Personal Medicine and Bone Metastases: Biomarkers, Micro-RNAs and Bone Metastases

Bone metastasis is a major cause of morbidity within solid tumours of the breast, prostate, lung and kidney. Metastasis to the skeleton is associated with a wide range of complications including bone fractures, spinal cord compression, hypercalcaemia and increased bone pain. Improved treatments for bone metastasis, such as the use of anti-bone resorptive bisphosphonate agents, within post-menopausal women have improved disease-free survival; however, these treatments are not without side effects. There is thus a need for biomarkers, which will predict the risk of developing the spread to bone within these cancers. The application of molecular profiling techniques, together with animal model systems and engineered cell-lines has enabled the identification of a series of potential bone-metastasis biomarker molecules predictive of bone metastasis risk. Some of these biomarker candidates have been validated within patient-derived samples providing a step towards clinical utility. Recent developments in multiplex biomarker quantification now enable the simultaneous measurement of up to 96 micro-RNA/protein molecules in a spatially defined manner with single-cell resolution, thus enabling the characterisation of the key molecules active at the sites of pre-metastatic niche formation as well as tumour-stroma signalling. These technologies have considerable potential to inform biomarker discovery. Additionally, a potential future extension of these discoveries could also be the identification of novel drug targets within cancer spread to bone. This chapter summarises recent findings in biomarker discovery within the key bone metastatic cancers (breast, prostate, lung and renal cell carcinoma). Tissue-based and circulating blood-based biomarkers are discussed from the fields of genomics, epigenetic regulation (micro-RNAs) and protein/cell-signalling together with a discussion of the potential future development of these markers towards clinical development.

Utility of urinary type I collagen cross-linked N-telopeptide as a prognostic indicator in breast cancer patients with bone metastases

BACKGROUND

Breast cancer patients with bone metastases are usually managed with bone modifying agents, such as zoledronic acid and denosumab, and some bone turnover markers (BTMs) have been recognized as prognostic indicators in such patients. Although several studies have demonstrated the validity of BTMs as prognostic markers in patients treated with zoledronic acid, few studies have reported the utility of BTMs with denosumab treatment. In this study, we evaluated whether urinary N-telopeptide of type I collagen (u-NTX) can be a prognostic indicator in patients treated with denosumab.

METHODS

Thirty-six breast cancer patients newly diagnosed with bone metastases were evaluated retrospectively. Patients were treated with denosumab and anti-cancer drugs. u-NTX levels were measured 1 month before and after administration of denosumab, and the ratio of u-NTX levels before and after denosumab (change ratio) was assessed for its association with prognosis.

RESULTS

Levels of u-NTX decreased after denosumab administration in all patients except for one. The median value of the u-NTX change ratio was 0.766. Based on the change ratio, patients were divided into either a "high group" (n = 18) or a "low group" (n = 18). The low group showed significantly shorter overall survival (OS) compared with the high group (low group 15.0 months; high group 54.0 months; P = 0.012). Multivariate analysis indicated that the "low group" was an independent prognostic factor for OS (P = 0.028).

CONCLUSION

We demonstrated that the u-NTX change ratio in denosumab-treated breast cancer patients with bone metastases can be a prognostic marker.

Effect of bisphosphonates on the mandibular bone and gingival epithelium of rats without tooth extraction

Osteonecrosis of the jaw (ONJ) is an adverse effect of bisphosphonate treatment that has become the subject of increasing investigations, in particular due to its poorly understood pathogenesis. Several experimental studies on animal models have been conducted; however, the majority of these replicate human ONJ following tooth extraction, and describe alterations in the bone and gingival epithelium when necrosis is manifested. The aim of the present study was to analyze the rat mandibular bone and gingival epithelium during 45 days of zoledronate treatment (which is a bisphosphonate agent), without tooth extraction. Intraperitoneal injections of zoledronate acid (0.1 mg/kg) were performed three times a week in normal male Wistar rats (n=20), while a control group of rats (n=20) was treated with saline solution for 45 days. After 7, 15, 30 and 45 days of drug treatment, all rats were sacrificed and hematoxilin and eosin staining, immunofluorescence and scanning electron microscopy analyses were performed. The results of the analyses after 7 and 15 days of treatment were similar in the treatment and control group. After 30 and 45 days of treatment, structural alterations were observed in the bone. No structural alterations to the gingival epithelium were observed. Based on these results, it was hypothesized that low doses of zoledronate act directly on the bone tissues to induce morphological alterations from bone to necrotic tissue following surgical procedures, although no cytotoxic effects were detected in the gingival epithelium.

Malignancy mimicking bisphosphonate-associated osteonecrosis of the jaw: a case series and literature review

OBJECTIVE

Bisphosphonate-related osteonecrosis of the jaw (BONJ) is a common complication of bisphosphonate treatment that has been well documented over the past decade. Nevertheless, its pathogenesis is poorly understood, and treatment guidelines are based mostly on expert recommendations. Clinicians must be aware of malignancy mimicking BONJ, of which a few cases have been documented in the literature.

STUDY DESIGN

Three patients undergoing long-term treatment with intravenous bisphosphonates for malignant disease demonstrated the distinct diagnostic signs of BONJ. Surgical treatment was performed by resecting the affected bone. In all cases, histologic specimens were taken for analysis.

RESULTS

Histologic analysis of the bone specimen with surrounding soft tissue revealed necrotic bone with signs of inflammation, but also with cells of the underlying malignant disease.

CONCLUSIONS

Clinical and radiographic diagnosis of BONJ should be confirmed by histologic analysis in patients with underlying malignant disease.

Zoledronic acid and irradiation in oral squamous cell carcinoma

OBJECTIVE

This in vitro study evaluated cytotoxicity and cell migration effects of zoledronic acid and irradiation upon oral squamous cell carcinoma.

MATERIALS AND METHODS

Zoledronic acid was administrated at doses of 10, 25, 50, and 100 μM to PE/CA-PJ15 oral squamous cell carcinoma cultures, irradiated with different doses (0, 5, 15, and 30 Gy), followed by evaluation of the effects on cell viability. Cell migration capacity was studied after 24- and 72-h incubation.

RESULTS

At 24 h, the 100 μM concentration of zoledronic acid combined with 15 Gy irradiation caused the greatest decrease in cell viability. At 72 h, statistically significant decreases in cell viability were found with all concentrations of zoledronic acid with or without irradiation: 0 Gy (P < 0.001), 5 Gy (P < 0.001), 15 Gy (P < 0.001), and 30 Gy (P < 0.001). 50 μM and 100 μM doses of zoledronic acid combined with 5 Gy irradiation yielded the greatest decrease in cell migration capacity.

CONCLUSIONS

Zoledronic acid increases cytotoxic activity in the PE/CA-PJ15 cell line and reduces cell migration capacity. These findings suggest that combination therapy using biphosphates and radiation may offer a promising therapy.

Comparing cost-effectiveness analyses of denosumab versus zoledronic acid for the treatment of bone metastases

BACKGROUND

Bone metastases from various cancers have been traditionally treated with bisphosphonates, such as zoledronic acid (ZA), to prevent future skeletal-related events (SREs). Denosumab (Dmab) has been shown to have more advantages in preventing SREs in clinical trials than ZA, but the cost to administer Dmab is significantly higher.

METHODS

A literature review was conducted to investigate the methodologies used to compare the cost-effectiveness of Dmab and ZA. MEDLINE and EMBASE were searched systematically for all cost-effectiveness analyses published between January week 1, 2006 to August week 1, 2012. Search strategies were designed to retrieve articles analyzing the cost-effectiveness and cost utility of Dmab compared to ZA in patients with bone metastases. From 12 references obtained in the initial database search, eight satisfied the predetermined criteria for full article review. Articles were analyzed for incremental costs per skeletal-related event avoided or incremental cost per quality-adjusted life year gained.

RESULTS

All the studies identified received funding from Novartis Pharmaceuticals (the manufacturer of ZA) or Amgen Incorporated (the manufacturer of Dmab). The studies looked at the economic analysis using different associated costs and over various time periods, ranging from a 1-year to a lifetime time horizon.

CONCLUSION

It is not clear whether the methods used across studies are consistent, which may account for the differences between estimated costs and effects. Future research is suggested to explore the cost-effectiveness between Dmab and ZA using a standardize time frame and endpoint.

Use of bisphosphonates in metastatic breast cancer: single institution review at the Dr. H. Bliss Murphy Cancer Centre

PURPOSE

Bone metastases occur in 65-75% of patients with metastatic breast cancer. These patients are at risk of developing skeletal-related events (SREs). SREs are defined as any pathological fracture, spinal cord compression, hypercalcemia, and surgery or radiation required for treatment of bone metastases. Bisphosphonates are used to prevent the development of SREs. The purpose of this study is to review the incidence of SREs in metastatic breast cancer patients with bony disease in Newfoundland and Labrador and to determine if there is an association between SREs and the type of bisphosphonate therapy given.

METHODS

This retrospective chart review includes all metastatic breast cancer patients with bony disease treated at the Dr. H. Bliss Murphy Cancer Centre from 2008 to 2010. Patient demographics, treatment received, and treatment changes were collected. Patients at the Centre received bisphosphonate, pamidronate or zolendronic acid to prevent SREs. The prescribing pattern of bisphosphonates was collected. The occurrences of SREs were then compared to the type of treatment received.

RESULTS

Sixty-five patients with breast cancer and bony metastasis were identified using the provincial tumor registry, three patients were excluded from the review as their charts could not be located. Following the initial diagnosis of bone metastasis, 8 patients (12.7%) were started on zolendronic acid, 50 patients (80.6%) were started on pamidronate, and 4 (6.4%) received no treatment. Six patients (75%) on zolendronic acid experienced one SRE; however, none experienced multiple SREs. Thirty-one patients (62%) on pamidronate experienced one SRE, and ten (20%) had multiple SREs. Of the 31 patients on pamidronate with an SRE, 4 (12.9%) were switched to zolendronic acid. Three of the four (75%) had multiple SREs despite treatment changes. Of the six patients on zolendronic acid with SREs, none were switched to pamidronate.

CONCLUSION

Our results show that the majority of patients with breast cancer, who develop bony metastases in Newfoundland and Labrador, are initially treated with the bisphosphonate, pamidronate. Over 60% of these patients experienced at least one SRE, and 20% had more than two SREs. A small proportion of the patients were initially started on zolendronic acid, and this group had better outcomes with fewer SREs and none had more than two SREs. It appears that zolendronic acid is superior to pamidronate in preventing SREs; however, zolendronic acid is being used primarily as second-line in Newfoundland and Labrador.

Skeletal-related events and clinical outcomes in patients with bone metastases and normal levels of osteolysis: exploratory analyses

AIMS

High levels of bone resorption markers (e.g. N-telopeptide of type I collagen; NTX) have been correlated with increased risks of skeletal-related events and death in patients with bone metastases from solid tumours. However, the disease course has not been well characterised in patients with bone metastases but normal NTX levels. Therefore, the aim of this study was to evaluate the patterns of skeletal morbidity in patients with normal NTX levels.

MATERIALS AND METHODS

Exploratory analyses were carried out on patients with bone metastases from breast cancer, castration-resistant prostate cancer, non-small cell lung cancer or other solid tumours treated with zoledronic acid (ZOL) in phase III trials. The effects of covariates on the relative risk of death were estimated using the Cox proportional hazard model. The prognostic values of covariates were compared between patients with normal (<64 nmol/mmol creatinine) versus elevated (≥64 nmol/mmol creatinine) NTX levels.

RESULTS

Among patients with normal baseline NTX (n = 501), less than 10% developed elevated NTX levels before a skeletal-related event or death during ZOL treatment over 12 months. The prognostic factors identified in these analyses were mostly similar across NTX groups. However, some indicators of aggressive disease (e.g. visceral/cerebral metastases from breast cancer) were associated with poor clinical outcomes only in the normal NTX group.

CONCLUSIONS

Skeletal-related events were generally not preceded or followed by transition to elevated NTX in patients treated with ZOL. Elevated baseline NTX and aggressive extraskeletal disease were independently associated with reduced survival.

Analgesic effects of the non-nitrogen-containing bisphosphonates etidronate and clodronate, independent of anti-resorptive effects on bone

Nitrogen-containing bisphosphonates (NBPs) have greater anti-bone-resorptive effects than non-nitrogen-containing bisphosphonates (non-NBPs). Hence, NBPs are the current first-choice drug for osteoporosis. However, NBPs carry a risk of osteonecrosis of jaws. Some animal and human studies suggest that non-NBPs may have anti-bone-resorptive effect-independent analgesic effects, but there has been no detailed comparison between NBPs and non-NBPs. Here, we compared the analgesic effects of several non-NBPs and NBPs, using (a) writhing responses induced in mice by intraperitoneal injection of 1% acetic acid, (b) acetic acid-induced neuronal expression of c-Fos, (c) acetic acid-induced elevation of blood corticosterone, and (d) hindpaw-licking/biting responses induced by intraplantar injection of capsaicin. Among the NBPs and non-NBPs tested, only etidronate and clodronate displayed clear analgesic effects, with various routes of administration (including the oral one) being effective. However, they were ineffective when intraperitoneally injected simultaneously with acetic acid. Intracerebroventricular administration of etidronate or clodronate, but not of minodronate (an NBP), was also effective. The effective doses of etidronate and clodronate were much lower in writhing-high-responder strains of mice. Etidronate and clodronate reduced acetic acid-induced c-Fos expression in the brain and spinal cord, and also the acetic acid-induced corticosterone increase in the blood. Etidronate and clodronate each displayed an analgesic effect in the capsaicin test. Etidronate and clodronate displayed their analgesic effects at doses lower than those inducing anti-bone-resorptive effects. These results suggest that etidronate and clodronate exert potent, anti-bone-resorptive effect-independent analgesic effects, possibly via an interaction with neurons, and that they warrant reappraisal as safe drugs for osteoporosis.

Inhibition of breast cancer cell proliferation in repeated and non-repeated treatment with zoledronic acid

Background

Zoledronic acid is used to treat bone metastases and has been shown to reduce skeletal-related events and exert antitumor activity. The present in vitro study investigates the mechanism of action of Zoledronic Acid on breast cancer cell lines with different hormonal and HER2 patterns. Furthermore, we investigated the efficacy of repeated versus non-repeated treatments.

Methods

The study was performed on 4 breast cancer cell lines (BRC-230, SkBr3, MCF-7 and MDA-MB-231). Non-repeated treatment (single exposure of 168 hrs’ duration) with zoledronic acid was compared with repeated treatment (separate exposures, each of 48 hrs’ duration, for a total of 168 hrs) at different dosages. A dose–response profile was generated using sulforhodamine B assay. Apoptosis was evaluated by TUNEL assay and biomolecular characteristics were analyzed by western blot.

Results

Zoledronic acid produced a dose-dependent inhibition of proliferation in all cell lines. Anti-proliferative activity was enhanced with the repeated treatment, proving to be statistically significant in the triple-negative lines. In these lines repeated treatment showed a cytocidal effect, with apoptotic cell death caused by caspase 3, 8 and 9 activation and decreased RAS and pMAPK expression. Apoptosis was not observed in estrogen receptor-positive line: p21 overexpression suggested a slowing down of cell cycle. A decrease in RAS and pMAPK expression was seen in HER2-overexpressing line after treatment.

Conclusions

The study suggests that zoledronic acid has an antitumor activity in breast cancer cell lines. Its mechanism of action involves the decrease of RAS and RHO, as in osteoclasts. Repeated treatment enhances antitumor activity compared to non-repeated treatment. Repeated treatment has a killing effect on triple-negative lines due to apoptosis activation. Further research is warranted especially in the treatment of triple-negative breast cancer.

Patient-reported outcome instruments used to assess pain and functioning in studies of bisphosphonate treatment for bone metastases

Purpose

When treating metastatic bone disease, relief of bone pain is often a key outcome. Because pain cannot be quantified with objective clinical measures, patient-reported outcome (PRO) measures are required to assess patients' subjective experience. The goal of the current review was to examine measures used to assess pain, as well as the impact of pain on functional status and health-related quality of life (HRQL), in trials of bisphosphonates for the treatment of bone metastases.

Methods

A literature search focused on articles published from January 1999 to April 2009.

Results

A total of 49 articles were located that used PROs to assess pain-related outcomes of bisphosphonate treatment for bone metastases. The Brief Pain Inventory was the most commonly used multi-item instrument. However, the most common approach for assessing pain was to administer a single-item scale such as a visual analog scale, numerical rating scale, or verbal rating scale. Of the 49 studies, 19 included a PRO assessing functional status or HRQL.

Conclusions

Although pain is an important outcome of trials examining treatment for bone metastases, the current review suggests that there is little consistency in PRO measurement across studies. Furthermore, presentation of measures often lacked clear description, information on measurement properties, citations, clarity regarding method of administration, and consistent instrument names. Recommendations are provided for instrument validation within the target population, assessment of content validity, use of PRO instruments recently developed for patients with bone metastases, clear description of instruments, and implementation of measures consistent with recommendations from instrument developers.

Pharmacoeconomics of bisphosphonates for skeletal-related event prevention in metastatic non-breast solid tumours

Bisphosphonates reduce the risk of skeletal-related events (SREs; i.e. spinal cord compression, pathological fracture, radiation or surgery to the bone, and hypercalcaemia) in patients with metastatic cancer. A number of analyses have been conducted to assess the cost effectiveness of bisphosphonates in patients with bone metastases secondary to breast cancer, but few in other solid tumours. This is a review of cost-effectiveness analyses in patients with non-breast solid tumours and bone metastases. A literature search was conducted to identify cost-effectiveness analyses reporting the cost per QALY gained of bisphosphonates in patients with metastatic bone disease secondary to non-breast solid tumours. Four analyses met inclusion criteria. These included two in prostate cancer (one of which used a global perspective but expressed results in $US, and the other reported from a multiple country perspective: France, Germany, Portugal and the Netherlands). The remaining analyses were in lung cancer (in the UK, France, Germany, Portugal and the Netherlands), and renal cell carcinoma (in the UK, France and Germany). In each analysis, the cost effectiveness of zoledronic acid versus placebo was analysed. Zoledronic acid was found to be cost effective in all European countries across all three indications but not in the sole global prostate cancer analysis. Across countries and indications, assumptions regarding patient survival, drug cost and baseline utility (i.e. patient utility with metastatic disease but without an SRE) were the most robust drivers of modelled estimates. Assumptions of SRE-related costs were most often the second strongest cost driver. Further review indicated that particular attention should be paid to the inclusion or exclusion of nonsignificant survival benefits, whether health state utilities were elicited from community or patient samples or author assumptions, delineation between symptomatic and asymptomatic SREs, and the methods with which SRE disutility was modelled over time. While the field of cost-effectiveness analysis in solid tumours other than breast cancer is still evolving, outcomes will likely continue to be driven by drug cost and assumptions regarding treatment benefits. Although considerations such as adverse events and administration costs are important, they were not found to influence cost-effectiveness estimates greatly. As zoledronic acid will lose patent protection in 2013 and subsequently be greatly reduced in price, it is likely that the field of cost effectiveness will change with regard to SRE-limiting agents. Meanwhile, research should be conducted to improve our understanding of the impact on quality of life and medical costs of preventing SREs.

Health-economic review of zoledronic acid for the management of skeletal-related events in bone-metastatic prostate cancer

Zoledronic acid is the only bisphosphonate approved for the prevention or delay of skeletal-related events in patients with bone metastases secondary to prostate cancer. Recently, the US FDA and the EMA approved denosumab (a fully human monoclonal antibody) to treat skeletal-related events in bone-metastatic prostate cancer. This article summarizes the cost-effectiveness literature pertaining to these two agents when used in the prevention of skeletal-related events secondary to malignancy. Zoledronic acid (and denosumab in comparison with zoledronic acid) have been found to be cost effective and cost ineffective depending on the analytical perspective and model parameters.

Indirect stimulation of human Vγ2Vδ2 T cells through alterations in isoprenoid metabolism

Human Vγ2Vδ2 T cells monitor isoprenoid metabolism by recognizing (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), an intermediate in the 2-C-methyl-d-erythritol-4-phosphate pathway used by microbes, and isopentenyl pyrophosphate (IPP), an intermediate in the mevalonate pathway used by humans. Aminobisphosphonates and alkylamines indirectly stimulate Vγ2Vδ2 cells by inhibiting farnesyl diphosphate synthase (FDPS) in the mevalonate pathway, thereby increasing IPP/triphosphoric acid 1-adenosin-5'-yl ester 3-(3-methylbut-3-enyl) ester that directly stimulate. In this study, we further characterize stimulation by these compounds and define pathways used by new classes of compounds. Consistent with FDPS inhibition, stimulation of Vγ2Vδ2 cells by aminobisphosphonates and alkylamines was much more sensitive to statin inhibition than stimulation by prenyl pyrophosphates; however, the continuous presence of aminobisphosphonates was toxic for T cells and blocked their proliferation. Aminobisphosphonate stimulation was rapid and prolonged, independent of known Ag-presenting molecules, and resistant to fixation. New classes of stimulatory compounds-mevalonate, the alcohol of HMBPP, and alkenyl phosphonates-likely stimulate differently. Mevalonate, a rate-limiting metabolite, appears to enter cells to increase IPP levels, whereas the alcohol of HMBPP and alkenyl phosphonates are directly recognized. The critical chemical feature of bisphosphonates is the amino moiety, because its loss switched aminobisphosphonates to direct Ags. Transfection of APCs with small interfering RNA downregulating FDPS rendered them stimulatory for Vγ2Vδ2 cells and increased cellular IPP. Small interfering RNAs for isopentenyl diphosphate isomerase functioned similarly. Our results show that a variety of manipulations affecting isoprenoid metabolism lead to stimulation of Vγ2Vδ2 T cells and that pulsing aminobisphosphonates would be more effective for the ex vivo expansion of Vγ2Vδ2 T cells for adoptive cancer immunotherapy.

Skeletal imaging effects of pamidronate therapy in osteosarcoma patients

BACKGROUND

After observing metaphyseal changes in pediatric and young adult patients with osteosarcoma who were treated with pamidronate, we initiated a retrospective study to identify bone findings on computed radiography of the chest and extremities, chest CT, extremity MRI, and radionuclide bone scans in this population.

OBJECTIVE

To review the generalized skeletal imaging findings on computed radiography, CT, and MR examinations in patients with osteosarcoma (OS) receiving pamidronate.

MATERIALS AND METHODS

A retrospective review of 40 patients with newly diagnosed OS (mean age, 16.5 years) receiving pamidronate with chemotherapy were identified at one institution. Computed radiography, CT, MR, and bone scans on 36 patients were reviewed for osseous changes.

RESULTS

Dense metaphyseal bands at the growth plates in long bones, epiphyseal ossification centers, anterior rib ends, sternum and spine were observed. Osseous changes occurred on CT in 69% of patients, and on computed chest radiography in 53%. Bone-within-bone appearance in the spine and ossification centers was identified on computed radiography in 36%.

CONCLUSION

OS patients treated with pamidronate can develop metaphyseal sclerotic bands as well as epiphyseal and vertebral endplate sclerosis progressing to a bone-within-bone appearance. Findings occur more frequently in younger patients with open epiphyses.

Cost effectiveness of zoledronic acid in the management of skeletal metastases in hormone-refractory prostate cancer patients in France, Germany, Portugal, and the Netherlands

OBJECTIVE

Zoledronic acid (ZOL) reduces the risk of skeletal related events (SREs) in hormone-refractory prostate cancer (HRPC) patients with bone metastases. This study assessed the cost effectiveness of ZOL for SRE management in French, German, Portuguese, and Dutch HRPC patients.

METHODS

This analysis was based on the results of a randomized phase III clinical trial wherein HRPC patients received up to 15 months of ZOL (n = 214) or placebo (n = 208). Clinical inputs were obtained from the trial. Costs were estimated using hospital tariffs, published, and internet sources. Quality adjusted life-years (QALYs) gained were estimated from a separate analysis of EQ-5D scores reported in the trial. Uncertainty surrounding outcomes was addressed via univariate sensitivity analyses.

RESULTS

ZOL patients experienced an estimated 0.759 fewer SREs and gained an estimated 0.03566 QALYs versus placebo patients. ZOL was associated with reduced SRE-related costs [net costs] (-€2396 [€1284] in France, -€2606 [€841] in Germany, -€3326 [€309] in Portugal and -€3617 [€87] in the Netherlands). Costs per QALY ranged from €2430 (Netherlands) to €36,007 (France).

CONCLUSIONS

This analysis is subject to the limitations of most cost-effectiveness analyses: it combines data from multiple sources. Nevertheless, the results strongly suggest that ZOL is cost effective versus placebo in French, German, Portuguese, and Dutch HRPC patients.

Pathological vertebral compression fracture of C3 due to a breast cancer metastasis in a male patient

STUDY DESIGN

A case of vertebral body fracture due to metastatic breast cancer in a male patient and a review of the literature are presented.

OBJECTIVE

To draw attention to the possible adverse skeletal events in breast cancer patients, and the need of a watchful staff within the multidisciplinary team in charge.

SUMMARY OF BACKGROUND DATA

Breast cancer is a rare condition in men, the male/female ratio is 1 of 100 approximately; in both sexes bone metastases are the most common. The pathologic fracture by spinal metastases can cause intense pain with difficult management. Vertebroplasty has been used successfully to treat pain and improve functional status in patients with vertebral compression fractures due to metastases.

METHODS

A 43-year-old male patient was diagnosed of having breast epithelial carcinoma after histologic analysis of a femur fracture. Following reconstruction, the patient started rehabilitative treatment. In a control visit, he referred sudden cervical pain which was initially treated with nonsteroidal anti-inflammatory drugs and rest. The patient was seen in a later visit and complained about poor response to analgesia. For this reason, a radiologic study was carried out, showing signs of fracture of the third cervical vertebral body (C3), and was completed with magnetic resonance imaging where the diagnosis of osteolytic metastasis was confirmed.

RESULTS

After consulting the interventionist radiology team, vertebroplasty was carried out aiming to diminishing the pain. There were no postoperative complications and the patient's recovery from cervicalgia permitted the nonsteroidal anti-inflammatory drugs suspension. Two weeks after the vertebroplasty, the patient resumed his rehabilitative treatment without presenting cervical pain or mobility limitation.

CONCLUSION

Spinal metastases treatment may include combinations of radiotherapy, vertebroplasty, and bisphosphonates, which have proved analgesic effect and a decrease of bone complications; however, out of these options, only vertebroplasty allows rapid stabilization and analgesia.

RANK, RANKL and osteoprotegerin in bone biology and disease

Upon the discovery of RANK, RANKL and OPG in the late 1990s, their importance in the maintenance of the skeletal structure and their dramatic role in bone disease were largely unexpected. In recent years the understanding of these proteins, in particular their regulation, has greatly increased. This review aims to bring the interested reader up to date with the latest news and views on the mechanisms controlling bone resorption in normal and pathological conditions.

Cost-effectiveness of Oral Clodronate Compared with Oral Ibandronate, Intravenous Zoledronate or Intravenous Pamidronate in Breast Cancer Patients

This study aimed to identify the effects of different bisphosphonates in reducing skeletal-related events, and to determine whether there are any differences in their cost-effectiveness, taking into account their efficacy, safety profile and administration routes. A systematic literature search of databases, such as PubMed and the Cochrane Controlled Trials Register, supplemented by the latest congress abstracts from meetings of the European Hematology Association and the American Society of Clinical Oncology was conducted up to November 2006. Important references in reviews published by peer-reviewed journals were also taken into consideration. Our base-case cost-effectiveness analysis for Germany and the UK showed cost savings for oral clodronate therapy compared with other bisphosphonate therapies. In Germany, costs per patient of treatment with oral clodronate were €1092.38, €2360.40 and €2500.29 less than with oral ibandronate, intravenous pamidronate and intravenous zoledronate, respectively. The UK results were similar, the costs per patient of treatment with oral clodronate being €841.79, €2989.99 and €3669.19 less than with oral ibandronate, intravenous pamidronate and intravenous zoledronate, respectively.

Bisphosphonate-associated osteonecrosis of the jaw in patients with multiple myeloma and breast cancer

Osteonecrosis of the jaw is an unremitting adverse outcome associated with bisphosphonate therapy in patients with multiple myeloma or bone metastases from solid tumors. Twelve patients who presented with exposed bone associated with bisphosphonates were reviewed to determine the type, dosage and duration of their bisphosphonate therapy, presenting findings, comorbidities and the event that incited the bone exposure. The discontinuation of bisphosphonate therapy has not helped reverse the presence of osteonecrosis, and the surgical manipulation of the involved site appears to worsen the underlying bone pathology. Hyperbaric oxygen, which has proven efficacious in other forms of osteonecrosis by establishing an oxygen gradient, is of no definitive benefit to patients with bisphosphonate-induced exposed bone. Antibiotic therapy is useful in controlling pain and swelling but ineffective in preventing the progression of the exposed bone. To date, prevention is the only currently possible therapeutic approach to the management of this complication.