Zoledronic acid (zoledronate) for postmenopausal women with early breast cancer receiving adjuvant letrozole (ZO-FAST study): final 60-month results

Beyond aspirin-cancer prevention with statins, metformin and bisphosphonates

Cancer risk reduction using pharmacological means is an attractive modern preventive approach that supplements the classical behavioural prevention recommendations. Medications that are commonly used by large populations to treat a variety of common, non-cancer-related, medical situations are an attractive candidate pool. This Review discusses three pharmacological agents with the most evidence for their potential as cancer chemopreventive agents: anti-hypercholesterolaemia medications (statins), an antidiabetic agent (metformin) and antiosteoporosis drugs (bisphosphonates). Data are accumulating to support a significant negative association of certain statins with cancer occurrence or survival in several major tumour sites (mostly gastrointestinal tumours and breast cancer), with an augmented combined effect with aspirin or other non-steroidal anti-inflammatory drugs. Metformin, but not other hypoglycaemic drugs, also seems to have some antitumour growth activity, but the amount of evidence in human studies, mainly in breast cancer, is still limited. Experimental and observational data have identified bisphosphonates as a pharmacological group that could have significant impact on incidence and mortality of more than one subsite of malignancy. At the current level of evidence these potential chemopreventive drugs should be considered in high-risk situations or using the personalized approach of maximizing individual benefits and minimizing the potential for adverse effects with the aid of pharmacogenetic indicators.

Bisphosphonate-related osteonecrosis of the jaw in patients with breast cancer

Bisphosphonate represents a well-established treatment option in the management of metastatic bone disease and bone loss/osteoporosis in women with breast cancer. These drugs reduce osteoclast. Some bisphosphonate also have osteoblastic function leading to a reducted bone turnover and thereby skeletal-related events. The aim of this review is to evaluate the bisphosphonate-related osteonecrosis of the jaw in patients with breast cancer. Based on the proven effect of bone protection during adjuvant endocrine therapy, new treatment guidelines recommend the routine use of bisphosphonates to prevent bone loss during adjuvant therapy, which may likely become the standard practice.

Osteoporosis and cancer

Cancer is a major risk factor for bone loss and fractures. This is due both to direct effects of cancer cells on the skeleton and to deleterious effects of cancer-specific therapies on bone cells. Marked improvements in survival for many cancers mean that strategies to limit bone loss and reduce fracture risk must be incorporated into the care plans for nearly all patients with cancer. The vast majority of effort thus far has focused on bone loss in patients with breast and prostate cancers, with comparatively few studies in other malignancies. Antiresorptive therapies have proven nearly universally effective for limiting bone loss in cancer patients, although few studies have been powered sufficiently to include fractures as primary endpoints, and patients are frequently neither identified nor treated according to published guidelines. Nonpharmacologic approaches to limit falls, particularly in elderly patients, are also likely important adjunctive measures for most cancer patients.

Personalizing the treatment of women with early breast cancer: highlights of the St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2013

The 13th St Gallen International Breast Cancer Conference (2013) Expert Panel reviewed and endorsed substantial new evidence on aspects of the local and regional therapies for early breast cancer, supporting less extensive surgery to the axilla and shorter durations of radiation therapy. It refined its earlier approach to the classification and management of luminal disease in the absence of amplification or overexpression of the Human Epidermal growth factor Receptor 2 (HER2) oncogene, while retaining essentially unchanged recommendations for the systemic adjuvant therapy of HER2-positive and 'triple-negative' disease. The Panel again accepted that conventional clinico-pathological factors provided a surrogate subtype classification, while noting that in those areas of the world where multi-gene molecular assays are readily available many clinicians prefer to base chemotherapy decisions for patients with luminal disease on these genomic results rather than the surrogate subtype definitions. Several multi-gene molecular assays were recognized as providing accurate and reproducible prognostic information, and in some cases prediction of response to chemotherapy. Cost and availability preclude their application in many environments at the present time. Broad treatment recommendations are presented. Such recommendations do not imply that each Panel member agrees: indeed, among more than 100 questions, only one (trastuzumab duration) commanded 100% agreement. The various recommendations in fact carried differing degrees of support, as reflected in the nuanced wording of the text below and in the votes recorded in supplementary Appendix S1, available at Annals of Oncology online. Detailed decisions on treatment will as always involve clinical consideration of disease extent, host factors, patient preferences and social and economic constraints.

Where Do Bone-Targeted Agents RANK in Breast Cancer Treatment?

Breast cancer cells preferentially metastasise to the skeleton, owing, in part, to the fertile environment provided by bone. Increased bone turnover releases growth factors that promote tumour cell growth. In turn, tumour cells release factors that stimulate further bone turnover, resulting in a vicious cycle of metastasis growth and bone destruction. The RANK-RANK ligand (RANKL) pathway plays a key role in this cycle, and inhibition of RANKL using the fully-human monoclonal antibody denosumab, has demonstrated efficacy in delaying skeletal complications associated with bone metastases in three phase 3 trials. Preclinical studies suggest that the RANKL pathway also plays a role in breast cancer tumourigenesis and migration to bone. In a subgroup analysis of the negative Adjuvant Zoledronic Acid to Reduce Recurrence (AZURE) trial, the bisphosphonate zoledronic acid showed potential for improving survival in patients who were postmenopausal; however, a prospective study in this patient population is required to validate this observation. Ongoing trials are examining whether adjuvant blockade of the RANKL pathway using denosumab can prevent disease recurrence in patients with high-risk breast cancer. These are building on analogous studies that have shown that denosumab improves bone metastasis-free survival in prostate cancer and suggested that it confers an overall survival benefit in non-small-cell lung cancer.

Role of bisphosphonates in postmenopausal women with breast cancer

Data suggest that bisphosphonates protect bone health and may have anticancer activity in postmenopausal women during adjuvant breast cancer therapy. However, key questions remain surrounding the role of adjuvant bisphosphonates in breast cancer, including patient populations deriving benefit, timing/scheduling of therapy, and specific clinical benefits. PubMed, Embase, and San Antonio Breast Cancer Symposium databases provide study results that address these issues in postmenopausal women. Review of these data would aid physicians in providing optimal management of breast cancer in postmenopausal women. For example, recent data reinforce use of intravenous bisphosphonates concurrently with adjuvant endocrine therapy to ameliorate bone loss in recently postmenopausal or osteopenic postmenopausal women with early breast cancer. In contrast, clinical data for oral bisphosphonates have not provided support for using anti-osteoporosis doses in this setting, and the optimal dose is unclear. Additionally, current clinical data show improvements in disease outcomes with bisphosphonates in many studies, although not in all patient subsets. Strong support for the potential adjuvant anticancer benefits from bisphosphonates has been demonstrated in women with established menopause (i.e., very low circulating estrogen levels). Initiating bisphosphonates early and concomitantly with adjuvant therapy generally provided the greatest benefits. However, questions remain such as schedule of treatment and relative potency among the intravenous bisphosphonates and elucidation of the role of oral bisphosphonates, as well as ongoing studies that might provide clarification. This review addresses these controversies in the context of translational research, which may provide the rationale for ongoing studies and evolving treatment paradigms in this area.

Luminal breast cancer: from biology to treatment

Oestrogen receptor (ER)-positive--or luminal--tumours represent around two-thirds of all breast cancers. Luminal breast cancer is a highly heterogeneous disease comprising different histologies, gene-expression profiles and mutational patterns, with very varied clinical courses and responses to systemic treatment. Despite adjuvant endocrine therapy and chemotherapy treatment for patients at high risk of relapse, both early and late relapses still occur, a fact that highlights the unmet medical needs of these patients. Ongoing research aims to identify those patients who can be spared adjuvant chemotherapy and who will benefit from extended adjuvant hormone therapy. This research also aims to explore the role of adjuvant bisphosphonates, to interrogate new agents for targeting minimal residual disease, and to address endocrine resistance. Data from next-generation sequencing studies have given us new insight into the biology of luminal breast cancer and, together with advances in preclinical models and the availability of newer targeted agents, have led to the testing of rationally chosen combination treatments in clinical trials. However, a major challenge will be to make sense of the large amount of patient genomic data that is becoming increasingly available. This analysis will be critical to our understanding how intertumour and intratumour heterogeneity can influence treatment response and resistance.

Osteonecrosis of the Jaw and Oral Health–Related Quality of Life After Adjuvant Zoledronic Acid: An Adjuvant Zoledronic Acid to Reduce Recurrence Trial Subprotocol (BIG01/04)

Purpose

In patients with early breast cancer, adjuvant zoledronic acid (zoledronate) may reduce recurrence and improve survival. However, zoledronate is associated with the occasional development of osteonecrosis of the jaw (ONJ). We report on the frequency of ONJ and investigate oral health–related quality of life (Oral-QoL) in a large randomized trial (Adjuvant Zoledronic Acid to Reduce Recurrence [AZURE]).

Patients and Methods

Three thousand three hundred sixty women with stage II or III breast cancer were randomly assigned to receive standard adjuvant systemic therapy alone or with zoledronate administered at a dose of 4 mg for 19 doses over 5 years. All potential occurrences of ONJ were reported as serious adverse events and centrally reviewed. Additionally, we invited 486 study participants to complete the Oral Health Impact Profile-14 (OHIP-14) to assess Oral-QoL around the time the patients completed 5 years on study. Multivariable linear regression was used to calculate mean scores and 95% CIs in addition to identifying independent prognostic factors.

Results

With a median follow-up time of 73.9 months (interquartile range, 60.7 to 84.2 months), 33 possible cases of ONJ were reported, all in the zoledronate-treated patients. Twenty-six cases were confirmed as being consistent with a diagnosis of ONJ, representing a cumulative incidence of 2.1% (95% CI, 0.9% to 3.3%) in the zoledronate arm. Three hundred sixty-two patients (74%) returned the OHIP-14 questionnaire. Neither the prevalence nor severity of impacts on Oral-QoL differed significantly between zoledronate patients and control patients.

Conclusion

Adjuvant zoledronate used in the intensive schedule studied in the AZURE trial is associated with a low incidence of ONJ but does not seem to adversely affect Oral-QoL.

Adjuvant bisphosphonates in breast cancer: has the time come?

SUMMARY Bone metabolism is highly affected by changes in ovarian function, which is a common consequence of the treatment of breast cancer patients. Osteopenia and osteoporosis increase the risk of fractures, which are associated with profound loss in quality of life. Bisphosphonates are used with the objective of preventing bone loss in patients with osteoporosis, but data suggest that agents such as zoledronic acid might play a role in the prevention of metastatic disease and therefore have been evaluated in numerous randomized trials in the adjuvant setting. This review article will discuss and analyze the available data regarding the use of bisphosphonates in the adjuvant setting for breast cancer patients. It will focus on the use of bisphosphonates as anticancer agents, but will also discuss the use of these agents for the prevention of bone loss.

Comparison of γδ T cell responses and farnesyl diphosphate synthase inhibition in tumor cells pretreated with zoledronic acid

Exposing human tumor cells to nitrogen-containing bisphosphonates, such as zoledronic acid (Zol), greatly increases their susceptibility to killing by γδ T cells. Based on this finding and other studies, cancer immunotherapy using γδ T cells and nitrogen-containing bisphosphonates has been studied in pilot clinical trials and has shown benefits. Although Zol treatment can render a wide variety of human tumor cells susceptible to γδ T cell killing, there has not been a systematic investigation to determine which types of tumor cells are the most susceptible to γδ T cell-mediated cytotoxicity. In this study, we determined the Zol concentrations required to stimulate half maximal tumor necrosis factor-α production by γδ T cells cultured with various tumor cell lines pretreated with Zol and compared these concentrations with those required for half maximal inhibition of farnesyl diphosphate synthase (FPPS) in the same tumor cell lines. The inhibition of tumor cell growth by Zol was also assessed. We found that FPPS inhibition strongly correlated with γδ T cell activation, confirming that the mechanism underlying γδ T cell activation by Zol is isopentenyl diphosphate (IPP) accumulation due to FPPS blockade. In addition, we showed that γδ T-cell receptor-mediated signaling correlated with γδ T cell tumor necrosis factor-α production and cytotoxicity. Some lymphoma, myeloid leukemia, and mammary carcinoma cell lines were relatively resistant to Zol treatment, suggesting that assessing tumor sensitivity to Zol may help select those patients most likely to benefit from immunotherapy with γδ T cells.

Long-term remission after multiple bone metastases following cervical cancer: A case report

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Multiple bone metastases following cervical cancer was completed resolved.

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Metastatic lesions were present within a previously irradiated zone of primary external radiation.

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Concurrent chemotherapy and bisphosphonate administration is promising.

Possible survival benefits from zoledronic acid treatment in patients with bone metastases from solid tumours and poor prognostic features-An exploratory analysis of placebo-controlled trials

Background

Zoledronic acid (ZOL) is an important component of therapy for patients with metastatic bone disease (MBD) to reduce the risk of skeletal-related events (SREs). We evaluated overall survival (OS) in patients with MBD secondary to solid tumours included in placebocontrolled ZOL trials.

Patients and methods

Exploratory analyses were performed using databases from three randomised trials of ZOL versus placebo. 1126 patients (ZOL, n=731; placebo, n=395) with complete baseline data for 18 predefined parameters were evaluated for OS. Relative risks (RRs) with 95% confidence intervals were assessed using stratified and adjusted Cox regression models. Baseline covariates defining patient populations with significantly different effects of ZOL treatment on OS (identified by stepwise backward elimination) were included in multivariate models.

Results

Although OS was similar between the overall treatment groups, ZOL significantly improved OS in the subset of patients (n=423; 38%) with elevated baseline NTX (≥100 nmol/mmol creatinine; RR, 0.692; P=.0028). Notably, this effect was independent of SRE prevention. Additional covariates associated with OS benefits with ZOL (e.g., low albumin, SRE history, elevated lactate dehydrogenase, shorter cancer duration) were characteristic of advanced disease.

Conclusion

These exploratory analyses suggest a beneficial effect of ZOL on OS in patients with highly aggressive or advanced MBD.

Mechanisms of action of bisphosphonates in oncology: a scientific concept evolving from antiresorptive to anticancer activities

Bisphosphonates are approved for treating malignant bone disease from advanced cancer because they are effective inhibitors of osteoclast-mediated bone resorption. However, there may be a greater role for the use of bisphosphonates than has previously been considered. There is a large body of preclinical evidence showing that bisphosphonates exert a variety of direct and indirect anticancer activities that affect both tumor cells and the surrounding microenvironment, and that stimulate immune reactions. Recent data from clinical trials have shown that adding the bisphosphonate zoledronate to endocrine therapy or chemotherapy improves disease-free survival of patients with endocrine-responsive early breast cancer in a low estrogen environment (that is, following ovarian suppression therapy or in women with established menopause at diagnosis). Adjuvant treatment with the bisphosphonate clodronate also improves disease-free survival in postmenopausal breast cancer. Additionally, zoledronate was found to prolong survival in patients with symptomatic multiple myeloma or other advanced cancers. Here, we present an overview of preclinical and clinical studies that demonstrate anticancer benefits of bisphosphonates, and we discuss potential mechanisms of action that might be responsible for the anticancer activity of bisphosphonates in the clinic.