Alternative indications for bisphosphonate therapy

Non-steroidal Anti-inflammatory Drug (NSAID)-, Potassium Supplement-, Bisphosphonate-, and Doxycycline-Mediated Peptic Ulcer Effects: A Narrative Review

Peptic ulcers are a common condition that arises from an imbalance between acid production and gastroduodenal protective factors. Various drugs, including non-steroidal anti-inflammatory drugs (NSAIDs), potassium supplements, bisphosphonates, and doxycycline, can increase the development of peptic ulcers. NSAIDs are one of the most common medications prescribed for pain relief, and they also inhibit the formation of cyclooxygenase-1 (COX-1). COX-1 helps in the production of mucus that lines the stomach, so by inhibiting COX-1, NSAIDs reduce the mucus produced by the stomach and increase the likelihood of gastric ulcer formation. Additionally, NSAIDs are acidic, and increasing the amount of any acid in the stomach can result in promoting ulcer development. Potassium supplements are used to reduce the effects of hypertension, decrease the development of kidney stones, and treat hypokalemia. The various types of transporters and channels used to move potassium across cell membranes increase hydrogen being pumped, increasing gastric acid production and ulcer formation. Bisphosphonates are used to treat a variety of skeletal disorders that require inhibition of osteoclast activity. Nitric oxide (NO) has been shown to have a therapeutic effect on gastric ulcers, and some bisphosphonates have been shown to decrease the production of nitric oxide, resulting in increased damage to the gastric mucosa. Finally, doxycycline is a broad-spectrum tetracycline antibiotic that is typically used to treat anthrax poisoning, skin lesions, and sexually transmitted diseases. A harmful adverse effect of doxycycline is the formation of peptic and gastric ulcers related to the drug being highly acidic once it has dissolved.

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.

Efficacy of the systemic co-administration of vitamin D3 in reversing the inhibitory effects of sodium alendronate on orthodontic tooth movement: A preliminary experimental animal study

INTRODUCTION

Bisphosphonates can severely slow down orthodontic tooth movement (OTM) by reducing bone turnover. This calls for materials and methods to reverse or neutralize their effects on OTM. We propose systemic vitamin D3 (D3) for this purpose.

METHODS

Thirty-two male Wistar rats were randomized into 4 groups of 8 each. Three groups were administered D3 (3 systemic doses of 24,000 IU/kg each), alendronate (ALN) (5 doses of 7 mg/kg each), and ALN+D3 (same doses as mentioned above). One group served as the negative control. The incisors were distalized at 30 g of force for 2 weeks. OTMs were measured blindly. Radicular pressure areas were searched histologically (blindly) for capillaries, Howship's lacunae, osteoclasts, and osteoblasts. Data were analyzed statistically (α = 0.05, α = 0.0083, β <0.1).

RESULTS

OTMs in the groups D3, ALN+D3, ALN, and control were 1.900 ± 0.237, 1.629 ± 0.219, 0.975 ± 0.145, and 1.565 ± 0.324 mm (analysis of variance, P <0.001), respectively. OTM in the ALN group was smaller than all other groups (Tukey, P <0.001). OTM in the D3 group was greater than in the control group (P = 0.054). The ALN+D3 group had greater OTM than the ALN group (P <0.001) but was not significantly different from the D3 (P = 0.153) or control (P = 0.951) groups. All histologic variables were significantly different across groups (Kruskal-Wallis, P <0.001). All the markers in the D3 group were more frequent than those of the other groups (Mann-Whitney U, P <0.001). There were fewer markers in the ALN group than in the control group (P ≤0.001). The ALN+D3 group had more markers than the ALN group in terms of capillaries, osteoclasts, and osteoblasts (P ≤0.007). The ALN+D3 group was similar to the control group regarding capillaries, osteoclasts, and osteoblasts (P ≥0.382).

CONCLUSIONS

Systemic vitamin D3 may accelerate OTM and increase histologic biomarkers of bone turnover. ALN reduces OTM and its histologic biomarkers. Systemic vitamin D3 can reverse this inhibitory effect of ALN on OTM back to normal.

Clinical and Radiologic Response of Central Giant Cell Granuloma to Denosumab: A 6-Year Prospective Observational Study

Central giant cell granuloma (CGCG) is a rare lesion of the jaw occurring in young adults and adolescents. Surgery, the traditional mainstay of therapy, is associated with significant morbidity. Denosumab, a humanised monoclonal antibody to RANKL, is effective in a related entity, giant cell tumour of bone (GCTB), but experience in the more indolent CGCG is limited. This prospective observational study of all denosumab-treated CGCG at a tertiary referral centre (2015-2021) aimed to evaluate the safety, efficacy and recurrence risk using denosumab in CGCG at lower-frequency dosing than used for GCTB. All received standardised, time-limited courses of denosumab 120 mg with stepwise increase in dosing interval based on response. They were followed for up to 75 months using a radiation-minimising protocol: 3-monthly clinical, biochemical and radiological assessment (orthopantomograms, cone beam CT). Eight patients, median age 20.5 years [IQR 6], received 13 initial doses [IQR 10] of denosumab 120 mg. Radiologic response was seen after 5.5 doses [IQR 4.5]: ossification in all and size reduction in three. Recurrence occurred in four of seven completing therapy, observed 12 months post-cessation [IQR 6.5]. Larger baseline size, aggressive subtype and fewer than 12 initial doses were more common in the recurrence group. There was no osteonecrosis of the jaw. Hypocalcaemia occurred in one receiving modified dosing. This study represents the largest, most diverse cohort of denosumab-treated CGCG with the longest follow-up in literature. It demonstrates the efficacy of lower-frequency, time-restricted course of denosumab but highlights the risk of recurrence. Long-term follow-up is critical.

Medication Management of Selected Pathological Jaw Lesions

Most jaw lesions are treated surgically. Areas of abnormal proliferation or destruction in bone are commonly treated by regional curettage, excision, or resection. However, surgery is invasive and leaves a defect where the lesion was removed. Surgical trauma to adjacent healthy tissue, including vital neurovascular bundles is often unavoidable, and can be especially traumatizing to the pediatric patient. Select jaw lesions with well-studied nonsurgical pharmaceutical treatments are presented here.

Multiple versus solitary giant cell lesions of the jaw: Similar or distinct entities?

The majority of giant cell lesions of the jaw present as a solitary focus of disease in bones of the maxillofacial skeleton. Less frequently they occur as multifocal lesions. This raises the clinical dilemma if these should be considered distinct entities and therefore each need a specific therapeutic approach. Solitary giant cell lesions of the jaw present with a great diversity of symptoms. Recent molecular analysis revealed that these are associated with somatic gain-of-function mutations in KRAS, FGFR1 or TRPV4 in a large component of the mononuclear stromal cells which all act on the RAS/MAPK pathway. For multifocal lesions, a small group of neoplastic multifocal giant cell lesions of the jaw remain after ruling out hyperparathyroidism. Strikingly, most of these patients are diagnosed with jaw lesions before the age of 20 years, thus before the completion of dental and jaw development. These multifocal lesions are often accompanied by a diagnosis or strong clinical suspicion of a syndrome. Many of the frequently reported syndromes belong to the so-called RASopathies, with germline or mosaic mutations leading to downstream upregulation of the RAS/MAPK pathway. The other frequently reported syndrome is cherubism, with gain-of-function mutations in the SH3BP2 gene leading through assumed and unknown signaling to an autoinflammatory bone disorder with hyperactive osteoclasts and defective osteoblastogenesis. Based on this extensive literature review, a RAS/MAPK pathway activation is hypothesized in all giant cell lesions of the jaw. The different interaction between and contribution of deregulated signaling in individual cell lineages and crosstalk with other pathways among the different germline- and non-germline-based alterations causing giant cell lesions of the jaw can be explanatory for the characteristic clinical features. As such, this might also aid in the understanding of the age-dependent symptomatology of syndrome associated giant cell lesions of the jaw; hopefully guiding ideal timing when installing treatment strategies in the future.

Effect of adjuvant bisphosphonates on treatment of periodontitis: Systematic review with meta-analyses

Background

Previous systematic reviews showed additional benefit of adjuvant bisphosphonates (BP) in the treatment of periodontitis. In contrast, it is unclear the effect of BP in patients with diabetes and smokers, its pooled effect when administered locally or systemically is also unknown.

Objectives

This study aimed to systematically review the literature about the use of BP as adjuvant to nonsurgical scaling and root planning (SRP).

Methodology

This study followed the PRISMA guideline. This study included randomized clinical trials that administered locally or systemically BPs as adjuvant for periodontal treatment. Five databases were used. Meta-analyses were performed, using the pooled mean differences (MD) for clinical attachment level (CAL) and probing pocket depth (PPD). Standard mean difference (SMD) was used for radiographic assessment (RADIO). Subgroup analyses were performed for locally delivered meta-analyses, considering diabetes and smoking exposure.

Results

Thirteen studies were included. It was showed MD of 1.52 ​mm (95%CI: 0.97-2.07) and 1.44 ​mm (95%CI: 1.08-1.79) for PPD reduction and CAL gain, respectively, for locally delivered BP. BP was not able to provide significant improvements in smokers (subgroup analysis) when considering CAL (MD: 1.37; 95%CI: -0.17-2.91) and PPD (MD: 1.35; 95%CI: -0.13-2.83). Locally delivered BP also improved significantly the RADIO assessments (SMD: 4.34; 95%CI: 2.94-5.74). MD for systemically administered BP was 0.40 ​mm (95%CI: 0.21-0.60), 0.51 ​mm (95%CI: 0.19-0.83) and 1.05 (95%CI: 0.80-1.31) for PPD, CAL and RADIO, respectively.

Conclusion

The administration of BP in adjunct to SRP may result in additional clinical effects.

Adjuvant Alendronic Acid in the Management of Severe Cherubism: A Case Report and Literature Review

Cherubism is a rare disease of the jaws characterized by bilateral symmetrical painless expansion of the mandible and maxilla. In extreme cases, larger lesions can become exophytic and have profound functional and esthetic implications. Several pharmacologic agents have been trialed in the treatment of cherubism with variable success reported. Bisphosphonates have not been significantly studied in this setting. We present a case where oral alendronic acid was used as an adjuvant treatment after surgical debulking of the maxilla in a 13-year-old boy with a severe case of cherubism.

The incidence and relative risk of adverse events in patients treated with bisphosphonate therapy for breast cancer: a systematic review and meta-analysis

Background:

Adjuvant bisphosphonates reduce the rate of breast cancer recurrence in the bone and improve breast cancer survival. However, the risk of adverse events associated with bisphosphonate therapy for breast cancer remains poorly defined.

Methods:

A literature search was conducted using the PubMed, EMBASE, Cochrane and Web of Science libraries. Risk ratio (RR) was calculated to evaluate the adverse events of the meta-analytic results. Osteonecrosis of the jaw (ONJ) incidence was calculated using the random effect model (D+L pooled) for meta-analysis.

Results:

A total of 47 studies comprising 20,607 patients were included; 23 randomized controlled studies (RCTs) provided data of adverse events for bisphosphonate therapy versus without bisphosphonates. Bisphosphonates were significantly associated with influenza-like illness (RR = 4.52), fatigue (RR = 1.08), fever (RR = 1.82), dyspepsia (RR = 1.25), anorexia (RR = 1.29), and urinary tract infection (RR = 1.32). No differences were observed in other adverse events. We combined the incidence of ONJ in 24 retrospective studies to analyze the incidence of ONJ using bisphosphonates. The pooled probability of ONJ toxicity in the bisphosphonates group was 2%.

Conclusions:

Bisphosphonates were significantly associated with influenza-like illness, fatigue, fever, dyspepsia, anorexia, and urinary tract infection. Furthermore, bisphosphonates increase the risk of ONJ toxicity.

Vanishing Mandible in a 7-year Old Child: Response to Radiation Therapy

Massive osteolysis in a 7-year old child is a rare condition. The etiology of massive osteolysis is unknown and it results in the progressive destruction of bony structures. There is no standard therapy available in the literature. Conservative treatment is often used for its management. Radiotherapy is considered as an accepted form of treatment with greater chance of success when it is used in the early course of disease. There are few case reports in the literature in which radiotherapy has been used for the treatment. This article highlights the literature update on various treatment modalities and a case managed by radiation therapy.

Pharmacological and surgical therapy for the central giant cell granuloma: A long-term retrospective cohort study

PURPOSE

This is a retrospective cohort study of patients with a central giant cell granuloma (CGCG) treated at a single center to assess and compare the different surgical and non-surgical approaches.

MATERIAL AND METHODS

A cohort with a single histologically proven non-syndrome-related CGCG was selected and reviewed. Patients were allocated to group I (surgery), group II (pharmacotherapy), and group III (pharmacotherapy and surgery). The primary outcome was long-term radiologic response using computed tomography. Secondary outcomes were intermediate radiologic responses and occurrence and severity of side effects.

RESULTS

Thirty-three subjects were included in the study. The surgical group (n = 4) included 1 patient with progression during follow-up and a relatively high post-surgical morbidity. Twenty-nine patients started on various pharmacological treatment regimens (groups II and III). Fourteen patients could be managed without additional surgery. One of these lesions showed progression during follow-up. The other 15 lesions underwent additional surgery, and none showed progression during follow-up. Interferon treatment was associated with the most side effects.

CONCLUSION

Pharmacological agents have a role in the treatment of aggressive and non-aggressive CGCGs by limiting the renewed progression during long-term follow up and the extent and morbidity of surgical treatment.

[Central giant cell granuloma in children: Presentation of different therapeutic options]

Central giant cell granuloma (CGCG) is a benign tumor that may be subdivided in a non-aggressive form and an aggressive form. In aggressive forms, tumor size and high recurrence risk need large surgical resections. In order to minimize surgical morbidity, especially in children, medical treatments acting on the tumor proliferation are currently being assessed: steroids (triamcinolone), anti-osteoclastic drugs (calcitonine, alendronate, denosumab), anti-angiogenic drugs (interferon α). However to date, there is no evidence for any superiority of medical over surgical treatment. Complete response is rarely obtained and additional surgery is often necessary to remove the tumor in case of tumor progression, to remove a remnant or to remodel bone. Moreover, these drugs have frequent local or systemic side effects such as osteonecrosis and growth deficiencies.

Lung Transplantation in Gaucher Disease: A Learning Lesson in Trying to Avoid Both Scylla and Charybdis

Gaucher disease (GD), a lysosomal storage disorder, may result in end-stage lung disease. We report successful bilateral lung transplantation in a 49-year-old woman with GD complicated by severe pulmonary hypertension and fibrotic changes in the lungs. Before receiving the lung transplant, the patient was undergoing both enzyme replacement therapy (imiglucerase) and triple pulmonary hypertension treatment (epoprostenol, bosentan, and sildenafil). She had a history of splenectomy, severe bone disease, and renal involvement, all of which were related to GD and considered as relative contraindications for a lung transplantation. In the literature, lung transplantation has been suggested for severe pulmonary involvement in GD but has been reported only once in a child. To our knowledge, until now, no successful procedure has been reported in adults, and no reports deal with the severe potential posttransplantation complications specifically related to GD.

Zoledronic Acid for the Treatment of Children With Refractory Central Giant Cell Granuloma

There are no approved medical therapies for the treatment of pediatric central giant cell granuloma (CGCG), a benign but potentially aggressive tumor of the jaw. Zoledronic acid (ZA), a third-generation bisphosphonate, has been used in CGCG occurring in adults. We describe 4 patients with CGCG treated with ZA, 3 of whom achieved resolution of disease up to 4 years of follow-up. Our experience suggests that ZA may be considered as treatment for pediatric CGCG.

An unusual case of atrophic mandible fracture in a patient with osteogenesis imperfecta and on oral bisphosphonate therapy: Case report

Fractures of severely atrophic (height < 10 mm) edentulous mandibles are infrequent and challenging to manage. Factors such as sclerotic bone and decreased vascularity combined with systemic diseases complicate the management of such fractures. Osteogenesis imperfecta (OI) is a heterogeneous group of inherited disorders of type I collagen metabolism. Patients with OI characteristically present with histories of long bone fractures, deformities, blue sclerae, and opalescent dentin. However, fractures of the facial skeleton are rare. Bisphosphonate therapy has been proven to effectively reduce the fracture risk in patients with OI. The purpose of this clinical report is to present an unusual case of spontaneous fracture of the atrophic mandible in a patient with OI. Despite open reduction and internal fixation (ORIF) with miniplate osteosynthesis, the patient developed a second fracture at a screw placement site distal to the first fracture. The patient was successfully treated with ORIF using locking reconstruction plates fixed in the symphyseal and angle regions. Bone healing following ORIF was normal, and no clinical sign of osteonecrosis as a result of bisphosphonate therapy was observed. Patients with OI can present with spontaneous fractures of already weakened mandibles. Although such fractures can be managed with care using established protocols, further research is required to examine the effects of concomitant medication, such as bisphosphonates.

Bisphosphonates use in children

Bisphosphonates are synthetic analogues of pyrophosphate that inhibit bone resorption by their action on osteoclasts. In recent years, bisphosphonates have been used in children for treatment of a growing number of disorders associated primarily with generalized or localized osteoporosis, genetic and acquired metabolic bone diseases, heterotopic calcifications in soft tissues, and for hypercalcemia. In this review, the authors address the role of and experience with bisphosphonate therapy in disorders of childhood.

Treatment of central giant cell lesions using bisphosphonates with intralesional corticosteroid injections

Central giant cell lesions are benign intraosseous proliferative lesions that have considerable local aggressiveness. Nonsurgical treatment methods, such as intralesional corticosteroid injections, systemic calcitonin and interferon have been reported. Recently, bisphosphonates have been used to treat central giant cell lesions. A case of a 36-year-old male with a central giant cell lesion crossing the mandibular midline was treated with intralesional corticosteroids combined with alendronate sodium for the control of systemic bone resorption. The steroid injections and the use of bisphosphonates were stopped after seven months when further needle penetration into the lesion was not possible due to new bone formation. After two years, the bony architecture was near normal, and only minimal radiolucency was present around the root apices of the involved teeth. The patient was followed up for four years, and panoramic radiography showed areas of new bone formation. Thus far, neither recurrence nor side effects of the medication have been detected.

Bisphosphonate related osteonecrosis of the jaws: a review

Bisphosphonate use has increased in veterinary medicine over the last decade. During this time, bisphosphonate related osteonecrosis of the jaws (BRONJ) in human patients has been identified. Only recently was a dog model for BRONJ developed for human oral surgery and medicine. Veterinary patients treated with bisphosphonates may be at an increased risk for BRONJ There has been little, to no, investigation of potential long term side-effects of bisphosphonate use in veterinary patients; potential sequelae are unknown. The history of bisphosphonates, their use, and BRONJ in veterinary patients are discussed.

Role of polyethylene particles in peri-prosthetic osteolysis: A review

There is convincing evidence that particles produced by the wear of joint prostheses are causal in the peri-prosthetic loss of bone, or osteolysis, which, if it progresses, leads to the phenomenon of aseptic loosening. It is important to fully understand the biology of this bone loss because it threatens prosthesis survival, and loosened implants can result in peri-prosthetic fracture, which is disastrous for the patient and presents a difficult surgical scenario. The focus of this review is the bioactivity of polyethylene (PE) particles, since there is evidence that these are major players in the development and progression of osteolysis around prostheses which use PE as the bearing surface. The review describes the biological consequences of interaction of PE particles with macrophages, osteoclasts and cells of the osteoblast lineage, including osteocytes. It explores the possible cellular mechanisms of action of PE and seeks to use the findings to date to propose potential non-surgical treatments for osteolysis. In particular, a non-surgical approach is likely to be applicable to implants containing newer, highly cross-linked PEs (HXLPEs), for which osteolysis seems to occur with much reduced PE wear compared with conventional PEs. The caveat here is that we know little as yet about the bioactivity of HXLPE particles and addressing this constitutes our next challenge.

Administration of sodium ibandronate in the treatment of complicated giant cell tumor of the spine

STUDY DESIGN

Case study.

OBJECTIVE

To present three complicated cases of giant cell tumor of the spine treated with sodium ibandronate.

SUMMARY OF BACKGROUND DATA

Spinal giant cell tumors are a rare clinical entity with a high recurrence rate after operation. Furthermore, complete resection of such lesions remains a challenging surgical problem. Up to this point, no effective adjuvant therapy has been reported for primary or recurrent spinal giant cell tumors.

METHODS

One patient with a recurrent giant cell tumor of the seventh thoracic vertebra, one patient with a fifth lumbar vertebral giant cell tumor, and one patient with recurrent giant cell tumor of the sacrum were treated with sodium ibandronate either postoperatively or upon recurrence of the tumor.

RESULTS

The first patient with recurrent thoracic giant cell tumor recovered both clinically and radiologically after treatment with sodium ibandronate without reoperation at 6-years follow-up. The second patient also recovered with no recurrence of the tumor at 4-years follow-up. In the third case, although not fully recovered, the recurrent sacral tumor was under control after treatment with sodium ibandronate at 2-years follow-up.

CONCLUSION

These case studies demonstrate the potential promise of using sodium ibandronate in the treatment of primary and recurrent giant cell tumors of the spine. Furthermore, clinical evaluation should be performed in future studies.

The role of bisphosphonates in multiple myeloma: mechanisms, side effects, and the future

Zoledronic acid and pamidronate are two potent anticatabolic nitrogen-containing bisphosphonates (BPs) used extensively in diseases with high bone turnover such as multiple myeloma (MM). In this review we focus on their biology and their current and future use in MM, and highlight some of the most common and emerging side effects. Although the primary target cells for BPs are osteoclasts, new insights suggest other cell types of the bone microenvironment as possible targets, including osteoblasts, endothelial cells, immune cells, and cancer cells. Here, we focus on the current guidelines for the use of BPs in MM and address side effects such as renal toxicity, osteonecrosis of the jaw, and low-energy fractures. Finally, we approach the future of BP use in MM in the context of other bone-targeted agents, evaluating ongoing clinical trials addressing alternate dosing and schedules of BP administration in MM patients.

Hemimandibulectomy after bisphosphonate treatment for complex regional pain syndrome: a case report and review on the prevention and treatment of bisphosphonate-related osteonecrosis of the jaw

BACKGROUND

The increase in reported cases of osteonecrosis of the jaw has increased the clinical significance of bisphosphonate therapeutic agents in the dentistry field.

METHODS

We present a rare and severe case of bisphosphonate-related osteonecrosis of the jaw caused by medicamentous treatment of complex regional pain syndrome. This article reviews the current international prevention and treatment guidelines with regard to bisphosphonate treatment.

RESULTS

Even rare indications for bisphosphonate treatment may lead to devastating effects on the patient.

CONCLUSIONS

Dentists and physicians who prescribe bisphosphonates should be familiar with the side effects of these drugs and the management of these side effects. To prevent negative outcomes, it is important that there be a close collaboration among the doctors involved and that a thorough medical history is obtained; this is especially true because the range of indications for bisphosphonate treatment increases every year.

Bisphosphonate associated osteonecrosis: an unusual case

The management of bisphosphonate associated osteonecrosis of the jaws (bisphosphonate associated ONJ) is emerging as a significant problem in the field of dentistry and oral and maxillofacial surgery. We present a case of a 55-year-old female taking oral bisphosphonates, steroids and immunosuppressant agents presenting with a life-threatening neck swelling. We discuss management options, as well as recent guidelines for treatment.

Use of aromatase inhibitors and bisphosphonates as an anticancer therapy in postmenopausal breast cancer

Breast cancer is a major cause of morbidity and mortality in postmenopausal women worldwide. Reducing the risk of distant disease recurrence is a primary goal of adjuvant endocrine therapy. As we await data from ongoing Phase III comparison trials, an emerging body of evidence demonstrates important differences between third-generation aromatase inhibitors, particularly with respect to potency and prevention of early distant metastases. Furthermore, a growing body of evidence demonstrates anticancer benefits of bisphosphonates in adjuvant breast cancer and other settings. This article outlines the proceedings from an Expert Panel meeting of regionally diverse breast cancer specialists regarding the appropriate use of aromatase inhibitors in postmenopausal hormone-responsive early breast cancer and bisphosphonates as anticancer therapy in adjuvant breast cancer.

Octreotide and the mTOR inhibitor RAD001 (everolimus) block proliferation and interact with the Akt-mTOR-p70S6K pathway in a neuro-endocrine tumour cell Line

BACKGROUND/AIM

The mode of action of the somatostatin analog octreotide on neuro-endocrine tumour proliferation is largely unknown. Overexpression of the proto-oncogene Akt/PKB (protein kinase B) has been demonstrated in certain neuro-endocrine tumours: Akt activates downstream proteins including mTOR and p70S6K, which play an important role in cell proliferation. RAD001 (everolimus) is a novel agent that is being trialled in the treatment of neuro-endocrine tumours, and is known to interact with mTOR. We explored the mechanism of action of octreotide, RAD001, and their combination on cell proliferation and kinase activation in a neuro-endocrine tumour cell line (rat insulinoma cell line, INS1).

METHODS

Proliferation assays were used to determine the effects of octreotide, RAD001, and their combination on cell proliferation. Western blotting was used to characterize the expression of phosphorylated Akt, phosphorylated TSC2, phosphorylated mTOR, and phosphorylated 70S6K.

RESULTS

Treatment with octreotide and RAD001 inhibited proliferation and attenuated phosphorylation of all downstream targets of Akt: TSC2, mTOR, and p70S6K.

CONCLUSIONS

In this cell model, octreotide and RAD001 appear to act through a similar pathway and inhibit the Akt-mTOR-p70S6 kinase pathway downstream of Akt. There may be some overlapping effects of the two inhibitors on the mTOR pathway, although it is likely that other additional effects may differentiate the two agents.