Bisphosphonate-associated osteonecrosis of the jaw in breast cancer patients: Recommendations for prevention and treatment

Volumetric analysis of the periodontal microstructure under antiresorptive therapy: an experimental study in rabbits

OBJECTIVES

The objective of this study was to volumetrically assess changes in the periodontal microstructure under antiresorptive therapy.

MATERIALS AND METHODS

Microtomographic scans from a total of 9 Dutch Belted rabbits having been randomly allocated to either the intravenous administration of amino-bisphosphonate (zoledronic acid) (Za) (n = 5) or a negative control group (nZa) (n = 4) were obtained at 10 months following a repeated drug administration. A quantification of the periodontal space thickness (P.Th) of both maxillary and mandibular most posterior premolars, as well as of the 2nd molars was performed. Bone micromorphometry was assessed by means of bone volume per total volume (BV/TV), the bone mineral density (BMD), trabecular thickness (Tb.Th), trabecular number (Tb.N), bone surface (BS), and the specific bone surface (BS/BV).

RESULTS

Za was associated with significantly higher P.Th (P = 0.010), which was most pronounced in the upper jaw. Bone micromorphometry revealed no significant differences among the two groups, i.e., Za and nZa, for all the investigated parameters.

CONCLUSIONS

Volumetric analysis revealed that antiresorptive therapy was associated with periodontal space widening, whereas major effects on the bone micro-morphology could not be observed.

CLINICAL RELEVANCE

A deep understanding of specific periodontal and alveolar bone alterations in patients under antiresorptive therapy might help to prevent the onset of medication-related osteonecrosis of the jaw.

Medication-Related Osteonecrosis of the Jaw in Dental Practice: A Retrospective Analysis of Data from the Milan Cohort

A retrospective analysis was performed with the aim of understanding whether the risk factors showed in the literature for medication-related osteonecrosis of the jaws (MRONJ) in cancer patients are also relevant in osteoporotic patients taking antiresorptive drugs (ARDs). Data were retrospectively pooled from health records of patients on ARDs who requested a dental visit between January 2006 and April 2020 in the Dental Unit at Fondazione Ca’ Granda IRCCS Ospedale Maggiore Policlinico, University of Milan. A total of 434 patients were included. The following variables were collected: sex, age, smoking habit, type of ARD, duration of treatment, route of administration, therapeutic indication, concurrent systemic therapies and pathologies. Statistical analysis confirmed the relevance of chemotherapy, smoking, and immunosuppressive drugs as risk factors. In addition, a higher frequency of MRONJ in osteoporotic patients was reported in our cohort in association with an immunodeficiency disorder of variable origin. In conclusion, the identification of individual risk-profile before dental treatments is crucial for prevention. Anamnesis should include main risk factors, such as immunosuppression, dental extractions, smoking, trauma, and poor dental health. Nevertheless, our suggestion for dental professionals is to conduct a complete medical history of patients who mention long-term per oral therapies with ARDs for osteoporosis. Osteoporotic, as well as cancer patients, may also benefit from periodic monitoring of the ARDs therapy in order to prevent MRONJ.

Frequency of osteonecrosis in bisphosphonate users submitted to dental procedures: A systematic review

OBJECTIVE

To determine the frequency of osteonecrosis of the jaw in bisphosphonate users submitted to dental procedures.

METHODS

This systematic review searched the sources: MEDLINE, EMBASE, Web of Science, Scopus, and Virtual Health Library, with no restriction on language or publication date. Reviewers, in pairs and independently, selected the studies, extracted their data, and assessed the risk of bias. Meta-analyses were pooled using the DerSimonian and Laird random effects model.

RESULTS

A total of 27 studies (5391 participants) were included. The most reported bisphosphonates were zoledronate (n = 17 studies) and alendronate (n = 19) for treating cancers (n = 11) and osteoporosis (n = 16), respectively. Twelve studies were of low methodological quality. The frequency of osteonecrosis was 2.7% (95% CI: 0.9-5.2%) and proved higher for intravenous [6.9% (0.7-17.3%)] than oral [0.2% (0.9-5.2%)] bisphosphonate use. No association between longer treatment duration and greater frequency of osteonecrosis was observed.

CONCLUSIONS

Higher frequency of osteonecrosis was observed in intravenous bisphosphonate users submitted to dental extraction. Further studies collecting more detailed information on the bisphosphonates used and of greater methodological rigor are warranted to confirm these findings and better inform prescribers, dental surgeons, and other professionals on risks of bisphosphonate use in this patient group.

Influence of ridge preservation procedures on extraction socket healing under antiresorptive therapy: An experimental study in rabbits

BACKGROUND

To assess the influence of ridge preservation procedures on the healing of extraction sockets under antiresorptive therapy.

MATERIAL AND METHODS

A total of 10 Dutch Belted rabbits were randomly allocated to either the intravenous administration of amino-bisphosphonate (zoledronic acid) (Za) (n = 5) or a negative control group (no Za [nZa]) (n = 5). At 6 months, the mandibular and maxillary molars were extracted and the four experimental sites randomly allocated to the following subgroups: (a) socket grafting using a collagen-coated natural bone mineral (BOC) + primary wound closure, (b) coronectomy (CO), or (c) spontaneous healing + primary wound closure (SP). Za medication was continued for another 4 months. Histomorphometrical analyses considered, for example, crestal hard tissue closure of the extraction site (C) and mineralized tissue (MT) formation.

RESULTS

Za-SP was associated with an incomplete median C (31.76% vs 100% in nZa-SP) and signs of bone arrosion along the confines of the socket. BOC had no major effects on increases in C and MT values in the Za group. CO commonly resulted in an encapsulation and partial replacement resorption of residual roots by MT without any histological signs of osteonecrosis.

CONCLUSIONS

(a) Za-SP was commonly associated with a compromised socket healing and signs of osteonecrosis, (b) BOC had no major effect on socket healing in the Za group, and (c) CO at noninfected teeth might be a feasible measure for the prevention of a Za-related osteonecrosis of the jaw.

Immediate hyperbaric oxygen after tooth extraction ameliorates bisphosphonate-related osteonecrotic lesion in rats

BACKGROUND

This study aims to assess whether hyperbaric oxygen (HBO) applied immediately after tooth extraction could ameliorate medication-related osteonecrosis of the jaw in rats.

METHODS

To evaluate whether osteonecrosis could be successfully induced, healing of extraction maxillary molars was examined in 40 female Sprague Dawley rats received zoledronic acid (7.5 µg/kg) plus dexamethasone (1 mg/kg). Rats were divided into four groups, receiving zero, two, four, or seven injection(s) for 7 days, respectively. Effect of HBO, pressurized to 2.5 atmospheres absolute (ATA) at rate of 0.15 ATA/min with 100% oxygen for 90 minutes, applied immediately after tooth extraction, on the development of osteonecrosis was evaluated. Lesions among groups were compared by size of ulceration, exact area (mm² ) or relative area (%), and by histology.

RESULTS

Unhealed ridge was observed in all nine rats in four and seven injection groups, but none of 10 rats in the control (non-injection) group. Immediate HBO significantly reduced the lesions in rats that received four injections, regardless of the distribution and the total/relative areas of lesions (P <0.01). Histological findings showed the lesions were uncovered epithelium and severe tissue inflammation.

CONCLUSION

This is the first in vivo study demonstrating the HBO applied immediately after tooth extraction effectively decreases the development of medication-related osteonecrosis.

Prevention of medication-related osteonecrosis of the jaws secondary to tooth extractions. A systematic review

Background

A study was made to identify the most effective protocol for reducing the risk of osteonecrosis of the jaws (ONJ) following tooth extraction in patients subjected to treatment with antiresorptive or antiangiogenic drugs.

Material and Methods

A MEDLINE and SCOPUS search (January 2003 - March 2015) was made with the purpose of conducting a systematic literature review based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. All articles contributing information on tooth extractions in patients treated with oral or intravenous antiresorptive or antiangiogenic drugs were included.

Results

Only 13 of the 380 selected articles were finally included in the review: 11 and 5 of them offered data on patients treated with intravenous and oral bisphosphonates, respectively. No randomized controlled trials were found – all publications corresponding to case series or cohort studies. The prevalence of ONJ in the patients treated with intravenous and oral bisphosphonates was 6,9% (range 0-34.7%) and 0.47% (range 0-2.5%), respectively. The main preventive measures comprised local and systemic infection control.

Conclusions

No conclusive scientific evidence is available to date on the efficacy of ONJ prevention protocols in patients treated with antiresorptive or antiangiogenic drugs subjected to tooth extraction.

Key words:Bisphosphonates, angiogenesis inhibitors, antiresorptive drugs, extraction, osteonecrosis.

Bone-Targeted Therapy

Bisphosphonates and denosumab are well established components of the therapy for osteoporosis and osseous metastases. Their relevance in the adjuvant situation for breast cancer patients is being discussed in part controversially due to the heterogeneous nature of the available data. In particular, it appears that post-menopausal women benefit from an adjuvant therapy with bisphosphonates. In the present contribution we discuss the clinical relevance of osteoprotective therapy in the metastatic and adjuvant settings. Above all the current AGO guidelines on osteo-oncology and bone health have been taken into consideration for recommendations to implement the available data.

Management of skeletal metastases: An orthopaedic surgeon's guide

Skeletal metastasis is a common cause of severe morbidity, reduction in quality of life (QOL) and often early mortality. Its prevalence is rising due to a higher rate of diagnosis, better systemic treatment, longer lives with the disease and higher disease burden rate. As people with cancer live longer and with rising sensitivity of body imaging and surveillance, the incidence of pathological fracture, metastatic epidural cord compression is rising and constitutes a challenge for the orthopedic surgeon to maintain their QOL. Metastatic disease is no longer a death sentence condemning patients to "terminal care." In the era of multidisciplinary care and effective systemic targeted and nontargeted therapy, patient expectations of QOL, even during palliative end of care period is high. We lay emphasis on proving the diagnosis of metastasis by biopsy and histopathology and discuss imaging modalities to help estimate fracture risk and map disease extent. This article discusses at length the evidence and decision-making process of various modalities to treat skeletal metastasis. The modalities range from radiation including image-guided, stereotactic and whole body radiation, systemic targeted or hormonal therapy, spinal decompression with or without stabilization, extended curettage with stabilization, resection in select cases with megaprosthetic or biological reconstruction, percutaneous procedures using radio frequency ablation, cementoplasties and discusses the role of emerging modalities like high frequency ultrasound-guided ablation, cryotherapy and whole body radionuclide therapy. The focus lies on the role of multidisciplinary care, which considers complex decisions on patient centric prognosis, comorbidities, cost, feasibility and expectations in order to maximize outcomes on QOL issues.

The phosphorous necrosis of the jaws and what can we learn from the past: a comparison of "phossy" and "bisphossy" jaw

INTRODUCTION

The osteopathology of the jaws associated with bone resorption inhibitors is a current topic that engages a variety of clinical specialists. This has increased after the approval of denosumab for treatment of osteoporosis and skeletal-related events in patients with solid malignancy. Early after the first publications, there is a possible connection between phosphorous necrosis of the jaws, a dreadful industrial disease mentioned, and bisphosphonate-induced pathology. The nineteenth century was the prime time for phosphorus necrosis of match factory workers.

RESULTS

This occurrence provides an interesting insight into the medical and surgical profession in the nineteenth century. There are striking parallels and repetition of current and old ideas in the approach to this "new disease." There are similar examples in case descriptions when compared with today's patients of bisphosphonate-related osteonecrosis of the jaws (BRONJ).

DISCUSSION

Phosphorus necrosis was first described in Austria. Soon after this, surgeons in German-speaking countries including well-known clinicians Wegner (1872) and von Schulthess-Rechberg (1879) pioneered the analysis, preventative measures, and treatment of this disease. The tendency at this time was to approach BRONJ as a "special kind of osteomyelitis" in pretreated and metabolically different bone. Not only the treatment strategy to wait until sequestrum formation with subsequent removal and preventative measures but also the idea of focusing on the periosteum as the triggering anatomical structure may have been adopted from specialists in the nineteenth century. Therefore, phosphorous necrosis of the jaw is an excellent example of "learning from the past."

Bisphosphonate-related osteonecrosis of the jaw in patients with breast cancer

Bisphosphonate represents a well-established treatment option in the management of metastatic bone disease and bone loss/osteoporosis in women with breast cancer. These drugs reduce osteoclast. Some bisphosphonate also have osteoblastic function leading to a reducted bone turnover and thereby skeletal-related events. The aim of this review is to evaluate the bisphosphonate-related osteonecrosis of the jaw in patients with breast cancer. Based on the proven effect of bone protection during adjuvant endocrine therapy, new treatment guidelines recommend the routine use of bisphosphonates to prevent bone loss during adjuvant therapy, which may likely become the standard practice.

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.

Biology of bone metastases

BACKGROUND

Bone metastases cause morbidity and mortality in multiple malignancies. In addition to portending a dire prognosis, bone metastases cause bone pain, fractures, hypercalcemia, spinal cord compression, and other nerve compression syndromes. Improved understanding of the mechanisms that predispose tumor metastases to bone is needed to improve patients' therapeutic options, maintain their quality of life, and improve their survival.

METHODS

This review discusses selected preclinical and clinical data regarding bone metastasis development and cytokine/molecular interactions predisposing to bone metastases formation. Potential interventions for reducing bone metastases are also described.

RESULTS

Biologic mechanisms resulting in metastases of tumor cells to bone are being studied. Among these are the RANKL pathway, osteoclast activation via cytokines (produced by tumor cell and cells in the bone microenvironment), interactions with transient and stromal cells in the bone microenvironment, and molecules such as PTHrP and endothelin-1. These molecules offer important opportunities for targeted interventions to decrease bone metastases-associated morbidity.

CONCLUSIONS

Knowledge of the pathophysiology of bone and cancer is developing rapidly. Relationships among cancer cells, bone-derived cells, and cytokines provide opportunities for the development of new interventions. Therapy targeting osteoclast/osteoblast interactions has proven benefit for patients with bone metastases.

Osteoporosis related to disease or therapy in patients with cancer

Osteoporosis is a major public health issue in the general population, particularly in postmenopausal women. Patients with cancer may not only be at risk for primary osteoporosis, but for secondary osteoporosis related to cancer therapies-particularly therapies that impair gonadal function, lead to loss of serum estrogen, and negatively affect bone turnover. Normal bone remodeling is influenced by the receptor activator for nuclear kappa-B ligand pathway, calcium, vitamin D, and other nutrition factors, as well as modifiable and nonmodifiable factors. Identifying which patients with cancer are at risk for bone mineral density loss is important and may include patients with breast or prostate cancer, some survivors of pediatric malignancies, and adults with other tumors. Nurses play a major role in identifying those patients and their risk for low-impact fractures, which can have a significant effect on patient morbidity and mortality. Counseling and teaching are central nursing functions, as well as safely administering therapies, particularly bisphosphonates and denosumab.

Osteopathology induced by bisphosphonates and dental implants: clinical observations

OBJECTIVES

Although there are many reports about risk factors for the development of BP-associated osteonecrosis of the jaws, the role of dental implants as a local risk factor is still discussed, especially in patients with oral BP treatment. Until now, a few case reports and surveys display a possible minor risk in patients with oral BP therapy, whereas the avoidance of implant placement is generally accepted in patients with intravenous BP therapy.

PATIENT AND METHODS

In this study, the cases of 14 patients with osteonecrosis of the jaws in association with BP therapy and dental implant placement were analyzed carefully with a detailed literature review.

RESULTS

Of 14 patients, nine had underlying malignant disease and five patients had osteoporosis. In ten patients, implants were placed either in the posterior mandible or maxilla; the mean interval between implant insertion and disease onset was 20.9 months. Pain (n12) and signs of infection (n10) were the most common symptoms. Histologically, signs of infection were found in nine of 11 analyzed patients with presence of Actinomyces in six patients. Two patients turned out to have infiltration of underlying malignant disease.

CONCLUSIONS

Posteriorly placed implants seem to be of higher risk of development of osteonecrosis of the jaws. Not only the implant placement but also the inserted implant itself seems to be a continuous risk factor.

CLINICAL RELEVANCE

The herein elaborated risk factors help dentists plan dental rehabilitation with implants in this high-risk group of patients and indicate careful and regular dental recall.

Proceedings of the First Global Workshop on Breast Cancer: pathways to the evaluation and clinical development of novel agents for breast cancer

The number of treatment options available to patients with breast cancer is larger and more complex than ever before. This is due in part to increased understanding of breast cancer tumor biology and the signaling pathways involved in tumor development and progression, which drives new areas of breast cancer research and the development of novel agents. Therapies targeting HER2 signaling, angiogenesis, DNA repair, and many other essential cellular processes that are dysregulated in cancer have produced significant improvements in disease outcome, although careful patient selection and toxicity management are required to maximize their therapeutic potential. Multigene assays have added to the ability to predict disease outcome and degree of response to adjuvant chemotherapy, but the application of these assays in the right clinical context is necessary. Unfortunately, despite the use of appropriate and effective local and adjuvant therapies, some patients with early-stage breast cancer will eventually develop metastatic disease. Most of these patients will have received standard therapies in the adjuvant setting and/or will develop resistance to these therapies at some point during treatment. Thus, implementation of novel strategies is necessary to overcome resistance and improve disease outcome. This in turn will require creative clinical trial designs, more efficient accrual, and rapid translation of results into the clinical setting. This summary highlights selected challenges in the current management of breast cancer and discusses expert perspectives, key questions, areas of debate, and future directions.