Bisphosphonates: prevention of bone metastases in breast cancer

Management of bone metastasis with zoledronic acid: A systematic review and Bayesian network meta-analysis

Background

While considered the mainstay of treatment for specific bone metastases, ZA is used predominantly to treat osteolytic lesions. The purpose of this network meta-analysis is to compare ZA to other treatment options in its ability to improve specific clinical outcomes in patients with bone metastases secondary to any primary tumor.

Methods

PubMed, Embase and Web of Science were systematically searched from inception to May 5th, 2022. Keywords used were solid tumor, lung neoplasm, kidney neoplasm, breast neoplasm, prostate neoplasm, ZA and bone metastasis. Every randomized controlled trial and non-randomized quasi-experimental study of systemic ZA administration for patients with bone metastases and any comparator were included. A Bayesian network meta-analysis was done on the primary outcomes including number of SREs, time to developing a first on-study SRE, overall survival, and disease progression-free survival. Secondary outcome was pain at 3, 6 and 12 months after treatment.

Results

Our search yielded 3861 titles with 27 meeting inclusion criteria. For the number of SRE, ZA in combination with chemotherapy or hormone therapy was statistically superior to placebo (OR 0.079; 95 % CrI: 0.022-0.27). For the time to the first on study SRE, the relative effectiveness of ZA 4 mg was statistically superior to placebo (HR 0.58; 95 % CrI:0.48-0.77). At 3 and 6 months, ZA 4 mg was significantly superior to placebo for reducing pain with a SMD of -0.85 (95 % CrI:-1.6, -0.0025) and -2.6 (95 % CrI:-4.7, -0.52) respectively.

Conclusions

This systematic review shows the benefits of ZA in decreasing the incidence of SREs, increasing the time to the first on-study SRE, and reducing the pain level at 3 and 6 months.

Prevention of breast cancer treatment-induced bone loss in premenopausal women treated with zoledronic acid: Final 5-year results from the randomized, double-blind, placebo-controlled ProBONE II trial

PURPOSE

Premenopausal women receiving chemotherapy or endocrine treatment for early breast cancer are at increased risk for cancer treatment induced bone loss (CTIBL). The aim of the randomized, double-blind ProBONE II trial was to investigate whether a 2-year adjuvant treatment with 4 mg intravenous zoledronic acid (ZOL) every 3 months versus placebo would prevent CTIBL after a five-year period.

METHODS

Thirty-one of the 34 participants in the ZOL arm and thirty-four of the 36 participants in the placebo arm were followed-up to the 5-year visit and completed the study as planned. The changes in Bone Mass Density (BMD) were assessed at baseline and each visit after treatment initiation.

RESULTS

After 24 months, BMD at the lumbar spine showed a 2.9% increase in patients treated with ZOL vs. a 7.1% decrease in placebo-treated participants compared to baseline (p < 0.001). Over the 60-month study period, we found a decrease of 2.2% vs. 7.3% in the BMD at the lumbar spine in patients receiving ZOL and placebo respectively (p < 0.001). Over the 60-month study period, BMD in the placebo arm showed a continuous decrease at all sites (p < 0001), whereas patients treated with ZOL reached baseline BMD-values at the femoral neck and total hip.

CONCLUSIONS

In ProBone II, a 2-year treatment with ZOL 4 mg intravenous every 3 months prevented cancer treatment induced bone loss in premenopausal women with breast cancer and maintained the BMD up to 3 years post-treatment.

Renal Impairment Hampers Bisphosphonate Treatment in a Quarter of Lung Cancer Patients with Bone Metastasis

Renal function impairment in lung cancer patients with bone metastases was investigated, as this can limit the application of bisphosphonates representing the gold standard in the management of such cases. Clinicopathological data of 570 lung cancer patients were retrospectively analysed for changes in renal function parameters. Comorbidities included hypertension (50%), COPD (33%) and diabetes mellitus (15%). Statistical analysis was performed with Fisher's exact tests and a Cox proportional hazards model. In patients suffering from hypertension, both median serum creatinine and blood urea nitrogen (BUN) were higher (81.9 versus 75.8 μmol/L, p < 0.001 and 6.0 versus 5.7 mmol/L, p = 0.005, respectively). Such a difference could not be observed in patients with diabetes. In patients with COPD, only serum creatinine was higher (81.1 versus 77.3 μmol/L, p = 0.004). In the whole cohort, we found that while at the time of lung cancer diagnosis the ratio of patients in the pathological range (PRR) was 8.67% for serum creatinine (median: 75 μmol/L) and 14.16% for BUN (median: 5.4 mmol/L), at the time of bone metastasis the PRR for serum creatinine increased to 16.11% (median: 77.0 μmol/L) and for BUN to 24.07% (median: 6.0 mmol/L), which is a significant increase for both parameters (p < 0.001). For the whole cohort, the last laboratory results showed a 26.37% PRR for serum creatinine and 45.66% PRR for BUN (significant increase for both, p < 0.001). Multivariate analysis revealed that patients with hypertension had a higher chance for switching to the pathological range sooner (p = 0.033, HR: 1.372, CI: 1.025-1.835). Also, the appearance of the bone metastasis correlated with an acceleration of the onset of such a switch (p < 0.001, HR: 2.655, CI: 1.581-4.456). Our results suggest that renal function is impaired in a significant proportion of patients with lung cancer and highlight the importance of non-nephrotoxic drug in the management of bone metastases.

Bisphosphonate-Functionalized Imaging Agents, Anti-Tumor Agents and Nanocarriers for Treatment of Bone Cancer

Bone metastases result from the invasion of primary tumors to bone. Current treatment modalities include local treatments such as surgery and radiotherapy, while systemic treatments include chemotherapy and (palliative) treatment of skeletal metastases. Nevertheless, once bone metastases have been established they remain incurable leading to morbidity and mortality. Bisphosphonates are a well-established class of drugs, which are increasingly applied in the treatment of bone cancers owing to their effective inhibition of tumor cells and suppression of bone metastases. The increased understanding of the mechanism of action of bisphosphonates on bone and tumor cells has prompted the development of novel bisphosphonate-functionalized imaging and therapeutic agents. This review provides an update on the preclinical efficacy of bisphosphonate-functionalized fluorophore, anti-tumor agents and nanocarriers for the treatment of bone metastases. After an overview of the general characteristics of bisphosphonates and their mechanisms of action, an outline is provided on the various conjugation strategies that have become available to functionalize imaging agents, anti-tumor agents and nanocarriers with bisphosphonates. Finally, the efficacy of these bisphosphonate-modified agents and carriers in preclinical studies is evaluated by reviewing their potential to target tumors and inhibit tumor growth in clinically relevant animal models for the treatment of bone cancer.

CT-diagnosed severe skull base bone destruction predicts distant bone metastasis in early N-stage nasopharyngeal carcinoma

Bone metastasis is the most frequent type of distant metastasis in nasopharyngeal carcinoma (NPC). In this study, we investigated the correlation between the skull base bone destruction and the distant bone metastasis in patients with NPC. A total of 449 cases with NPC who were diagnosed and had definitive radiotherapy from 2001 to 2006 were enrolled in this study. The skull base bone destruction was diagnosed by computed tomography (CT) in all cases, and 191 patients also underwent magnetic resonance imaging scan. Kaplan–Meier method was adopted to perform the univariate analysis; Cox regression model was used to perform multivariate analysis to determine whether the skull base bone destruction when diagnosed by CT was an independent impact factor of the distant bone metastases. The group with skull base bone destruction had a distant bone metastases rate of 9.0% (14/155), whereas the group without skull base bone destruction had rate of 4.1% (12/294). The multivariate analysis showed that the skull base bone destruction, when diagnosed by CT, was an independent impact factor of the distant bone metastases-free survival in the early N-staging cases, but was not an independent impact factor when diagnosed by MRI. The skull base bone destruction diagnosed by CT in patients with NPC had predictive value for the distant bone metastases, especially for the early N-staging cases.

The cast of clasts: catabolism and vascular invasion during bone growth, repair, and disease by osteoclasts, chondroclasts, and septoclasts

Three named cell types degrade and remove skeletal tissues during growth, repair, or disease: osteoclasts, chondroclasts, and septoclasts. A fourth type, unnamed and less understood, removes nonmineralized cartilage during development of secondary ossification centers. "Osteoclasts," best known and studied, are polykaryons formed by fusion of monocyte precursors under the influence of colony stimulating factor 1 (CSF)-1 (M-CSF) and RANKL. They resorb bone during growth, remodeling, repair, and disease. "Chondroclasts," originally described as highly similar in cytological detail to osteoclasts, reside on and degrade mineralized cartilage. They may be identical to osteoclasts since to date there are no distinguishing markers for them. Because osteoclasts also consume cartilage cores along with bone during growth, the term "chondroclast" might best be reserved for cells attached only to cartilage. "Septoclasts" are less studied and appreciated. They are mononuclear perivascular cells rich in cathepsin B. They extend a cytoplasmic projection with a ruffled membrane and degrade the last transverse septum of hypertrophic cartilage in the growth plate, permitting capillaries to bud into it. To do this, antiangiogenic signals in cartilage must give way to vascular trophic factors, mainly vascular endothelial growth factor (VEGF). The final cell type excavates cartilage canals for vascular invasion of articular cartilage during development of secondary ossification centers. The "clasts" are considered in the context of fracture repair and diseases such as arthritis and tumor metastasis. Many observations support an essential role for hypertrophic chondrocytes in recruiting septoclasts and osteoclasts/chondroclasts by supplying VEGF and RANKL. The intimate relationship between blood vessels and skeletal turnover and repair is also examined.

Management of pathological femoral fracture secondary to breast cancer in pregnancy: A case report

Bone metastasis resulting from breast cancer in pregnancy is rare. In the literature there are few reports regarding osteolytic lesions in pregnancy and no data on the treatment of such femoral fractures. The present study reports a case of a 29-week primigravida presenting with severe lumbosciatica in the left side, refractory to medical therapy. During neurosurgical examination a spontaneous pathological fracture of the left femur occurred. Damage control orthopedic principals were applied and a biopsy specimen from the femoral lesion was obtained, providing a diagnosis of metastases from breast adenocarcinoma. Cesarean section was performed at 32 gestational weeks. Following delivery, an internal fixator was placed in the left femur for definitive treatment of the fracture and staging of cancer was conducted. Subsequently, adjuvant treatment comprising left mastectomy and percutaneous radiofrequency thermoablation of the sacroiliac lesion were performed. A follow-up one-year following percutaneous radiofrequency thermoablation of the sacroiliac lesion detected no metastatic bone pain, and identified a stable sacroiliac lesion.

Bisphosphonate-related osteonecrosis of the jaw in metastatic breast cancer patients: a review of 25 cases

Background

Intravenous bisphosphonates have been used in metastatic breast cancer patients to reduce pathologic bone fracture and bone pain. However, necrosis of the jaw has been reported in those who received intravenous bisphosphonates. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is caused by dental extraction, dental implant surgery, and denture wearing; however, it occurs spontaneously. The purpose of this study was to report BRONJ in metastatic breast cancer patients.

Methods

Consecutive 25 female patients were referred from the Department of Oncology from 2008 to 2014 for jaw bone discomfort. Staging of breast cancer, history of bisphosphonate infusion, etiology of BRONJ, and treatment results were reviewed. Average age of the patients was 55.4 years old (38–74). Twelve maxillae and 16 mandibles were involved. Conservative treatments such as irrigation, antibiotic medication, analgesics, and oral gargle were applied for all patients for the initial treatment. Patients who had sequestrum underwent debridement and primary closure.

Results

The etiologies of BRONJ were dental extraction (19 cases), dental implant (2 cases), and endodontic treatment (1 case). However, three patients did not have any risk factors to cause BRONJ. Three patients died of progression of metastasis during follow-up periods. Surgical debridement was performed in 21 patients with success in 18 patients. Three patients showed recurred bone exposure and infection after operation.

Conclusions

Prevention of the BRONJ is critical in metastatic breast cancer patients. Conservative treatment to reduce pain, discomfort, and infection is recommended for the initial therapy. However, if there is a sequestrum, surgical debridement and primary closure is the key to treat the BRONJ.

Depletion of cutaneous macrophages and dendritic cells promotes growth of basal cell carcinoma in mice

Basal cell carcinoma (BCC) belongs to the group of non-melanoma skin tumors and is the most common tumor in the western world. BCC arises due to mutations in the tumor suppressor gene Patched1 (Ptch). Analysis of the conditional Ptch knockout mouse model for BCC reveals that macrophages and dendritic cells (DC) of the skin play an important role in BCC growth restraining processes. This is based on the observation that a clodronate-liposome mediated depletion of these cells in the tumor-bearing skin results in significant BCC enlargement. The depletion of these cells does not modulate Ki67 or K10 expression, but is accompanied by a decrease in collagen-producing cells in the tumor stroma. Together, the data suggest that cutaneous macrophages and DC in the tumor microenvironment exert an antitumor effect on BCC.

Oral paricalcitol (19-nor-1,25-dihydroxyvitamin D2) in women receiving chemotherapy for metastatic breast cancer: a feasibility trial

The vitamin D hormone, [1,25(OH) 2D, calcitriol], inhibits proliferation and angiogenesis in breast cancer but its therapeutic use is limited by hypercalcemia. Synthetic analogs of 1,25(OH) 2D that are less calcemic, such as paricalcitol (19-nor-1,25-Dihydroxyvitamin D 2), are used to treat hyperparathyroidism associated with chronic kidney disease. We sought to determine the safety and feasibility of taking oral paricalcitol with taxane-based chemotherapy in women with metastatic breast cancer (MBC). Oral paricalcitol was considered safe if it did not result in excessive toxicity, defined as grade 3 or higher serum calcium levels. It was considered feasible if the majority of women could take eight weeks of continuous therapy in the first three months. Serum calcium was monitored weekly and the paricalcitol dose was adjusted based on its calcemic effect. Intact parathyroid hormone (iPTH) was monitored as a marker of paricalcitol activity. Twenty-four women with MBC were enrolled. Twenty women (83%) received eight weeks of continuous therapy. Paricalcitol was well-tolerated with no instances of hypercalcemia grade 2 or greater. Fourteen women (54%) were able to escalate the dose. The dose range of paricalcitol in the first 3 mo was 2-7 ug/day. Serum iPTH levels at baseline were significantly higher in women with serum 25-Hydroxyvitamin D (25-OHD) levels less than 30 ng/ml (96.4 ± 40.9 pg/ml) vs. 46.2 ± 20.3 pg/ml (p = 0 0.001) (iPTH reference 12-72 pg/ml). We conclude that paricalcitol is safe and feasible in women with MBC who are receiving chemotherapy.

Combination of the c-Met inhibitor tivantinib and zoledronic acid prevents tumor bone engraftment and inhibits progression of established bone metastases in a breast xenograft model

Bone is the most common metastatic site for breast cancer. There is a significant need to understand the molecular mechanisms controlling the engraftment and growth of tumor cells in bone and to discover novel effective therapeutic strategies. The aim of this study was to assess the effects of tivantinib and Zoledronic Acid (ZA) in combination in a breast xenograft model of bone metastases. Cancer cells were intracardially implanted into immunodeficient mice and the effects of drugs alone or in combination on bone metastasis were evaluated by in vivo non-invasive optical and micro-CT imaging technologies. Drugs were administered either before (preventive regimen) or after (therapeutic regimen) bone metastases were detectable. In the preventive regimen, the combination of tivantinib plus ZA was much more effective than single agents in delaying bone metastatic tumor growth. When administered in the therapeutic schedule, the combination delayed metastatic progression and was effective in improving survival. These effects were not ascribed to a direct cytotoxic effect of the combined therapy on breast cancer cells in vitro. The results of this study provide the rationale for the design of new combinatorial strategies with tivantinib and ZA for the treatment of breast cancer bone metastases.

Critical research gaps and translational priorities for the successful prevention and treatment of breast cancer

INTRODUCTION

Breast cancer remains a significant scientific, clinical and societal challenge. This gap analysis has reviewed and critically assessed enduring issues and new challenges emerging from recent research, and proposes strategies for translating solutions into practice.

METHODS

More than 100 internationally recognised specialist breast cancer scientists, clinicians and healthcare professionals collaborated to address nine thematic areas: genetics, epigenetics and epidemiology; molecular pathology and cell biology; hormonal influences and endocrine therapy; imaging, detection and screening; current/novel therapies and biomarkers; drug resistance; metastasis, angiogenesis, circulating tumour cells, cancer 'stem' cells; risk and prevention; living with and managing breast cancer and its treatment. The groups developed summary papers through an iterative process which, following further appraisal from experts and patients, were melded into this summary account.

RESULTS

The 10 major gaps identified were: (1) understanding the functions and contextual interactions of genetic and epigenetic changes in normal breast development and during malignant transformation; (2) how to implement sustainable lifestyle changes (diet, exercise and weight) and chemopreventive strategies; (3) the need for tailored screening approaches including clinically actionable tests; (4) enhancing knowledge of molecular drivers behind breast cancer subtypes, progression and metastasis; (5) understanding the molecular mechanisms of tumour heterogeneity, dormancy, de novo or acquired resistance and how to target key nodes in these dynamic processes; (6) developing validated markers for chemosensitivity and radiosensitivity; (7) understanding the optimal duration, sequencing and rational combinations of treatment for improved personalised therapy; (8) validating multimodality imaging biomarkers for minimally invasive diagnosis and monitoring of responses in primary and metastatic disease; (9) developing interventions and support to improve the survivorship experience; (10) a continuing need for clinical material for translational research derived from normal breast, blood, primary, relapsed, metastatic and drug-resistant cancers with expert bioinformatics support to maximise its utility. The proposed infrastructural enablers include enhanced resources to support clinically relevant in vitro and in vivo tumour models; improved access to appropriate, fully annotated clinical samples; extended biomarker discovery, validation and standardisation; and facilitated cross-discipline working.

CONCLUSIONS

With resources to conduct further high-quality targeted research focusing on the gaps identified, increased knowledge translating into improved clinical care should be achievable within five years.

Prevention and Treatment of Bone Metastases in Breast Cancer

In breast cancer patients, bone is the most common site of metastases. Medical therapies are the basic therapy to prevent distant metastases and recurrence and to cure them. Radiotherapy has a primary role in pain relief, recalcification and stabilization of the bone, as well as the reduction of the risk of complications (e.g., bone fractures, spinal cord compression). Bisphosphonates, as potent inhibitors of osteoclastic-mediated bone resorption are a well-established, standard-of-care treatment option to reduce the frequency, severity and time of onset of the skeletal related events in breast cancer patients with bone metastases. Moreover bisphosphonates prevent cancer treatment-induced bone loss. Recent data shows the anti-tumor activity of bisphosphonates, in particular, in postmenopausal women and in older premenopausal women with hormone-sensitive disease treated with ovarian suppression. Pain is the most frequent symptom reported in patients with bone metastases, and its prevention and treatment must be considered at any stage of the disease. The prevention and treatment of bone metastases in breast cancer must consider an integrated multidisciplinary approach.

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.

Role of bisphosphonates in postmenopausal women with breast cancer

Data suggest that bisphosphonates protect bone health and may have anticancer activity in postmenopausal women during adjuvant breast cancer therapy. However, key questions remain surrounding the role of adjuvant bisphosphonates in breast cancer, including patient populations deriving benefit, timing/scheduling of therapy, and specific clinical benefits. PubMed, Embase, and San Antonio Breast Cancer Symposium databases provide study results that address these issues in postmenopausal women. Review of these data would aid physicians in providing optimal management of breast cancer in postmenopausal women. For example, recent data reinforce use of intravenous bisphosphonates concurrently with adjuvant endocrine therapy to ameliorate bone loss in recently postmenopausal or osteopenic postmenopausal women with early breast cancer. In contrast, clinical data for oral bisphosphonates have not provided support for using anti-osteoporosis doses in this setting, and the optimal dose is unclear. Additionally, current clinical data show improvements in disease outcomes with bisphosphonates in many studies, although not in all patient subsets. Strong support for the potential adjuvant anticancer benefits from bisphosphonates has been demonstrated in women with established menopause (i.e., very low circulating estrogen levels). Initiating bisphosphonates early and concomitantly with adjuvant therapy generally provided the greatest benefits. However, questions remain such as schedule of treatment and relative potency among the intravenous bisphosphonates and elucidation of the role of oral bisphosphonates, as well as ongoing studies that might provide clarification. This review addresses these controversies in the context of translational research, which may provide the rationale for ongoing studies and evolving treatment paradigms in this area.

Myeloid-derived suppressor cells as osteoclast progenitors: a novel target for controlling osteolytic bone metastasis

Immune cells and their secreted growth factors play major roles in tumor growth and metastasis. Interplay between the growing tumor and infiltrating immune cells determines the nature of immune response and ultimately, tumor fate. Increased infiltration of protumorigenic immune cells promotes tumor growth as well as dissemination to distant sites. These cells induce immunosuppression that inhibits proliferation and functions of cells of antitumor immune response. One population of immunosuppressive cells that is increasingly gaining attention is myeloid-derived suppressor cells (MDSC). MDSCs are immature myeloid progenitors that suppress T-cell effector functions and promote angiogenesis. MDSC numbers are elevated at both the primary tumor and metastatic sites, including bone. In addition to immunosuppressive functions of MDSCs, we and others have recently discovered a novel function for MDSCs as osteoclast progenitors. Osteolysis is a common complication in the carcinomas of breast, lung, prostate, and multiple myeloma with poor prognosis. Therefore, targeting the functions of MDSCs may exert dual therapeutic effects on immunosuppression and bone pathology. Cancer Res; 73(15); 4606-10. ©2013 AACR.

Myeloid-derived suppressor cells function as novel osteoclast progenitors enhancing bone loss in breast cancer

Enhanced bone destruction is a hallmark of various carcinomas such as breast cancer, where osteolytic bone metastasis is associated with increased morbidity and mortality. Immune cells contribute to osteolysis in cancer growth, but the factors contributing to aggressive bone destruction are not well understood. In this study, we show the importance of myeloid-derived suppressor cells (MDSC) in this process at bone metastatic sites. Because MDSC originate from the same myeloid lineage as macrophages, which are osteoclast precursors, we hypothesized that MDSC may undergo osteoclast differentiation and contribute to enhanced bone destruction and tumor growth. Using an immunocompetent mouse model of breast cancer bone metastasis, we confirmed that MDSC isolated from the tumor-bone microenvironment differentiated into functional osteoclasts both in vitro and in vivo. Mechanistic investigations revealed that nitric oxide signaling was critical for differentiation of MDSC into osteoclasts. Remarkably, osteoclast differentiation did not occur in MDSC isolated from control or tumor-bearing mice that lacked bone metastasis, signifying the essential cross-talk between tumor cells and myeloid progenitors in the bone microenvironment as a requirement for osteoclast differentiation of MDSC. Overall, our results identify a wholly new facet to the multifunctionality of MDSC in driving tumor progression, in this case as a novel osteoclast progenitor that specifically drives bone metastasis during cancer progression.

Potential of human γδ T cells for immunotherapy of osteosarcoma

Recurrent or metastatic osteosarcomas remain a challenging malignancy to treat. Therefore, development and testing of novel therapeutic strategies to target these patients are needed. Adoptive cellular therapy strategies are being evaluated intensively as a novel therapeutic strategy for cancer. Unlike αβ T cells requiring antigen processing and MHC-restricted peptide displayed by antigen-presenting cells, γδ T cells exhibit the potent MHC-unrestricted lytic activity against various tumors in vitro and in vivo. The recent considerable success of γδ T cell-based immunotherapy in lung metastasis of renal cell carcinoma warrants further efforts to apply this treatment to other cancers including osteosarcoma, especially recurrent and metastatic osteosarcomas. In this review, we summarize the available evidence on γδ T cell-based immunotherapy for osteosarcoma that has been achieved to date. More importantly, we discuss potential strategies of the combination of expanded γδ T cells and bisphosphonates, and modification and expansion of αβ TCR modified γδ T cells for improving its efficacy for the treatment of osteosarcoma.

Bisphosphonate-related osteonecrosis of jaw (BRONJ): an anti-angiogenic side-effect?

Bisphosphonates are recommended in the treatment of osteoporosis and some cancers, in which case they prevent the appearance of bone metastasis. The patients taking bisphosphonates are at increased risk of developing bisphosphonate-related osteonecrosis of jaw (BRONJ) which is characterised by the presence of an un-healing wound after dental surgery. BRONJ might represent an anti-angiogenic side effect. However, the real number of patients with BRONJ might be higher than currently recorded. Considering the differential diagnosis which includes various primary and secondary cancers, a correct histopathological diagnosis is very important. The morphological criteria for diagnosis of BRONJ are highlighted in this material.