who discontinued long-term intravenous bisphosphonate (BP) therapy.

PATIENTS AND METHODS

Serum samples were obtained from 25 BRONJ patients who had discontinued long-term intravenous BP therapy for an average of 11.4 ± 8.7 months and 48 non-BRONJ controls who continued receiving intravenous BP therapy. Samples were analyzed for total alkaline phosphatase, bone-specific alkaline phosphatase, osteocalcin, C-telopeptide, vascular endothelial growth factor, triiodothyronine, thyroxine, thyroid-stimulating hormone, 25-hydroxyvitamin D, and C-reactive protein.

RESULTS

The mean number of BP infusions was significantly higher in BRONJ patients compared with controls (38.4 ± 26.3 infusions vs 18.8 ± 7.2 infusions, P < .0001); however, the duration of BP therapy was not significantly different between the groups (P = .23). Overall, there were no significant differences in any of the markers between BRONJ patients and controls (all P values ≥ .16). In a subgroup analysis that matched BRONJ patients and controls according to mean age and number of BP infusions (10 BRONJ patients and 48 controls), log10 vascular endothelial growth factor (2.9 ± 0.4 pg/mL vs 2.4 ± 0.4 pg/mL, P < .001) and C-reactive protein (34 ± 26 mg/L vs 13 ± 8 mg/L, P < .01) levels were significantly higher in BRONJ patients compared with controls. Within BRONJ patients, none of the serum markers were correlated with duration of BP discontinuation.

CONCLUSIONS

Levels of bone turnover and endocrine markers in BRONJ patients who discontinue long-term intravenous BP therapy are similar to those in non-BRONJ controls receiving intravenous BP therapy. However, levels of angiogenesis and inflammation markers are higher in BRONJ patients who discontinue long-term intravenous BP therapy. The prolonged skeletal half-life of BPs may suppress bone turnover markers in BRONJ patients for several years after discontinuation of intravenous BP therapy, suggesting an extended effect on bone homeostasis.

Genetic association between VEGF polymorphisms and BRONJ in the Korean population

OBJECTIVES

The purpose of this study was to evaluate the association between vascular endothelial growth factor (VEGF) polymorphisms and bisphosphonate-related osteonecrosis of the jaw (BRONJ) in the Korean population.

SUBJECTS AND METHODS

Forty-five individuals (2 men, 43 women; mean age: 68.7 ± 12.3 years) were recruited for this study. All visited the Yonsei University Dental Hospital for surgical intervention from January 2012 to January 2013 and had a history of bisphosphonate (BP) administration (oral and/or intravenous). Patients were allocated to case (n = 26) or control (n = 19) groups according to the patients' selection criteria. Association between three VEGF single nucleotide polymorphisms (rs699947 (-2578 C>A), rs2010963 (-634 G>C) and rs3025039 (+936 C>T)) and BRONJ were investigated using multiple logistic regression analysis and Fisher's exact test where appropriate (α = 0.05).

RESULTS

The CC homozygotes of rs2010963 and rs3025039 of VEGF gene were associated with an increased risk of BRONJ (P = 0.04, 0.03, respectively). In haplotype analysis, no differences in haplotype C-C (-2578/-634) and haplotype C-C-C (-2578/-634/+936) were observed.

CONCLUSION

The CC homozygotes of rs2010963 and rs3025039 polymorphisms in the VEGF gene were associated with an increased risk of BRONJ in the Korean population. Further epidemiological cohort studies with a larger sample size would be required to confirm the suggestive correlations.

Salivary Biomarkers Associated With Bone Deterioration in Patients With Medication-Related Osteonecrosis of the Jaws

PURPOSE

The purpose of this study was to investigate the use of saliva as a medium for the identification of biomarkers associated with bone resorption and formation. The authors hypothesized that biomarkers, such as N-telopeptide of type I collagen (NTX) and bone-specific alkaline phosphatase (B-AP), could be identified in saliva. They further hypothesized that there would be a difference between these biomarkers in the saliva of patients with medication-relation osteonecrosis of the jaws (MRONJ) and those who have no risk factors for the development of MRONJ.

PATIENTS AND METHODS

This case-and-control study compared 2 salivary biomarkers, NTX and B-AP, in a group of patients with MRONJ and a control group. The predictor variable was the presence or absence of the disease (MRONJ or control group); the outcome variables were the levels of the 2 salivary biomarkers, NTX and B-AP. Saliva samples from 20 patients with a diagnosis of MRONJ and 14 control participants who were comparable to the study group with no history of antiresorptive medication use were collected. The saliva samples were analyzed using 2 commercially available assays for NTX and B-AP to evaluate for levels of each marker. A 2-tailed t test for 2 groups of unequal distribution was used for statistical analysis, with P values less than .05 considered statistically.

RESULTS

The 2 biomarkers, NTX and B-AP, were detected in saliva samples from the MRONJ and control groups. A statistically significant difference was found in the levels of NTX in saliva of patients with MRONJ compared with the control participants (P = .0067).

CONCLUSIONS

In this exploratory study, the 2 bone deterioration biomarkers (NTX and B-AP) were detected in saliva. There was a statistical difference in the levels of salivary NTX between patients with MRONJ and controls. Saliva evaluation could provide a novel method to detect, diagnose, stage, and potentially guide treatment decisions and monitor outcomes for patients with MRONJ in the future.

Biomarkers for Bisphosphonate-Related Osteonecrosis of the Jaw

PURPOSE

The aim of this study was to investigate a possible biomarker for bisphosphonate-related osteonecrosis of the jaw (BRONJ) in an animal model.

MATERIALS AND METHODS

Forty-eight Sprague-Dawley rats were randomly divided into the bisphosphonate group (n = 36), who were injected once a week with zoledronic acid, and the control group (n = 12), who were injected once a week with saline. After 6 weeks, surgical intervention was performed, and injections were continued up to 8 weeks. Rats in the bisphosphonate group were then further classified to the ONJ group, and the non-ONJ group, and biomarkers, including CTx, Glu-OC, TRACP 5b, RANKL, and OPG, were assessed at baseline (T0), at surgical intervention (T1), and at sacrifice (T2). Histomorphometric analysis for quantification of osteoclasts was performed.

RESULTS

Repeated measures analysis of variance revealed that TRACP 5b levels and the RANKL/OPG ratio were significantly decreased over time in the ONJ group compared with the non-ONJ group (p < .05). At T2, the area under the curve was 0.807 for TRACP 5b (sensitivity: 88.9%, specificity 66.7% at cutoff) and 0.765 for the RANKL/OPG ratio (sensitivity: 77.8%, specificity 62.9% at cutoff). TRACP 5b showed a lower least significant change (29.6%) with lower intra-assay coefficient of variability (CV; 6.32%) and interassay CV (11.20%) compared with those of the RANKL/OPG ratio (39.27%) and showed a higher signal-to-noise ratio (2.76) than that of the RANKL/OPG ratio (1.62). N.Oc/T.Ar and N.Oc/B.Ar demonstrated significantly decreased number of osteoclasts in ONJ group versus non-ONJ group.

CONCLUSIONS

These results show that serum TRACP 5b and the RANKL/OPG ratio were possible biomarkers for BRONJ. These data may provide useful additional information for future ONJ research. Further studies are needed to validate these results in humans with ONJ.

Diagnosis and management of osteonecrosis of the jaw: a systematic review and international consensus

This work provides a systematic review of the literature from January 2003 to April 2014 pertaining to the incidence, pathophysiology, diagnosis, and treatment of osteonecrosis of the jaw (ONJ), and offers recommendations for its management based on multidisciplinary international consensus. ONJ is associated with oncology-dose parenteral antiresorptive therapy of bisphosphonates (BP) and denosumab (Dmab). The incidence of ONJ is greatest in the oncology patient population (1% to 15%), where high doses of these medications are used at frequent intervals. In the osteoporosis patient population, the incidence of ONJ is estimated at 0.001% to 0.01%, marginally higher than the incidence in the general population (<0.001%). New insights into the pathophysiology of ONJ include antiresorptive effects of BPs and Dmab, effects of BPs on gamma delta T-cells and on monocyte and macrophage function, as well as the role of local bacterial infection, inflammation, and necrosis. Advances in imaging include the use of cone beam computerized tomography assessing cortical and cancellous architecture with lower radiation exposure, magnetic resonance imaging, bone scanning, and positron emission tomography, although plain films often suffice. Other risk factors for ONJ include glucocorticoid use, maxillary or mandibular bone surgery, poor oral hygiene, chronic inflammation, diabetes mellitus, ill-fitting dentures, as well as other drugs, including antiangiogenic agents. Prevention strategies for ONJ include elimination or stabilization of oral disease prior to initiation of antiresorptive agents, as well as maintenance of good oral hygiene. In those patients at high risk for the development of ONJ, including cancer patients receiving high-dose BP or Dmab therapy, consideration should be given to withholding antiresorptive therapy following extensive oral surgery until the surgical site heals with mature mucosal coverage. Management of ONJ is based on the stage of the disease, size of the lesions, and the presence of contributing drug therapy and comorbidity. Conservative therapy includes topical antibiotic oral rinses and systemic antibiotic therapy. Localized surgical debridement is indicated in advanced nonresponsive disease and has been successful. Early data have suggested enhanced osseous wound healing with teriparatide in those without contraindications for its use. Experimental therapy includes bone marrow stem cell intralesional transplantation, low-level laser therapy, local platelet-derived growth factor application, hyperbaric oxygen, and tissue grafting.

Prospective biomarker evaluation in patients with osteonecrosis of the jaw who received bisphosphonates

Bone biomarkers have been suggested for the risk assessment for osteonecrosis of the jaw, a serious complication associated with bisphosphonate (BP) use; however, no consensus has been reached. This study investigated the possible associations between bone biomarkers and the development of bisphosphonates-related osteonecrosis of the jaw (BRONJ). This is a case-control study of 37 patients with BRONJ (age, 73.6±11.2years) who had at least 1 sample available at diagnosis, out of which, 35 were taking BPs for osteoporosis and 2 patients for bone metastasis. Age- and gender-matched 37 patients who had been exposed to BPs for >24months and had no evidence of BRONJ after dentoalveolar surgery served as control group. The association between biomarkers (osteocalcin [OC], deoxypyridinoline [DPD], C-terminal telopeptide of collagen I [CTX], N-terminal telopeptides [NTX], bone-specific alkaline phosphatase [BAP], and parathyroid hormone [PTH]) and BRONJ development, the effects of BP discontinuation on biomarkers, and the performance of biomarkers for risk assessment were investigated. In our study, the PTH levels were found to be significantly higher in BRONJ patients compared to controls (P<0.05). But the OC, DPD, CTX, NTX, and BAP levels were not significantly different between the 2 groups (P>0.05). The CTX level in reference to a 150pg/mL cutoff was also not significant for BRONJ development (P>0.05). Among BRONJ patients who discontinued BP, in a linear mixed model, only CTX showed a significant increase over time (β=0.002, P=0.007). The cutoff PTH level was >41.52pg/mL (AUC=0.719, P=0.009), and that of CTX was ≤0.094ng/mL (AUC=0.619, P=0.069). In conclusion, there is insufficient evidence for the risk prediction for BRONJ of current bone biomarkers; additional research is necessary.

Oral care and the use of bone-targeted agents in patients with metastatic cancers: A practical guide for dental surgeons and oncologists

BACKGROUND

Bone-targeted agents such as bisphosphonates and the RANKL antibody have revolutionised the care of patients with bone metastases. There has, however been increasing concern about the oral health of these patients and in particular osteonecrosis of the jaw (ONJ), especially with the increasing use of these agents at higher potencies for greater periods of time.

METHODS

A review of the published data in PubMed and meeting abstracts was performed to examine incidence, risk factors, pathogenesis, clinical course and management of osteonecrosis of the jaw with focus on cancer patients treated with bone-targeted agents (BTA) for bone metastases. This manuscript takes the most frequent and pertinent questions raised by oncologists, dentists and oral and maxillofacial surgeons and tries to give a pragmatic overview of the literature.

RESULTS

The incidence of ONJ varies depending on types of bone-targeted agents, duration of treatment and additional risk factors. The causes and pathogenesis of ONJ is not fully elucidated, however bone-targeted therapy induced impaired bone remodelling, microtrauma secondary to jaw activity, and oral bacterial infection seem to be important factors. Since the treatment options for ONJ are limited and not well established, preventive strategies have to be included in patients management.

CONCLUSIONS

Many unanswered questions remain about the optimal oral care of patients receiving bone-targeted agents. Prospective data collection will remedy this and help to provide practical guidelines for the management and treatment of those patients that require dental intervention.