Comparative tolerability of drug therapies for hypercalcaemia of malignancy

New solutions for combatting implant bacterial infection based on silver nano-dispersed and gallium incorporated phosphate bioactive glass sputtered films: A preliminary study

Ag/Ga were incorporated into resorbable orthopaedic phosphate bioactive glasses (PBG, containing P, Ca, Mg, Na, and Fe) thin films to demonstrate their potential to limit growth of Staphylococcus aureus and Escherichia coli in post-operative prosthetic implantation. Dual target consecutive co-sputtering was uniquely employed to produce a 46 nm Ag:PBG composite observed by high resolution TEM to consist of uniformly dispersed ~5 nm metallic Ag nano-particles in a glass matrix. Ga3+ was integrated into a phosphate glass preform target which was magnetron sputtered to film thicknesses of ~400 or 1400 nm. All coatings exhibited high surface energy of 75.4-77.3 mN/m, attributed to the presence of hydrolytic P-O-P structural surface bonds. Degradation profiles obtained in deionized water, nutrient broth and cell culture medium showed varying ion release profiles, whereby Ga release was measured in 1400 nm coating by ICP-MS to be ~6, 27, and 4 ppm respectively, fully dissolving by 24 h. Solubility of Ag nanoparticles was only observed in nutrient broth (~9 ppm by 24 h). Quantification of colony forming units after 24 h showed encouraging antibacterial efficacy towards both S. aureus (4-log reduction for Ag:PBG and 6-log reduction for Ga-PBG≈1400 nm) and E. coli (5-log reduction for all physical vapour deposited layers) strains. Human Hs27 fibroblast and mesenchymal stem cell line in vitro tests indicated good cytocompatibility for all sputtered layers, with a marginal cell proliferation inertia in the case of the Ag:PBG composite thin film. The study therefore highlights the (i) significant manufacturing development via the controlled inclusion of metallic nanoparticles into a PBG glass matrix by dual consecutive target co-sputtering and (ii) potential of PBG resorbable thin-film structures to incorporate and release cytocompatible/antibacterial oxides. Both architectures showed prospective bio-functional performance for a future generation of endo-osseous implant-type coatings.

Prognostic Effect of Bisphosphonate Exposure for Patients With Diagnosed Solid Cancer: A Systematic Review With Meta-Analysis of Observational Studies

Background: Bisphosphonates are widely prescribed for the prevention and treatment of osteoporosis. Recent epidemiological studies indicate that people with bisphosphonate use may have lower cancer risk and have improved survival. The aim of this study is to determine the association between bisphosphonate use and survival outcomes in solid cancer patients using systematic review and meta-analysis.

Methods: A systematic literature search was performed using the PubMed, Embase, and Cochrane databases. Original articles published until April, 2018 were selected. The survival outcome measures assessed included overall survival (OS), cancer-specific survival (CSS) and recurrence-free survival (RFS). Pooled hazard ratio (HR) and their 95% confidence interval (95% CI) were derived using a random-effects model.

Results: Out of 9,742 retrieved citations, six cohort studies and two nested case-control studies satisfying the inclusion criteria were included for analyses. Bisphosphonate use was significantly associated with improved OS (HR 0.84, 95% CI 0.76–0.93), CSS (HR 0.73, 95% CI 0.58–0.90) and RFS (HR 0.72, 95% CI 0.53–0.96). The results of subgroup analyses stratified by major study characteristics were generally consistent with the main findings. For individual cancer type, we found that bisphosphonate use was significantly associated with longer OS for patients with gastroesophageal cancer (HR 0.62, 95% CI 0.40–0.98), as well as longer CSS for patients with breast cancer (HR 0.73, 95% CI 0.55–0.95).

Conclusions: Current evidence indicates that bisphosphonate use is significantly associated with improved survival for patients with solid cancer. However, the prognostic effects in specific solid tumors remains to be confirmed by further large prospective cohort studies.

The role of vitamin E in the prevention of zoledronic acid-induced nephrotoxicity in rats: a light and electron microscopy study

INTRODUCTION

Bisphosphonates are widely used in metastatic cancer such as prostate and breast cancer, and their nephrotoxic effects have been established previously. In this study we aimed to evaluate both the nephrotoxic effects of zoledronic acid (ZA) and the protective effects of vitamin E (Vit-E) on this process under light and electron microscopy.

MATERIAL AND METHODS

A total of 30 male Sprague-Dawley rats were divided into 3 groups. The first group constituted the control group. The second group was given i.v. ZA of 3 mg/kg once every 3 weeks for 12 weeks from the tail vein. The third group received the same dosage of ZA with an additional i.m. injection of 15 mg Vit-E every week for 12 weeks. Tissues were taken 4 days after the last dose of ZA for histopathological and ultrastructural evaluation. Paller score, tubular epithelial thickness and basal membrane thickness were calculated for each group.

RESULTS

For group 2, the p-values are all < 0.001 for Paller score, epitelial thickness, and basal membrane thickness. For group 3 (ZA + Vit. E), the p-values are < 0.001 for Paller score, 0.996 for epitelial thickness, and < 0.001 basal membrane thickness. Significant differences were also observed in ultrastructural changes for group 2. However, adding Vit-E to ZA administration reversed all the histopathological changes to some degree, with statistical significance.

CONCLUSIONS

Administration of ZA had nephrotoxic effects on rat kidney observed under both light and electron microscopy. Concomitant administration of Vit-E significantly reduces toxic histopathological effects of ZA.

Exposure Potential and Health Impacts of Indium and Gallium, Metals Critical to Emerging Electronics and Energy Technologies

The rapid growth of new electronics and energy technologies requires the use of rare elements of the periodic table. For many of these elements, little is known about their environmental behavior or human health impacts. This is true for indium and gallium, two technology critical elements. Increased environmental concentrations of both indium and gallium create the potential for increased environmental exposure, though little is known about the extent of this exposure. Evidence is mounting that indium and gallium can have substantial toxicity, including in occupational settings where indium lung disease has been recognized as a potentially fatal disease caused by the inhalation of indium particles. This paper aims to review the basic chemistry, changing environmental concentrations, potential for human exposure, and known health effects of indium and gallium.

Possible alendronate-induced polyarticular synovitis

We present a case of polyarticular synovitis following alendronate treatment for osteoporosis.

The patient had no evidence of rheumatoid arthritis, pyrophosphate arthropathy, or seronegative/seropositive arthritis. Our main aim in this study is to highlight the potential adverse effects of alendronate and to warn orthopedic surgeons about the possibility of such a side effect that might lead orthopedic surgeons to administer wrong and unnecessary treatments like arthrocentesis. The withdrawal of alendronate is found to be the treatment of choice. Alendronate should be considered as a possible cause of synovitis or polyarthritis in patients treated with this agent in the absence of any other pathology. An association between alendronate and synovitis has rarely been described in the literature. We present a patient who developed polyarticular synovitis after treatment with alendronate and responded to its withdrawal.

Pharmacokinetic and therapeutic efficacy of intrapulmonary administration of zoledronate for the prevention of bone destruction in rheumatoid arthritis

Zoledronate, a third-generation nitrogen-containing bisphosphonate, is a new therapeutic agent for the prevention of joint destruction in rheumatoid arthritis (RA). Due to the poor oral absorption of zoledronate, the intravenous route has been the preferred method of administration. To evaluate whether the lung is a promising alternative route of zoledronate administration for the prevention of joint destruction in RA, we examined the pharmacokinetics, safety and therapeutic potential of zoledronate after intrapulmonary administration. The bioavailability of zoledronate was 55% after intrapulmonary administration in rats. In a collagen-induced RA mouse model, an intrapulmonary administration of zoledronate given 7 d before the 2nd collagen immunization effectively suppressed bone loss and joint destruction to a level similar to that achieved with intravenous injection at 21 d after the 2nd collagen immunization. Zoledronate only slightly affected lactate dehydrogenase activity in bronchoalveolar lavage fluid 4 h after intrapulmonary administration of the therapeutic dose in rats. Moreover, zoledronate only slightly changed the plasma level of creatinine after intrapulmonary administration while creatinine significantly increased after intravenous injection of zoledronate in mice. These results indicate that the lung is a promising alternative route of zoledronate administration for the treatment and prevention of joint destruction in RA.

Molecular Design of Bisphosphonate-Modified Proteins for Efficient Bone Targeting In Vivo

To establish a rational molecular design for bisphosphonate (BP)-modified proteins for efficient bone targeting, a pharmacokinetic study was performed using a series of alendronate (ALN), a nitrogen-containing BP, modified proteins with various molecular weights and varying degrees of modification. Four proteins with different molecular weight—yeast glutathione reductase (GR; MW: 112,000 Da), bovine serum albumin (BSA; MW: 67,000 Da), recombinant human superoxide dismutase (SOD; MW: 32,000 Da), and chicken egg white lysozyme (LZM; MW: 14,000 Da)—were modified with ALN to obtain ALN-modified proteins. Pharmacokinetic analysis of the tissue distribution of the ALN-modified and unmodified proteins was performed after radiolabeling them with indium-111 (¹¹¹In) by using a bifunctional chelating agent. Calculation of tissue uptake clearances revealed that the bone uptake clearances of ¹¹¹In-ALN-modified proteins were proportional to the degree of ALN modification. ¹¹¹In-GR-ALN and BSA-ALN, the two high-molecular-weight proteins, efficiently accumulated in bones, regardless of the degree of ALN modification. Approximately 36 and 34% of the dose, respectively, was calculated to be delivered to the bones. In contrast, the maximum amounts taken up by bone were 18 and 13% of the dose for ¹¹¹In-SOD-ALN(32) and LZM-ALN(9), respectively, because of their high renal clearance. ¹¹¹In-SOD modified with both polyethylene glycol (PEG) and ALN (¹¹¹In-PEG-SOD-ALN) was efficiently delivered to the bone. Approximately 36% of the dose was estimated to be delivered to the bones. In an experimental bone metastasis mouse model, treatment with PEG-SOD-ALN significantly reduced the number of tumor cells in the bone of the mice. These results indicate that the combination of PEG and ALN modification is a promising approach for efficient bone targeting of proteins with a high total-body clearance.

Inflammatory eye reactions with bisphosphonates and other osteoporosis medications: what are the risks?

Inflammatory eye reactions (IERs) are rare but have been associated with medications to treat osteoporosis. The aim of this review is to summarize the current literature on the association between IERs and specific medications to treat osteoporosis (bisphosphonates, selective estrogen receptor modulators, strontium, denosumab and teriparatide). We cover the known epidemiology, potential pathogenic mechanisms and a resume of unanswered questions. Briefly, this review highlights that none of the existing randomized clinical trials were powered to identify these rare adverse events, and the majority of the information available is from spontaneous case reports and case series reporting associations between bisphosphonates and IERs. No case reports describe IERs after other anti-osteoporosis medications. Importantly, some case reports describe recurrence of the IER after affected patients were rechallenged with the same or another bisphosphonate, and that no reported cases resolved without discontinuation of the bisphosphonate. However, three large population-based cohort studies have shown conflicting results between osteoporosis treatments and IERs, but overall these studies suggest that IERs may actually be part of underlying inflammatory disease processes that also cause osteoporosis, rather than due to the medications used to treat osteoporosis themselves. There are no clear pathogenic mechanisms for how bisphosphonates could potentially cause IERs. However, the drug is secreted into the tears by the lacrimal gland and could cause irritation to the mucous membranes with subsequent release of inflammatory mediators, similar to the systemic response typically seen after infusion of bisphosphonates. However, in summary it is still not known whether there is a true causal association between bisphosphonates or other anti-osteoporosis medications and IERs, or whether it is confounding by indication and is actually due to underlying inflammatory diseases that cause both osteoporosis and IERs.

Long-term risks of bisphosphonate therapy

The objective this study was to summarize long-term risks associated with bisphosphonate therapy. Search of relevant medical publications for data from clinical trials, trial extensions, observational studies and post-marketing reports. Trial extensions and modifications did not reveal significant long-term safety issues. Observational data suggest at least as many benefits as risks. Post-marketing reports of musculoskeletal pain, osteonecrosis of the jaw and atypical femur fractures have been widely circulated in the lay press. Most focus on long-terms risks has been on osteonecrosis of the jaw and atypical femur fractures which occur in patients who have not received bisphosphonate therapy but may be more frequent (though still uncommon) in patients who have been on treatment for 5 years or longer. Lower-risk patients may be able to stop treatment after 3-5 years for a “drug holiday,” which mitigates these long-term risks; for higher risk patients, therapy through 6-10 years appears to be advisable and offers more benefits than risks.

Prolonged recovery time from zoledronic Acid induced acute tubular necrosis: a case report and review of the literature

Acute tubular necrosis (ATN) due to bisphosphonates has been reported with Zoledronic acid but the time to recovery (if any) has been usually less than 4 months. Possible recovery time from ATN of any cause is usually less than 6 months. In this paper, we present the case of a 59-year-old Caucasian female with metastatic breast cancer who had received 16 monthly injections of Zoledronic acid for treatment of tumor induced hypercalcemia and developed several episodes of mild acute kidney injury which resolved by withholding treatment. Unfortunately, after the sixteenth injection, the patient experienced severe acute kidney injury, with a peak serum creatinine of 8.0 mg/dL. Although urinalysis showed muddy brown casts, because of atypical recovery time and presence of eosinophiluria and subnephrotic range proteinuria, a kidney biopsy was performed. Diagnosis of typical acute tubular necrosis was confirmed without any other concomitant findings. The course was remarkable for an unusually slow recovery of renal function over 15 months without need for renal replacement therapy until the patient expired from her metastatic cancer two years later. We reviewed all the published cases of acute kidney injury due to Zoledronic acid and suggest recommendations for clinicians and researchers.

Molecular insight into substrate recognition and catalysis of Baeyer-Villiger monooxygenase MtmOIV, the key frame-modifying enzyme in the biosynthesis of anticancer agent mithramycin

Baeyer-Villiger monooxygenases (BVMOs) have been shown to play key roles for the biosynthesis of important natural products. MtmOIV, a homodimeric FAD- and NADPH-dependent BVMO, catalyzes the key frame-modifying steps of the mithramycin biosynthetic pathway, including an oxidative C-C bond cleavage, by converting its natural substrate premithramycin B into mithramycin DK, the immediate precursor of mithramycin. The drastically improved protein structure of MtmOIV along with the high-resolution structure of MtmOIV in complex with its natural substrate premithramycin B are reported here, revealing previously undetected key residues that are important for substrate recognition and catalysis. Kinetic analyses of selected mutants allowed us to probe the substrate binding pocket of MtmOIV and also to discover the putative NADPH binding site. This is the first substrate-bound structure of MtmOIV providing new insights into substrate recognition and catalysis, which paves the way for the future design of a tailored enzyme for the chemo-enzymatic preparation of novel mithramycin analogues.

Hypercalcemia in the Intensive Care Unit: A Review of Pathophysiology, Diagnosis, and Modern Therapy

Hypercalcemia may be seen in a variety of clinical settings and often requires intensive management when serum calcium levels are dramatically elevated. All of the many etiologies of mild hypercalcemia can lead to severe hypercalcemia. Knowledge of the physiologic mechanisms involved in maintaining normocalcemia and basic pathophysiology is essential for making a timely diagnosis and hence prompt institution of etiology-specific therapy. The development of new medications and critical reviews of traditional therapies have changed the treatment paradigm for severe hypercalcemia, calling for a more limited role for aggressive isotonic fluid administration and furosemide and an expanded role for calcitonin and the bisphosphonates. Experimental therapies such as denosumab show promise.

Zoledronate for metastatic bone disease and pain: a meta-analysis of randomized clinical trials

BACKGROUND

Randomized controlled trials (RCTs) have reported different results when using zoledronate to treat skeletal-related events (SREs) and bone pain in patients with metastatic bone disease (MBD), and few have looked at the risks and benefits of long-term use of the drug. This meta-analysis aimed to investigate the efficacy and safety of zoledronate to treat MBD in the short and long-term.

METHODS

PubMed, EMBASE, and the Cochrane Library were searched to identify RCTs evaluating zoledronate for MBD. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Twelve RCTs involving 4,450 patients were included in the meta-analysis. Zoledronate decreased the risk of developing SREs compared with placebo (RR 0.75, 95% CI 0.69 to 0.81, P < 0.001). Zoledronate consistently reduced the brief pain inventory (BPI) below baseline compared with placebo at 3, 12, and 24 months. In addition, the likelihood of experiencing a bone pain event was significantly lower in the zoledronate group than in the placebo group (RR 0.83, 95% CI 0.76 to 0.89, P < 0.001). While the two groups did not differ significantly in the incidence of nausea(RR = 1.07, 95% CI 0.96 to 1.19, P = 0.250), emesis (RR 0.94, 95% CI 0.81 to 1.09, P = 0.420), or adverse renal events (RR 1.41, 95% CI 0.94 to 2.11, P = 0.09), the zoledronate group showed a significantly higher relative risk of pyrexia (RR 1.43, 95% CI 1.20 to 1.70, P < 0.001), fatigue (RR 1.26, 95% CI 1.10 to 1.43, P < 0.001), and anemia (RR 1.33, 95% CI 1.14 to 1.55, P < 0.001).

CONCLUSION

Compared to placebo, zoledronate significantly reduced the incidence of bone pain and SREs in patients with MBD for periods as long as 24 months. In addition, zoledronate is generally well tolerated over this long period.

Bisphosphonates in the treatment of osteoporosis

Bisphosphonates are widely used in the treatment of osteoporosis to reduce fracture risk. Because of their long retention time in bone and uncommon side effects, questions have been raised about the optimal duration of therapy. Potential side effects appear to be rare and may not be causally related. Although there is no strong science to guide "drug holidays," there appears to be some lingering antifracture benefit when treatment is stopped, so some time off treatment should be offered to most patients on long-term bisphosphonate therapy. For most patients with osteoporosis, the benefits of treatment outweigh the risks.

Onco-nephrology: the pathophysiology and treatment of malignancy-associated hypercalcemia

Hypercalcemia complicates the course of 10%-30% of all patients with malignancies and can be a sign of very poor prognosis and advanced malignancy. Prompt recognition of the nonspecific signs and symptoms of hypercalcemia and institution of therapy can be lifesaving, affording the opportunity to address the underlying etiology. The mechanisms of malignancy-associated hypercalcemia generally fall into three categories: humoral hypercalcemia due to secreted factors (such as parathyroid-related hormone), local osteolysis due to tumor invasion of bone, and absorptive hypercalcemia due to excess vitamin D produced by malignancies. The mainstays of therapy for hypercalcemia are aggressive intravenous volume expansion with saline, bisphosphonate therapy, and perhaps loop diuretics. Adjunctive therapy may include calcitonin and corticosteroids. In refractory cases, gallium nitrate and perhaps denosumab are alternatives. In patients presenting with severe AKI, hemodialysis with a low-calcium bath can be effective. In most cases, therapy normalizes calcium levels and allows for palliation or curative therapy of the malignancy.

The Sp1 transcription factor is essential for the expression of gliostatin/thymidine phosphorylase in rheumatoid fibroblast-like synoviocytes

INTRODUCTION

Gliostatin/thymidine phosphorylase (GLS/TP) has angiogenic and arthritogenic activities, and aberrant GLS production has been observed in the active synovial membranes of rheumatoid arthritis (RA) patients. The human GLS gene promoter contains at least seven consensus binding sites for the DNA binding protein Sp1. Here we examined whether Sp1 is necessary for GLS production in RA. We also studied the effects of the Sp1 inhibitor mithramycin on GLS production in RA fibroblast-like synoviocytes (FLSs).

METHODS

FLSs from RA patients were treated with specific inhibitors. The gene and protein expression of GLS were studied using the quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and an enzyme immunoassay. Intracellular signalling pathway activation was determined by western blotting analysis, a luciferase assay, a chromatin immunoprecipitation (ChIP) assay and a small interfering RNA (siRNA) transfection.

RESULTS

The luciferase and ChIP assays showed that Sp1 binding sites in the GLS promoter were essential for GLS messenger RNA (mRNA) expression. GLS production was suppressed in FLSs by siRNA against Sp1 transfection. Mithramycin decreased GLS promoter activity, mRNA and protein expression in FLSs. Tumour necrosis factor-α (TNF-α) significantly increased GLS expression in RA FLSs; this effect was reduced by pre-treatment with cycloheximide and mithramycin.

CONCLUSIONS

Pretreatment of mithramycin and Sp1 silencing resulted in a significant suppression of GLS production in TNF-α-stimulated FLSs compared to controls. GLS gene expression enhanced by TNF-α was partly mediated through Sp1. As physiological concentrations of mithramycin can regulate GLS production in RA, mithramycin is a promising candidate for anti-rheumatic therapy.

Evolution of bisphosphonate-related osteonecrosis of the jaw in patients with multiple myeloma and Waldenstrom's macroglobulinemia: a retrospective multicentric study

Bisphosphonates (BPs) are used intravenously to treat cancer-related conditions for the prevention of pathological fractures. Osteonecrosis of the jaw (BRONJ) is a rare complication reported in 4-15% of patients. We studied, retrospectively, 55 patients with multiple myeloma or Waldenstrom's macroglobulinemia followed up from different haematological departments who developed BRONJ. All patients were treated with BPs for bone lesions and/or fractures. The most common trigger for BRONJ was dental alveolar surgery. After a median observation of 26 months, no death caused by BRONJ complication was reported. In all, 51 patients were treated with antibiotic therapy, and in 6 patients, this was performed in association with surgical debridement of necrotic bone, in 16 with hyperbaric O(2) therapy/ozonotherapy and curettage and in 12 with sequestrectomy and O(2)/hyperbaric therapy. Complete response was observed in 20 cases, partial response in 21, unchanged in 9 and worsening in 3. The association of surgical treatment with antibiotic therapy seems to be more effective in eradicating the necrotic bone than antibiotic treatment alone. O(2) hyperbaric/ozonotherapy is a very effective treatment. The cumulative dosage of BPs is important for the evolution of BRONJ. Because the most common trigger for BRONJ was dental extractions, all patients, before BP treatment, must achieve an optimal periodontal health.

Sp1king out cancer (....and fibrosis?)

It is becoming increasingly apparent that many of the basic mechanisms underlying cancers also underlie fibrotic diseases. For example, the Sp1 family of transcription factors plays an essential role in controlling the gene expression of proteins that promote both oncogenesis and fibrogenesis. The drug mithramycin, which prevents Sp1 binding to DNA, has been in use clinically for some cancers, but has side-effects. However, other drugs exist that affect Sp1 activity through promoting Sp1 protein degradation. Evidence has emerged that low levels of mithramycin can be combined with these drugs to result in potent antitumorigenic effects without resulting in obvious toxicity (Gao et al. Cancer Res 2011 Jun 20; Jia et al. Cancer Res 70:1111-1119, 2010). Given that Sp1 proteins also promote expression of profibrotic genes such as collagen type I and CCN2, it is possible that this combinatorial approach may be taken in the future to block not only cancer but also fibrosis.

The risk of cumulative renal effects of intravenous bisphosphonates

Some level of renal dysfunction is common in patients with cancer. This could be a result of an age-related kidney function decrease, the underlying disease (eg, multiple myeloma), or the effects of nephrotoxic medications. Some intravenous (I.V.) bisphosphonates have been associated with occasional renal toxicity in the clinical setting. Therefore, the choice of an I.V. bisphosphonate should take into account the risk of renal deterioration. Preclinical studies also suggest that there might be considerable differences between the renal safety profiles of commonly used I.V. bisphosphonates. Variations in the risk of histopathologic damage and the ability to cause cumulative toxicity have been observed in comparative preclinical studies of I.V. bisphosphonates. The reasons for these apparent differences are not fully understood. Research shows that renal safety profiles might be influenced by pharmacokinetic properties, such as renal tissue half-life, protein binding, and intracellular potency. Preclinical analyses are warranted in order to confirm and evaluate these differences between bisphosphonates.

Osteoporosis update from the 2010 santa fe bone symposium

The 11th Santa Fe Bone Symposium was held in Santa Fe, NM, USA, on August 6-7, 2010. This annual event addresses clinically relevant advances in the fields of osteoporosis and metabolic bone disease. The venue includes plenary presentations by internationally recognized experts, oral presentations of abstracts, and interactive panel discussions of challenging cases and controversial issues. Attendees are active participants throughout the symposium program. Topics for the 2010 symposium included potential applications of novel technologies for the assessment of skeletal health for research and clinical practice; new and emerging treatments for osteoporosis; appropriate use of pharmacological agents to prevent osteoporosis; controversies with bisphosphonate therapy; practical applications of the World Health Organization fracture risk assessment tool (FRAX; World Health Organization Collaborating Centre for Metabolic Bone Diseases, University of Sheffield, UK); insights into the use of osteoanabolic agents to enhance fracture healing; and challenges in laboratory testing in the assessment of factors contributing to skeletal fragility. Concurrent sessions focused on critical thinking for technologists in the acquisition and analysis of data with dual-energy X-ray absorptiometry. The key messages from each presentation, including the best available medical evidence and potential current and future clinical applications, are provided here.

Haematological emergencies managing hypercalcaemia in adults and children with haematological disorders

Hypercalcaemia is a common metabolic complication of malignant disease often requiring emergency intervention. Although it is more frequently associated with solid tumours, malignancy-associated hypercalcaemia (MAH) is seen in a significant number of patients with blood diseases. Its association with myeloma and adult T-cell leukaemia/lymphoma is well recognized but the incidence of hypercalcaemia in other haematological neoplasms, affecting adults and children, is less clearly defined. Haematologists need to be familiar with the clinical manifestations of, the differential diagnosis to be considered and the most effective management strategies that are currently available for MAH. The key components of management of MAH include aggressive rehydration, specific therapy to inhibit bone resorption and, crucially, treatment of the underlying malignancy. Bisphosphonates have revolutionized the management of MAH over the last 20 years, however the elucidation of molecular pathways implicated in MAH is facilitating the development of more targeted approaches to treatment.

Long-term use of bisphosphonates in osteoporosis

CONTEXT

Bisphosphonates have been widely used in the treatment of osteoporosis. Uncommon side effects have emerged in postapproval use. Because bisphosphonates accumulate in bone and are released for months or years after treatment is stopped, it is reasonable to consider the clinical question of how long to treat.

OBJECTIVE

In this personal perspective, we review the pharmacology and mechanism of action of bisphosphonates and the clinical studies that support their efficacy. We then review the literature for longer-term studies and reports of possible side effects that were not seen in clinical trials.

RESULTS

Bisphosphonates have demonstrated antifracture efficacy in randomized, placebo-controlled trials of 3 and 4 yr duration and have been widely used since the initial release of alendronate in 1995. For zoledronic acid and risedronate, an early effect (fractures reduced within 6-12 months of starting therapy) has been shown. A sustained effect for risedronate has been shown through 5 yr and suggested through 7 yr. Ten-year data with alendronate and 8 yr data with risedronate indicated good tolerability and safety; it is unlikely that longer-term studies will be done. Side effects that emerged in clinical trials include esophageal irritation with oral administration and acute phase response with iv treatment or high-dose oral therapy. Uncommon side effects that have been noted with wide clinical use include osteonecrosis of the jaw, musculoskeletal complaints, and atypical fractures. The numbers of events are small, and a clear cause-and-effect relationship between these events and bisphosphonate treatment has not been established. Because bisphosphonates accumulate in bone, they create a reservoir leading to continued release from bone for months or years after treatment is stopped. Studies with risedronate and alendronate suggest that if treatment is stopped after 3-5 yr, there is persisting antifracture efficacy, at least for 1-2 yr.

CONCLUSIONS

Bisphosphonates are popular and effective for treatment of osteoporosis. Because they accumulate in bone and provide some residual antifracture reduction when treatment is stopped, we recommend a drug holiday after 5-10 yr of bisphosphonate treatment. The duration of treatment and length of the holiday are based on fracture risk and pharmacokinetics of the bisphosphonate used. Patients at mild risk might stop treatment after 5 yr and remain off as long as bone mineral density is stable and no fractures occur. Higher risk patients should be treated for 10 yr, have a holiday of no more than a year or two, and perhaps be on a nonbisphosphonate treatment during that time.

Bone health and prostate cancer

Bone metastases are a substantial burden to men with advanced prostate cancer as they often cause pain and can cause fractures and spinal cord compression. Osteoblasts and osteoclasts are both pathologically activated in the setting of prostate cancer bone metastases. As osteoclast activation is associated with disease progression, skeletal complications and death, osteoclast-targeted therapies are a rational approach to disease management. Zoledronic acid is standard of care for castration-resistant prostate cancer with bone metastases as it reduces the risk for skeletal-related events. Additional trials are needed to better define the ideal dose, frequency and duration of zoledronic acid therapy. No bisphosphonate has yet been shown to prevent bone metastases or to benefit men with androgen-sensitive disease. Denosumab is an experimental osteoclast-targeted monoclonal antibody against receptor activator of nuclear factor-kappaB ligand. Two ongoing phase III trials are expected to define its efficacy in preventing bone metastases and disease-related skeletal events in men with prostate cancer. Androgen-deprivation therapy (ADT) for prostate cancer is associated with osteoporosis and fragility fractures. Several bisphosphonates have been shown to improve bone mineral density in men receiving ADT. Two recent phase III trials have shown that denosumab and toremifene reduce the incidence of fragility fractures in these men. The World Health Organization has developed a fracture risk assessment model (FRAX) for the general population to guide the selection of patients who may benefit from pharmacotherapy. In the absence of a prostate cancer-specific algorithm, we advocate the use of FRAX for men receiving ADT.

The Effect of Alendronate, Risedronate, and Raloxifene on Renal Functions, Based on the Cockcroft and Gault Method, in Postmenopausal Women

BACKGROUND

Oral alendronate, risedronate, and raloxifene are effective treatment options in the management of postmenopausal osteoporosis. There is little previously reported about the renal safety profiles of these three agents in osteoporosis. We aimed to assess the risk of renal toxicity associated with oral alendronate, risedronate, and raloxifene in the treatment of osteoporosis, prospectively.

METHODS

One hundred and twenty-seven patients with osteoporosis and osteopenia according to lumbar or femoral-neck bone mineral density t score were enrolled in the study. The patients were randomized to alendronate 70 mg once weekly (n = 47), risedronate 35 mg once weekly (n = 44), or raloxifene 60 mg per day (n = 36) for one year. Preliminary screening included medical history, physical examination, lumbar and femoral bone mineral densitometry measurement, and blood biochemical tests, including renal function tests. The biochemical markers were then assessed at the end of 12 months.

RESULTS

There was no significant difference between basal and final renal function parameters of each group. Also these parameters did not differ between the three groups after 12 months of treatment period.

CONCLUSIONS

These results demonstrate that alendronate, risedronate, and raloxifene are all safe drugs for renal functions in the treatment of osteoporosis.

High incidence of hypocalcemia and serum creatinine increase in patients with bone metastases treated with zoledronic acid

BACKGROUND

Zoledronic acid belongs to the new generation of bisphosphonates with demonstrated clinical benefit for the treatment of bone metastases from different kinds of neoplasms. Hypocalcemia and serum creatinine elevation are expected adverse events during this therapy. The monitoring of serum calcium and creatinine is therefore recommended. The primary aim of this study was to establish the actual incidence of hypocalcemia and serum creatinine elevation during treatment with zoledronic acid. Skeletal-related events and side effects were also assessed.

METHODS

Serum creatinine and calcium levels were evaluated in 240 consecutive patients (83 males, 157 females; mean age, 62 years) with metastatic bone lesions from different solid tumors treated with zoledronic acid.

RESULTS

Overall, 93 of 240 patients (38.8%) developed hypocalcemia, which was grade (G)1 in 45 patients (48.4%), G2 in 37 patients (39.8%), G3 in 10 patients (10.8%), and G4 in one patient (1.1%). The median time to occurrence of hypocalcemia (any grade) was 2.3 months after the beginning of the treatment (range, 0-34.9 months). Increased serum creatinine was observed in 33 of 240 patients (13.7%), of whom 19 had G1 (57.6%), 11 had G2 (33.3%), and three had G3 (9.1%). The median time to serum creatinine increase (for any grade) was 4.7 months (range, 0-29.2 months).

CONCLUSIONS

Our analysis shows a high incidence of hypocalcemia and increased serum creatinine level during treatment with zoledronic acid. These results strongly support the need for accurate monitoring of plasma calcium and creatinine levels.

Treatment Options for Breast Cancer and Bone Metastases

The most common destination for breast cancer metastases is bone. If bone metastases are detected, treatment algorithms should include the continuation of cytoreductive therapy with the addition of treatment to counter skeletal-related events, including bone pain. The range of current treatment options includes bisphosphonates, surgical intervention to improve structural integrity and palliative focal radiotherapy. This article focuses on the role of bisphosphonate therapy in metastatic breast cancer. Bisphosphonate therapy significantly reduces the impact of skeletal-related events, reduces bone pain and increases patient quality of life. Our current understanding is that bisphosphonates may also disrupt the metastatic process and reduce the development of bone lesions. Ultimately, this may lead to further expansion of bisphosphonate-based therapy in the future.

Osteoclast targeted therapy for prostate cancer: bisphosphonates and beyond

Bone metastases are a major cause of morbidity for men with prostate cancer. Although typical bone metastases from prostate cancer appear osteoblastic by radiographic imaging, excess number and activity of both osteoblasts and osteoclasts characterize most "osteoblastic" bone metastases. Additionally, pathological osteoclast activation is associated with increased risk of skeletal complications, disease progression, and death. Zoledronic acid, a potent intravenous bisphosphonate, reduces markers of osteoclast activity and significantly decreases the risk of skeletal complications in men with androgen-independent prostate cancer and bone metastases. Additional studies are needed to determine the optimal timing, schedule, and duration of bisphosphonate treatment in men with bone metastases as well as the potential role of bisphosphonates in other settings, including the prevention of bone metastases. Denosumab is a human monoclonal antibody that binds and neutralizes human receptor activator of NF-kappaB ligand (RANKL), a critical mediator of osteoclast activation, differentiation, and survival. Three ongoing pivotal studies involving more than 4,500 subjects will evaluate the role of denosumab for prevention of treatment-related fractures, bone metastases, and disease-related skeletal complications in men with prostate cancer.

Significance and impact of bisphosphonate-induced acute phase responses

BACKGROUND

Bisphosphonates are synthetic analogs of inorganic pyrophosphates with high avidity for bone, where they bind to hydroxyapatite crystals. Bisphosphonates are effective in decreasing bone resorption, the incidence of skeletal-related events, and pain from bone metastases. These agents have recently become incorporated into the treatment regimen of patients with osteolytic and osteoblastic metastatic bone disease. Although relatively well tolerated, the initial dose(s) of intravenous aminobisphosphonates can be associated with an acute phase response, a nonspecific physiologic reaction associated with increased levels of inflammatory cytokines, fever, and flu like symptoms including fatigue, nausea, and myalgia.

OBJECTIVE

The purpose of this article is to provide an updated review of the literature in this field.

DATA SOURCE

A search of PubMed was performed using the key terms bisphosphonate, acute phase response, and cancer, and limited to publications in English. The published literature on acute phase response with bisphosphonate therapy was reviewed.

RESULTS AND CONCLUSIONS

Approximately 40% of patients receiving aminobisphosphonates experience an acute phase response, which generally occurs only on first exposure to the drug and typically last <72 h. Not all bisphosphonates induce acute phase responses to the same extent. This article reviews acute phase response in patients with metastatic bone disease treated with aminobisphosphonates.

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.

Analgesic efficacy of zoledronic acid and its effect on functional status of prostate cancer patients with metastasis

OBJECTIVES

A multi-centered observational study evaluated the efficacy of zoledronic acid for improving pain and mobility, and preventing skeletal-related events (SRE) (fracture, spinal compression, pain-relieving radiotherapy), in patients with prostate cancer and bone metastasis.

MATERIALS AND METHODS

Males (n = 218) with prostate cancer and bone metastasis undergoing oncologic therapy received zoledronic acid (4 mg iv/month) for 6 months. Parameters evaluated were: 1) pain and movement after 2 consecutive doses; 2) quality of life; 3) SRE incidence and time-to-appearance. Medication tolerance and treatment satisfaction were assessed using a questionnaire.

RESULTS

A total of 170 that matched all the inclusion criteria (78%) out of 218 were evaluable for efficacy. There was a measurable statistically significant reduction in pain at rest and on movement as well as an improvement in the quality of life compared with baseline. Best results were obtained with early treatment. Overall incidence of bone events was 11.2%. Of the 212 patients (97.2%) evaluable for safety, 16% suffered adverse events and 66% expressed satisfaction with the treatment

DISCUSSION

Zoledronic acid is effective for reducing pain, improving mobility, and increasing the quality of life in patients with prostate cancer with bone metastasis. Its easy administration and good tolerability make zoledronic acid one of the principal therapeutic tools in the management of patients with pain associated with bone metastasis from prostate cancer.

Renal safety of intravenous bisphosphonates in the treatment of osteoporosis

Oral bisphosphonates are the mainstay of treatment for osteoporosis but cannot be used in some patients due to gastrointestinal contraindications, gastrointestinal intolerance, malabsorption or the inability to comply with dosing requirements. In such patients, intravenous bisphosphonates are a useful alternative. This review summarises the renal safety issues associated with the use of intravenous bisphosphonates for osteoporosis. Intravenous bisphosphonates are generally well tolerated, which may be a reflection of their selective activity in bone and metabolic stability. Adverse effects on renal function are primarily related to infusion rate and dose. Due to lack of data, no conclusions can be made regarding bisphosphonate safety in patients with intrinsic renal disease or an estimated glomerular filtration rate of < 30 ml/min.

Zoledronic acid in the management of metastatic bone disease

Bisphosphonate therapy has become a standard of therapy for patients with malignant bone disease. Moreover, in vivo preclinical and preliminary clinical data suggest that bisphosphonates may prevent cancer treatment-induced bone loss and the onset of malignant bone disease in patients with early-stage cancer. This comprehensive review critically reports the several preclinical evidences of action of bisphosphonates on osteoclasts, lymphocytes and tumour cells. In addition, all the clinical trials evaluating the effects of principal bisphosphonates on skeletal disease progression in patients with breast cancer, prostate cancer, non-small cell lung cancer and other cancers have been reported. Of the available bisphosphonates, intravenous zoledronic acid has demonstrated the broadest clinical activity and is actually approved for the treatment of bone metastases from any solid tumour in many countries. Renal safety is an important consideration for oncologists who are treating patients with bisphosphonates. This issue and the other topics relating to the safety of bisphosphonates are discussed in this review.

The use of bisphosphonates in elderly cancer patients

As life expectancy increases throughout the 21st century, the size of the elderly population will also expand. This will have a marked effect on the number of patients with cancer who are classified as elderly. Despite this, the design of most clinical studies of cancer therapies excludes those patients who are > or =70 years of age. Bisphosphonates are an example of a cancer therapy that has not been examined in randomized clinical trials of elderly patients. These agents are used for the prevention of skeletal complications and the relief of bone pain in patients with bone metastases. When deciding which bisphosphonate to prescribe to an elderly patient, each drug should be considered on its individual merits. Examples of areas of concern with bisphosphonates in elderly patients include their relative renal safety profiles and propensity for osteonecrosis of the jaw. Another consideration when choosing the most appropriate formulation is the preferred method of administration (oral or i.v.), which may affect patient compliance with therapy. As the use of bisphosphonates increases, the need for data on their use in elderly patients also becomes greater. Clinical trials of bisphosphonates in this patient population are currently under way, and their results are keenly awaited.

Tolerability of different dosing regimens of bisphosphonates for the treatment of osteoporosis and malignant bone disease

Bisphosphonates are the primary pharmacological agents used for the management of osteoporosis and hypercalcaemia of malignant bone disease. The efficacy of these agents in these two conditions has been demonstrated in many well designed trials published over the past 2 decades. The variety of bisphosphonates currently available to us provides a wide range of tolerability and dosing profiles thus necessitating a thorough comparison of the most recent oral and intravenous bisphosphonates to differentiate the clinical context in which they should be used. Despite the fact that bisphosphonates are generally well accepted, their tolerability is dependent on complications which encompass gastrointestinal (GI) and renal toxicity. Other adverse events include osteonecrosis of the jaw, arthralgias, flu-like symptoms and uveitis. Studies have shown that various dosing regimens are able to modulate these rates of toxicity. To maximise tolerability, the direction of future therapy will likely fall into a pattern of decreasing the frequency of administration of bisphosphonates, whether it is oral or intravenous formulations, thus improving patient adherence. To review the literature on different dosing regimens of various bisphosphonates and their associated tolerability, we searched MEDLINE for articles from 1975 to 2006. Oral bisphosphonates, in particular alendronate and risedronate, have been systematically evaluated with regards to GI toxicity. Overall tolerability with these oral formulations has found GI toxicity to be the primary adverse event of interest. Both alendronate and risedronate have been found to have similar rates of GI toxicity when compared with placebo. Mounting evidence has developed validating the use of intravenous ibandronate and zoledronic acid for the purpose of treating hypercalcaemia secondary to malignancy. Unique to all other bisphosphonates, ibandronate also has an oral form which has a similar GI-toxicity profile to placebo. In addition, no significant differences in renal toxicity have been observed between those receiving intravenous ibandronate compared with placebo. Because of its potency and mode of administration, zoledronic acid has been widely accepted for the treatment of hypercalcaemia secondary to malignancy. However, a decrease in renal function, albeit rare, remains a significant complication of zoledronic acid; therefore, regular renal monitoring is recommended.

Oncologic Emergencies

It has been estimated that genitourinary malignancies will account for 25% of new cancer diagnoses in the United States in 2005 (Jemal et al. 2005). While the incidence of many of these malignancies has increased over the past two decades, the mortality rates appear to be decreasing. Early cancer detection combined with improvements in surgical and nonsurgical oncologic therapy account for these trends. Although not common, newly diagnosed cancer patients occasionally present in an emergent, life-threatening manner that warrants immediate medical or surgical intervention. As the prevalence of genitourinary malignancies continues to expand, additional patients can be expected to develop disease or treatment-related complications. This chapter will serve to review the diagnosis and management of oncologic emergencies as they pertain to the urologist.