Zoledronic acid: a pharmacoeconomic review of its use in the management of bone metastases

Hyaluronic acid-covered ferric ion-rich nanobullets with high zoledronic acid payload for breast tumor-targeted chemo/chemodynamic therapy

Due to the heterogeneity of the tumor microenvironment, the clinical efficacy of tumor treatment is not satisfied, highlighting the necessity for new strategies to tackle this issue. To effectively treat breast tumors by tumor-targeted chemo/chemodynamic therapy, herein, the Fe3+-rich MIL-88B nanobullets (MNs) covered with hyaluronic acid (HA) were fabricated as vehicles of zoledronic acid (ZA). The attained ZA@HMNs showed a high ZA payload (ca 29.6 %), outstanding colloidal stability in the serum-containing milieu, and accelerated ZA as well as Fe3+ release under weakly acidic and glutathione (GSH)-rich conditions. Also, the ZA@HMNs consumed GSH by GSH-mediated Fe3+ reduction and converted H2O2 into OH via Fenton or Fenton-like reaction with pH reduction. After being internalized by 4T1 cells upon CD44-mediated endocytosis, the ZA@HMNs depleted intracellular GSH and degraded H2O2 into OH, thus eliciting lipid peroxidation and mitochondria damage to suppress cell proliferation. Also, the ZA@HMNs remarkably killed macrophage-like RAW 264.7 cells. Importantly, the in vivo studies and ki67 and GPX4 staining of tumor sections demonstrated that the ZA@HMNs efficiently accumulated in 4T1 tumors to hinder tumor growth via ZA chemotherapy combined with OH-mediated ferroptosis. This work presents a practicable strategy to fabricate ZA@HMNs for breast tumor-targeted chemo/chemodynamic therapy with potential clinical translation.

Geranylgeraniol Application in Human Osteoblasts and Osteoclasts for Reversal of the Effect of Bisphosphonates

Nitrogen-containing bisphosphonates lead to the depletion of geranylgeranyl pyrophosphate involved in the mevalonate pathway. The effect of geranylgeraniol (GGOH) on human osteoblast and osteoclast activities suppressed by zoledronate was investigated in this study. The effect of GGOH on human osteoblasts and osteoclasts subjected to treatment with zoledronate was analyzed by assessing cell viability, osteoclast differentiation, resorption ability, gene expression, and protein synthesis. Cell viability suppressed by bisphosphonates in osteoblasts and osteoprogenitor cells was restored with GGOH. Osteoclast differentiation was analyzed by vitronectin receptor immunofluorescence staining, and the addition of GGOH to zoledronate significantly increased osteoclast differentiation compared with zoledronate alone. A trend of reversal of osteoclast resorption by GGOH was observed; however, it was not significant in all groups. The expression of ALP, type 1 collagen, and RUNX2 in osteoblasts was recovered by the addition of GGOH. Only CALCR expression in osteoclasts was significantly recovered by GGOH addition in the zoledronate group. Although the activities of osteoblasts and osteoclasts were not entirely restored, the possibility that the topical application of GGOH in MRONJ patients or patients with dental problems and bisphosphonates might lessen the risk of development and recurrence of MRONJ is shown.

Tumor acidity-responsive polymeric nanoparticles to promote intracellular delivery of zoledronic acid by PEG detachment and positive charge exposure for enhanced antitumor potency

Zoledronic acid (ZA), a third-generation bisphosphonate, has been extensively used to treat osteoporosis and cancer bone metastasis and demonstrated to suppress proliferation of varied cancer cells and selectively kill tumor-associated...

A cost-effectiveness analysis of denosumab for the prevention of skeletal-related events in patients with multiple myeloma in the United States of America

OBJECTIVE

A large, pivotal, phase 3 trial in patients with newly diagnosed multiple myeloma (MM) demonstrated that denosumab, compared with zoledronic acid, was non-inferior for the prevention of skeletal-related events (SREs), extended the observed median progression-free survival (PFS) by 10.7 months, and showed significantly less renal toxicity. The cost-effectiveness of denosumab vs zoledronic acid in MM in the US was assessed from societal and payer perspectives.

METHODS

The XGEVA Global Economic Model was developed by integrating data from the phase 3 trial comparing the efficacy of denosumab with zoledronic acid for the prevention of SREs in MM. SRE rates were adjusted to reflect the real-world incidence. The model included utility decrements for SREs, administration, serious adverse events (SAEs), and disease progression. Drug, administration, SRE management, SAEs, and anti-MM treatment costs were based on data from published studies. For the societal perspective, the model additionally included SRE-related direct non-medical costs and indirect costs. The net monetary benefit (NMB) was calculated using a willingness-to-pay threshold of US$150,000. One-way deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

From a societal perspective, compared with zoledronic acid, the use of denosumab resulted in an incremental cost of US$26,329 and an incremental quality-adjusted life-year (QALY) of 0.2439, translating into a cost per QALY gained of US$107,939 and a NMB of US$10,259 in favor of denosumab. Results were sensitive to SRE rates and PFS parameters.

LIMITATIONS

Costs were estimated from multiple sources, which varied by tumor type, patient population, country, and other parameters. PFS and overall survival were extrapolated beyond the follow-up of the primary analysis using fitted parametric curves.

CONCLUSION

Denosumab's efficacy in delaying or preventing SREs, potential to improve PFS, and lack of renal toxicity make it a cost-effective option for the prevention of SREs in MM compared with zoledronic acid.

Treatment of Osteonecrosis of the Jaw (ONJ) by Medical Ozone Gas Insufflation. A Case Report

Osteonecrosis of the jaw (ONJ) is an adverse event reported in patients receiving cancer treatment, especially bisphosphonates and denosumab. A patient with multiple myeloma who underwent up to 22 intravenous zoledronic acid infusions without previous dental examination developed a devastating ONJ lesion in the right horizontal mandibular ramus. He was treated with local ozone gas applications every third day by means of a special bell to avoid O3 diffusion. Azithromycin 500 mg/day was administered for 10 days prior to the O3 applications. O3 therapy resulted in sequestration of the necrotic bone after a median of 15 applications, following which surgery was necessary to remove it. Interestingly, removal was possible without the resection of the healthy mandible edge because of the presence of the bone sequestrum. Medical O3 gas administration was effective and safe in a patient treated with bisphosphonates who developed a >2.5 cm ONJ lesion. Future research is needed to demonstrate the efficacy and tolerability of such treatment in a larger number of patients.

Metastatic Bone Disease in the Era of Bone-Targeted Therapy: Clinical Impact

Advances in the diagnosis and treatment of tumors by surgery, chemotherapy, biotherapy, radiotherapy and other modalities have increased the survival of cancer patients over the last 20 years. As a consequence, bone now represents the third most common site of metastatic involvement after the lung and liver. Approximately 20–25% of patients with neoplastic disease develop clinically evident bone metastases (BMs) during the natural course of their illness, with a further 50% of such lesions being identified during autopsy. BMs are the major cause of morbidity in cancer patients because of their epidemiological and clinical impact. Pain is the most frequent symptom in about 75% of patients but other serious complications can also occur, such as pathological fractures, spinal cord compression, hypercalcemia and bone marrow suppression. These complications worsen the patient's general condition and reduce patients’ mobility, facilitating the development of lung infections, skin ulcers, deep vein thrombosis, etc., and ultimately reducing prognosis and quality of life. The frequency of serious complications depends on the site and type of lesions and the treatment administered. Over the last 10 years, the introduction of bisphosphonates for the treatment of patients with BMs has led to a marked decrease in the frequency of complications, thus improving quality of life and clinical outcome. Furthermore, progress in understanding the pathophysiology of bone metastases has resulted in the development of new bone-targeted molecules such as denosumab. We therefore felt it would be useful to report on the epidemiological, clinical and economic impact of bone disease in a cancer setting.

Care of cancer patients with liver and bone metastases - the place of pharmaceutical care in a balanced plan, focused on the patient's needs and goals

Metastatic cancer, especially in the growing population of geriatric patients, presents a big challenge to these patients, as well as to treatment teams and the entire health care system. This article describes some common medical problems faced by patients with metastases to liver and bone, and presents a diagnostic approach, and therapeutic management of various symptoms, relevant to advanced stages of the malignant disease. The article highlights the importance of patient education on various aspects of metastatic cancer, and underscores the unique position of pharmacists practicing pharmaceutical care, which is particularly beneficial in this group of patients with advanced malignancy. Also, this paper emphasizes that achieving a proper balance between managing the malignant disease and maintaining the patients' quality of life, especially in the elderly population, should involve coordinated efforts of the oncology treatment team, primary care physicians, pharmacists, therapists and nurses, as well as patients, their families and caregivers.

Prostate cancer

Much progress has been made in research for prostate cancer in the past decade. There is now greater understanding for the genetic basis of familial prostate cancer with identification of rare but high-risk mutations (eg, BRCA2, HOXB13) and low-risk but common alleles (77 identified so far by genome-wide association studies) that could lead to targeted screening of patients at risk. This is especially important because screening for prostate cancer based on prostate-specific antigen remains controversial due to the high rate of overdiagnosis and unnecessary prostate biopsies, despite evidence that it reduces mortality. Classification of prostate cancer into distinct molecular subtypes, including mutually exclusive ETS-gene-fusion-positive and SPINK1-overexpressing, CHD1-loss cancers, could allow stratification of patients for different management strategies. Presently, men with localised disease can have very different prognoses and treatment options, ranging from observation alone through to radical surgery, with few good-quality randomised trials to inform on the best approach for an individual patient. The survival of patients with metastatic prostate cancer progressing on androgen-deprivation therapy (castration-resistant prostate cancer) has improved substantially. In addition to docetaxel, which has been used for more than a decade, in the past 4 years five new drugs have shown efficacy with improvements in overall survival leading to licensing for the treatment of metastatic castration-resistant prostate cancer. Because of this rapid change in the therapeutic landscape, no robust data exist to inform on the selection of patients for a specific treatment for castration-resistant prostate cancer or the best sequence of administration. Moreover, the high cost of the newer drugs limits their widespread use in several countries. Data from continuing clinical and translational research are urgently needed to improve, and, crucially, to personalise management.

Folate-targeted pH-responsive calcium zoledronate nanoscale metal-organic frameworks: Turning a bone antiresorptive agent into an anticancer therapeutic

Zoledronate (Zol) is a third-generation bisphosphonate that is widely used as an anti-resorptive agent for the treatment of cancer bone metastasis. While there is preclinical data indicating that bisphosphonates such as Zol have direct cytotoxic effects on cancer cells, such effect has not been firmly established in the clinical setting. This is likely due to the rapid absorption of bisphosphonates by the skeleton after intravenous (i.v.) administration. Herein, we report the reformulation of Zol using nanotechnology and evaluation of this novel nanoscale metal-organic frameworks (nMOFs) formulation of Zol as an anticancer agent. The nMOF formulation is comprised of a calcium zoledronate (CaZol) core and a polyethylene glycol (PEG) surface. To preferentially deliver CaZol nMOFs to tumors as well as facilitate cellular uptake of Zol, we incorporated folate (Fol)-targeted ligands on the nMOFs. The folate receptor (FR) is known to be overexpressed in several tumor types, including head-and-neck, prostate, and non-small cell lung cancers. We demonstrated that these targeted CaZol nMOFs possess excellent chemical and colloidal stability in physiological conditions. The release of encapsulated Zol from the nMOFs occurs in the mid-endosomes during nMOF endocytosis. In vitro toxicity studies demonstrated that Fol-targeted CaZol nMOFs are more efficient than small molecule Zol in inhibiting cell proliferation and inducing apoptosis in FR-overexpressing H460 non-small cell lung and PC3 prostate cancer cells. Our findings were further validated in vivo using mouse xenograft models of H460 and PC3. We demonstrated that Fol-targeted CaZol nMOFs are effective anticancer agents and increase the direct antitumor activity of Zol by 80-85% in vivo through inhibition of tumor neovasculature, and inhibiting cell proliferation and inducing apoptosis.

Administration of teriparatide improves the symptoms of advanced bisphosphonate-related osteonecrosis of the jaw: preliminary findings

Teriparatide is a synthetic polypeptide hormone that contains the 1-34 amino acid fragment of the recombinant human parathyroid hormone that stimulates bone formation. Currently, it is approved only for the treatment of osteoporosis. The outcomes of daily teriparatide injections for the treatment of bisphosphonate-related osteonecrosis of the jaw in 10 patients are reported here. Two of the 10 cases dropped out due to adverse events. Of the remaining eight cases, seven exhibited clinical improvement of the jaw-related symptoms of osteonecrosis and progression of the sequestration, while one case did not show improvement of the symptoms. Administration of teriparatide in patients with osteonecrosis of the jaw promotes bone formation and subsequent sequestration over a short period of time. These results suggest that adjunctive teriparatide therapy is a viable and effective option for treating osteonecrosis of the jaw.

Value of nonsurgical therapeutic management of stage I bisphosphonate-related osteonecrosis of the jaw

There is still controversy about the best treatment strategy for patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) stage I. Therefore, the aim of the present study was to analyse the effect of a nonsurgical treatment protocol in patients with BRONJ stage I. During the study period we included 17 patients (11 male; 6 female) who presented with a total of 24 separate areas of BRONJ, stage I. All patients were exclusively treated with a monthly intravenous regime of zoledronic acid due to an underlying malignant disease. All patients were treated using a standardized nonsurgical protocol consisting of antimicrobial mouth rinsing with chlorhexidine (CHX) (0.12%) three times a day, and daily CHX gel application. In 11 patients (45.8%) the surface area of the exposed jawbone was completely healed by nonsurgical treatment. In seven patients (29.2%), nonsurgical treatment reduced the size of the exposed bone area by a mean of 64.7% (range 20.0-96.8%). None of the patients showed an increase in size of the area of exposed jawbone, or a worsening of the BRONJ from stage I to stages II or III. However, the duration of nonsurgical treatment or the duration of intravenous bisphosphonate therapy did not significantly influence the treatment outcome (p = 0.6628, p = 0.6077, respectively). The results of the present study support the beneficial role of nonsurgical treatment in patients presenting with BRONJ stage I. Surgical therapy of BRONJ should be restricted to patients with advanced stages with clinical symptoms and local signs of infection.

Ossification and increased bone mineral density with zoledronic acid in a patient with lung adenocarcinoma: A case report

Cases of ossification and increased bone mineral density (BMD) at sites of bone metastasis following zoledronic acid (ZA) treatment have not been reported. The current study presents the case of a 65-year-old patient with lung adenocarcinoma and bone metastases in the lumbar vertebrae and femurs. Ossification and an increase in BMD at the metastatic sites was achieved following treatment with ZA and irradiation of the bone metastatic sites. The patient was able to maintain a normal lifestyle for over two years, despite the bone metastases. Therefore, as treatment with ZA was demonstrated to improve patient quality of life, physicians should consider this treatment strategy, particularly for the treatment of metastasis in weight-bearing bones.

Utilities associated with subcutaneous injections and intravenous infusions for treatment of patients with bone metastases

INTRODUCTION

Although cost-utility models are often used to estimate the value of treatments for metastatic cancer, limited information is available on the utility of common treatment modalities. Bisphosphonate treatment for bone metastases is frequently administered via intravenous infusion, while a newer treatment is administered as a subcutaneous injection. This study estimated the impact of these treatment modalities on health state preference.

METHODS

Participants from the UK general population completed time trade-off interviews to assess the utility of health state vignettes. Respondents first rated a health state representing cancer with bone metastases. Subsequent health states added descriptions of treatment modalities (ie, injection or infusion) to this basic health state. The two treatment modalities were presented with and without chemotherapy, and infusion characteristics were varied by duration (30 minutes or 2 hours) and renal monitoring.

RESULTS

A total of 121 participants completed the interviews (52.1% female, 76.9% white). Cancer with bone metastases had a mean utility of 0.40 on a standard utility scale (1 = full health; 0 = dead). The injection, 30-minute infusion, and 2-hour infusion had mean disutilities of -0.004, -0.02, and -0.04, respectively. The mean disutility of the 30-minute infusion was greater with renal monitoring than without. Chemotherapy was associated with substantial disutility (-0.17). When added to health states with chemotherapy, the mean disutilities of injection, 30-minute infusion, and 2-hour infusion were -0.02, -0.03, and -0.04, respectively. The disutility associated with injection was significantly lower than the disutility of the 30-minute and 2-hour infusions (P < 0.05), regardless of chemotherapy status.

CONCLUSION

Respondents perceived an inconvenience with each type of treatment modality, but injections were preferred over infusions. The resulting utilities may be used in cost-utility models examining the value of treatments for the prevention of skeletal-related events in patients with bone metastases.

Reducing the burden of bone metastases: current concepts and treatment options

BACKGROUND

Bone metastases occur frequently in patients with solid tumours such as those of the prostate, breast and lung, and are associated with an increased risk of skeletal-related events (SREs). This article reviews the personal, social and economic burdens of bone metastases and SREs, and approaches to treatment.

METHODS

PubMed searches were conducted using a broad range of search terms. Articles identified were refined by author review of abstracts. Additional material was identified by searching recent relevant congress abstracts.

RESULTS

Bone metastases often decrease quality of life, but quantitative data on the extent of this effect are limited. Data from the USA demonstrate a significant financial burden associated with bone metastases; similar trends are now being uncovered in Europe as the number of assessments of health economics and healthcare resource utilisation in the region increases. The bisphosphonate zoledronic acid reduces the incidence of SREs compared with placebo. Recent phase 3 studies have shown that therapy with the RANK ligand inhibitor denosumab is superior to zoledronic acid for preventing or delaying SREs in patients with bone metastases from solid tumours. Denosumab also has a comparable safety profile to bisphosphonates, with reduced risk of renal toxicity and acute phase reactions. Data from Europe suggest that denosumab is cost-effective for the prevention of SREs compared with zoledronic acid. Additionally, several new experimental bone-targeted agents show promise.

CONCLUSION

Recent progress may help to reshape evidence-based guidelines to improve patient care and reduce the economic burden of bone metastases.

The outcomes of conservative and surgical treatment of stage 2 bisphosphonate-related osteonecrosis of the jaws: a case series

The purpose of the current retrospective chart review is to describe the outcomes of conservative or surgical treatment of stage 2 bisphosphonate-related osteonecrosis of the jaws (BRONJ). 14 charts (mean patient age 69.07 ± 10.37 years) describing 19 BRONJ stage 2 sites were identified. According to the treatment protocol, all patients received conservative treatment. Surgical treatment was delivered only to sites that did not respond to conservative treatment. Conservative treatment alone was delivered to 11 sites in 8 patients (mean postoperative follow-up 17.6 ± 9.4 months). Surgical treatment was delivered to 8 sites in 6 patients (mean postoperative follow-up 10.0 ± 6.1 months). Bisphosphonate exposure ranged from 1 to 8 years. In most cases, tooth extractions and wearing dentures were reported as triggers for BRONJ. At the last follow-up, BRONJ stage 0 was noted in 7 sites that received conservative treatment and 5 sites that received surgical treatment. Within the limitations of the current chart review, the results showed that although conservative treatment for BRONJ stage 2 can provide favourable outcomes, surgical treatment represents a suitable alternative in non-responsive cases.

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.

Cost-effectiveness of denosumab vs zoledronic acid for prevention of skeletal-related events in patients with solid tumors and bone metastases in the United States

OBJECTIVE

With increasing healthcare resource constraints, it has become important to understand the incremental cost-effectiveness of new medicines. Subcutaneous denosumab is superior to intravenous zoledronic acid (ZA) for the prevention of skeletal-related events (SREs) in patients with advanced solid tumors and bone metastases. This study sought to determine the lifetime cost-effectiveness of denosumab vs ZA in this setting, from a US managed-care perspective.

METHODS

A lifetime Markov model was developed, with relative rate reductions in SREs for denosumab vs ZA derived from three pivotal Phase 3 trials involving patients with castration-resistant prostate cancer (CRPC), breast cancer, and non-small-cell lung cancer (NSCLC), and bone metastases. The real-world SRE rates in ZA-treated patients were derived from a large commercial database. SRE and treatment administration quality-adjusted life year (QALY) decrements were estimated with time-trade-off studies. SRE costs were estimated from a nationally representative commercial claims database. Drug, drug administration, and renal monitoring costs were included. Costs and QALYs were discounted at 3% annually. One-way and probabilistic sensitivity analyses were conducted.

RESULTS

Across tumor types, denosumab was associated with a reduced number of SREs, increased QALYs, and increased lifetime total costs vs ZA. The costs per QALY gained for denosumab vs ZA in CRPC, breast cancer, and NSCLC were $49,405, $78,915, and $67,931, respectively, commonly considered good value in the US. Costs per SRE avoided were $8567, $13,557, and $10,513, respectively. Results were sensitive to drug costs and SRE rates.

LIMITATIONS

Differences in pain severity and analgesic use favoring denosumab over ZA were not captured. Mortality was extrapolated from fitted generalized gamma function beyond the trial duration.

CONCLUSION

Denosumab is a cost-effective treatment option for the prevention of SREs in patients with advanced solid tumors and bone metastases compared to ZA. The overall value of denosumab is based on superior efficacy, favorable safety, and more efficient administration.

Epidemiology and treatment costs of bone metastases from lung cancer: a French prospective, observational, multicenter study (GFPC 0601)

INTRODUCTION

The aim of this prospective, observational, multicenter study was to examine the epidemiology and management costs of bone metastatic disease (BMD) in patients with lung cancer.

METHODS

The analysis included all patients with BMD from lung cancer diagnosed between May 2006 and May 2007 in 40 centers. We analyzed their management and the direct costs of BMD from the health care provider's perspective, using a Markov model. Skeletal-related event (SRE) was defined as pathological fractures, spinal cord compression, or hypercalcemia (clinical SRE [cSRE]) for an initial analysis; a second analysis included palliative radiotherapy and surgery (therapeutic SRE [tSRE]).

RESULTS

Among the 554 patients enrolled (62 ± 11 years, 76.5% males, 69.3% performance status 0/1, 91% non-small cell lung cancer), 24.7% had a cSRE and 26.7% a tSRE at baseline and 9% and 39% during follow-up, respectively; 81.8% received at least one chemotherapy cycle. The median survival time was 5.8 months, and the 1- and 2-year survival rates were 22% and 7%, respectively; there was no significant difference in overall survival between the patients with and without SRE at enrollment. The main BMD treatments were opiate therapy (77.7%), biphosphonates (52.3%), radiotherapy (42.1%), and surgery (9.2%). The mean monthly BMD treatment costs in euros were €190, €374, and €4672 for asymptomatic patients, symptomatic patients, and patients with SRE, respectively. The average first-year BMD management cost in euros was €3999 ± 4135 (95% confidence interval: 374-15,886), and 49.5% of this cost was attributable to patients with SRE.

CONCLUSIONS

This analysis confirms the poor prognosis of BMD from lung cancer and underlines the burden of SRE in overall treatment costs.

Preserving functional independence in elderly patients with cancer-associated bone disease: the role of zoledronic acid

Increases in life expectancy in the developed world will inevitably lead to larger numbers of elderly patients with cancer-associated (malignant) bone disease. Most elderly patients with metastatic cancer also suffer from numerous comorbidities. The management of bone health in this setting requires special consideration. This article centers on malignant bone disease in the elderly and the role of bisphosphonates in geriatric oncology. The challenges involved in the treatment of older patients with bone metastases are described, and the potential utility of bisphosphonates, such as zoledronic acid, is discussed. Moreover, recent data from several large clinical trials suggest that zoledronic acid provides additional benefits, including antitumor effects that may extend beyond the preservation of bone health and prevention of skeletal-related events.

Zoledronic acid: a review of its use in breast cancer

Zoledronic acid 4 mg administered as a 15-minute infusion every 3-4 weeks is effective and well tolerated in the treatment of patients with breast cancer metastatic to bone. It is effective in reducing complications arising from metastatic bone disease in this patient population, with a clinical profile that compares favourably with that of pamidronate. Zoledronic acid administered on a less frequent schedule (every 3-6 months) has also shown potential in preventing cancer treatment-induced bone loss in pre- and postmenopausal women with breast cancer receiving adjuvant hormonal therapy. Preliminary data suggest that zoledronic acid may have antitumour effects, which may reduce the risk of overall disease progression in patients with malignant disease. Thus, zoledronic acid has a well established role as first-line treatment in patients with bone metastases secondary to breast cancer, and may prove useful as a preventive treatment for cancer treatment-induced bone loss or an adjuvant therapy in women with breast cancer.

Current and future treatments of bone metastases

Bone metastases contribute to a significant degree of morbidity in patients with common cancers through the development of skeletal related events (SRE) such as bone pain and pathological fracture. Traditional therapy has relied on surgical removal of lesions and, with the advent of adjuvant therapies, has been combined with radiotherapy, chemotherapy, and more recently osteoclast inhibiting agents like bisphosphonates. Although these therapeutic combinations can achieve a degree of local control, and rarely cure, across the vast majority of metastatic cancers they provide only palliation. Newer molecular agents currently under investigation, combined with innovations in surgery and radiation therapy offer a more targeted approach to bone metastasis. These utilise our understanding of key steps in the metastatic cascade including chemotactic attraction to bone, secretion of proteases, the cancer supporting microenvironment of bone matrix and the RANK-RANKL interaction for osteoclast activation. Direct inhibition of metastasis progression and osteolysis with less reliance on cytotoxic agents and invasive therapy should result in improved metastatic control, longer survival and less overall morbidity.

Zoledronic acid : a review of its use in the management of bone metastases of malignancy

Zoledronic acid (Zometa), a third-generation amino-bisphosphonate, has been approved in the US, the EU and many other countries worldwide for the prevention of skeletal-related events in patients with bone metastases of malignancy. In several well designed trials, zoledronic acid 4 mg administered as a 15-minute infusion every 3-4 weeks was effective in reducing the occurrence of skeletal complications in patients with bone metastases secondary to multiple myeloma, breast cancer or prostate cancer. Zoledronic acid was as effective as pamidronic acid in reducing the occurrence of skeletal complications in patients with multiple myeloma or breast cancer. In patients with solid tumours other than breast or prostate cancer, zoledronic acid did not show significant clinical benefit over placebo in terms of the primary endpoint; however, some benefit of therapy in terms of secondary endpoints was observed with zoledronic acid relative to placebo. Its efficacy in a broad range of tumours and short infusion time (15 minutes) are an advantage over other available bisphosphonates. Modelled pharmacoeconomic analyses in patients with breast cancer suggested that zoledronic acid therapy is cost effective relative to no therapy with regard to the cost per quality-adjusted life-year (QALY) gained; however, results were mixed when zoledronic acid was compared with other commonly used bisphosphonates. Zoledronic acid is generally well tolerated; the risk of osteonecrosis of the jaw may be minimized by adhering to recommendations regarding dental therapy. Additional efficacy and economic data are required to definitively position zoledronic acid with respect to other bisphosphonates. Nevertheless, available clinical data indicate that zoledronic acid is an effective treatment option for the management of bone metastases of malignancy.

Risks and benefits of bisphosphonates

Bone is the most common site for metastasis in cancer and is of particular clinical importance in breast and prostate cancers due to the prevalence of these diseases. Bone metastases result in considerable morbidity and complex demands on health care resources, affecting quality of life and independence over years rather than months. The bisphosphonates have been shown to reduce skeletal morbidity in multiple myeloma as well as a wide range of solid tumours affecting bone by 30-50%. Quite appropriately, these agents are increasingly used alongside anticancer treatments to prevent skeletal complications and relieve bone pain. The use of bisphosphonates in early cancer is also increasingly important to prevent the adverse effects of cancer treatments on bone health. These include ovarian suppression and the use of aromatase inhibitors in breast cancer patients and androgen deprivation therapy in those with prostate cancer. Bisphosphonate strategies, similar to those used to treat postmenopausal osteoporosis, have suggested that bisphosphonates are a safe and effective treatment for the prevention of treatment-induced bone loss. When compared to other cancer therapies, the frequency and severity of adverse events related to bisphosphonate therapy are generally mild and infrequent; thus, the benefits of treatment with any bisphosphonate almost always outweigh the risks. However, renal dysfunction may occasionally occur and over recent years, a new entity, bisphosphonate-associated osteonecrosis of the jaw (ONJ), has been described. The incidence, clinical importance and prevention strategies to minimise the impact of this problem on patients requiring bisphosphonates is discussed.