Comparing the Surgical Response of Bisphosphonate-Related Versus Denosumab-Related Osteonecrosis of the Jaws

Bone complications of cancer treatment

With the advancements in conventional treatment modalities such as radiation, chemotherapy, and surgery, as well as the emergence of immunotherapy, the overall cure rate for solid tumor malignancies has experienced a significant increase. However, it is unfortunate that exposure to cancer treatments can have detrimental effects on the function of osteoblasts and osteoclasts, disturbing bone metabolic homeostasis in patients, as well as causing damage to bone marrow cells and other bone tissues. Consequently, certain tumor treatment options may pose a risk for subsequent bone diseases. Common bone disorders associated with cancer treatment include osteonecrosis, bone loss, and secondary bone tumors. (1)Cancer treatment-related osteonecrosis is primarily linked to the use of radiation therapy and certain chemicals, such as bisphosphonates, denosumab, antiangiogenic agents, and immunomodulators. It has been observed that high-dose radiation therapy is more likely to result in osteonecrosis. (2)Chemicals and hormones, particularly sex hormones, glucocorticoids, and thyroid hormones or thyrotropic hormones, are among the factors that can contribute to cancer treatment-related bone loss. (3)Secondary bone tumors differ from metastases originating from primary tumors, and radiotherapy plays a significant role in their development, while chemotherapy may also exert some influence. Radiogenic secondary bone tumors are predominantly malignant, with osteosarcoma being the most common type. Chemotherapy may be a risk factor for the relatively rare occurrence of secondary Ewing sarcoma of the bone. These treatment-related bone disorders have a considerable adverse impact on the prognosis of cancer patients. Hence, it is imperative to prioritize the bone health of patients undergoing cancer treatment and give it further attention.

Preventing bisphosphonate induced osteonecrosis of the jaw with a polyguanidine conjugate (GuaDex): A promising new approach

Osteonecrosis of the jaw (ONJ) is a relatively rare side effect after prolonged use of bisphosphonates, which are drugs used to treat bone resorption in osteoporosis and certain cancers. This study introduces a novel ONJ model in rats by combining exposure to bisphosphonates, oral surgery, and bacterial inoculation. Potential ONJ preventive effects of polyguanidine (GuaDex) or antibiotics were evaluated. The study consisted of twenty-four male Wistar rats were divided into four groups. Groups 1 to 3 were given weekly doses of i.v. Zoledronic acid (ZA), four weeks before and two weeks after an osteotomy procedure on their left mandibular first molar. Group 4 was a negative control. Streptococcus gordonii bacteria were introduced into the osteotomy pulp chamber and via the food for seven days. On day eight, the rats were given different treatments. Group 1 was given a GuaDex injection into the osteotomy socket, Group 2 was given an intramuscular (i.m.) injection of clindamycin, Group 3 (positive control) was given an i.m. injection of saline, and Group 4 was given an i.m. injection of saline. Blood samples were taken two weeks after the osteotomy procedure, after which the rats were euthanized. Bone healing, bone mineral density, histology, and blood status were analyzed. The results showed that Group 1 (GuaDex) had no ONJ, extensive ongoing bone regeneration, active healing activity, vascularization, and no presence of bacteria. Group 2 (clindamycin) showed early stages of ONJ, avascular areas, and bacteria. Group 3 showed stages of ONJ, inflammatory infiltrates, defective healing, and bacterial presence, and Group 4 had normal healing activity and no bacterial presence. Conclusion: ZA treatment and bacterial inoculation after tooth extraction inhibited bone remodeling/healing and induced ONJ characteristic lesions in the rats. Only GuaDex apparently prevented ONJ development, stimulated bone remodeling, and provided an antimicrobial effect.

Cumulative incidence and risk factors for medication-related osteonecrosis of the jaw during long-term prostate cancer management

Bone-modifying agents (BMA) are extensively used in treating patients with prostate cancer with bone metastases. However, this increases the risk of medication-related osteonecrosis of the jaw (MRONJ). The safety of long-term BMA administration in clinical practice remains unclear. We aimed to determine the cumulative incidence and risk factors of MRONJ. One hundred and seventy-nine patients with prostate cancer with bone metastases treated with BMA at our institution since 2008 were included in this study. Twenty-seven patients (15%) had MRONJ during the follow-up period (median, 19 months; interquartile range, 9-43 months). The 2-year, 5-year, and 10-year cumulative MRONJ incidence rates were 18%, 27%, and 61%, respectively. Multivariate analysis identified denosumab use as a risk factor for MRONJ, compared with zoledronic acid use (HR 4.64, 95% CI 1.93-11.1). Additionally, BMA use at longer than one-month intervals was associated with a lower risk of MRONJ (HR 0.08, 95% CI 0.01-0.64). Furthermore, six or more bone metastases (HR 3.65, 95% CI 1.13-11.7) and diabetes mellitus (HR 5.07, 95% CI 1.68-15.2) were risk factors for stage 2 or more severe MRONJ. MRONJ should be considered during long-term BMA administration in prostate cancer patients with bone metastases.

Antiresorptive agent-related osteonecrosis of the jaw risk in cancer patients before bone-modifying agent therapy: A retrospective study of 511 patients

INTRODUCTION

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is a serious adverse event associated with therapies for advanced cancer involving bone-modifying agents (BMAs). Although many studies have investigated the risk factors for ARONJ, none have provided sufficient clarifications. We aimed to determine whether there is a correlation between tooth extraction before BMA therapy and the development of ARONJ.

PATIENTS AND METHODS

We included 511 patients who were admitted to our department before BMA therapy. The incidence of ARONJ and its risk factors was retrospectively evaluated, focusing on tooth extraction before BMA therapy and radiological findings of the extracted tooth.

RESULTS

Of the 511 patients, 135 underwent tooth extraction before undergoing BMA therapy. ARONJ was observed in 17.7 % and 7.2 % of patients in the extraction and non-extraction groups, respectively (p = 0.0002). Regarding the findings of panoramic radiographs before tooth extraction, the incidence of periapical disease was significantly higher in the ARONJ group than that in the non-ARONJ group (50 % and 27 %, respectively, p = 0.034), and the proportion of bone sclerotic changes in the surrounding teeth was significantly higher in the ARONJ group (58.3 %) than in the non-ARONJ group (24.4 %) (p = 0.0004).

CONCLUSION

The presence of a hopeless tooth that requires extraction prior to BMA therapy is a risk factor for MRONJ. However, extraction of such teeth should be considered, as this is known to decrease the risk of MRONJ development after BMA therapy initiation. Moreover, the radiological findings of periapical disease and bone sclerotic changes in the extracted teeth identified in this study can be used as novel predictive factors for ARONJ.

Medication-related osteonecrosis of the jaw: A disease of significant importance for older patients

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is clinically defined as a non-healing jawbone ulcerative-necrotic lesion appearing after dental therapy or minor trauma in patients treated previously with anti-resorptive, anti-angiogenic or immunomodulators. Older patients with osteoporosis and cancer receive these pharmacological agents regularly. As these patients are long-term survivors, efficient treatment is of paramount importance for their quality of life.

METHODS

Literature searches via PubMed were conducted to identify relevant MRONJ studies. Basic information on MRONJ classification, clinical features, and pathosphysiology is presented herein as well as various clinical studies dealing with MRONJ in patients with osteoporosis and cancer. Lastly, we discuss current managment of patients and new trends in treatment of MRONJ.

RESULTS

Although close follow-up and local hygiene have been advocated by some authors, severe forms of MRONJ are not responsive to conservative therapy. At present, there is no "gold standard" therapy for this condition. However, as the physiopathological basis of MRONJ is represented by the anti-angiogenic action of various pharmacological agents, new methods to increase and promote local angiogenesis and vascularization have recently been successfully tested in vitro, limited preclinical studies, and in a pilot clinical study.

CONCLUSIONS

It appears that the best method implies application on the lesion of endothelial progenitor cells as well as pro-angiogenic factors such as Vascular Endothelial Growth Factor (VEGF) and other related molecules. More recently, scaffolds in which these factors have been incorporated have shown positive results in limited trials. However, these studies must be replicated to include a large number of cases before any official therapeutic protocol is adopted.

Clinical risk factors for severity and prognosis of antiresorptive agent-related osteonecrosis of the jaw: a retrospective observational study

INTRODUCTION

The incidence of antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is rare, and its management has not yet been established. This study aimed to investigate the predictors for advanced stage and healing of ARONJ to establish an appropriate treatment strategy.

MATERIALS AND METHODS

We retrospectively analyzed patients diagnosed with ARONJ at Kobe City Medical Center General Hospital between April 2014 and March 2020. Outcomes were defined as stage ≥ 2 ARONJ (primary) and healing of ARONJ (secondary). Multivariate logistic regression analysis was used to detect factors associated with the outcomes, and odds ratios (OR) and 95% confidence intervals (CI) were calculated.

RESULTS

This study included 143 patients (stage ≥ 2 ARONJ, 51%; healing of ARONJ, 60%). Multivariate logistic regression analysis revealed that advanced age (per year) (OR 1.037; 95% CI 1.003-1.072; p = 0.028) and serum albumin (per g/dL) (OR 0.430; 95% CI 0.213-0.869; p = 0.018) were significantly associated with stage ≥ 2 ARONJ. Furthermore, multivariate logistic regression analysis revealed that cancer (yes) (OR 0.099; 95% CI 0.029-0.339; p < 0.001), conservative surgical treatment (yes) (OR 15.42; 95% CI 5.657-42.0; p < 0.001), C-reactive protein (per mg/dL) (OR 0.599; 95% CI 0.415-0.864; p < 0.001), and vitamin D analog (yes) (OR 0.167; 95% CI 0.034-0.827; p = 0.028) were factors associated with healing.

CONCLUSION

Our findings suggest that age and hypoalbuminemia are associated with the severity of ARONJ, and cancer, high inflammation, and vitamin D analog may impair healing. In contrast, conservative surgical treatment can overcome the poor treatment outcomes associated with ARONJ.