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

Treatment of bone metastases from solid tumors with bone-modifying agents: a web survey of Italian oncologists investigating patterns of practice drug prescription and prevention of side effects

PURPOSE

Optimal use of bone-modifying agents (BMAs) in patients with bone metastases from solid tumors is uncertain in some aspects: the drug choice; the planned treatment duration and long-term therapy; the prevention and management of possible side effects, including renal toxicity, hypocalcaemia, and medication-related osteonecrosis of the jaw (MRONJ).

METHODS

Italian oncologists were invited to fulfil a 24-question web survey about prescription of BMAs for bone metastases of breast cancer, prostate cancer, and other solid tumors. Prevention and management of side effects were also investigated.

RESULTS

Answers of 191 oncologists were collected. BMAs are usually prescribed at the time of diagnosis of bone metastases by 87.0% (breast cancer) and 76.1% (solid tumors except breast and prostate cancers) of oncologists; the decision is more articulated for prostate cancer (endocrine-sensitive versus castration-resistant). The creatinine level (32.3%), the availability of patient venous access (15.8%), and the type of primary neoplasm (13.6%) are the most reported factors involved in choice between bisphosphonates and denosumab. Zoledronic acid every 3 months was considered as a valid alternative to monthly administration by 94% of Italian oncologists. Oncologists reported a good confidence with measures aimed to prevent MRONJ, whereas uncertainness about prevention and management of hypocalcemia was registered.

CONCLUSION

Italian oncologists showed a high attitude in prescribing bisphosphonates or denosumab at the time of diagnosis of bone metastases, with a large application of preventive measures of side effects. Further studies are needed to investigate some controversial aspects, such as optimal drug treatment duration and long-term drug schedules.

Treatment of Medication-Related Osteonecrosis of the Jaw: Controversies in Causality and Therapy

Medication-related osteonecrosis of the jaw (MRONJ) is a most interesting, complex and "elusive" condition seen by the oral health care provider. It is plagued by controversy and although a wealth of research has created clinical treatment databases, there is no "gold standard" algorithm to be applied in a universal fashion. The purpose of this article is to explore several controversies associated with the etiology(s), staging, treatments, and long-term resolution of MRONJ in patients who are treated by the oral health care provider. Controversies for optimizing prevention, and disease control will also be discussed from an interdisciplinary perspective.

Immune Dysfunction in Medication-Related Osteonecrosis of the Jaw

The pathogenesis of medication-related osteonecrosis of the jaw (MRONJ) is multifactorial and there is a substantial consensus on the role of antiresorptive drugs (ARDs), including bisphosphonates (BPs) and denosumab (Dmab), as one of the main determinants. The time exposure, cumulative dose and administration intensity of these drugs are critical parameters to be considered in the treatment of patients, as cancer patients show the highest incidence of MRONJ. BPs and Dmab have distinct mechanisms of action on bone, but they also exert different effects on immune subsets which interact with bone cells, thus contributing to the onset of MRONJ. Here, we summarized the main effects of ARDs on the different immune cell subsets, which consequently affect bone cells, particularly osteoclasts and osteoblasts. Data from animal models and MRONJ patients showed a deep interference of ARDs in modulating immune cells, even though a large part of the literature concerns the effects of BPs and there is a lack of data on Dmab, demonstrating the need to further studies.

The use of bone-modifying agents in multiple myeloma

Multiple myeloma is a hematological neoplasm characterized by abnormal proliferation of plasma cells in the bone marrow and is usually associated with increased bone pain and skeletal-related events such as pathological fracture and/or spinal cord compression. Myeloma bone disease results in changes in the bone-marrow microenvironment evidenced by increased osteoclastic activity and/or decreased osteoblastic activity, which negatively affect quality of life. Treatment of myeloma bone disease includes bisphosphonates or denosumab (bone-modifying agents). These agents do not induce the formation of new bone or repair existing bone damage, but they can decrease bone pain and the risk of pathological fracture. While these agents improve quality of life, it is not known whether they improve overall survival. This review focuses on different classes of bone-modifying agents, their mechanisms of action, time of initiation, duration of therapy, and potential survival benefits.

Successful Non-surgical Management of a Mandible Fracture Secondary to Medication-related Osteonecrosis of the Jaw: A Unique Case Report

Background:

Medication-related osteonecrosis of the jaw (MRONJ) may be a severe side effect of bone-modifying agents.

Objective:

Pathologic fractures treatment in patients with MRONJ remains challenging. The authors reported a unique case of successful non-surgical management of a mandible fracture secondary to MRONJ.

Methods:

A 78-year-old osteoporotic woman with a 4-year history of oral bisphosphonate therapy and a compromised dental condition developed an MRONJ-related right mandibular body fracture. Treatment consisted of systemic antibiotic administration (amoxiclav and metronidazole) and chlorhexidine mouthwash.

Results:

Follow-up visits revealed progressive healing of the mandibular fracture with bone callus formation and complete recovery of the ipsilateral lip and chin sensitivity after one year.

Conclusion:

Non-surgical management of pathological fractures related to MRONJ might be of interest in patients that refuse any type of surgery, but preventive measures, such as careful dental examination, should be taken before start antiresorptive therapy and during the treatment. The authors reported the first case in the literature of successful management of a mandibular fracture secondary to MRONJ with only antibiotics and mouthwashes.

Case reports of medication-related osteonecrosis of the jaw (MRONJ) treated with uncultured stromal vascular fraction and L-PRF

Medication-related osteonecrosis of the jaw (MRONJ) is a challenging affection, considering the absence of a "Gold Standard" treatment. Cell therapy and tissue engineering, using adipose-tissue stromal vascular fraction (SVF) containing mesenchymal stromal cells (MSC) and endothelial progenitor cells (EPC); and a scaffold with healing properties, l-platelet-rich fibrin (L-PRF), could be a therapeutic option. Two cases of MRONJ were treated by tissue engineering. The patients presented respectively a stage-II and a stage-III MRONJ. The protocol consists of SVF injection in the L-PRF applied on the cleaned bone. Patients are followed clinically and by medical imaging (MI) for 18 months. The buccal mucosa was closed within a month. No recurrence was observed during the follow-up. The MI highlighted bone formation. MSC and EPC presence, in the SVF, were confirmed by immunophenotyping. We report the preliminary results of MRONJ patients successfully treated with the association of autologous fresh L-PRF-SVF.