Preventive effect of zoledronic acid on aromatase inhibitor-associated bone loss for postmenopausal breast cancer patients receiving adjuvant letrozole

Bone Health Management in Men Commencing Androgen Deprivation Therapy for Prostate Cancer and Women Commencing Anti-Oestrogen Therapy for Breast Cancer

BACKGROUND

Survival of patients with prostate and breast cancer, the commonest cancer in men and women, respectively, has markedly improved with advances in early diagnosis, treatment and multi-disciplinary care by the oncology and surgical community. However, the use of increasingly potent endocrine therapies may cause bone loss, resulting in secondary osteoporosis.

REVIEW

This review summarises the current management of cancer treatment-induced bone loss in this group of patients at high risk of osteoporotic fractures with their attendant morbidity and mortality.

CONCLUSION

Bone health is an increasingly important part of cancer survivorship. Radiation and medical oncologists, urologists, bone health experts, general practitioners, healthcare professional bodies and bone health and cancer consumer organisations should increase awareness of the potential adverse effect of endocrine therapy on bone health. While this should never delay cancer treatment, bone health should be part of routine care for men and women receiving endocrine therapy for prostate and breast cancer.

Bone-modifying agents for reducing bone loss in women with early and locally advanced breast cancer: a network meta-analysis

BACKGROUND

Bisphosphonates and receptor activator of nuclear factor-kappa B ligand (RANKL)-inhibitors are amongst the bone-modifying agents used as supportive treatment in women with breast cancer who do not have bone metastases. These agents aim to reduce bone loss and the risk of fractures. Bisphosphonates have demonstrated survival benefits, particularly in postmenopausal women.

OBJECTIVES

To assess and compare the effects of different bone-modifying agents as supportive treatment to reduce bone mineral density loss and osteoporotic fractures in women with breast cancer without bone metastases and generate a ranking of treatment options using network meta-analyses (NMAs).

SEARCH METHODS

We identified studies by electronically searching CENTRAL, MEDLINE and Embase until January 2023. We searched various trial registries and screened abstracts of conference proceedings and reference lists of identified trials.

SELECTION CRITERIA

We included randomised controlled trials comparing different bisphosphonates and RANKL-inihibitors with each other or against no further treatment or placebo for women with breast cancer without bone metastases.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of included studies and certainty of evidence using GRADE. Outcomes were bone mineral density, quality of life, overall fractures, overall survival and adverse events. We conducted NMAs and generated treatment rankings.

MAIN RESULTS

Forty-seven trials (35,163 participants) fulfilled our inclusion criteria; 34 trials (33,793 participants) could be considered in the NMA (8 different treatment options). Bone mineral density We estimated that the bone mineral density of participants with no treatment/placebo measured as total T-score was -1.34. Evidence from the NMA (9 trials; 1166 participants) suggests that treatment with ibandronate (T-score -0.77; MD 0.57, 95% CI -0.05 to 1.19) may slightly increase bone mineral density (low certainty) and treatment with zoledronic acid (T-score -0.45; MD 0.89, 95% CI 0.62 to 1.16) probably slightly increases bone mineral density compared to no treatment/placebo (moderate certainty). Risedronate (T-score -1.08; MD 0.26, 95% CI -0.32 to 0.84) may result in little to no difference compared to no treatment/placebo (low certainty). We are uncertain whether alendronate (T-score 2.36; MD 3.70, 95% CI -2.01 to 9.41) increases bone mineral density compared to no treatment/placebo (very low certainty). Quality of life No quantitative analyses could be performed for quality of life, as only three studies reported this outcome. All three studies showed only minimal differences between the respective interventions examined. Overall fracture rate We estimated that 70 of 1000 participants with no treatment/placebo had fractures. Evidence from the NMA (16 trials; 19,492 participants) indicates that treatment with clodronate or ibandronate (42 of 1000; RR 0.60, 95% CI 0.39 to 0.92; 40 of 1000; RR 0.57, 95% CI 0.38 to 0.86, respectively) decreases the number of fractures compared to no treatment/placebo (high certainty). Denosumab or zoledronic acid (51 of 1000; RR 0.73, 95% CI 0.52 to 1.01; 55 of 1000; RR 0.79, 95% CI 0.56 to 1.11, respectively) probably slightly decreases the number of fractures; and risedronate (39 of 1000; RR 0.56, 95% CI 0.15 to 2.16) probably decreases the number of fractures compared to no treatment/placebo (moderate certainty). Pamidronate (106 of 1000; RR 1.52, 95% CI 0.75 to 3.06) probably increases the number of fractures compared to no treatment/placebo (moderate certainty). Overall survival We estimated that 920 of 1000 participants with no treatment/placebo survived overall. Evidence from the NMA (17 trials; 30,991 participants) suggests that clodronate (924 of 1000; HR 0.95, 95% CI 0.77 to 1.17), denosumab (927 of 1000; HR 0.91, 95% CI 0.69 to 1.21), ibandronate (915 of 1000; HR 1.06, 95% CI 0.83 to 1.34) and zoledronic acid (925 of 1000; HR 0.93, 95% CI 0.76 to 1.14) may result in little to no difference regarding overall survival compared to no treatment/placebo (low certainty). Additionally, we are uncertain whether pamidronate (905 of 1000; HR 1.20, 95% CI 0.81 to 1.78) decreases overall survival compared to no treatment/placebo (very low certainty). Osteonecrosis of the jaw We estimated that 1 of 1000 participants with no treatment/placebo developed osteonecrosis of the jaw. Evidence from the NMA (12 trials; 23,527 participants) suggests that denosumab (25 of 1000; RR 24.70, 95% CI 9.56 to 63.83), ibandronate (6 of 1000; RR 5.77, 95% CI 2.04 to 16.35) and zoledronic acid (9 of 1000; RR 9.41, 95% CI 3.54 to 24.99) probably increases the occurrence of osteonecrosis of the jaw compared to no treatment/placebo (moderate certainty). Additionally, clodronate (3 of 1000; RR 2.65, 95% CI 0.83 to 8.50) may increase the occurrence of osteonecrosis of the jaw compared to no treatment/placebo (low certainty). Renal impairment We estimated that 14 of 1000 participants with no treatment/placebo developed renal impairment. Evidence from the NMA (12 trials; 22,469 participants) suggests that ibandronate (28 of 1000; RR 1.98, 95% CI 1.01 to 3.88) probably increases the occurrence of renal impairment compared to no treatment/placebo (moderate certainty). Zoledronic acid (21 of 1000; RR 1.49, 95% CI 0.87 to 2.58) probably increases the occurrence of renal impairment while clodronate (12 of 1000; RR 0.88, 95% CI 0.55 to 1.39) and denosumab (11 of 1000; RR 0.80, 95% CI 0.54 to 1.19) probably results in little to no difference regarding the occurrence of renal impairment compared to no treatment/placebo (moderate certainty).

AUTHORS' CONCLUSIONS

When considering bone-modifying agents for managing bone loss in women with early or locally advanced breast cancer, one has to balance between efficacy and safety. Our findings suggest that bisphosphonates (excluding alendronate and pamidronate) or denosumab compared to no treatment or placebo likely results in increased bone mineral density and reduced fracture rates. Our survival analysis that included pre and postmenopausal women showed little to no difference regarding overall survival. These treatments may lead to more adverse events. Therefore, forming an overall judgement of the best ranked bone-modifying agent is challenging. More head-to-head comparisons, especially comparing denosumab with any bisphosphonate, are needed to address gaps and validate the findings of this review.

Zoledronic acid improves bone quality and muscle function in a high bone turnover state

SUMMARY

Zoledronic acid (ZA) prevents muscle weakness in mice with bone metastases; however, its role in muscle weakness in non-tumor-associated metabolic bone diseases and as an effective treatment modality for the prevention of muscle weakness associated with bone disorders, is unknown. We demonstrate the role of ZA-treatment on bone and muscle using a mouse model of accelerated bone remodeling, which represents the clinical manifestation of non-tumor associated metabolic bone disease. ZA increased bone mass and strength and rescued osteocyte lacunocanalicular organization. Short-term ZA treatment increased muscle mass, whereas prolonged, preventive treatment improved muscle mass and function. In these mice, muscle fiber-type shifted from oxidative to glycolytic and ZA restored normal muscle fiber distribution. By blocking TGFβ release from bone, ZA improved muscle function, promoted myoblast differentiation and stabilized Ryanodine Receptor-1 calcium channel. These data demonstrate the beneficial effects of ZA in maintaining bone health and preserving muscle mass and function in a model of metabolic bone disease.

Context and significance

TGFβ is a bone regulatory molecule which is stored in bone matrix, released during bone remodeling, and must be maintained at an optimal level for the good health of the bone. Excess TGFβ causes several bone disorders and skeletal muscle weakness. Reducing excess TGFβ release from bone using zoledronic acid in mice not only improved bone volume and strength but also increased muscle mass, and muscle function. Progressive muscle weakness coexists with bone disorders, decreasing quality of life and increasing morbidity and mortality. Currently, there is a critical need for treatments improving muscle mass and function in patients with debilitating weakness. Zoledronic acid's benefit extends beyond bone and could also be useful in treating muscle weakness associated with bone disorders.

Real-World Effectiveness of Denosumab and Bisphosphonates on Risk of Vertebral Fractures in Women with Breast Cancer Undergoing Treatment with Aromatase Inhibitors

Bone-active drugs are recommended to protect the skeleton from detrimental actions of aromatase inhibitors (AIs). However, most of literature data are focused on bone mineral density (BMD), whereas data on fractures are scant. The aim of this prospective study was to investigate the real-life effectiveness of denosumab, oral bisphosphonates (BPs) and intravenous zoledronate on risk of vertebral fractures (VFs) induced by AIs. 567 consecutive women (median age 62 years, range 28-83) with early breast cancer undergoing treatment with AIs were evaluated for morphometric VFs and BMD at baseline and after 18-24 months of follow-up. After enrollment, 268 women (47.3%) started denosumab 60 mg subcutaneously every 6 months, 115 (20.3%) BPs (59 with oral BPs and, 56 with intravenous zoledronate 5 mg/12 months), whereas 184 women (32.5%) were not treated with bone-active drugs for several reasons. During follow-up, 54 women (9.5%) developed incident VFs in association with age of subjects (P < 0.001), baseline FRAX scores for major fractures (P < 0.001) and hip fractures (P = 0.003), pre-existing VFs (P < 0.001), change in BMD at lumbar spine (P = 0.015), femoral neck (P = 0.003) and total hip (P < 0.001). Risk of VFs was higher in subjects who were untreated as compared to those treated with bone-active drugs (32/184 vs. 22/383; P < 0.001). Specifically, fracture risk was significantly decreased by denosumab [odds ratio (OR) 0.22; P < 0.001] and zoledronate (OR 0.27; P = 0.035), but not by oral BPs (P = 0.317). These data suggest that in real-world clinical practice, denosumab and zoledronate can reduce AI-related risk of VFs after only 24 months of treatment.

Bisphosphonates and Prevention of the Perimenopausal Breast Cancer Recurrence: A Systematic Review and Meta-Analysis

PURPOSE

Bisphosphonates (BPs) have a powerful effect on reducing bone resorption and improving the survival of patients with breast cancer. We aimed to investigate the impact of BP treatment on the prevention of recurrence, metastasis, and death of breast cancer survivors in the perimenopausal period.

METHODS

The search strategy aimed to identify both published and unpublished studies in PubMed, Web of Science, Scopus, Embase, ProQuest, and Google Scholar in March 2021. Two independent reviewers assessed quantitative papers selected for retrieval for methodological validity before being included in the review using standardized critical appraisal instruments from the Joanna Briggs Institute (JBI) Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI). Statistical meta-analysis was performed using Review Manager (RevMan) 5.4 statistical software when the data were homogenous. Meta-analysis was performed by calculating the effect size (hazard ratio; HR) and 95% confidence intervals (CIs).

RESULTS

Twenty-one studies were eligible for this systematic review and meta-analysis. The overall The HRs for disease-free survival (DFS) and overall survival (OS) in women who received BPs were 0.89 (95% CI, 0.83-0.97; p = 0.005), and 0.75 (95% CI, 0.63-0.89; p = 0.001), respectively. The results showed that BPs had a significant effect on the prevention of locoregional (HR, 0.64; 95% CI, 0.42-0.97; p = 0.04), bone (95% CI, 0.74-0.95; p ≤ 0.001), and distant metastases (HR, 0.77; 95% CI, 0.62-0.94; p = 0.01). In the subgroup analysis based on study design, the only insignificant HR in the included randomized controlled trials (RCTs) was that of locoregional metastasis.

CONCLUSION

Although BPs have a promising effect on DFS, OS, and bone metastasis of perimenopausal women survivors of breast cancer, more RCTs are needed to evaluate their effect on other survivors' outcomes.

Effect of antiresorptive therapy on aromatase inhibitor induced bone loss in postmenopausal women with early-stage breast cancer: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Aromatase inhibitors (AIs) are routinely used to treat postmenopausal women with early-stage breast cancer. Although AIs improve breast cancer outcomes, they increase the risk of osteoporosis and fractures. This systematic review and meta-analysis assesses the effect of antiresorptive drugs on AI induced bone loss in postmenopausal women with non-metastatic breast cancer.

METHODS

We searched four databases until November 4th 2020. We included Randomized controlled trials (RCTs) of antiresorptive drugs in postmenopausal women with breast cancer treated with AI. Two authors screened studies, extracted data and assessed the risk of bias independently and in duplicate.

RESULTS

We identified 14 RCTs: 7 on zoledronic acid, 6 on oral bisphosphonates and 1 on denosumab. The mean difference in bone mineral density (BMD) was 5% at the lumbar spine and 4% at the total hip, at 12 months, favoring zoledronic acid compared to control. The certainty of the evidence was low for lumbar spine and moderate for total hip BMD. Similarly, the mean difference was 3% at the lumbar spine and 2% at the total hip, favoring oral bisphosphonates with moderate certainty. The mean difference was 6% at the lumbar spine, and 4% at the total hip BMD favoring denosumab compared to placebo. In addition, zoledronic acid resulted in a mean difference in bone turnover marker levels of -35-41%, and the relarive risk for morphometric vertebral fractures was 0.7 [0.3-1.4], compared to control. Denosumab reduced fracture incidence by 50% compared to placebo.

CONCLUSION

Evidence suggests a protective effect of antiresorptive drugs on BMD and bone turnover markers in postmenopausal women with non-metastatic breast cancer on AI. However, data on fracture risk reduction remains unclear.

Letrozole and zoledronic acid changed signalling pathways involved in the apoptosis of breast cancer cells

OBJECTIVES

Oestrogen plays a key role in the development of breast malignancies. Therefore, aromatase inhibitors (e.g. letrozole [LTZ]) are widely used in the treatment of breast cancer. On the other hand, oestrogen is important to the integrity of bone mass. Research has shown that zoledronic acid (ZLA) may prevent osteoporosis. Therefore, the present research aims to investigate the effect of a combination of LTZ and ZLA in the treatment of breast cancer and in reducing osteoporosis in patients with breast cancer.

METHODS

We used immunocytochemistry and Western immunoblotting techniques in this study.

RESULTS

We observed that LTZ inhibited cellular growth of Michigan Cancer Foundation-7 (MCF-7) and T-47D at IC50 (70 ± 0.001) and (140 ± 0.004) nM, respectively, whereas ZLA inhibited cellular growth at IC50 (50 ± 0.005) μM and (150 ± 0.004) μM for MCF-7 and T-47D cell lines, respectively. Interestingly, the LTZ and ZLA combination down-regulated the protein expression of signal transducer and activator of transcription 3 (STAT3) and up-regulated BRCA1 protein expression in both cell lines. Moreover, a notable enhancement in the nuclear localisation of the BRCA1 protein was obtained after treatment of T-47D cells with LTZ for 24 h compared to the control cells. In contrast, there was a reduction in the nuclear localisation of STAT3 protein, which could be an attractive target for inhibition of breast cancer proliferation and progression.

CONCLUSION

Our study has shown that a combination of LTZ and ZLA enhanced apoptosis and inhibited growth of both breast cancer cell lines. This combination can be used to maintain bone integrity in women with breast cancer.

Bone modifying agents for bone loss in patients with aromatase inhibitor as adjuvant treatment for breast cancer; insights from a network meta-analysis

PURPOSE

The data of head-to-head comparisons of the anti-fracture efficacy of bone modifying agents (BMAs) in patients with hormone receptor-positive breast cancer receiving aromatase inhibitor (AI) are not available. Therefore, we conducted a network meta-analysis to compare the efficacy of different BMAs in patients with breast cancer receiving adjuvant AI.

METHODS

We performed a network meta-analysis to compare the change of bone mineral densities (BMDs) and the risk of fracture in the selected studies using a random effect model. The primary outcomes are the change of BMD of lumbar spine (LS) and total hip (TH) from the baseline (ΔBMD, %) at 1 and 2 years and the risk of fracture.

RESULTS

We identified and included a total of 16 randomized controlled trials for this analysis. All BMAs included (risedronate, zoledronate, and denosumab) were associated with a significant increase in BMD of LS and TH at 1 and 2 years compared with no upfront treatment group. Among BMAs, zoledronate and denosumab use resulted in significantly higher BMD of LS and TH at 1 and 2 years compared with risedronate. The risk of fracture was significantly lower in the patients who received denosumab or risedronate compared with the patients without upfront treatment (Relative risk (RR) [95% CI] 0.51 [0.38-0.67] and 0.54 [0.35-0.83], respectively).

CONCLUSION

Among the bisphosphonates, zoledronate increased BMD the most, but risedronate, not zoledronate, use was associated with lower risk of fracture. Denosumab increased BMD not only of LS but also of the cortical-bone-rich hip, and showed a significant reduction of fracture risk.

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.

Suppression of human breast cancer cells by tectorigenin through downregulation of matrix metalloproteinases and MAPK signaling in vitro

Breast cancer is a major life‑threatening malignancy and is the second highest cause of mortality. The aim of the present study was to investigate the effects of tectorigenin (Tec), a Traditional Chinese Medicine, against human breast cancer cells in vitro. MDA‑MB‑231 and MCF‑7 human breast cancer cells were treated with various concentrations of Tec. Cell proliferation was evaluated using the Cell Counting kit‑8 assay, and apoptosis and the cell cycle were examined by flow cytometry. The migratory and invasive abilities of these cells were detected by Transwell and Matrigel assays, respectively. Metastasis‑, apoptosis‑ and survival‑related gene expression levels were measured by reverse transcription‑quantitative polymerase chain reaction and western blotting. The results indicated that Tec was able to inhibit the proliferation of MDA‑MB‑231 and MCF‑7 cells in a dose‑ and time‑dependent manner. Furthermore, Tec treatment induced apoptosis and G0/G1‑phase arrest, and inhibited cell migration and invasion. Tec treatment decreased the expression of matrix metalloproteinase (MMP)‑2, MMP9, BCL‑2, phosphorylated‑AKT and components of the mitogen‑activated protein kinase (MAPK) signaling pathway, and increased the expression of BCL‑2‑associated X, cleaved poly [ADP‑ribose] polymerase and cleaved caspase‑3. In conclusion, Tec treatment suppressed human breast cancer cells through the downregulation of AKT and MAPK signaling and the upregulated expression and/or activity of the caspase family in vitro. Therefore, Tec may be a potential therapeutic drug to treat human breast cancer.