The (mis) use of bone resorption markers in the context of bisphosphonate exposure, dental surgery and osteonecrosis of the jaw

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.

Bone scintigraphy predicts bisphosphonate-induced osteonecrosis of the jaw (BRONJ) in patients with metastatic castration-resistant prostate cancer (mCRPC)

OBJECTIVES

The aim of this study was to evaluate the role of bone scintigraphy (BS) in early prediction of clinically asymptomatic bisphosphonate (BP)-related osteonecrosis of the jaws (BRONJ) in patients with metastatic castration-resistant prostate cancer (mCRPC).

MATERIAL AND METHODS

BS of mCRPC patients treated with BP was evaluated for pathologic tracer uptake of the jaws in BS suspicious for BRONJ. Results were compared to development of clinically evident BRONJ. Sensitivity, specificity and predictive values of BS for the detection of BRONJ as well as time from beginning of BP therapy to pathologic tracer uptake in BS and time from pathologic tracer uptake in BS to clinically evident BRONJ were determined.

RESULTS

Thirty BP-treated patients were included. Nine patients (30%) had pathologic BS lesions of the jaws. Six patients (20%) developed BRONJ. Sensitivity and specificity of BS for BRONJ prediction were 67 and 79%. Median time from the start of BP treatment to pathologic tracer uptake in BS was 28 months (range 10-33) and from pathologic tracer uptake in BS to clinically evident BRONJ 6.5 months (range 2-19). Pathologic tracer uptake in BS was significantly more often observed in patients who developed BRONJ compared to patients who did not (p = 0.049; OR 7.6).

CONCLUSIONS

Patients with pathologic tracer uptake in the jaws in BS significantly more often develop BRONJ. An unsuspicious BS is predictive for absence of BRONJ in the future.

CLINICAL RELEVANCE

We conclude that when BS has been performed, it should not only be used to assess tumour stage and treatment response but also to check for pathologic tracer uptake in the jaws in BS to detect BRONJ at an early stage in mCRPC patients receiving bisphosphonates.

Relationship between periodontal disease and osteoporosis

BACKGROUND

For many years an association between the low bone density of osteoporosis and increased risk of periodontal bone loss has been suspected. In this review the relationship between osteoporosis and periodontal disease is considered.

METHODS

For this narrative review a very broad search strategy of the literature was developed using both PubMed and Scopus databases using the search words "perio" and "osteoporosis". The reference lists from the selected papers were also scanned and this provided an additional source of papers for inclusion. The inclusion/exclusion criteria, were also quite liberal with only those papers dealing with bisphosphonates and osteonecrosis of the jaws, osteoporosis in edentulous individuals, as well as those not written in English being excluded.

RESULTS

The data available suggest that reduced bone mineral density is a shared risk factor for periodontitis rather than a causal factor. However, more prospective studies are required to fully determine what, if any, relationship truly exists between periodontitis and reduced bone mineral density.

CONCLUSIONS

More prospective studies are required to determine what, if any, relationships exist between periodontal disease and reduced bone mineral density.

Biochemical markers of bone turnover in osteonecrosis of the jaw in patients with osteoporosis and advanced cancer involving the bone

Osteonecrosis of the jaw (ONJ) has been hypothesized to result in part from a relative "oversuppression" of normal physiologic bone remodeling at the jaw brought about by bisphosphonate therapy. Biochemical markers of bone turnover give readily measurable information on integrated systemic bone remodeling activity, as measured by blood and urine assays. The intra- and interassay variability of most currently available assays is less than 10%, although many biological factors can influence levels of bone turnover markers. Bone turnover markers may show a dynamic response to changes in clinical status for a given disease state. Elevated bone turnover on and off treatment appears to predict adverse clinical consequences in both osteoporosis and cancer. Bisphosphonates effectively decrease the level of the bone turnover markers with a pattern depending on the marker, the bisphosphonate, the dose regimen, and the disease. However, long-term (10-year) treatment with bisphosphonates for osteoporosis does not appear to result in a progressive decline in bone turnover, as measured by markers and bone histology. The effects of long-term (greater than 2 years) treatment with monthly intravenous bisphosphonates on bone turnover markers in cancer are unknown. Discontinuation of bisphosphonate therapy appears to allow a recovery of bone turnover, which is related to the bisphosphonate, the duration of therapy, and the disease being treated. At this time, data are limited with regard to the utility of bone turnover markers in assessing risk for ONJ and whether bone marker-directed bisphosphonate holidays would be useful in prevention or treatment of ONJ.

Adverse effects of bisphosphonates

Use of bisphosphonates has been growing steadily in the last decade. This follows the introduction of simpler dosing regimes, the availability of lower-priced generics, and concerns about the safety of hormone-replacement therapy. Bisphosphonates have a relatively good safety record and are tolerated by the majority of patients, but serious adverse events have been recorded in some cases. Only the most common of adverse effects are robustly observable in clinical trials. In general, studies were not powered to detect effects that were lower in incidence than fractures. This review of adverse events in bisphosphonate-treated patients was based on published information from case reports, case series, claims databases, national databases, surveys, adverse event reporting databases, and single or pooled clinical trials. The most common acute adverse events with bisphosphonates for osteoporosis are gastrointestinal discomfort and acute influenza-like illness. Renal complications are very rare with oral bisphosphonates and rare with i.v. bisphosphonates when used appropriately. Based on our current knowledge, skeletal events in the form of osteonecrosis of the jaw and atypical fragility fractures are rare compared with the risk of osteoporotic fractures, at least in patients with the same risk of fractures as those in the phase III trials. It is biologically plausible that atypical fragility fractures could follow from suppression of bone remodeling, but high-quality studies proving causality are lacking. Physicians are advised to critically reassess BMD and risk profile after 3-5 years of therapy to avoid treatment in patients at low risk.

Dental management of patients at risk of osteochemonecrosis of the jaws: a critical review

Osteonecrosis of the jaw bones is a complication of bisphosphonate (BP) drug usage characterised by trans-mucosal exposure of necrotic bone, often followed by infection and pain. Osteonecrosis is observed in cancer patients on high-potency intravenous BP more frequently than in osteoporotic individuals using low-potency oral BP. The management of osteonecrosis caused by BP is often unsatisfactory and control of risk factors is considered the most effective means of prevention. Surgical manipulation and dental infection of the jawbone are the major risk factors, hence it is suggested that careful management of oral health and relevant dental procedures may decrease the risk of osteonecrosis in individuals on BP. Recommendations for dentists and oral surgeons have been suggested by different groups of clinicians but they are often controversial and there is no clear evidence for their efficacy in reducing the likelihood of osteonecrosis development. This report critically reviews current dental recommendations for individuals using BP with the aim of helping the reader to transfer them into practice as part of pragmatic and non-detrimental clinical decisions making.