Bisphosphonates for cancer patients: why, how, and when?

Management of metastatic bone disease of melanoma

One of the most aggressive tumors arising from the skin, mucosa, and uvea is malignant melanoma, which easily metastasizes. Bone tissue is one of the most typical locations for distant metastasis, and around 5%-20% of patients eventually acquired skeletal metastases. For decades, the incidence of bone metastases was higher, bringing greater burden on the family, society, and healthcare system owing to the progress of targeted therapy and immunotherapy, which prolonging the survival time substantially. Moreover, bone metastases result in skeletal-related events, which influence the quality of life, obviously. Appropriate intervention is therefore crucial. To obtain the optimum cost-effectiveness, existing treatment algorithm must be integrated, which is still controversial. We have aimed to throw light on current views concerning the formation, biological and clinical features, and treatment protocol of melanoma bone metastases to guide the decision-making process.

Retrospective assessment of tolerability and efficacy of zoledronate in the palliative treatment of cancer-bearing dogs

Zoledronate is a bisphosphonate frequently used for the treatment of hypercalcaemia of malignancy and tumour-associated bone pain in dogs, however, there is a paucity of information regarding its use in veterinary medicine. The aim of this retrospective study was to report the tolerability of zoledronate in the palliative treatment of cancer-bearing dogs and secondarily to to assess the efficacy of zoledronate for the treatment of hypercalcaemia of malignancy. Thirty-seven dogs (22 with tumour-associated bone pain and 15 with hypercalcaemia of malignancy) that received 114 zoledronate infusions were included. Tolerability was assessed by the absence of post-zoledronate hypocalcaemia or other adverse events as defined by Veterinary Cooperative Oncology Group-Common Terminology Criteria for Adverse Events criteria. Efficacy was assessed by comparison of available ionized calcium levels before and after zoledronate administration in hypercalcaemic dogs. In 79% of zoledronate infusions, no adverse events were reported. The majority of adverse events which occurred in the other 21% of infusions could be attributed to concurrent chemotherapy or the underlying neoplastic disease. There was a small but significant increase in creatinine following treatment with zoledronate, however, none of the dogs developed clinically significant renal disease. In eight hypercalcaemic dogs with available ionized calcium following zoledronate administration, ionized calcium decreased rapidly within 7 days following treatment with zoledronate. Zoledronate is well-tolerated with few recorded adverse events, however, monitoring of serum creatinine is advised. Zoledronate seems to be effective in the treatment of hypercalcaemia of malignancy.

Organic Bone Matrix Component Type I and V Collagen Are Not Destructed in Bisphosphonate-Associated Osteonecrosis of the Jaws

Background and objectives: The investigation of the pathophysiology behind medication-related osteonecrosis (MRONJ) of the jaw mostly focuses on alterations in osteoclast and osteoblast cell activity, but changes in the organic and inorganic bone matrix have rarely been studied. The aim of this study was to investigate whether collagen, the main organic component of extracellular bone matrix, is destructed in osteonecrosis of the jaw secondary to antiresorptive medication. Material and methods: Bone samples of patients with MRONJ (n = 15, control group n = 3) were demineralized, and collagen fragments were separated from intact collagen pellets by ultrafiltration. The quantification of mature collagen cross-links hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) in pellets and ultrafiltrates was performed by high-performance liquid chromatography (HPLC). The detection of hydroxyproline (Hyp) was carried out using a spectrophotometric assay. In addition, collagen chains were analyzed by sodium dodecylsulfate-polyacrylamide gel (SDS-PAGE). Results: The results revealed significantly higher concentrations of HP, LP and Hyp in pellet samples. In addition, there were no significant differences between samples from MRONJ patients and those of the control group. These results were paralleled by SDS- PAGE. Conclusion: These findings suggest that MRONJ does not involve the destruction of type I and V collagen molecules, in contrast to previously reported destruction by osteoradionecrosis.

Bioinformatic Data Mining for Candidate Drugs Affecting Risk of Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) in Cancer Patients

Background. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) leads to significant morbidity. Other coadministered drugs may modulate the risk for BRONJ. The present study aimed to leverage bioinformatic data mining to identify drugs that potentially modulate the risk of BRONJ in cancer. Methods. A GEO gene expression dataset of peripheral blood mononuclear cells related to BRONJ in multiple myeloma patients was downloaded, and differentially expressed genes (DEGs) in patients with BRONJ versus those without BRONJ were identified. A protein-protein interaction network of the DEGs was constructed using experimentally validated interactions in the STRING database. Overrepresented Gene Ontology (GO) molecular function terms and KEGG pathways in the network were analysed. Network topology was determined, and ‘hub genes’ with degree ≥2 in the network were identified. Known drug targets of the hub genes were mined from the ‘drug gene interaction database’ (DGIdb) and labelled as candidate drugs affecting the risk of BRONJ. Results. 751 annotated DEGs ( $\log \text{FC}\ge 1.5$ , $p<0.05$ ) were obtained from the microarray gene expression dataset GSE7116. A PPI network with 633 nodes and 168 edges was constructed. Data mining for drugs interacting with 49 gene nodes was performed. 37 drug interactions were found for 9 of the hub genes including TBP, TAF1, PPP2CA, PRPF31, CASP8, UQCRB, ACTR2, CFLAR, and FAS. Interactions were found for several established and novel anticancer chemotherapeutic, kinase inhibitor, caspase inhibitor, antiangiogenic, and immunomodulatory agents. Aspirin, metformin, atrovastatin, thrombin, androgen and antiandrogen drugs, progesterone, Vitamin D, and Ginsengoside 20(S)-Protopanaxadiol were also documented. Conclusions. A bioinformatic data mining strategy identified several anticancer, immunomodulator, and other candidate drugs that may affect the risk of BRONJ in cancer patients.

Phosphonate-Modified Cellulose Nanocrystals Potentiate the Th1 Polarising Capacity of Monocyte-Derived Dendritic Cells via GABA-B Receptor

Purpose

Phosphonates, like 3-AminoPropylphosphonic Acid (ApA), possess a great potential for the therapy of bone tumours, and their delivery via cellulose nanocrystals (CNCs) seems a promising approach for their increased efficacy in target tissues. However, the immunological effects of CNC-phosphonates have not been investigated thoroughly. The main aim was to examine how the modification of CNCs with phosphonate affects their immunomodulatory properties in human cells.

Methods

Wood-based native (n) CNCs were modified via oxidation (ox-CNCs) and subsequent conjugation with ApA (ApA-CNCs). CNCs were characterised by atomic force microscopy (AFM) and nanoindentation. Cytotoxicity and immunomodulatory potential of CNCs were investigated in cultures of human peripheral blood mononuclear cells (PBMCs) and monocyte-derived dendritic cells (MoDCs)/T cells co-cultures by monitoring phenotype, cytokines production, allostimulatory and Th/Treg polarisation capacity.

Results

AFM showed an increase in CNCs' thickens, elasticity modulus and hardness during the modification with ApA. When applied at non-toxic doses, nCNCs showed a tolerogenic potential upon internalisation by MoDCs, as judged by their increased capacity to up-regulate tolerogenic markers and induce regulatory T cells (Treg), especially when present during the differentiation of MoDCs. In contrast, ox- and ApA-CNCs induced oxidative stress and autophagy in MoDCs, which correlated with their stimulatory effect on the maturation of MoDCs, but also inhibition of MoDCs differentiation. ApA-CNC-treated MoDCs displayed the highest allostimulatory and Th1/CTL polarising activity in co-cultures with T cells. These effects of ApA-CNCs were mediated via GABA-B receptor-induced lowering of cAMP levels in MoDCs, and they could be blocked by GABA-B receptor inhibitor. Moreover, the Th1 polarising and allostimulatory capacity of MoDCs differentiated with ApA-CNC were largely preserved upon the maturation of MoDCs, whereas nCNC- and ox-CNC-differentiated MoDCs displayed an increased tolerogenic potential.

Conclusion

The delivery of ApA via CNCs induces potent DC-mediated Th1 polarisation, which could be beneficial in their potential application in tumour therapy.

Titanium alkalinization improves response of osteoblasts to zoledronic acid

This investigation is aimed to determine the effect of the modification of titanium surface with NaOH on the metabolism of osteoblasts treated with zoledronic acid (ZA). Machined and NaOH-treated titanium disks were used. Surfaces were characterized by scanning electron microscopy, confocal microscopy, and x-ray photoelectron spectroscopy (XPS) analysis. Human osteoblasts were seeded onto the disks. After 24 h, cells were treated with ZA at 5 μM for 7 days. At this point, cell viability, collagen synthesis, total protein production, alkaline phosphatase activity, and mineral nodule deposition were assessed. The results of surface roughness were descriptively and statistically analyzed (t-Student), while the XPS results were qualitatively described. Cell metabolism data were analyzed by the analysis of variance two-way and Tukey tests at a 5% significance level. The results demonstrated that NaOH-treatment increased surface roughness (p < .05) and confirmed the presence of sodium titanate and a pH switch on the NaOH-treated disks. This modification also resulted in higher cell viability, collagen synthesis, total protein production, and alkaline phosphatase by osteoblasts when compared to cells seeded onto machined disks (p < 0.05). In the presence of ZA, all cellular metabolism and differentiation parameters were significantly reduced for cells seeded on both surfaces (p < 0.05); however, the cells seeded onto modified surfaces showed higher values for these parameters, except for mineral nodule deposition (p < 0.05). NaOH modification improved cell adhesion and metabolism of osteogenic cells even in the presence of ZA. The surface modification of titanium with NaOH solution may be an interesting strategy to improve metabolism and differentiation of osteoblasts and accelerate osseointegration process, mainly for tissues exposed to ZA.

Skeletal Metastases of Unknown Primary: Biological Landscape and Clinical Overview

Skeletal metastases of unknown primary (SMUP) represent a clinical challenge in dealing with patients diagnosed with bone metastases. Management of these patients has improved significantly in the past few years. however, it is fraught with a lack of evidence. While some patients have achieved impressive gains, a more systematic and tailored treatment is required. Nevertheless, in real-life practice, the outlook at the beginning of treatment for SMUP is decidedly somber. An incomplete translational relevance of pathological and clinical data on the mortality and morbidity rate has had unsatisfactory consequences for SMUP patients and their physicians. We examined several approaches to confront the available evidence; three key points emerged. The characterization of the SMUP biological profile is essential to driving clinical decisions by integrating genetic and molecular profiles into a multi-step diagnostic work-up. Nonetheless, a pragmatic investigation plan and therapy of SMUP cannot follow a single template; it must be adapted to different pathophysiological dynamics and coordinated with efforts of a systematic algorithm and high-quality data derived from statistically powered clinical trials. The discussion in this review points out that greater efforts are required to face the unmet needs present in SMUP patients in oncology.

Seeking for Correlative Genes and Signaling Pathways With Bone Metastasis From Breast Cancer by Integrated Analysis

Background: Bone metastasis frequently occurs in advanced breast cancer patients, and it is one of major causes of breast cancer associated mortality. The aim of the current study is to identify potential genes and related signaling pathways in the pathophysiology of breast cancer bone metastasis.

Methods: Three mRNA expression datasets for breast cancer bone metastasis were obtained from Gene Expression Omnibus (GEO) dataset. The differentially expressed genes (DEGs) were obtained. Functional analyses, protein-protein interaction (PPI) network, and transcription factors (TFs)-target genes network was constructed. Real-time PCR using clinical specimens was conducted to justify the results from integrated analysis.

Results: A 749 DEGs were obtained. Osteoclast differentiation and rheumatoid arthritis were two significantly enriched signaling pathways for DEGs in the bone metastasis of breast cancer. SMAD7 (degree = 10), TGFBR2 (degree = 9), VIM (degree = 8), FOS (degree = 8), PDGFRB (degree = 7), COL5A1 (degree = 6), ARRB2 (degree = 6), and ITGAV (degree = 6) were high degree genes in the PPI network. ETS1 (degree = 12), SPI1 (degree = 12), FOS (degree = 10), FLI1 (degree = 5), KLF4 (degree = 4), JUNB (degree = 4), NR3C1 (degree = 4) were high degree genes in the TFs-target genes network. Validated by QRT-PCR, the expression levels of IBSP, MMP9, MMP13, TNFAIP6, CD200, DHRS3, ASS1, RIPK4, VIM, and PROM1 were roughly consistent with our integrated analysis. Except PROM1, the other genes had a diagnose value for breast cancer bone metastasis.

Conclusions: The identified DEGs and signaling pathways may make contribution for understanding the pathological mechanism of bone metastasis from breast cancer.

Multimodal Treatment of Bone Metastasis-A Surgical Perspective

Over the past decades there has been an increase in the incidence of cancer worldwide. With the advancement in treatment, patient survival has improved in tandem with the increasing incidence. This, together with the availability of advanced modern diagnostic modalities, has resulted in more cases of metastatic bone disease being identified. Bone metastasis is an ongoing problem and has significant morbidity implications for patients affected. Multimodal treatment strategies are required in dealing with metastatic bone disease, which include both surgical and non-surgical treatment options. In the multidisciplinary team, orthopedic surgeons play an important role in improving the quality of life of cancer patients. Surgical intervention in this setting is aimed at pain relief, restoration of function and improvement in functional independence. In selected cases with resectable solitary metastasis, surgical treatment may be curative. With the advancement of surgical technique and improvement in implant design and manufacture, a vast array of surgical options are available in the modern orthopedic arena. In the majority of cases, limb salvage procedures have become the standard of care in the treatment of metastatic bone disease. Non-surgical adjuvant treatment also contributes significantly to the improvement of cancer patient care. A multidisciplinary approach in this setting is of paramount importance.

Predictors of skeletal-related events among cancer patients with bone metastases treated with zoledronic acid: a secondary analysis of a randomized study

BACKGROUND

The purpose of the current study is to assess the predictors of skeletal-related events (SREs) among advanced cancer patients with bone metastases treated with zoledronic acid within a randomized study.

RESEARCH DESIGN AND METHODS

This is a secondary analysis of patient-level data of advanced cancer patients with bone metastases who were treated with monthly zoledronic acid in the NCT00330759 clinical trial.

RESULTS

A total of 702 patients were included in the current analysis. In univariate logistic regression analysis, higher body mass index (P = 0.034) and lytic nature of bone metastasis (P = 0.008) were found to be predictive of a higher probability of SREs. When the two factors were included in a multivariate logistic regression model, both of them were predictive of the later development of SREs (P value for higher body mass index = 0.015; P value for lytic bone lesions = 0.005).

CONCLUSION

Among advanced cancer patients with bone metastases, lytic nature of metastases, as well as higher body mass index, are associated with a higher probability of SREs.

TRIAL REGISTRATION NUMBER

this clinical trial was registered at clinicaltrials.gov with the number: nct0033.

Usefulness of Bone Formation Markers in Breast Cancer

The skeleton is the main site affected by metastases and breast cancer is the most frequent tumor to invade bone. The assessment of bone metastases is difficult and biochemical markers of bone formation (BFMs) could be a promising alternative. Although the essential role of osteoblasts in the metastatic process of bone destruction is now well established, little attention has been paid to BFMs. We conducted a Medline search for studies about BFMs in breast cancer. Our review allows us to conclude that BFMs have high specificity but low sensitivity for the diagnosis of bone metastases. The available biochemical markers cannot replace imaging techniques for the diagnosis of bone metastases. Several studies indicate that BFM serum levels reflect total tumor burden in the skeleton. BFM levels are higher in patients with blastic lesions compared to those with lytic lesions. Serial measurements of BFMs could be useful for the clinical assessment of response to antineoplastic treatment or to bisphosphonate therapy. Besides markers of bone resorption, biochemical markers of bone formation are a promising alternative for the assessment of metastatic bone disease, but large prospective studies are needed to address this important issue.

Influence of bisphosphonates on the adherence and metabolism of epithelial cells and gingival fibroblasts to titanium surfaces

OBJECTIVES

To evaluate the effects of sodium alendronate (SA) and zoledronic acid (ZA), on the adhesion and metabolism of epithelial cells and gingival fibroblasts to titanium surfaces considering cell functions related to an effective mucosal barrier around the implant.

MATERIALS AND METHODS

Cells were seeded onto titanium discs and incubated for 24 h. Then, serum-free DMEM containing selected bisphosphonates (0, 0.5, 1, or 5 μM) was added for 24 and 48 h. Factors related to the achievement of an effective mechanical and immunological barrier-cell adhesion, viability, collagen epidermal growth factor, and immunoglobulin synthesis-were evaluated. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests as well as by ANOVA and Tukey's tests, (α = 0.05).

RESULTS

The presence of bisphosphonates culminated in lower cell adhesion to the titanium discs, particularly for SA at 5 μM (40%) and ZA at all concentrations (from 30 to 50%, according to increased concentrations). Reduced cell viability occurred after exposing these cells to ZA (40%); however, only 5 μM SA-treated cells had decreased viability (30%). Reduced synthesis of growth factors and collagen was observed when cells were reated with ZA (20 and 40%, respectively), while about 70% of IgG synthesis was enhanced.

CONCLUSION

Bisphosphonates negatively affected the adhesion and metabolism of oral mucosal cells, and this effect was related to the type of bisphosphonate as well as to concentration and period of treatment.

CLINICAL RELEVANCE

The negative effects of bisphosphonates on oral mucosal cells can hamper the formation of an effective biological seal in osseointegrated implants.

Pamidronate Disodium Leads to Bone Necrosis via Suppression of Wnt/β-Catenin Signaling in Human Bone Marrow Mesenchymal Stem Cells In Vitro

PURPOSE

Pamidronate disodium-associated bone necrosis is poorly understood at the cellular and molecular levels. This study proposes a pathway leading to the pamidronate disodium-mediated inhibition of osteogenic differentiation of human bone marrow mesenchymal stem cells (BMMSCs) derived from the mandible in vitro.

MATERIALS AND METHODS

Primary human BMMSCs were isolated from the mandible and marrow tissue. A proliferation assay was performed to determine the experimental concentration of pamidronate disodium. Alkaline phosphatase (ALP) activity, ALP staining, and Alizarin red S (ARS) staining were assessed after treatment with pamidronate disodium (0, 0.1, 0.5, 1, 5, 10 μg/mL). Quantitative real-time polymerase chain reaction and western blotting specific for Wnt and β-catenin signaling genes or proteins were performed after treatment with pamidronate disodium 0.5 μg/mL. Wnt3a was used to observe the osteogenic differentiation of BMMSCs during treatment with pamidronate disodium 0.5 μg/mL.

RESULTS

As expected, pamidronate disodium 1, 5, and 10 μg/ml were unfavorable for BMMSC growth (P < .05), whereas 0.1 and 0.5 μg/mL did not affect BMMSC growth (P ≥ .05). BMMSCs treated with pamidronate disodium 0.5 μg/mL had lower ALP activity, ALP staining, and ARS staining (P < .05), and BMMSCs treated with low concentrations (<0.5 μg/mL) of pamidronate disodium had the same levels of ALP activity, ALP staining, and ARS staining as the control (0 μg/mL). Pamidronate disodium 0.5 μg/mL decreased the expression of genes and proteins involved in Wnt and β-catenin signaling. BMMSCs with Wnt3a and pamidronate disodium 0.5 μg/mL had higher ALP activity, ALP staining, and ARS staining (P < .05).

CONCLUSIONS

Pamidronate disodium inhibited Wnt and β-catenin signaling, which controls osteogenic differentiation in BMMSCs. Wnt3a, a Wnt and β-catenin signaling activator, reversed the negative effects caused by pamidronate disodium to salvage the osteogenic defect in BMMSCs.

Ibandronate: The loading dose concept in the treatment of metastatic bone pain

Background/Aim

Severe bone pain is experienced by 60–80% of patients with metastatic bone disease, and has a profound impact on quality of life. Therefore, effective pain relief is an important goal in managing metastatic bone disease. Orthopedic surgeons are often challenged with patients presenting with newly diagnosed bone metastases and severe and disabling bone pain. It is important to provide fast and sufficient analgesia. Clinical trials have demonstrated that bisphosphonates reduce effectively and sustained bone pain by approved standard dosage over time. Open label prospective trials have shown that short time high dose i.v. Ibandronate is effective in rapid pain relief in different primary tumors.

Patients and methods

In 33 patients with metastatic bone pain from newly diagnosed skeletal metastases we utilized the loading-dose concept for intravenous ibandronate (6 mg infused over 1 h on 3 consecutive days).

Results

In 33 patients loading-dose ibandronate therapy significantly reduced bone pain within the first 5–7 days (VAS day 0: 6–8 vs. day 7: 3–4). Only 3 patients showed no response concerning a distinct pain reduction within the first days of therapy. There was no increase in pain medication.

Conclusion

This clinical observational study in selected patients with severe metastatic bone pain undergoing an intensive high dosed ibandronate-therapy for a short period demonstrated that loading-dose ibandronate (6 mg i.v., 3 consecutive days) resulted in a reduction of pain within days.

Selenium-Substituted Hydroxyapatite/Biodegradable Polymer/Pamidronate Combined Scaffold for the Therapy of Bone Tumour

The present study evaluated a new concept of combined scaffolds as a promising bone replacement material for patients with a bone tumour or bone metastasis. The scaffolds were composed of hydroxyapatite doped with selenium ions and a biodegradable polymer (linear or branched), and contained an active substance—bisphosphonate. For this purpose, a series of biodegradable polyesters were synthesized through a ring-opening polymerization of ε-caprolactone or d,l-lactide in the presence of 2-hydroxyethyl methacrylate (HEMA) or hyperbranched 2,2-bis(hydroxymethyl)propionic acid polyester-16-hydroxyl (bis-MPA) initiators, substances often used in the synthesis of medical materials. The polymers were obtained with a high yield and a number-average molecular weight up to 45,300 (g/mol). The combined scaffolds were then manufactured by a direct compression of pre-synthesized hydroxyapatite doped with selenite or selenate ions, obtained polymer and pamidronate as a model drug. It was found that the kinetic release of the drug from the scaffolds tested in vitro under physiological conditions is strongly dependent on the physicochemical properties and average molecular weight of the polymers. Furthermore, there was good correlation with the hydrolytic biodegradation results of the scaffolds fabricated without drug. The preliminary findings suggest that the fabricated combined scaffolds could be effectively used for the sustained delivery of bioactive molecules at bone defect sites.

Zoledronic acid inhibits human osteoblast activities

BACKGROUND

Bisphosphonates are potent inhibitors of bone resorption. These kinds of drugs, which are used for the treatment of osteolytic diseases, have been associated with the occurrence of oral osteonecrosis, especially in patients over 60 years old. Current studies have demonstrated that the cytotoxic effects of bisphosphonates on osteoblasts play an important role in oral osteonecrosis development.

OBJECTIVE

The aim of this study was to evaluate the effect of long-term application of a highly potent bisphosphonate - zoledronic acid (ZA) - on human osteoblasts in vitro.

METHODS

Human osteoblasts (MG63 cell line) were seeded for 72 h in wells of 24-well plates. The Dulbecco's modified Eagle's medium (DMEM) was then replaced by culture medium without fetal bovine serum (FBS), and the cells were incubated for an additional 24 h, after which ZA was added to the DMEM without FBS and incubated in contact with osteoblasts for 7, 14 or 21 days. Cell viability (CV), total protein production (TPP), alkaline phosphatase (ALP) activity, mineral nodule formation (MNF), and gene expression of ALP and osteocalcin (OCN), as well as cell morphology by scanning electronic microscopy, were evaluated. Data were statistically analyzed by Kruskal-Wallis and Mann-Whitney tests, with a significance level of 5%.

RESULTS

The cytotoxic effects of ZA on osteoblasts were characterized by reduction of CV, TPP, ALP and MNF production. In addition, ZA MNF caused a decrease in gene expression of ALP and OCN, as well as intense cell morphology alterations. All these negative effects of ZA were concentration and period dependent.

CONCLUSION

Both concentrations of ZA (1 and 5 μM) caused cytotoxic effects to osteoblasts which reduced the production and expression of proteins that play an important role in bone matrix synthesis and mineralization.

Complications in the management of metastatic spinal disease

Metastatic spine disease accounts for 10% to 30% of new cancer diagnoses annually. The most frequent presentation is axial spinal pain. No treatment has been proven to increase the life expectancy of patients with spinal metastasis. The goals of therapy are pain control and functional preservation. The most important prognostic indicator for spinal metastases is the initial functional score. Treatment is multidisciplinary, and virtually all treatment is palliative. Management is guided by three key issues; neurologic compromise, spinal instability, and individual patient factors. Site-directed radiation, with or without chemotherapy is the most commonly used treatment modality for those patients presenting with spinal pain, causative by tumours which are not impinging on neural elements. Operative intervention has, until recently been advocated for establishing a tissue diagnosis, mechanical stabilization and for reduction of tumor burden but not for a curative approach. It is treatment of choice patients with diseaseadvancement despite radiotherapy and in those with known radiotherapy-resistant tumors. Vertebral resection and anterior stabilization with methacrylate or hardware (e.g., cages) has been advocated.Surgical decompression and stabilization, however, along with radiotherapy, may provide the most promising treatment. It stabilizes the metastatic deposited areaand allows ambulation with pain relief. In general, patients who are nonambulatory at diagnosis do poorly, as do patients in whom more than one vertebra is involved. Surgical intervention is indicated in patients with radiation-resistant tumors, spinal instability, spinal compression with bone or disk fragments, progressive neurologic deterioration, previous radiation exposure, and uncertain diagnosis that requires tissue diagnosis. The main goal in the management of spinal metastatic deposits is always palliative rather than curative, with the primary aim being pain relief and improved mobility. This however, does not come without complications, regardless of the surgical intervention technique used. These complication range from the general surgical complications of bleeding, infection, damage to surrounding structures and post operative DT/PE to spinal specific complications of persistent neurologic deficit and paralysis.

Bisphosphonate therapy in multiple myeloma in preventing vertebral collapses: preliminary report

PURPOSE

The aim of the study was to report and discuss the preliminary data obtained in a homogeneous series of 50 patients affected by multiple myeloma treated with bisphosphonates.

METHODS

Patients were followed for a minimum of 1 year. Main orthopaedic data were recorded. Visual Analogue Score and QLQ-C30 and MY 20 were used to assess the quality of life.

RESULTS

Statistical analysis showed less lytic lesions in the group with zoledronate therapy and stable primary disease compared with a greater number of lesions in the non-treated group. Results regarding VAS score and QLQ-C30 and MY were statistically better in the first group than in the second.

CONCLUSIONS

Our results confirm the efficacy of zoledronate in ensuring an acceptable quality of life restraining the aggressiveness of the myeloma on bone tissue, especially in spine although further prospective studies have to be conducted to determine its correct use in myeloma patients.

Optimal management of bone metastases in breast cancer patients

Bone metastasis in breast cancer is a significant clinical problem. It not only indicates incurable disease with a guarded prognosis, but is also associated with skeletal-related morbidities including bone pain, pathological fractures, spinal cord compression, and hypercalcemia. In recent years, the mechanism of bone metastasis has been further elucidated. Bone metastasis involves a vicious cycle of close interaction between the tumor and the bone microenvironment. In patients with bone metastases, the goal of management is to prevent further skeletal-related events, manage complications, reduce bone pain, and improve quality of life. Bisphosphonates are a proven therapy for the above indications. Recently, a drug of a different class, the RANK ligand antibody, denosumab, has been shown to reduce skeletal-related events more than the bisphosphonate, zoledronic acid. Other strategies of clinical value may include surgery, radiotherapy, radiopharmaceuticals, and, of course, effective systemic therapy. In early breast cancer, bisphosphonates may have an antitumor effect and prevent both bone and non-bone metastases. Whilst two important Phase III trials with conflicting results have led to controversy in this topic, final results from these and other key Phase III trials must still be awaited before a firm conclusion can be drawn about the use of bisphosphonates in this setting. Advances in bone markers, predictive biomarkers, multi-imaging modalities, and the introduction of novel agents have ushered in a new era of proactive management for bone metastases in breast cancer.

Atrial fibrillation and stroke associated with intravenous bisphosphonate therapy in older patients with cancer

PURPOSE

Recent studies have linked the use of intravenous and orally administered bisphosphonates with subsequent development of atrial fibrillation. Patients with cancer who receive intravenous bisphosphonate therapy may be at particular risk for this adverse event because they receive higher doses of these drugs than do patients treated for other indications. We examined the association of intravenous bisphosphonates with atrial fibrillation, all classifications of supraventricular tachycardia (SVT), and stroke among older patients with cancer.

PATIENTS AND METHODS

Using Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked data, we identified older (≥ age 65 years) patients with cancer who were treated with intravenous infusions of bisphosphonates between January 1, 1995 and December 31, 2003. We then matched 13,714 bisphosphonate nonusers to 6,857 bisphosphonate users, at a 2:1 ratio, on cancer type, age, sex, presence of bone metastases, and SEER geographic region. Patients were observed until December 31, 2003 or until they lost coverage from Medicare Parts A and B; enrolled in a health maintenance organization; received a diagnosis of atrial fibrillation, any SVT, or stroke; or died.

RESULTS

Receipt of intravenous bisphosphonates was modestly associated with an increased risk for atrial fibrillation (hazard ratio [HR] = 1.30; 95% CI, 1.18 to 1.43), all SVT (HR = 1.28; 95% CI, 1.19 to 1.38), and stroke (HR = 1.30; 95% CI, 1.09 to 1.54). The risk for all SVT increased 7% for each increase of five bisphosphonate dose equivalents (HR = 1.07; 95% CI, 1.02 to 1.12).

CONCLUSION

Clinicians who treat patients with cancer who have received intravenous bisphosphonates should be aware of the possible cardiovascular adverse events associated with this treatment.

Targeting the {alpha} receptor for platelet-derived growth factor as a primary or combination therapy in a preclinical model of prostate cancer skeletal metastasis

PURPOSE

Platelet-derived growth factor α (PDGFRα) is highly expressed in primary prostate cancer and associated skeletal metastases. Here, we tested whether targeting this receptor could impair metastatic colonization and progression, as well as prolong survival, either as primary or as combination therapy.

EXPERIMENTAL DESIGN

We used a preclinical animal model of metastasis in which PC3-ML human prostate cancer cells are inoculated directly in the blood circulation. First, the humanized, monoclonal antibody IMC-3G3 was administered to mice bearing established skeletal metastases. Second, we targeted the stromal PDGFRα with IMC-1E10, an antibody specific for the murine receptor. Third, IMC-3G3 and the bisphosphonate zoledronic acid (ZA), administered separately or in combination, were tested on the progression of skeletal lesions and overall survival. In addition, the ability of IMC-3G3 and ZA to impair initial colonization of the bone marrow by prostate cancer cells was investigated.

RESULTS

The blockade of PDGFRα on prostate cancer cells by IMC-3G3 reduces the size of established skeletal metastases, whereas the IMC-1E10 antibody directed against the stromal PDGFRα fails to inhibit metastatic progression. IMC-3G3 and ZA, either separately or in combination, significantly slow tumor growth and seem to prolong survival. Lastly, the blockade of PDGFRα by IMC-3G3 inhibits the initial phase of bone colonization, whereas ZA is ineffective at this stage.

CONCLUSION

This study presents compelling evidence that targeting PDGFRα with IMC-3G3 delays the progression of early metastatic foci and reduces the size of more established lesions. In addition, IMC-3G3, either alone or in combination with ZA, prolongs survival in animal models.

Use of bisphosphonates for the treatment of stress fractures in athletes

A literature review was performed to investigate the potential role of bisphosphonates for the treatment of stress fractures in athletes. Given the inhibitory action on osteoclast-mediated bone resorption, short-term suppression of bone remodeling using bisphosphonates could potentially treat stress fractures and prevent stress fractures from becoming regular fractures. To date, while there are some animal studies showing the scientific basis of bisphosphonates on stress fractures, there is still no conclusive evidence to prove any effect of bisphosphonates on stress fracture healing in humans. Further well-designed clinical trials should be carried out to establish their usefulness and safety. Until the results are available, it is prudent to limit the use of bisphosphonates for the treatment of stress fractures.

Randomized phase II trial of denosumab in patients with bone metastases from prostate cancer, breast cancer, or other neoplasms after intravenous bisphosphonates

PURPOSE

Patients with bone metastases and elevated urinary N-telopeptide (uNTx), representing excessive bone resorption, are at increased risk for skeletal-related events (SREs), cancer progression, and death. Osteoclast-mediated bone resorption is regulated by RANKL. We evaluated the effect of denosumab, a fully human monoclonal antibody against RANKL, in patients with bone metastases and elevated uNTx levels despite ongoing intravenous (IV) bisphosphonate (BP) therapy.

PATIENTS AND METHODS

Eligible patients had histologically confirmed malignancy, > or = 1 bone metastases, and uNTx levels higher than 50 nmol/L bone collagen equivalents (BCE)/mM creatinine despite IV BPs. They were stratified by tumor type and screening uNTx levels (50 to 100 or > 100 nmol/L BCE/mM creatinine), and randomly assigned to continue IV BPs every 4 weeks or receive subcutaneous denosumab 180 mg every 4 weeks or every 12 weeks.

RESULTS

Among 111 patients accrued, the primary end point of uNTx levels lower than 50 nmol/L BCE/mM creatinine (uNTx < 50) at week 13 was achieved by 49 (71%) of 69 patients in the denosumab arms, compared with 10 (29%) of 35 patients in the IV BP arm (P < .001). The proportion of patients with uNTx lower than 50 was maintained at week 25 (64% denosumab arms; 37% IV BP arm; P = .01). The incidence of SREs was six (8%) of 73 and six (17%) of 35 in the denosumab group and IV BP group, respectively. Rates of adverse events were similar between treatment groups.

CONCLUSION

Among patients with elevated uNTx despite ongoing IV BP therapy, denosumab normalized uNTx levels more frequently than the continuation of IV BP. Fewer patients receiving denosumab experienced on-study SREs than those receiving IV BPs.

Metastatic bone pain: treatment options with an emphasis on bisphosphonates

INTRODUCTION

One of the key targets for metastatic cancer cells is the skeleton. Once metastatic cells are established within the bone matrix, skeletal integrity becomes increasingly compromised. Bone lesions lead to various complications, including bone pain, fractures and spinal cord compression.

MECHANISMS OF BONE PAIN

Bone pain is debilitating and affects quality of life of the patient. In addition, it increases the use of health care resources. Many patients with metastatic bone disease experience substantial bone pain despite state-of-the-art systemic analgesic treatment. Incident pain is the predominant pain syndrome.

TREATMENT OPTIONS FOR BONE PAIN

Typically, this syndrome requires moderate baseline analgesia with increased on-demand doses. Other techniques for treating bone pain, including radiation therapy, neuraxial application of analgesics, nerve blocks and local stabilisation procedures, should be considered. In addition, therapy with bisphosphonates targeting bone-specific pain is an important strategy. This review discusses the various management options for bone pain arising from metastatic bone disease.

Management of breakthrough pain in patients with cancer

Breakthrough pain (BTP) in patients with cancer lacks a consensus definition and is subsequently inadequately diagnosed and assessed, therefore making it more challenging to manage. Cancer pain is generally moderate to severe in intensity and persistent in nature. Despite the problematic definition of BTP, it is generally described as having similar intensity, but may also be transitory and variable in predictability. Most breakthrough analgesia fails to be effective in the time required for BTP. No useful analgesia is therefore provided but drug adverse effects escalate. Cancer pain management relies on the WHO analgesic ladder. The frequency of BTP and its inadequate management means that it has significant adverse effects on patients, their families and those involved in their care. This article outlines a systematic, clinical and evidence-based approach to managing BTP in patients with cancer that emphasizes a holistic approach and an understanding of multidimensional 'total pain'. Guidelines for managing BTP are presented and areas of developing research are identified.

Guidance on the use of bisphosphonates in solid tumours: recommendations of an international expert panel

Bisphosphonates (BP) prevent, reduce, and delay cancer-related skeletal complications in patients, and have substantially decreased the prevalence of such events since their introduction. Today, a broad range of BP with differences in potency, efficacy, dosing, and administration as well as approved indications is available. In addition, results of clinical trials investigating the efficacy of BP in cancer treatment-induced bone loss (CTIBL) have been recently published. The purpose of this paper is to review the current evidence on the use of BP in solid tumours and provide clinical recommendations. An interdisciplinary expert panel of clinical oncologists and of specialists in metabolic bone diseases assessed the widespread evidence and information on the efficacy of BP in the metastatic and nonmetastatic setting, as well as ongoing research on the adjuvant use of BP. Based on available evidence, the panel recommends amino-bisphosphonates for patients with metastatic bone disease from breast cancer and zoledronic acid for patients with other solid tumours as primary disease. Dosing of BP should follow approved indications with adjustments if necessary. While i.v. administration is most often preferable, oral administration (clodronate, IBA) may be considered for breast cancer patients who cannot or do not need to attend regular hospital care. Early-stage cancer patients at risk of developing CTIBL should be considered for preventative BP treatment. The strongest evidence in this setting is now available for ZOL. Overall, BP are well-tolerated, and most common adverse events are influenza-like syndrome, arthralgia, and when used orally, gastrointestinal symptoms. The dose of BP may need to be adapted to renal function and initial creatinine clearance calculation is mandatory according to the panel for use of any BP. Subsequent monitoring is recommended for ZOL and PAM, as described by the regulatory authority guidelines. Patients scheduled to receive BP (mainly every 3-4 weeks i.v.) should have a dental examination and be advised on appropriate measures for reducing the risk of jaw osteonecrosis. BP are well established as supportive therapy to reduce the frequency and severity of skeletal complications in patients with bone metastases from different cancers.

On the horizon: can bisphosphonates prevent bone metastases?

Skeletal complications of bone metastases increase the risk of death and undermine patients' functional independence and quality of life. Although bisphosphonates are integral in the treatment regimen of patients with metastatic bone disease and have demonstrated efficacy in delaying the onset and reducing the incidence of skeletal-related events, there is great interest in developing treatments to prevent metastasis to bone. Emerging evidence indicates that the potential benefits of bisphosphonate therapy extend beyond the treatment of metastatic bone lesions. Data from preclinical studies suggest that bisphosphonates may have antitumour activity and may prevent bone metastasis. The mechanisms of these antitumour effects are currently under investigation and may include induction of apoptosis, inhibition of tumour cell invasion and angiogenesis, and tumour growth reduction. Therefore, patients with early-stage disease may benefit from early bisphosphonate therapy, before bone metastasis develops, and investigations are ongoing to determine the clinical utility of bisphosphonates in this setting.

Bisphosphonates for bone metastatic disease from breast cancer: clinical practice in the Czech Republic

BACKGROUND

The use of bisphosphonates (BPs) represents a standard therapy of bone metastatic disease from breast cancer and has been incorporated in many systemic international guidelines. We have tried to evaluate the use of BPs in current clinical practice across the Czech Republic.

PARTICIPANTS AND METHODS

A covering letter, questionnaires and pre-paid envelopes were mailed to the head oncologists of 64 workplaces of Czech Oncology Society. Total 310 questionnaires were sent out. The questionnaire consisted of 23 questions.

RESULTS

The questionnaires were completed and returned by 91 oncologists from 32 workplaces. Most of the responding oncologists worked at university hospitals (42%), the most frequent length of work experience was 5 to 10 years (30%) and the most frequent rate of breast cancer patients was from 10 to 25% (45%). Ninety-five percent of the oncologists regularly initiated BP therapy, and oral clodronate was the first choice BP (77%). Once initiated, the treatment was discontinued in less than 5% patients (24%). Seventy-one (79%) oncologists stated that the most important reason leading to therapy termination was impairment of performance status.

CONCLUSIONS

The consensual agreement pointed out that it could be a fundamental step towards establishing the national treatment guidelines for the BP use in metastatic breast cancer patients.

Biochemical markers of bone turnover in diagnosis of myeloma bone disease

This study was designed to explore the value of markers of bone turnover, macrophage inflammatory protein-1alpha (MIP-1alpha), and osteopontin (OPN) in the diagnosis of myeloma bone disease. Twenty-five patients with newly diagnosed and untreated multiple myeloma (MM), and 22 age-, sex-, and bone mineral density-matched control subjects were enrolled. Levels of MIP-1alpha, OPN, carboxy-terminal telopeptide of Type-1 collagen (C-telopeptide or Ctx), deoxypyridinoline (DPD), Type-1 collagen propeptide (T1Pro), and bone-specific alkaline phosphatase (BALP) were assessed in both groups. Twenty-two of the patients had bone involvement documented by skeletal surveys and lumbar spinal magnetic resonance imaging. Levels of serum Ctx, OPN, MIP-1alpha, and urine DPD were significantly higher in MM patients with bone disease than in controls (P<0.01). Serum Ctx levels were elevated in 90.9% of patients with MM and 40.9% of controls (P<0.001). Urine DPD levels were elevated in 90.4% of the patients and 31.8% of the controls (P<0.001). The serum OPN and MIP-1alpha levels of the patients were significantly correlated with beta2-microglobulin and lactate dehydrogenase levels (P<0.05). Our study indicates that Ctx and DPD are sensitive markers of bone disease in MM, and higher than normal values suggest presence of bone disease rather than benign osteoporosis in MM. The utility of OPN and MIP-1alpha needs to be further investigated.

Chirurgisches Management von Wirbelsäulenmetastasen

The spine is the most frequent site of skeletal metastases. Among all spinal malignancies metastatic disease is most frequent and indicative of disseminating tumor disease. Depending on primary tumor entity, estimated survival time, general health status of the patient, presence of spinal instability and neurological deficits an oncological useful and patient-specific therapeutic intervention should be performed. New anterior approaches, resections and reconstruction techniques are making surgery a preferred method over radiation therapy. For differential indication of the multiple surgical treatment modalities prognostic scores are available to assist individual decision making. Indications for surgery include survival prognosis of minimum 3 months, intractable pain, progress of myelon compression and/or neurological deficits under radiochemotherapy, spinal instability and necessity for histological diagnosis. Resulting quality of life depends on efficient decompression of the spinal cord and restoration of spinal stability. To achieve these ultimate goals there are different anterior and posterior approaches, instrumentations and vertebral body replacement implants available. Preoperative embolization should be performed in hypervascular tumors, e.g., renal cell cancer. Vertebro-/Kyphoplasty as a percutaneous intervention should be considered for painful multisegmental disease and symptomatic osteolysis without epidural tumor compression to reach analgesia and stability. A multidisciplinary approach in patient selection, decision making and management is an essential precondition for complication avoidance and acceptable quality of life.

Ibandronate for the treatment of hypercalcemia or nephrocalcinosis in patients with multiple myeloma and acute renal failure: Case reports

Multiple myeloma disrupts calcium homeostasis by a variety of mechanisms, including bone destruction and resorption. This causes hypercalcemia. When left untreated, hypercalcemia leads to nephrocalcinosis, impairment of kidney function, and eventually renal failure. Some degree of renal dysfunction is common in myeloma patients. Here, we report case studies showing the efficacy and renal safety of the single-nitrogen bisphosphonate, ibandronate, for the treatment of hypercalcemia and/or nephrocalcinosis in multiple myeloma patients hospitalized with acute renal failure. Patients (n = 7) received either one or two intravenous infusions of ibandronate (2-6 mg). Ibandronate was well tolerated in all patients and returned elevated blood calcium levels to normal. Renal function improved for all patients and normalized in 3/7 patients. We conclude that ibandronate is involved in rapidly improving or restoring acute renal function and calcium levels to within the normal range in this patient population. To clarify the exact value of ibandronate, further investigation is warranted in randomized prospective trials.

Intravenous ibandronate does not affect time to renal function deterioration in patients with skeletal metastases from breast cancer: phase III trial results

As patients with metastatic bone disease typically receive long-term treatment with bisphosphonates, and often antineoplastic compounds, drug-related safety is of considerable importance. Clinical trial data for intravenous (i.v.) ibandronate suggest that its nephrotoxic potential is comparable with placebo. We conducted a post hoc Kaplan-Meier analysis of time to serum creatinine increase with i.v. ibandronate throughout 2 years of treatment. After 96 weeks, 12% of patients in the placebo group and 6% in the ibandronate 6 mg group (ns, P = 0.22) had defined serum creatinine increases. After 12 treatment months (48 weeks), 4% of patients receiving placebo and 2% of patients receiving ibandronate 6 mg showed increased serum creatinine. These results suggest that there is no clinically relevant change in serum creatinine levels with i.v. ibandronate 6 mg infused every 3-4 weeks for 2 years. Comparative trials to examine the renal safety of ibandronate and other i.v. bisphosphonates are warranted.

Administration of bisphosphonate for hypercalcemia associated with oral cancer

BACKGROUND

The efficacy of treating hypercalcemia with bisphosphonate (BP) in patients with advanced oral cancer has not been fully investigated. This retrospective study evaluated the clinical course of hypercalcemic patients with and without BP treatment.

METHODS

Sixteen hypercalcemic patients, most of whom had uncontrollable locoregional lesions and lung metastases, were studied. Nine patients had been given BP, and the rest had not.

RESULTS

There were significant differences in age and serum ALT between the BP-treated and -untreated groups. The first administration of BP effectively and safely decreased the serum calcium level, but repeated administrations were less effective. Although the patients treated with BP survived significantly longer than the untreated subjects, the difference of the median was only about 2 weeks.

CONCLUSION

The occurrence of hypercalcemia in oral cancer patients apparently implies an extremely poor prognosis, and long-term survival cannot be expected, even with BP treatment.

Bisphosphonates for malignancy-related bone disease: current status, future developments

This review relates to the efficacy and safety of bisphosphonates in metastatic bone disease. It discusses practical recommendations and possible future indications for bisphosphonate therapy. The current aims of bisphosphonates for metastatic bone disease are to prevent skeletal-related events (SREs), reduce bone pain and improve quality of life. Phase III clinical trials of clodronate and pamidronate have established their efficacy against bone complications in patients with breast cancer and multiple myeloma, while randomized trials have shown SRE reductions with zoledronic acid in patients with breast cancer and multiple myeloma, prostate cancer, and lung and other solid tumors. These bisphosphonates also have some effect on metastatic bone pain. Ibandronate is a new aminobisphosphonate, available in more than 40 countries outside of the US as intravenous and oral formulations for the prevention of skeletal events in patients with breast cancer and bone metastases. Phase III studies have shown that both intravenously and orally administered ibandronate have efficacy for the prevention of skeletal events and for the reduction of metastatic bone pain. In addition to efficacy, the long-term tolerability of bisphosphonates in metastatic bone disease influences drug selection. Besides their use in patients with established bone metastases, recent and ongoing research suggests that bisphosphonates also have clinical benefit in the adjuvant setting, and for the treatment of cancer-treatment-induced bone loss. Such interesting new developments may underpin a new era of bisphosphonate use sometime in the near future.

Effective and rapid treatment of painful localized transient osteoporosis (bone marrow edema) with intravenous ibandronate

Localized transient osteoporosis (LTO; bone marrow edema syndrome) is a rare disorder of generally unknown etiology that is characterized by acute onset of disabling bone pain. Treatment options are currently limited and largely ineffective. The locally increased bone turnover and low bone mineral density (BMD) typical of LTO indicate a potential role for bisphosphonate therapy. Ibandronate, a potent nitrogen-containing bisphosphonate, has proven efficacy in the management of postmenopausal osteoporosis and corticosteroid-induced osteoporosis when administered as a convenient intermittent intravenous (i.v.) injection with a between-dose interval of 2 or 3 months. In a study of 12 patients with LTO, ibandronate was administered as an initial 4-mg i.v. dose with a second, optional injection of 2 mg at 3 months. Daily calcium and vitamin D supplements were provided. Pain was measured at baseline and at 1, 2, 3, and 6 months using a visual analog scale (VAS) of 1-10, and BMD was measured at baseline and 6 months. I.v. ibandronate provided rapid and substantial pain relief. The mean (SD) VAS score decreased from 8.4 (1.3) at baseline to 0.5 (0.7) at 6 months, at which time seven patients had achieved complete pain relief. At 6 months, mean lumbar spine BMD had increased by 4.0% (range -0.8 to 7.7%) in the overall population. I.v. ibandronate injection affords advantages over currently available oral and i.v. bisphosphonates and thus offers a promising therapeutic advance in the treatment of LTO.

High dosage treatment of nitrogen-containing bisphosphonate ibandronate is required for osseointegration of cementless metal implants

BACKGROUND

There is evidence that application of a bisphosphonate can improve fixation of cementless metal implants by enhancing the extent of osseointegration, but the required dose regimen is still under discussion. The current preclinical study was designed to determine the optimal treatment dose of the nitrogen-containing bisphosphonate ibandronate to improve osseointegration of cementless metal implants.

METHODS

The study was conducted in 52 female Sprague-Dawley rats in which uncoated and hydroxyapatite-coated titanium implants were surgically inserted into the medullary canal of each femur. The animals were randomly assigned to receive subcutaneous treatment with ibandronate 1 microg/kg body weight (osteoporosis dose) or 25 microg/kg (tumor dose) per day or saline solution for control.

RESULTS

Histomorphometric evaluation revealed a significant enhanced extent of osseointegrated implant surface in the high-dose treatment group for both implants compared to the low-dose group and the control group. No significant differences were observed between the two implants in any group.

CONCLUSIONS

The results of the present study indicate that improved osseointegration of hydroxyapatite-coated and uncoated titanium implants is dose-dependent and requires high-dose application of bisphosphonate ibandronate equivalent to that needed to treat patients with tumor disease. Lower doses equivalent to those for treatment of osteoporosis showed no beneficial effect.

Preclinical Perspectives on Bisphosphonate Renal Safety

Renal insufficiency is not rare in cancer patients who may receive nephrotoxic medications as antineo-plastic agents or for comorbid conditions. Thus, the choice of a particular bisphosphonate for patients with metastatic bone disease should be based not only on efficacy but also on the risk for renal deterioration. Some i.v. bisphosphonates have been associated with occasional renal toxicity in the clinical setting. Preclinical studies have also shown that there may be considerable differences among bisphosphonate renal safety profiles. Comparative studies show variations in the risk for histopathologic damage and the ability to cause cumulative toxicity during intermittent dosing. Reasons for the differences among bisphosphonates are not fully understood; however, research shows that they may be influenced by pharmacokinetic properties such as renal tissue half-life or protein binding and intracellular potency. Further preclinical analyses are needed to confirm and evaluate differences among bisphosphonates.

Diagnosis and treatment of vertebral column metastases

The vertebral column is recognized as the most common site for bony metastases in patients with systemic malignancy. Patients with metastatic spinal tumors may present with pain, neurologic deficit, or both. Some tumors are asymptomatic and are detected during screening examinations. Treatment options include medical therapy, surgery, and radiation. However, diversity of patient condition, tumor pathology, and anatomical extent of disease complicate broad generalizations for treatment. Historically, surgery was considered the most appropriate initial therapy in patients with spinal metastasis with the goal of eradication of gross disease. However, such an aggressive approach has not been practical for many patients. Now, operative intervention is often palliative, with pain control and maintenance of function and stability the major goals. Surgery is reserved for neurologic compromise, radiation failure, spinal instability, or uncertain diagnosis. Recent literature has revealed that surgical outcomes have improved with advances in surgical technique, including refinement of anterior, lateral, posterolateral, and various approaches to the anterior spine, where most metastatic disease is located. We review these surgical approaches for which a team of surgeons often is needed, including neurosurgeons and orthopedic, general, vascular, and thoracic surgeons. Overall, a multimodality approach is useful in caring for these patients. It is important that clinicians are aware of the various therapeutic options and their indications. The optimal treatment of individual patients with spinal metastases should include consideration of their neurologic status, anatomical extent of disease, general health, age, and qualilty of life.

Controversies in pharmacotherapy of pain management

Since the establishment of the WHO three-step ladder for management of cancer pain, several controversies have arisen, which are partly due to new drug development, reformulations of older analgesics, and technological advancements. As a result, clinicians need clarification of several questions. Is morphine the opioid of choice for moderate to severe pain in cancer? Should combinations of opioids be used? When should spinal opioids be used to treat pain in cancer? What are the appropriate opioid doses for breakthrough pain? Should selective cyclo-oxygenase (COX) 2 inhibitors be used? What is the best tactic to treat neuropathic pain, and what first-line adjuvant analgesic should be used? And do bisphosphonates relieve bone pain in cancers other than breast cancer and myeloma? This review addresses these questions.

Approaches to managing bone metastases from breast cancer: The role of bisphosphonates

Conventional management of metastatic bone disease involves local and systemic therapies in various combinations, along with symptomatic management to provide optimal care. In recent years, it has become clear that adding bisphosphonates to these treatments reduces the incidence and severity of skeletal complications. Bisphosphonates can also relieve metastatic bone pain and improve quality of life, although the extent to which they have demonstrated these effects may differ between agents. While bisphosphonates are the standard of care for the treatment of bone metastases, clinical trials are investigating additional indications for these agents, including the use of intensive dosing regimens for the relief of severe or opioid-resistant metastatic bone pain and adjuvant treatment for the prevention of bone metastases and cancer treatment-induced bone loss. Current and future indications demand effective, well-tolerated and convenient bisphosphonates, and the benefits of different drugs must be balanced against their limitations. The cost-effectiveness of bisphosphonate treatment is also a consideration, given the high economic burden of metastatic bone disease from breast cancer.

Monitoring of skeletal progression of prostate cancer by GFP imaging, X-ray, and serum OPG and PTHrP

BACKGROUND

Prostate cancers (PCas) produce factors that can serve as biomarkers for tumor metastasis and bone progression. Transduced GFP expression by cancer cells can be imaged to monitor therapy. We exploited both concepts by developing a GFP-expressing PCa cell line that expresses PTHrP and studying it in an animal model of malignancy with methods that assess the skeletal progression of this tumor.

METHODS

We developed a GFP-producing PCa cell line by stable transduction of PC-3 PCa cells. This PC-3 variant was used to study tumor progression in an immunocompromised mouse model. Skeletal progression of the PCa cells and the effects of pamidronate administration were evaluated radiologically, fluorometrically, and by measurement of serum tumor markers.

RESULTS

The PC-3 cells produced extensive bone lesions when injected into the tibia of immunocompromised mice. The skeletal progression of the PC-3 cells could be monitored by GFP optical imaging, X-ray, and by measurements of tumor products in serum, notably PTHrP and OPG. Pamidronate treatment reduced tumor burden as assessed at autopsy by imaging and biomarkers.

CONCLUSIONS

Pamidronate treatment exhibited anti-tumor effects that were reflected by decreases in serum PTHrP, OPG, and by GFP and radiological imaging procedures. Imaging of GFP expression enables real-time monitoring of tumor growth in the bone. PTHrP and OPG may be useful as tumor biomarkers for PCa that has metastasized to bone. This novel human PCa model can be used to study the clinical potential of diagnostic and therapeutic modalities in the skeletal progression of PCas.

Ibandronate: a clinical pharmacological and pharmacokinetic update

Ibandronate is a potent nitrogen-containing bisphosphonate. It has a strong affinity for bone mineral and potently inhibits osteoclast-mediated bone resorption. Ibandronate is effective for the treatment of hypercalcemia of malignancy, metastatic bone disease, postmenopausal osteoporosis, corticosteroid-induced osteoporosis, and Paget's disease. Oral ibandronate is rapidly absorbed (t(max) < 1 hour), with a low bioavailability (0.63%) that is further reduced (by up to 90%) in the presence of food. Ibandronate has a wide therapeutic index and is not metabolized and, therefore, has a low potential for drug interactions. Given its metabolic stability, ibandronate is eliminated from the blood by partitioning into bone (40%-50%) and through renal clearance (CL(R) approximately 60 mL/min). The CL(R) of ibandronate is linearly related to creatinine clearance. The sequestration of ibandronate in bone (V(D) > 90 L) results in a multiphasic elimination (t((1/2)) range approximately 10-60 hours), characterized by the slow release of ibandronate from the bone compartment. The potency of ibandronate and its sequestration into bone allow ibandronate to be developed as oral and intravenous injection formulations that can be administered with convenient extended between-dose intervals.

Efficacy and Safety of Ibandronate in the Treatment of Opioid-Resistant Bone Pain Associated With Metastatic Bone Disease: A Pilot Study

Purpose

Bone metastases are associated with severe and sometimes intractable pain, compromising patient quality of life (QOL). This open-label pilot study investigated the effects of short-term intensive treatment with intravenous (IV) ibandronate on opioid-resistant bone pain in patients with skeletal metastases.

Patients and Methods

Eighteen patients with advanced tumors and metastatic bone disease received nonstandard treatment with 4 mg of ibandronate administered IV (2-hour infusion) for 4 consecutive days (16-mg total dose). Baseline opioid analgesic use was equivalent to 400 mg/d of morphine. Patients were assessed for 6 weeks or until death. Changes from baseline were determined for bone pain, opioid consumption, patient functioning, QOL, performance status, and biochemical markers of calcium metabolism and bone turnover. Renal function was assessed by serum urea and creatinine measurement.

Results

Short-term, intensive ibandronate treatment significantly reduced bone pain scores within 7 days (P < .001). Pain reductions were sustained over the study period. Ibandronate significantly improved QOL, patient functioning, and performance status (P < .05). Mean values of the urinary cross-links pyridinoline and deoxypyridinoline tended to increase after day 21, returning close to baseline values by day 42. There was no correlation between the change in crosslinks values and the change in pain scores after ibandronate treatment. Ibandronate was well tolerated, with no evidence of renal toxicity.

Conclusion

Nonstandard, intensive treatment with IV ibandronate seems to have a marked analgesic effect in patients with opioid-resistant bone pain from metastatic bone disease. Further investigation is warranted.

Bisphosphonate use for the management of breast cancer patients with bone metastases: a survey of Canadian Medical Oncologists

BACKGROUND

The use of bisphosphonates (BP) in breast cancer patients with bone metastases (BM) has been shown to reduce bone pain and lower the risk of skeletal-related events (SREs). Many practice guidelines exist for the use of BPs in patients with BM. Unfortunately, none clearly address whether the benefits of BP use apply equally to all subgroups of patients, the duration of therapy, and when to discontinue BP therapy. A questionnaire was therefore developed and administered to determine how medical oncologists in Canada use BPs in clinical practice.

METHODS

A structured mailing strategy was adopted. The population consisted of 100 medical oncologists with active breast cancer practices in Canada. All regions of Canada were represented. The questionnaire was developed to capture data on respondent demographics, BPs used, major factors influencing decision making, and clinical practice in situations where there is a lack of high-quality data.

RESULTS

Completed questionnaires were returned by 76 medical oncologists. All treated breast cancer and the majority (68%) were based at teaching hospitals. Ninety-six percent of respondents regularly prescribed BPs, initiating therapy at the time the patient presented with BM. Although 79% of respondents recognized that there was no clear data to support the continued use of BP after bony progression, 53% stated that they rarely or never discontinue a BP once started. In situations where a BP was discontinued, the majority of respondents report the reason for discontinuation was a decrease in patient performance status. In the patient with clearly progressive visceral metastases and an estimated prognosis of less than 6 months, 75% of respondents would still commence BP therapy.

CONCLUSIONS

This study confirms that most medical oncologists in Canada, while acknowledging lack of evidence, maintain patients on BP therapy when patients have an expected survival of less than 6 months or even after patients progress while on a BP. More research is needed to determine the role of continuing, switching, or discontinuing BP therapy in the context of disease progression or shortened expected survival.