American society of clinical oncology clinical practice guideline update: recommendations on the role of bone-modifying agents in metastatic breast cancer

The association of osteoporosis knowledge and beliefs with preventive behaviors in postmenopausal breast cancer survivors

BACKGROUND

Postmenopausal breast cancer survivors (PBCS) are at increased risk of bone loss and fractures due to age-related decline of estrogen, and this risk is compounded by aromatase inhibitor cancer therapy. Several patient-level targetable risk factors can mitigate osteoporosis risk; however, adequate health behavior and risk perception in this population are underreported. The goal of this study was to evaluate osteoporosis knowledge and beliefs and assess their association with engagement in osteoporosis preventive behaviors among PBCS.

METHODS

In this cross-sectional descriptive study, early stage I-IIIA PBCS (ages 55-86 years) completed the Facts on Osteoporosis Quiz, Osteoporosis Health Beliefs Scale, and Osteoporosis Preventive Behaviors questionnaires. Participants who were non-English speaking or declined to participate were excluded. Clinical and sociodemographic information were obtained from chart review and baseline questionnaire, respectively. Fisher's exact test, Student t-test, and Wilcoxon Mann-Whitney tests were used where appropriate to assess the association between knowledge and beliefs with engagement in osteoporosis preventive behaviors.

RESULTS

The mean participant age was 66.1 years with 20% self-reporting as non-Hispanic White, 40% non-Hispanic Black, 27% Hispanic, and 13% other. Approximately 83% of the cohort had estrogen receptor positive breast cancer and received a bone density scan within the last six years. Osteoporosis knowledge (10.5 ± 3.4), seriousness (14.9 ± 3.8), and susceptibility (14.0 ± 3.5) mean scores were low among PBCS. Most PBCS (75%) were adherent to calcium and vitamin D supplements, but only 47% reported engagement in strength-training exercises. Married/partnered, higher osteoporosis knowledge and health motivation scores were associated with strength-training exercise. After adjustment for marital status and osteoporosis knowledge, only health motivation score remained significantly associated with strength-training exercise (OR 5.56, 95% CI 1.35-22.93).

CONCLUSIONS

PBCS are highly motivated to keep a healthy lifestyle despite limited osteoporosis knowledge, perceived risk, and susceptibility. However, < 50% participated in strength-training exercise. Our findings suggest that oncologic care should include osteoporosis and fracture prevention strategies, directed at encouraging cancer survivors to increase their engagement in osteoporosis preventive behaviors, particularly strength-training exercises.

"The use of bisphosphonates to treat skeletal complications in solid tumours"

The skeleton is the most common site of secondary disease in breast cancer and prostate cancer, with up to 80% of patients with advanced disease developing bone metastases (BM). The proportion is also substantial in advanced lung cancer (20%-40%). Because of the high prevalence of cancers of the breast, prostate and lung, these cancers account for more than 80% of cases of metastatic bone disease occurring in solid tumours. Metastatic bone disease is associated with greatly increased bone resorption by osteoclasts, leading to moderate to severe pain and other skeletal complications, with major impact on quality of life (QoL). Skeletal Related Events (SREs) have been defined as: pathological long bone or vertebral fractures; spinal cord compression; need for radiation for pain relief or to prevent fracture/spinal cord compression, need for surgery to bone and hypercalcaemia. More recently, Symptomatic Skeletal Events (SSEs) have been defined to monitor QoL. Although there are currently no curative treatments for metastatic bone disease, patients with breast or prostate cancer and BM are now surviving for several years and sometimes longer, and prevention of SREs is the key aim to optimization of QoL. Since their discovery 50 years ago and their introduction more than 30 years ago into the field of metastatic bone disease, a range of oral and intravenous bisphosphonate drugs have made a major contribution to prevention of SREs. Large trials have clearly demonstrated the clinical value of different bisphosphonate-based drugs (including the oral drugs ibandronate and clodronate and intravenous agents such as zoledronate and pamidronate), in treatment of hypercalcaemia of malignancy and the reduction of SREs and SSEs in a range of cancers. Despite the success of denosumab in reducing osteolysis, bisphosphonates also remain mainstay drugs for treatment of metastatic bone disease. Recognizing the 50th Anniversary of the discovery of bisphosphonates, this review focuses on their continuing value in BM treatment and their future potential, for example in providing a bone-targeting vehicle for cytotoxic drugs.

Review of Bone Modifying Agents in Metastatic Breast Cancer

Bone is the most common site for distant metastases in breast cancer and can cause significant morbidity and mortality. Bone modifying agents (BMAs) that include bisphosphonates (BPAs) and denosumab help in decreasing and delaying skeletal-related events (SREs) associated with metastatic breast cancer. BPAs approved for use by the Food and Drug Administration (FDA) in bone metastases (BM) in the United States are pamidronate and zolendronic acid, while clodronate and ibandronate are licensed for use in other countries. Current American Society of Clinical Oncology (ASCO) guidelines recommend denosumab 120 mg subcutaneously every four weeks, or zolendronic acid 4 mg every four weeks or every 12 weeks, or intravenous pamidronate 90 mg every four weeks. Current guidelines do not recommend one BMA over another, however, zolendronic acid and denosumab were the most commonly used BMAs in population-based studies. Side effects of BMAs include acute phase reactions, hypocalcemia, nephrotoxicity, osteonecrosis of jaw, etc. While other side effects are common with both BPAs and denosumab, the latter has less nephrotoxic potential and is preferred for use in patients with renal failure. Current ASCO guidelines recommend continuing BMAs indefinitely, however, in clinical practice, this decision needs to be individualized, especially since there is no data on the impact of long-term use of BMAs. Further studies would need to be developed to develop an algorithm of SRE risk assessment and to determine which patients would benefit from BMAs.

Risk of osteoporosis and fracture in long-term breast cancer survivors

Purpose

High incidence of osteoporosis has been reported in breast cancer patients due to early menopause triggered by adjuvant treatment and temporary ovarian function suppression. In this study, we sought to determine whether long-term breast cancer survivors had an elevated risk of low bone density compared to the general population.

Methods

Long-term breast cancer survivors who had been treated for more than 5 years were selected for this study. Data were obtained from medical records and using a questionnaire from the Korea National Health and Nutrition Examination Survey (KNHANES). An age-matched non-cancer control group was selected from the KNHANES records. Incidence of fracture and bone mineral density (BMD) were compared between the two groups.

Results

In total, 74 long-term breast cancer survivors and 296 non-cancer controls were evaluated. The incidence of fracture did not differ between the two groups (P=0.130). No differences were detected in lumbar BMD (P=0.051) following adjustment for body mass index, while hip BMD was significantly lower in breast cancer survivors (P=0.028). Chemotherapy and endocrine treatment were not related to low BMD in breast cancer survivors. In more than half of the survivors, the 10-year risk of osteoporotic fracture was less than 1%.

Conclusion

Long-term breast cancer survivors had low bone density but a comparable risk of fracture compared to non-cancer age-matched controls. Further studies on the factors related to low bone density in long-term breast cancer survivors are required.

Skeletal Metastases of Unknown Primary: Biological Landscape and Clinical Overview

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

De-escalation of bone-modifying agents in patients with bone metastases from breast cancer: a systematic review and meta-analysis

PURPOSE

Bone-modifying agents (BMAs) such as bisphosphonates and denosumab are usually administered every 4 weeks (standard) in patients with bone metastases from breast cancer to prevent skeletal-related events (SREs). Recent randomized controlled trials suggest every 12-week (de-escalated) dosing interval may be non-inferior. The objective of this systematic review and meta-analysis was to compare the efficacy and harms of standard with de-escalated administration of BMA's in patients with bone metastases from breast cancer.

METHODS

We searched Medline, PubMed, and the Cochrane Register of Controlled Trials from 1947 to March 14, 2018 and conference abstracts from (2014-March 14, 2018) for randomized clinical trials comparing every 4-week and every 12-week dosing interval of bone-modifying agents. Using PRISMA guidelines, meta-analyses were performed using random-effects models, with findings reported as risk ratios with 95% confidence intervals (CI).

RESULTS

From a total of 1311 citations, we identified 8 full-text articles and 1 abstract comprising data from 5 completed randomized clinical trials (n = 1807). Zoledronate administration every 12 weeks compared to every 4 weeks produced a summary risk ratio of 1.05 (95% CI 0.88-1.25) for patients with ≥ 1 on-study SRE indicating similar efficacy. These results did not differ whether patients had received prior intravenous bisphosphonate. De-escalation was associated with a non-statistically significant lower risk of increased creatinine (summary risk ratio 0.41 [95% CI 0.15-1.16]). Currently, there are insufficient data for pamidronate and denosumab de-escalation.

CONCLUSIONS

These data are supportive of de-escalation of zoledronate from onset for patients with bone metastases from breast cancer.

Effect of denosumab versus zoledronic acid on calcium levels in cancer patients with bone metastasis: A retrospective cohort study

Objective

To identify the incidence of hypercalcemia and hypocalcemia in zoledronic acid and denosumab groups. Secondary objective was to determine the correlation between calcium supplement and calcium level control.

Methods

An observational retrospective cohort study was conducted by reviewing patient electronic records, laboratory results, and medication charts from 1 August 2015 to 31 July 2016. Adult cancer patients who were diagnosed with bone metastasis secondary to a solid tumor or multiple myeloma and who received either zoledronic acid or denosumab were included. Other indications for bone targeting agents were excluded. Data of bone targeting agents administration encounters were collected, evaluated, and analyzed.

Results

A total of 1141 encounters (for 271 patients) were included. The incidence of hypocalcemia was higher in denosumab compared to zoledronic acid group (5.5% vs. 3.1%, OR = 0.55, 95% CI [0.3–1.0]; P = 0.05). Hypercalcemia incidence was also higher in denosumab group (8.5% vs. 3.1%, OR = 2.9, 95% CI [1.68–5.03]; P < 0.0001). Breast cancer was the most common malignancy associated with hypocalcemia (27.3%) followed by ovarian cancer (25%) and multiple myeloma (22.7%). The risk of developing hypocalcemia was reduced by 16% in patients receiving calcium supplementation (RR = 0.84, 95% CI [0.55–1.20]; P = 0.39).

Conclusion

Denosumab use was associated with higher rates of both hypercalcemia and hypocalcemia compared to zoledronic acid. Adequate supplementation with calcium substantially reduced the risk of hypocalcemia. Our results highlight the importance of taking preventative measures upon bone targeting agents initiation and during treatment including regular monitoring of calcium levels and providing supplements accordingly.

Understanding the Progression of Bone Metastases to Identify Novel Therapeutic Targets

Bone is one of the most preferential target site for cancer metastases, particularly for prostate, breast, kidney, lung and thyroid primary tumours. Indeed, numerous chemical signals and growth factors produced by the bone microenvironment constitute factors promoting cancer cell invasion and aggression. After reviewing the different theories proposed to provide mechanism for metastatic progression, we report on the gene expression profile of bone-seeking cancer cells. We also discuss the cross-talk between the bone microenvironment and invading cells, which impacts on the tumour actions on surrounding bone tissue. Lastly, we detail therapies for bone metastases. Due to poor prognosis for patients, the strategies mainly aim at reducing the impact of skeletal-related events on patients' quality of life. However, recent advances have led to a better understanding of molecular mechanisms underlying bone metastases progression, and therefore of novel therapeutic targets.

Role of Bone-Modifying Agents in Metastatic Breast Cancer: An American Society of Clinical Oncology–Cancer Care Ontario Focused Guideline Update

Purpose

To update, in collaboration with Cancer Care Ontario (CCO), key recommendations of the American Society of Clinical Oncology (ASCO) guideline on the role of bone-modifying agents (BMAs) in metastatic breast cancer. This focused update addressed the new data on intervals between dosing and the role of BMAs in control of bone pain.

Methods

A joint ASCO-CCO Update Committee conducted targeted systematic literature reviews to identify relevant studies.

Results

The Update Committee reviewed three phase III noninferiority trials of dosing intervals, one systematic review and meta-analysis of studies of de-escalation of BMAs, and two randomized trials of BMAs in control of pain secondary to bone metastases.

Recommendations

Patients with breast cancer who have evidence of bone metastases should be treated with BMAs. Options include denosumab, 120 mg subcutaneously, every 4 weeks; pamidronate, 90 mg intravenously, every 3 to 4 weeks; or zoledronic acid, 4 mg intravenously every 12 weeks or every 3 to 4 weeks. The analgesic effects of BMAs are modest, and they should not be used alone for bone pain. The Update Committee recommends that the current standard of care for supportive care and pain management—analgesia, adjunct therapies, radiotherapy, surgery, systemic anticancer therapy, and referral to supportive care and pain management—be applied. Evidence is insufficient to support the use of one BMA over another. Additional information is available at www.asco.org/breast-cancer-guidelines and www.asco.org/guidelineswiki .

N-Telopeptide of Type I Collagen Long-Term Dynamics in Breast Cancer Patients With Bone Metastases: Clinical Outcomes and Influence of Extraskeletal Metastases

BACKGROUND

Markers of bone metabolism, such as N-telopeptide of type I collagen (NTX), have been demonstrated to be prognostic in previous trials of breast cancer (BC) patients with bone metastases (BMs). In the present study, we tested the survival effect of the NTX response to zoledronic acid (ZA) at 3 and 12 months in a contemporaneous cohort of BC patients with BMs and evaluated the influence of extraskeletal metastatic disease on NTX variation.

PATIENTS AND METHODS

The present study was a prospective cohort study of consecutive BC patients diagnosed and treated at a single center. Patients presenting with de novo radiological evidence of BMs who started monthly intravenous ZA were included. Urinary NTX was measured at baseline and 1, 3, 6, 9, and 12 months after ZA introduction.

RESULTS

Overall, 71 patients were enrolled, 32 with BMs and 39 with BMs plus extraskeletal metastases. The proportion of patients with elevated NTX at baseline and 3 and 12 months was 49.3%, 26.6%, and 34.2%, respectively. The variables associated with survival included age at diagnosis, tumor estrogen receptor status, and NTX at 3 and 12 months. Multivariate analysis showed that, in addition to age at diagnosis, only the 3-month NTX level was significantly associated with survival. Patients with BMs plus extraskeletal metastases had an erratic NTX variation pattern, unrelated to survival.

CONCLUSION

In the present contemporaneous cohort of BC patients with BMs, the NTX response at 3 months was strongly associated with survival. Furthermore, an early response to ZA was strongly associated with long-term NTX control. Finally, patients with BMs plus extraskeletal metastases had an erratic NTX variation.

IMPLICATIONS FOR PRACTICE

The present study showed that when accommodating recent therapy innovations and longer patient survival, the N-telopeptide (NTX) variation at 3 months is strongly associated with survival. In this setting, in addition to a few other clinicopathological features, NTX is a powerful prognostic marker. Moreover, early NTX correction associates with persistently normal NTX. This might identify a subgroup of patients with a good prognosis who are eligible for premature zoledronic acid (ZA) de-escalation. Finally, patients with bone plus extraskeletal metastases showed an erratic variation of NTX, raising concerns that a single ZA regimen might not fit all patients. Future trials should test its effect according to the presence of extraskeletal involvement.

Zoledronate in combination with chemotherapy and surgery to treat osteosarcoma (OS2006): a randomised, multicentre, open-label, phase 3 trial

BACKGROUND

Based on preclinical data for the antitumour effect of zoledronate in osteosarcoma, we assessed whether zoledronate combined with chemotherapy and surgery improved event-free survival in children and adults with osteosarcoma.

METHODS

In this randomised, multicentre, open-label, phase 3 trial (OS2006), patients aged between 5 years and 50 years with newly diagnosed high-grade osteosarcoma were randomly assigned to receive standard chemotherapy with or without ten zoledronate intravenous infusions (four preoperative and six postoperative). Adults older than 25 years received 4 mg zoledronate per infusion, patients aged 18-25 years received 0·05 mg/kg for the first two infusions and 4 mg for the remaining eight infusions, and younger patients received 0·05 mg/kg per infusion. Chemotherapy comprised high-dose methotrexate based chemotherapy in patients younger than 18 years, and doxorubicin, ifosfamide, and cisplatin in adults older than 25 years; patients aged 18-25 years were treated with either regime at the discretion of the treating centre. Balanced randomisation between the two groups was done centrally with online randomisation software, based on a minimisation algorithm taking into account centre, age, combined with chemotherapy regimen, and risk group (resectable primary and no metastasis vs other). Patients and investigators were not masked to treatment assignment, but the endpoint adjudication committee members who reviewed suspected early progressions were masked to group allocation. The primary endpoint was event-free survival, estimated from the randomisation to the time of first failure (local or distant relapse, progression, death) or to the last follow-up visit for the patients in first complete remission, analysed on a modified intention-to-treat population, which excluded patients found not to have a malignant tumour after central review. Three interim analyses were planned. This trial is registered with ClinicalTrials.gov, number NCT00470223.

FINDINGS

Between April 23, 2007, and March 11, 2014, 318 patients, median age 15·5 years (range 5·8-50·9), were enrolled from 40 French centres; of whom 158 were assigned to the control group (chemotherapy alone) and 160 to the zoledronate group, including 55 (17%) patients with definite metastases. The trial was stopped for futility after the second interim analysis. With a median follow-up of 3·9 years (IQR 2·7-5·1), 125 events occurred (55 in the control group and 70 in the with zoledronate group). Event-free survival at 3 years for all 315 randomly assigned patients was 60·3% (95% CI 64·5-65·9); 3-year event-free survival was 63·4% (55·2-70·9) for the control group and 57·1% (48·8-65·0) for the zoledronate group. The risk of failure was not reduced and was even marginally higher in the zoledronate group than in the control group (hazard ratio [HR] 1·36 [95% CI 0·95-1·96]; p=0·094). No major increase in severe toxic effects of grade 3 or higher associated with zoledronate, barring expected hypocalcaemia (45 [29%] of 153 participants in the zoledronate group vs ten [6%] of 155 participants in the control group; p<0·0001) and hypophosphataemia (61 [40%] of 151 in the zoledronate group vs 26 [17%] of 156 in the control group; p<0·0001). No significant difference in orthopaedic complications was noted between the two groups (27 in the control group and 29 in the zoledronate group). Two treatment-related deaths were reported (one from cardiomyopathy in the control group and one from multiorgan failure in the zoledronate group before the first zoledronate infusion).

INTERPRETATION

From the results observed in this study, we do not recommend zoledronate in osteosarcoma patients. Further biological studies are required to understand the discordance between the results of OS2006 trial and preclinical data.

FUNDING

French National Cancer Institute (INCa), Novartis, Chugai, Ligue Nationale contre le Cancer, Fédération Enfants et Santé, Société Française des Cancers et Leucémies de l'Enfant.

Risk Factors for Developing Skeletal-Related Events in Breast Cancer Patients With Bone Metastases Undergoing Treatment With Bone-Modifying Agents

BACKGROUND

Bone-modifying agents (BMAs) reduce the incidence of skeletal-related events (SREs) and are thus recommended for breast cancer patients with bone metastases. However, the risk factors for SREs during BMA treatment are not well-understood. This study evaluated the number and timing of SREs from case studies to identify these factors.

METHODS

The medical records of 534 women with breast cancer who developed bone metastases between 1999 and 2011 were reviewed. SREs were defined as a pathologic fracture, spinal cord compression, or the need for bone irradiation or surgery. Multiple variables were assessed and were analyzed by using the Cox proportional hazard analyses and the Andersen and Gill method.

RESULTS

Multivariate analyses for both the time to the first SRE and the primary and subsequent SRE frequency demonstrated that significant baseline risk factors included luminal B type disease, a history of palliative radiation therapy, BMA treatment within 2 years, and elevated serum calcium levels at the time of the initial BMA dose. Additionally, for the time to the first SRE and for the primary and subsequent SRE frequency, the presence of extraskeletal metastases and BMA administration initiation ≥6 months after the detection of bone metastases were also significant risk factors, respectively.

CONCLUSION

In breast cancer patients with bone metastases, more vigilant observation should be considered for patients with the identified risk factors. To reduce the risk for SRE, BMAs should be administered within 6 months of bone metastases diagnosis and before palliative radiation therapy.

IMPLICATIONS FOR PRACTICE

Retrospectively, risk factors were identified for skeletal-related events (SREs) in breast cancer patients with bone metastasis who were treated with bone-modifying agents (BMAs). For the time to the first SRE and for the SRE frequency, presence of extraskeletal metastases and BMA initiation ≥6 months after the detection of bone metastases were risk factors, respectively. Luminal B type disease, a history of palliative radiation therapy, BMA treatment within 2 years, and elevated serum calcium levels at initial BMA dose were risk factors for both first SRE and SRE frequency. More vigilant observation should be considered for patients with these risk factors.

A comprehensive review of denosumab for bone metastasis in patients with solid tumors

BACKGROUND

Denosumab is fully human monoclonal antibody that specifically binds and inactivates receptor activator of NF-kB ligand (RANKL), an important ligand that regulates bone remodeling. In this review, we aimed to show the clinical data about denosumab treatment and discuss its advantages for the management of patients with solid tumors and bone metastasis.

SCOPE

Denosumab showed positive results in clinical studies of solid tumors with bone metastasis. PubMed database and ASCO Symposium Meeting abstracts were searched until August 2015 by using the terms 'denosumab', 'RANKL inhibitor' and 'bone metastasis'. The last search was on 21 August 2015. All resulting studies were retrieved and were also checked for related publications. Clinical trials in this review fulfilled the following criterion: inclusion of sufficient data to allow estimation of the efficacy and safety of denosumab.

FINDINGS

The effects of denosumab on skeletal-related events (SREs) were investigated in three large randomized trials: one in patients with breast cancer, one in patients with prostate cancer, and one in patients with multiple myeloma or solid tumors other than breast or prostate cancer. In the breast cancer and prostate cancer studies denosumab was non-inferior and also superior to zoledronic acid in terms of the primary outcome time to first on-study SRE. In the third study denosumab was non-inferior to zoledronic acid but was not superior to zoledronic acid in solid tumors excluding breast and prostate cancer with bone metastases. In the three studies median overall survival and disease progression rates were similar between zoledronic acid and denosumab. Denosumab has also been studied in bone loss associated with hormonal therapy in both breast and prostate cancer. Adjuvant denosumab significantly reduced the risk of clinical fracture risk by 50% in breast cancer patients and by 62% in non-metastatic prostate cancer patients treated with adjuvant aromatase inhibitors or androgen deprivation therapy. In addition, biochemical markers of bone turnover and fractures were significantly reduced in patients under denosumab treatment.

CONCLUSION

The promising outcomes in the initial trials with denosumab have shown clinical activity and a favorable safety profile in patients with solid tumors and bone metastasis. Denosumab significantly reduced treatment-related osteoporosis associated with breast and prostate cancer and was superior to zoledronic acid in prevention or delaying of SRE.

Collapsing focal segmental glomerulosclerosis following long-term treatment with oral ibandronate: case report and review of literature

Background

Renal toxicity has been reported with bisphosphonates such as pamidronate and zolidronate but not with ibandronate, in the treatment of breast cancer patients with bone metastasis. One of the patterns of bisphosphonate-induced nephrotoxicity is focal segmental glomerulosclerosis (FSGS) or its morphological variant, collapsing focal segmental glomerulosclerosis (CFSGS).

Case presentation

We describe a breast cancer patient who developed heavy proteinuria (protein/creatinine ratio 9.1) and nephrotic syndrome following treatment with oral ibandronate for 29 months. CFSGS was proven by biopsy. There was no improvement 1 month after ibandronate was discontinued. Prednisone and tacrolimus were started and she experienced a decreased in proteinuria.

Conclusion

In patient who develops ibandronate-associated CFSGS, proteinuria appears to be at least partially reversible with the treatment of prednisone and/or tacrolimus if the syndrome is recognized early and ibandronate is stopped.

Drug induced osteonecrosis of the jaw. Cancer Treat Rev. 2015;41:455-464. [PMID: 25913713 DOI: 10.1016/j.ctrv.2015.04.007]

Despite the widespread use of bisphosphonates and their unequivocal efficacy for the treatment of various disease states, osteonecrosis of the jaw remains one of the most feared complications associated with their use. Current evidence, however, suggests that there is also a relationship between occurrence of osteonecrosis of the jaw and use of other classes of pharmacotherapies namely RANKL inhibitors as well as angiogenesis inhibitors. Although these drugs have different mechanisms of action than bisphosphonates, they all seem to interfere with the bone remodeling process i.e. alter the balance between bone resorption and bone formation which may be the most plausible explanation for pathogenesis of osteonecrosis of the jaw. The main objective of this review is to introduce the readership to a number of relatively new medications that may cause osteonecrosis of the jaw. Accordingly, we will summarize latest findings from clinical studies, meta analyses and case reports published in medical literature on this topic. For some of these medications, the evidence may not appear as robust as that for bisphosphonates; yet, the possibility of this adverse event occurring with these non bisphosphonate drugs should never be precluded unless proven otherwise. Thus, it is imperative that health care providers implement preventive measures so as to circumvent the incidence of osteonecrosis of the jaw. In this day of age where medical care is becoming personalized, we will highlight some of significant findings from studies seeking to identify genetic markers that may potentially play a role in development of osteonecrosis of the jaw.

Salivary Biomarkers Associated With Bone Deterioration in Patients With Medication-Related Osteonecrosis of the Jaws

PURPOSE

The purpose of this study was to investigate the use of saliva as a medium for the identification of biomarkers associated with bone resorption and formation. The authors hypothesized that biomarkers, such as N-telopeptide of type I collagen (NTX) and bone-specific alkaline phosphatase (B-AP), could be identified in saliva. They further hypothesized that there would be a difference between these biomarkers in the saliva of patients with medication-relation osteonecrosis of the jaws (MRONJ) and those who have no risk factors for the development of MRONJ.

PATIENTS AND METHODS

This case-and-control study compared 2 salivary biomarkers, NTX and B-AP, in a group of patients with MRONJ and a control group. The predictor variable was the presence or absence of the disease (MRONJ or control group); the outcome variables were the levels of the 2 salivary biomarkers, NTX and B-AP. Saliva samples from 20 patients with a diagnosis of MRONJ and 14 control participants who were comparable to the study group with no history of antiresorptive medication use were collected. The saliva samples were analyzed using 2 commercially available assays for NTX and B-AP to evaluate for levels of each marker. A 2-tailed t test for 2 groups of unequal distribution was used for statistical analysis, with P values less than .05 considered statistically.

RESULTS

The 2 biomarkers, NTX and B-AP, were detected in saliva samples from the MRONJ and control groups. A statistically significant difference was found in the levels of NTX in saliva of patients with MRONJ compared with the control participants (P = .0067).

CONCLUSIONS

In this exploratory study, the 2 bone deterioration biomarkers (NTX and B-AP) were detected in saliva. There was a statistical difference in the levels of salivary NTX between patients with MRONJ and controls. Saliva evaluation could provide a novel method to detect, diagnose, stage, and potentially guide treatment decisions and monitor outcomes for patients with MRONJ in the future.

Side effects of bone-targeted therapies in advanced breast cancer

In up to 75% of cases, advanced breast cancer patients eventually develop bone metastases with often debilitating skeletal-related events (SREs). Osteoclast inhibitors are commonly used as therapeutic mainstay with clinical studies showing superiority of denosumab over bisphosphonates (e.g., zoledronate) for the prevention of SREs. The present review discusses the adverse event profile of these agents, and addresses the prevention and management of untoward side effects. Adverse events associated with osteoclast inhibitors comprise osteonecrosis of the jaw and hypocalcemia. Hypocalcemia is more common with denosumab, particularly in severe renal dysfunction. During therapy, the appropriate prevention of these adverse events includes close attention to dental health, avoidance of invasive dental procedures, supplementation with calcium and vitamin D unless patients are hypercalcemic, and regular monitoring of relevant serum values. Relating to the risk of nephrotoxicity, bisphosphonates but not denosumab have been incriminated. Therefore, serum creatinine levels should be checked prior to each dose of zoledronate, and in severe renal dysfunction (creatinine clearance < 30 ml/min) zoledronate is contraindicated anyway. Acute-phase reactions are particularly linked to bisphosphonates. Consequently, if these adverse events predominate, switching to denosumab is recommended.

Zoledronic acid in the treatment of metastatic breast cancer

Bone is the most common location of metastatic disease. Approximately 80% of all bone metastases are observed in patients with breast or prostate tumours and are responsible for more than 300 000 deaths every year. Treatment of malignant bone disease with bisphosphonates has been shown to reduce bone events and delay their onset, and several reviews and meta-analyses have confirmed the benefit of these drugs in controlling bone metastases. Zoledronic acid is a bisphosphonate that has been shown to delay or prevent the development of skeletal-related events in patients with bone metastases. Furthermore, compared with other bisphosphonates, zoledronic acid has also shown better pain control and various studies also suggest an improvement in quality of life, although with no impact on overall survival. The duration and optimal regimen for long-term zoledronic acid therapy have not yet been defined, but some studies suggest that continuing zoledronic acid therapy for more than 2 years could also extend its beneficial effect.

Cancer-associated bone disease

Bone is commonly affected in cancer. Cancer-induced bone disease results from the primary disease, or from therapies against the primary condition, causing bone fragility. Bone-modifying agents, such as bisphosphonates and denosumab, are efficacious in preventing and delaying cancer-related bone disease. With evidence-based care pathways, guidelines assist physicians in clinical decision-making. Of the 57 million deaths in 2008 worldwide, almost two thirds were due to non-communicable diseases, led by cardiovascular diseases and cancers. Bone is a commonly affected organ in cancer, and although the incidence of metastatic bone disease is not well defined, it is estimated that around half of patients who die from cancer in the USA each year have bone involvement. Furthermore, cancer-induced bone disease can result from the primary disease itself, either due to circulating bone resorbing substances or metastatic bone disease, such as commonly occurs with breast, lung and prostate cancer, or from therapies administered to treat the primary condition thus causing bone loss and fractures. Treatment-induced osteoporosis may occur in the setting of glucocorticoid therapy or oestrogen deprivation therapy, chemotherapy-induced ovarian failure and androgen deprivation therapy. Tumour skeletal-related events include pathologic fractures, spinal cord compression, surgery and radiotherapy to bone and may or may not include hypercalcaemia of malignancy while skeletal complication refers to pain and other symptoms. Some evidence demonstrates the efficacy of various interventions including bone-modifying agents, such as bisphosphonates and denosumab, in preventing or delaying cancer-related bone disease. The latter includes treatment of patients with metastatic skeletal lesions in general, adjuvant treatment of breast and prostate cancer in particular, and the prevention of cancer-associated bone disease. This has led to the development of guidelines by several societies and working groups to assist physicians in clinical decision making, providing them with evidence-based care pathways to prevent skeletal-related events and bone loss. The goal of this paper is to put forth an IOF position paper addressing bone diseases and cancer and summarizing the position papers of other organizations.

Molecular target therapy for bone metastasis: starting a new era with denosumab, a RANKL inhibitor

INTRODUCTION

The skeleton is generally the primary, and sometimes the only, site of metastasis in patients with advanced solid tumors. Bone metastases are the most frequent cause of cancer-related pain and the origin of severe morbidity in patients. Among the treatment options available for the prevention of skeletal-related events (SREs) associated with bone metastasis, zoledronic acid, an antiresorptive treatment from the group of bisphosphonates, is currently the standard of care in this setting.

AREAS COVERED

Zoledronic acid, together with denosumab (a monoclonal antibody against the receptor activator of nuclear factor kappa B ligand), is the most frequent approach for the prevention of cancer-related events in skeleton. This paper reviews several trials evaluating the efficacy of denosumab in comparison with zoledronic acid in patients with solid osteotropic tumors. In this setting of skeleton-invading cancers, denosumab was demonstrated to be superior to zoledronic acid in preventing or delaying SREs. In comparison with zoledronic acid, denosumab significantly delayed the time to first SRE by 17%.

EXPERT OPINION

Current research on denosumab is addressed to prove the immunomodulator effect of this agent in humans. Other avenue of research is focused on its antitumor activity observed in some Phase III trials.

Acute kidney injury and bisphosphonate use in cancer: a report from the research on adverse drug events and reports (RADAR) project

PURPOSE

To determine whether acute kidney injury (AKI) is identified within the US Food and Drug Administration's Adverse Events and Reporting System (FDA AERS) as an adverse event resulting from bisphosphonate (BP) use in cancer therapy.

METHODS

A search of the FDA AERS records from January 1998 through June 2009 was performed; search terms were "renal problems" and all drug names for BPs. The search resulted in 2,091 reports. We analyzed for signals of disproportional association by calculating the proportional reporting ratio for zoledronic acid (ZOL) and pamidronate. Literature review of BP-associated renal injury within the cancer setting was conducted.

RESULTS

Four hundred eighty cases of BP-associated acute kidney injury (AKI) were identified in patients with cancer. Two hundred ninety-eight patients (56%) were female; mean age was 66 ± 10 years. Multiple myeloma (n = 220, 46%), breast cancer (n = 98, 20%), and prostate cancer (n = 24, 5%) were identified. Agents included ZOL (n = 411, 87.5%), pamidronate (n = 8, 17%), and alendronate (n = 36, 2%). Outcomes included hospitalization (n = 304, 63.3%) and death (n = 68, 14%). The proportional reporting ratio for ZOL was 1.22 (95% CI, 1.13 to 1.32) and for pamidronate was 1.55 (95% CI, 1.25 to 1.65), reflecting a nonsignificant safety signal for both drugs.

CONCLUSION

AKI was identified in BP cancer clinical trials, although a safety signal for BPs and AKI within the FDA AERS was not detected. Our findings may be attributed, in part, to clinicians who believe that AKI occurs infrequently; ascribe the AKI to underlying premorbid disease, therapy, or cancer progression; or consider that AKI is a known adverse drug reaction of BPs and thus under-report AKI to the AERS.

Supportive care during treatment for breast cancer: resource allocations in low- and middle-income countries. A Breast Health Global Initiative 2013 consensus statement

Breast cancer patients may have unmet supportive care needs during treatment, including symptom management of treatment-related toxicities, and educational, psychosocial, and spiritual needs. Delivery of supportive care is often a low priority in low- and middle-income settings, and is also dependent on resources available. This consensus statement describes twelve key recommendations for supportive care during treatment in low- and middle-income countries, identified by an expert international panel as part of the 5th Breast Health Global Initiative (BHGI) Global Summit for Supportive Care, which was held in October 2012, in Vienna, Austria. Panel recommendations are presented in a 4-tier resource-stratified table to illustrate how health systems can provide supportive care services during treatment to breast cancer patients, starting at a basic level of resource allocation and incrementally adding program resources as they become available. These recommendations include: health professional and patient and family education; management of treatment related toxicities, management of treatment-related symptoms of fatigue, insomnia and non-specific pain, and management of psychosocial and spiritual issues related to breast cancer treatment. Establishing supportive care during breast cancer treatment will help ensure that breast cancer patients receive comprehensive care that can help 1) improve adherence to treatment recommendations, 2) manage treatment-related toxicities and other treatment related symptoms, and 3) address the psychosocial and spiritual aspects of breast cancer and breast cancer treatments.

Supportive and palliative care for metastatic breast cancer: resource allocations in low- and middle-income countries. A Breast Health Global Initiative 2013 consensus statement

Many women diagnosed with breast cancer in low- and middle-income countries (LMICs) present with advanced-stage disease. While cure is not a realistic outcome, site-specific interventions, supportive care, and palliative care can achieve meaningful outcomes and improve quality of life. As part of the 5th Breast Health Global Initiative (BHGI) Global Summit, an expert international panel identified thirteen key resource recommendations for supportive and palliative care for metastatic breast cancer. The recommendations are presented in three resource-stratified tables: health system resource allocations, resource allocations for organ-based metastatic breast cancer, and resource allocations for palliative care. These tables illustrate how health systems can provide supportive and palliative care services for patients at a basic level of available resources, and incrementally add services as more resources become available. The health systems table includes health professional education, patient and family education, palliative care models, and diagnostic testing. The metastatic disease management table provides recommendations for supportive care for bone, brain, liver, lung, and skin metastases as well as bowel obstruction. The third table includes the palliative care recommendations: pain management, and psychosocial and spiritual aspects of care. The panel considered pain management a priority at a basic level of resource allocation and emphasized the need for morphine to be easily available in LMICs. Regular pain assessments and the proper use of pharmacologic and non-pharmacologic interventions are recommended. Basic-level resources for psychosocial and spiritual aspects of care include health professional and patient and family education, as well as patient support, including community-based peer support.

Expert opinion 2011 on the use of new anti-resorptive agents in the prevention of skeletal-related events in metastatic bone disease

Bisphosphonates have been a mainstay in the treatment of cancer-related bone disease and have greatly reduced the risk of skeletal complications. More recently, clinical studies suggested additional benefits of denosumab over zoledronic acid in the prevention of skeletal related events. Similar adverse event profiles have been reported for bisphosphonates and denosumab, with infrequent occurrences of osteonecrosis of the jaw with both agents, higher incidence of renal deterioration with zoledronic acid, and higher incidence of hypocalcaemia with denosumab. Based on current evidence, the American Society of Clinical Oncology (ASCO) and National Comprehensive Cancer Network (NCCN) guidelines do not recommend one drug class over the other in patients with metastatic bone disease. Denosumab, however, may present advantages over bisphosphonates in patients suffering from chronic renal insufficiency. Further research and growing clinical experience will refine the evidence based on which decisions in daily clinical practice can be taken.

Bone-targeted agent use for bone metastases from breast cancer and prostate cancer: A patient survey

Background

In order to design studies assessing the optimal use of bone-targeted agents (BTAs) patient input is clearly desirable.

Methods

Patients who were receiving a BTA for metastatic prostate or breast cancer were surveyed at two Canadian cancer centres. Statistical analysis of respondent data was performed to establish relevant proportions of patient responses.

Results

Responses were received from 141 patients, 76 (53.9%) with prostate cancer and 65 (46.1%) with breast cancer. Duration of BTA use was <3 months (15.9%) to >24 months (35.2%). Patients were uncertain how long they would remain on a BTA. While most felt their BTA was given to reduce the chance of bone fractures (77%), 52% thought it would slow tumour growth. Prostate patients were more likely to receive denosumab and breast cancer patients, pamidronate. There was more variability in the dosing interval for breast cancer patients. Given a choice, most patients (49–57%) would prefer injection therapy to oral therapy (21–23%). Most patients (58–64%) were interested in enrolling in clinical trials of de-escalated therapy.

Conclusion

While there were clear differences in the types of BTAs patients received, our survey showed similarity for both prostate and breast cancer patients with respect to their perceptions of the goals of therapy. Patients were interested in participating in trials of de-escalated therapy. However, given that patients receive a range of agents for varying periods of time and in different locations (e.g. hospital vs. home), the design of future trials will need to be pragmatic to reflect this.

De-escalated administration of bone-targeted agents in patients with breast and prostate cancer-A survey of Canadian oncologists

Objective

Questions remain regarding the optimal use of bone-targeted agents in patients with metastatic bone disease. The purpose of this study was to assess current clinical practice regarding the use and administration of bone-targeted agents by Canadian oncologists in patients with metastatic breast and prostate cancer.

Methods

A survey was designed to explore; bone-targeted agent use in metastatic bone disease, variability in the choice and the frequency of administration of these agents. Opinions were sought on potential outcomes for future trials.

Results

A total of 193 clinicians were contacted and 90 completed our survey (response rate 49% after adjustment for inactivity). Survey respondents were medical oncologists (71.1%), radiation oncologists (21.1%) and urologists (7.8%). The findings suggest that once bone-targeted agents are started they are rarely discontinued. More agents are used in breast cancer than in prostate cancer. There was considerable interest in performing studies of de-escalated therapy in both breast and prostate cancer. Physicians requested (86%) that the primary study endpoint be the occurrence of skeletal related events and not biomarker driven.

Conclusions

Despite clinical practice guidelines and widespread use, significant areas of clinical equipoise with respect to use of bone-targeted agents exist. Findings from this survey suggest that physicians are interested in de-escalated therapy for both breast and prostate patients. However, the use of multiple agents in breast cancer and the desire for skeletal related events to be the primary endpoint means that very large randomized studies will be required.

Zoledronate effects on systemic and jaw osteopenias in ovariectomized periostin-deficient mice

Osteoporosis and periodontal disease (PD) are frequently associated in the elderly, both concurring to the loss of jaw alveolar bone and finally of teeth. Bisphosphonates improve alveolar bone loss but have also been associated with osteonecrosis of the jaw (ONJ), particularly using oncological doses of zoledronate. The effects and therapeutic margin of zoledronate on jaw bone therefore remain uncertain. We reappraised the efficacy and safety of Zoledronate (Zol) in ovariectomized (OVX) periostin (Postn)-deficient mice, a unique genetic model of systemic and jaw osteopenia. Compared to vehicle, Zol 1M (100 µg/kg/month) and Zol 1W (100 µg/kg/week) for 3 months both significantly improved femur BMD, trabecular bone volume on tissue volume (BV/TV) and cortical bone volume in both OVX Postn^+/+ and Postn^−/− (all p<0.01). Zol 1M and Zol 1W also improved jaw alveolar and basal BV/TV, although the highest dose (Zol 1W) was less efficient, particularly in Postn^−/−. Zol decreased osteoclast number and bone formation indices, i.e. MAR, MPm/BPm and BFR, independently in Postn^−/− and Postn^+/+, both in the long bones and in deep jaw alveolar bone, without differences between Zol doses. Zol 1M and Zol 1W did not reactivate inflammation nor increase fibrous tissue in the bone marrow of the jaw, whereas the distance between the root and the enamel of the incisor (DRI) remained high in Postn^−/− vs Postn^+/+ confirming latent inflammation and lack of crestal alveolar bone. Zol 1W and Zol 1M decreased osteocyte numbers in Postn^−/− and Postn^+/+ mandible, and Zol 1W increased the number of empty lacunae in Postn^−/−, however no areas of necrotic bone were observed. These results demonstrate that zoledronate improves jaw osteopenia and suggest that in Postn^−/− mice, zoledronate is not sufficient to induce bone necrosis.