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

Therapeutic Options in the Management of Aromatase Inhibitor-Associated Bone Loss

BACKGROUND

Breast cancer is the most commonly occurring cancer in women worldwide. Early breast cancer is a kind of invasive neoplasm that has not proliferated beyond the breast or the axillary lymph nodes. Current therapeutic strategies for breast cancer mainly include local therapies such as surgery or radiotherapy and systemic therapies like chemotherapy, endocrine, and targeted therapy.Nowadays, the adjuvant treatment for hormone receptor-positive early breast cancer in postmenopausal women remains the main effective systemic therapy which can improve disease-free survival and overall survival; it involves several endocrine treatment regimens including selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs), or a combination of them. AIs have been shown to be more effective in preventing recurrence in postmenopausal women with early breast cancer when compared with tamoxifen, thus representing the standard of care for adjuvant endocrine therapy. Although AIs are usually well-tolerated, they can have some side effects. Apart from the appearance of arthralgias or myalgias and cardiovascular events, AI therapies, reducing already low endogenous postmenopausal estradiol levels, cause increased bone loss and increase fracture risk in postmenopausal women.

OBJECTIVES

To evaluate the therapeutic options in the management of aromatase inhibitor-associated bone loss (AIBL).

METHODS

We reviewed the current literature dealing with different therapeutic options in the treatment of AIBL.

RESULTS

Clinical practice guidelines recommend a careful evaluation of skeletal health in all women with breast cancer before AI therapy initiation. Adequate calcium and vitamin D intake have also been suggested. Pharmacological attempts to minimize AI-related bone loss have focused on the use of antiresorptive agents, such as bisphosphonates and denosumab, to protect bone integrity and reduce the risk of fractures. Furthermore, clinical trials have shown that by making the bone microenvironment less susceptible to breast cancer metastasis, these drugs are able to increase disease-free survival.

CONCLUSIONS

AI, thatare the pillar of the systemic treatment for patients with hormone receptor-positive breast cancer, are associated with different side effects, and in particular osteoporosis and fractures. Both bisphosphonates and denosumab are able to prevent this negative effect.

Prognosis of Patients With Early Breast Cancer Receiving 5 Years vs 2 Years of Adjuvant Bisphosphonate Treatment: A Phase 3 Randomized Clinical Trial

Importance

Bisphosphonate treatment in patients with early breast cancer has become part of care, but the optimal treatment duration is still unclear.

Objective

To compare 2 vs 5 years of zoledronate treatment following adjuvant chemotherapy in patients with early breast cancer.

Design, Setting, and Participants

The SUCCESS A phase 3 multicenter randomized open-label clinical trial with a 2 × 2 factorial design enrolled 3754 patients from September 21, 2005, to March 12, 2007 (last patient out, May 7, 2014). Final data analysis was conducted from September 2019 to October 2020. In 250 German study centers, patients were eligible for participation in the SUCCESS A trial if they had either node-positive or high-risk node-negative (defined as at least 1 of the following: tumor size ≥ pT2, histologic grade 3, negative hormone receptor status, or age ≤35 years) primary invasive breast cancer.

Interventions

Patients were first randomized to adjuvant chemotherapy with 3 cycles of fluorouracil, epirubicin, and cyclophosphamide followed by 3 cycles of docetaxel with or without gemcitabine (not presented in this report). After chemotherapy, patients underwent a second randomization of 5 years of zoledronate treatment (4 mg intravenously every 3 months for 2 years, followed by 4 mg intravenously every 6 months for 3 years) vs 2 years of zoledronate treatment (4 mg intravenously every 3 months for 2 years).

Main Outcomes and Measures

The primary end point of the study was disease-free survival; secondary end points were overall survival, distant disease-free survival, and the incidence of skeletal-related adverse events. Survival times were measured from 2 years after the start of zoledronate treatment (landmark analysis).

Results

Overall, data on 2987 patients were available for analysis; median age was 53 (range, 21-86) years. Disease-free survival, overall survival, and distant disease-free survival did not differ significantly between the 2 treatment arms (5 vs 2 years) as shown by adjusted multivariable Cox proportional hazards regression models (disease-free survival: hazard ratio [HR], 0.97; 95% CI, 0.75-1.25; P = .81; overall survival: HR, 0.98; 95% CI, 0.67-1.42; P = .90; distant disease-free survival: HR, 0.87; 95% CI, 0.65-1.18; P = .38). Adverse events were observed more often in the 5-year (46.2%) vs 2-year (27.2%) zoledronate treatment arm, which was particularly true for the skeletal-related events bone pain (5 years, 8.3% vs 2 years, 3.7%) and arthralgia (5 years, 5.1% vs 2 years, 3.1%).

Conclusions and Relevance

The results of this phase 3 randomized clinical trial indicate that extending the zoledronate treatment beyond 2 years does not improve the prognosis of high-risk patients with early breast cancer receiving chemotherapy, suggesting that the currently recommended bisphosphonate treatment duration of 3 to 5 years could be reduced.

Trial Registration

ClinicalTrials.gov Identifier: NCT02181101.

Denosumab vs. zoledronic acid treatment in post-menopausal breast cancer: a 2-year prospective observational study

Adjuvant treatment for post-menopausal women with early breast cancer (BC) includes aromatase inhibitors (AI), known to decrease bone mineral density (BMD). In this study, we investigate whether denosumab is a valid second option for patients unable to receive standard adjuvant i.v. zoledronic acid (ZA). In total, 212 patients have been evaluated after they did not receive ZA. Of those 194 were included. After evaluation by an endocrinologist, all patients were offered ZA as their first choice and 15% accepted (N = 29). The remaining 85% were offered denosumab (N = 165). All patients were followed prospectively with blood tests up to 24 months. DXA scans were performed at baseline and 24 months. No difference was observed between the two treatment groups at baseline, with regard to anthropometry and standard biochemistry. Markers of bone turnover (p-PINP, p-CTX, p-bone-specific alkaline phosphatase and p-osteocalcin) all showed significant suppression compared to baseline and remained suppressed throughout the 2 years. BMD showed small and significant increases at the spine (0.024 g/cm²) and total hip (0.019 g/cm²) in the denosumab group but no change at the femoral neck(-0.011g/cm²). In the ZA group, we observed no significant change at the spine (0.015 g/cm²) and total hip (-0.001g/cm²) and a small significant decrease at the femoral neck (-0.037 g/cm²). However, when we compared BMD change between the treatment groups, we found no significant difference.Conclusions: Our data indicate that for BC patients in AI treatment who refused or were not able to receive ZA treatment, denosumab might be recommended as a second choice. Regarding markers of bone turnover and BMD denosumab is equal to ZA.Summary: Women with early breast cancer receiving anti-estrogen treatment are at risk of developing osteoporosis.We followed 194 women receiving zoledronic acid (ZA) or denosumab for up to 2 years.We find that with regard to bone protection, denosumab is a viable alternative to ZA and might be recommended as a second choice.

Updated guidance on the management of cancer treatment-induced bone loss (CTIBL) in pre- and postmenopausal women with early-stage breast cancer

INTRODUCTION

Adjuvant endocrine therapy induces bone loss and increases fracture risk in women with hormone-receptor positive, early-stage breast cancer (EBC). We aimed to update a previous position statement on the management of aromatase inhibitors (AIs) induced bone loss and now included premenopausal women.

METHODS

We conducted a systematic literature search of the medical databases from January 2017 to May 2020 and assessed 144 new studies.

RESULTS

Extended use of AIs beyond 5 years leads to persistent bone loss in breast cancer extended adjuvant trials and meta-analyses. In addition to bone mineral density (BMD), vertebral fracture assessment (VFA) and trabecular bone score (TBS) were shown to independently predict fracture risk in real life prospective studies. FRAX® tool does not seem to be reliable for assessing fracture risk in CTIBL. In premenopausal women, there is strong evidence that intravenous zoledronate prevents bone loss but weak conflicting evidence on reducing disease recurrence from independent randomised controlled trials (RCTs). In postmenopausal women, the strongest evidence for fracture prevention is for denosumab based on a well-powered RCT while there is strong evidence for bisphosphonates (BPs) to prevent and reduce CTIBL but no convincing data on fractures. Adjuvant denosumab has failed to show anticancer benefits in a large, well-designed RCT.

DISCUSSION AND CONCLUSIONS

Extended use of AIs and persistent bone loss from recent data reinforce the need to evaluate fracture risk in EBC women initiated on AIs. Fracture risk should be assessed with clinical risk factors and BMD along with VFA, but FRAX is not adapted to CTIBL. Anti-resorptive therapy should be considered in those with a BMD T-score < -2.0 SD or with ≥ 2 clinical risk factors including a BMD T-score < -1.0 SD. In premenopausal women, intravenous zoledronate is the only drug reported to prevent bone loss and may have additional anticancer benefits. In postmenopausal women, either denosumab or BPs can be prescribed for fracture prevention with pertinent attention to the rebound phenomenon after stopping denosumab. Adjuvant BPs, in contrast to denosumab, have shown high level evidence for reducing breast cancer recurrence in high-risk post-MP women which should be taken into account when choosing between these two.

Bone Mineral Density at the Time of Initiating Aromatase Inhibitor Therapy Is Associated With Decreased Fractures in Women With Breast Cancer

Women with estrogen receptor-positive breast cancer who receive an aromatase inhibitor (AI) are at risk for fractures. We aim to determine if dual-energy X-ray absorptiometry (DXA) scans made at the time of AI initiation are associated with decreased fractures. We retrospectively identified 25,158 women with local or regional breast cancer diagnosed between 2005 and 2013 who received AI therapy between 2007 and 2013 from the Medicare-linked Surveillance, Epidemiology, and End Results Program and Texas Cancer Registry databases. We defined baseline DXA screening using claims made between 1 year before and 6 months after each patient's first AI claim to examine determinants of baseline screening using a multivariable GENMOD model. We included a propensity score adjustment in Cox proportional hazard models to assess the association between time-varying DXA screening and the risk of fractures. Additionally, we compared the use of antiresorptive therapy drugs between the two groups. Of the study cohort, 14,738 (58.6%) received DXA screening. The screening rates increased annually from 52.1% in 2007 to 61.7% in 2013. Higher screening rates were observed in patients with younger age, married status, non-Hispanic white race, localized disease, fewer comorbidities, more than one type of aromatase inhibitor drug claim, no state buy-in (surrogate for low socioeconomic status), higher education level, and prior osteoporosis diagnosis. Baseline DXA screening was associated with decreased risk of subsequent fractures (hazard ratio = 0.91; 95% confidence interval, 0.86-0.97, p < .001) after multivariable and propensity score adjustment. Bone-modifying drugs were prescribed to 4440 (30.1%) patients with screening compared with 1766 (16.9%) without (p < .001). Of the 4440 patients who received treatment, 95% received bisphosphonates. Our study demonstrated baseline DXA screening was associated with a decreased risk of fractures and a higher likelihood of receiving antiresorptive therapies. Improvement of the baseline DXA screening is still needed in practice. © 2021 American Society for Bone and Mineral Research (ASBMR).

Bone-modifying Agents (BMAs) in Breast Cancer

Bone-modifying agents (BMAs) are mainstays in breast cancer and prevent and treat osteoporosis in early-stage disease and reduce skeletal metastases complications in advanced disease. There is some evidence to support that BMA also prevents skeletal metastases and improves overall survival. Bone loss occurs with chemotherapy-induced ovarian failure, gonadotrophin-releasing hormone (GnRH) agonists, and aromatase inhibitors. In some women, the bone loss will be of sufficient magnitude to increase the risks of osteoporosis or fractures. Recommended steps in osteoporosis prevention or treatment include risk factor assessment, taking adequate amounts of calcium and vitamin D3, and periodic evaluations with dual-energy x-ray absorptiometry scanning. If clinically indicated by the T-scores and fracture-risk prediction algorithms treat with oral, IV bisphosphonates or subcutaneous denosumab (DEN). Zoledronic acid (ZA) or DEN reduces skeletal metastases complications, including pathological fracture, spinal cord compression, or the necessity for radiation or surgery to bone. Also, both of these drugs have the side-effect of osteonecrosis at a similar incidence. Monthly administration of ZA or DEN is standard, but several recent randomized trials show noninferiority between ZA monthly and every 3-month ZA. Every 3-month ZA is a new standard of care. Similar trials of the schedule of DEN are ongoing. ZA anticancer effect is only in postmenopausal women or premenopausal women rendered postmenopausal by GnRH agonists or bilateral oopherectomy. High-risk women, either postmenopausal or premenopausal, receiving GnRH/oopherctomy should consider adjuvant ZA. There are insufficient data to support DEN in this setting. Herein, this narrative review covers the mechanism of action of BMA, randomized clinical trials, and adverse events, both common and rare.

Cancer Treatment-Induced Bone Loss (CTIBL): State of the Art and Proper Management in Breast Cancer Patients on Endocrine Therapy

OPINION STATEMENT

About 70-80% of early breast cancer (BC) patients receive adjuvant endocrine therapy (ET) for at least 5 years. ET includes in the majority of cases the use of aromatase inhibitors, as upfront or switch strategy, that lead to impaired bone health. Given the high incidence and also the high prevalence of BC, cancer treatment-induced bone loss (CTIBL) represents the most common long-term adverse event experimented by patients with hormone receptor positive tumours. CTIBL is responsible for osteoporosis occurrence and, as a consequence, fragility fractures that may negatively affect quality of life and survival expectancy. As recommended by main international guidelines, BC women on aromatase inhibitors should be carefully assessed for their fracture risk at baseline and periodically reassessed during adjuvant ET in order to early detect significant worsening in terms of bone health. Antiresorptive agents, together with adequate intake of calcium and vitamin D, should be administered in BC patients during all course of ET, especially in those at high risk of osteoporotic fractures, as calculated by tools available for clinicians. Bisphosphonates, such as zoledronate or pamidronate, and anti-RANKL antibody, denosumab, are the two classes of antiresorptive drugs used in clinical practice with similar efficacy in preventing bone loss induced by aromatase inhibitor therapy. The choice between them, in the absence of direct comparison, should be based on patients' preference and compliance; the different safety profile is mainly related to the route of administration, although both types of drugs are manageable with due care, since most of the adverse events are predictable and preventable. Despite advances in management of CTIBL, several issues such as the optimal time of starting antiresorptive agents and the duration of treatment remain unanswered. Future clinical trials as well as increased awareness of bone health are needed to improve prevention, assessment and treatment of CTIBL in these long-term survivor patients.

Managing Common Estrogen Deprivation Side Effects in HR+ Breast Cancer: an Evidence-Based Review

PURPOSE OF REVIEW

The article reviews the consequences of estrogen deprivation during endocrine therapy for breast cancer and provides an update on alternative therapies for the management of symptoms.

RECENT FINDINGS

Endocrine therapy has progressed substantially in recent years, and its use is recommended for all breast cancer patients expressing hormone receptors. The main adverse events of this treatment can be controlled with medications and nonpharmacological measures. Antidepressants are effective in controlling vasomotor symptoms. Vaginal discomfort can be treated with local lubricants and pelvic floor physiotherapy, which may help in sexual dysfunction. Pathophysiological mechanisms of musculoskeletal symptoms during aromatase inhibitors treatment are not well understood, but some studies evaluating treatment with duloxetine, yoga, and acupuncture have shown some benefits. For prevention of bone loss, patients with risk factors should be offered bisphosphonates or denosumab. Individualization of treatment is crucial. Consideration should be given to therapy effects on quality of life, and strategies for controlling associated symptoms should be offered.

A Review of Literature on Updates of Bisphosphonates Administration, Cancer Biomarkers for Bisphosphonate Therapy, and Bisphosphonate-related Osteonecrosis of the Jaw in Breast Cancer

Context: The emergence of bone health maintenance in breast cancer patients is known as an indispensable aspect in survival and morbidity improvement; therefore, bisphosphonates play a substantial role in the prevention/delaying of cancer treatment induced bone loss and skeletal-related events (SREs) in these patients, although this drug can cause necrosis of the jaw. In this article, we aimed at summarizing updated evidence on bisphosphonates administration, biomarkers representative of the efficacy of bisphosphonate therapy, and bisphosphonate-related osteonecrosis of the jaw (BRONJ) affection in patients involved in breast cancer. Methods: Associated published articles were searched for in EMBASE, MEDLINE, CDSR, PubMed, Google Scholar, and CINAHL, using the following keywords or, in the case of PubMed database, medical subject headings (MeSH): ‘Diphosphonate’, ‘osteonecrosis’, ‘breast cancer’, and ‘biomarker’ in the abstract or title, and was limited by "clinical trials, meta-analysis and randomized controlled trial” published in English language from 2015 to 2020-09-15. Results: Bisphosphonates depicted remarkable advantages in improving SREs, skeletal morbidity rate (SMR), survival rate, and treatment-emergent adverse events in breast cancer patients in almost all aspects of breast cancer therapy, from adjuvant therapy for the early stage breast cancer to bone metastatic breast cancer (BMBC). The identification of breast cancer biomarkers that are capable of reflecting the outcomes of bisphosphonates therapy is a highly advantageous aid in the optimal utilization of these drugs. Breast cancer biomarkers such as MAF, DOCK4, CD73, TLR9, and CAPG/GIPC1 composite illustrated a significant correlation with bisphosphonates administration. Medication-related osteonecrosis of the jaw (MRONJ) stands out as the most hazardous adverse event of the bisphosphonates with a rationally high incidence among breast cancer patients, which requires cautious prescription of bisphosphonates as well as regular dental health counseling for being prevented. Conclusions: Bisphosphonates are great weapons in the arsenal of breast cancer treatment and, therefore, comprehensive studying of their features leads to the optimal and safe administration of them. Unfortunately, as this procedure can cause necrosis of the jaw, dental procedures should be performed in these patients before starting bisphosphonate treatment.

Adjuvant bisphosphonate use in patients with early stage breast cancer: a physician survey

Purpose

Despite the increasing use of adjuvant bone-modifying agents (BMAs) such as zoledronate and clodronate in the treatment of patients with early stage breast cancer (EBC), little is known about real world practice patterns. A physician survey was performed to address this deficit and determine interest in clinical trials of alternative strategies for BMA administration.

Methods

Canadian oncologists treating patients with EBC were surveyed via an anonymized online survey. The survey collected information on: physician demographics, knowledge and interpretation of adjuvant bisphosphonate guidelines, and real world prescribing practices. Questions also determined thoughts around the design of future adjuvant BMA trials.

Results

Of 127 surveyed physicians, 53 eligible invitees responded (response rate 42%). The majority of physicians are offering high-risk postmenopausal patients adjuvant BMAs. The most common BMA regimen was adjuvant zoledronate (45/53, 85%) every 6 months for 3 years. Concerns around toxicities and repeated visits to the cancer centre were perceived as the greatest barriers to adjuvant bisphosphonate use. Respondents were interested in future trials of de-escalation of BMAs comparing a single infusion of zoledronate vs. 6-monthly zoledronate for 3 years. The most favoured primary endpoints for such a trial included disease recurrence and fragility fracture rates.

Conclusion

Questions around optimal use of adjuvant bisphosphonates in patients with EBC still exist. There is interest among physicians in performing trials of de-escalation of these agents. The results of this survey will assist in designing pragmatic clinical trials to address this question.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06147-1.

From Theory to Practice: Bone Health in Women with Early Breast Cancer Treated with Aromatase Inhibitors

Aromatase inhibitors (AI) are extensively used as adjuvant endocrine therapy in post-menopausal women with hormone receptor-positive early breast cancer (HR+ EBC), but their impact on bone health is not negligible. This work aimed to assess bone loss, fracture incidence, and risk factors associated with these events, as well as the prognostic influence of fractures. We have conducted a retrospective cohort study of women with HR+ EBC under adjuvant therapy with AI, during a 3-year period. Four-hundred-and-fifty-one eligible women were reviewed (median age 68 years). Median time under AI was 40 months. A fracture event occurred in 8.4%, mostly in the radium and femoral neck and in older women (mean 74 vs. 68 years, p = 0.006). Age (OR 1.01, 95% CI 1.01-1.07, p = 0.024) and time under AI (OR 1.02, 95% CI 1.00-1.04, p = 0.037) were independent predictors of fracture, with a fair discrimination (AUC 0.71). Analysis of disease-free survival according to fracture event varied between groups, disfavoring the fracture cohort (at 73 months, survival 78.6%, 95% CI, 47.6-92.4 vs. 95.6%, 95% CI, 91.2-97.8, p = 0.027). The multivariate model confirmed the prognostic impact of fracture occurrence (adjusted HR of 3.17, 95% CI 1.10-9.11; p = 0.032). Bone health is often forgotten, despite its great impact in survivorship. Our results validate the pathophysiologic link between EBC and bone metabolism, which translates into EBC recurrence. Further research in this area may help refine these findings. Moreover, early identification of women at higher risk for fractures is warranted.

Adjuvant bisphosphonate use in patients with early stage breast cancer: Patient perspectives on treatment acceptability and potential de-escalation

Background

Despite the increasing use of adjuvant bisphosphonates for early stage breast cancer (EBC), little is known about the patient experience with such treatments. A patient survey was performed to identify current prescribing practices, perceptions around the role of treatment, the impact of treatment on patients' quality of life, and future trial designs.

Methods

EBC patients who had either completed or were currently receiving adjuvant bisphosphonates were sent an anonymized survey. The survey collected information on patient and disease characteristics, bisphosphonate scheduling, compliance, and tolerance. Questions also assessed patient interest in trials of de-escalated bisphosphonate therapy.

Results

A total of 255 patients were contacted, with 164 eligible respondents (eligible response rate 164/255, 64.3%). Median patient age was 52 years (range 28 to 82 years). The majority (111/163, 68.1%) were postmenopausal at the time of diagnosis, 23.3% (38/163) were premenopausal, and 7.4% (12/163) were perimenopausal. Most patients (78%) had received chemotherapy. Zoledronate was the most commonly used bisphosphonate (92%), with the majority receiving treatment every 6 months for 3 years (73%). While 66% (107/161) of respondents had experienced side effects with treatment, most had, or expected to, complete treatment (154/163, 94%). Provided there was no detriment in breast cancer outcomes, there was strong interest in future studies of de-escalating adjuvant bisphosphonate therapy.

Conclusion

While most patients tolerate their treatment, there is interest in performing trials of de-escalation of these agents.

Long-term outcome of (neo)adjuvant zoledronic acid therapy in locally advanced breast cancer

PURPOSE

The role of zoledronic acid (ZOL), a bone-targeted bisphosphonate, in the treatment of patients with breast cancer remains an active area of study. Here, we report the long-term outcomes of a randomized placebo-controlled phase II clinical trial in which ZOL treatment was added to neoadjuvant chemotherapy in women with locally advanced breast cancer.

METHODS

120 women with clinical stage II-III (≥ T2 and/or ≥ N1) newly diagnosed breast cancer were randomized to receive either 4 mg intravenous ZOL every 3 weeks for 1 year (17 total doses) beginning with the first dose of neoadjuvant chemotherapy, or chemotherapy alone. Clinical endpoints included time to recurrence (TTR), time to bone recurrence (TTBR), time to non-bone recurrence (TTNBR), breast cancer survival (BCS) and overall survival (OS).

RESULTS

With a median follow-up interval of 14.4 years, there were no significant differences in any of the clinical endpoints studied between the control and ZOL groups in the overall study population. However, ER+/HER2- patients younger than age 45 who were treated with ZOL had significantly worse TTR and TTNBR with a trend towards worse TTBR, BCS and OS (TTR: P = 0.024, HR 6.05 [1.26-29.1]; TTNBR: P = 0.026, HR 6.94 [1.26-38.1]; TTBR: P = 0.054, HR 6.01 [0.97-37.1]; BCS: P = 0.138, HR 4.43 [0.62-31.7]; OS: P = 0.138, HR 4.43 [0.62-31.7]). These differences were not seen in older ER+/HER2- patients or triple-negative patients of any age.

CONCLUSION

Addition of ZOL to neoadjuvant therapy did not significantly affect clinical outcomes in the overall study population but was associated with increased extra-skeletal recurrence and a trend towards worse survival in ER+/HER2- patients younger than age 45. These findings suggest caution when using zoledronic acid in young, premenopausal women with locally advanced breast cancer and warrant further investigation. Clinical Trial Registration Number NCT00242203, Date of Registration: 10/17/2005.

Synthesis and preliminary anticancer evaluation of new triazole bisphosphonate-based isoprenoid biosynthesis inhibitors

The synthesis of a new set of triazole bisphosphonates 8a-d and 9a-d presenting an alkyl or phenyl substituent at the C-4 or C-5 position of the triazole ring is described. These compounds have been evaluated for their antiproliferative activity against MIA PaCa-2 (pancreas), MDA-MB-231 (breast) and A549 (lung) human tumor cell lines. 4-hexyl- and 4-octyltriazole bisphosphonates 8b-c both displayed remarkable antiproliferative activities with IC₅₀ values in the micromolar range (0.75-2.4 μM) and were approximately 4 to 12-fold more potent than zoledronate. Moreover, compound 8b inhibits geranylgeranyl pyrophosphate biosynthesis in MIA PaCa-2 cells which ultimately led to tumor cells death.

Update on the Role of Neuropeptide Y and Other Related Factors in Breast Cancer and Osteoporosis

Breast cancer and osteoporosis are common diseases that affect the survival and quality of life in postmenopausal women. Women with breast cancer are more likely to develop osteoporosis than women without breast cancer due to certain factors that can affect both diseases simultaneously. For instance, estrogen and the receptor activator of nuclear factor-κB ligand (RANKL) play important roles in the occurrence and development of these two diseases. Moreover, chemotherapy and hormone therapy administered to breast cancer patients also increase the incidence of osteoporosis, and in recent years, neuropeptide Y (NPY) has also been found to impact breast cancer and osteoporosis.Y1 and Y5 receptors are highly expressed in breast cancer, and Y1 and Y2 receptors affect osteogenic response, thus potentially highlighting a potential new direction for treatment strategies. In this paper, the relationship between breast cancer and osteoporosis, the influence of NPY on both diseases, and the recent progress in the research and treatment of these diseases are reviewed.

Bone metastasis: mechanisms, therapies, and biomarkers

Skeletal metastases are frequent complications of many cancers, causing bone complications (fractures, bone pain, disability) that negatively affect the patient's quality of life. Here, we first discuss the burden of skeletal complications in cancer bone metastasis. We then describe the pathophysiology of bone metastasis. Bone metastasis is a multistage process: long before the development of clinically detectable metastases, circulating tumor cells settle and enter a dormant state in normal vascular and endosteal niches present in the bone marrow, which provide immediate attachment and shelter, and only become active years later as they proliferate and alter the functions of bone-resorbing (osteoclasts) and bone-forming (osteoblasts) cells, promoting skeletal destruction. The molecular mechanisms involved in mediating each of these steps are described, and we also explain how tumor cells interact with a myriad of interconnected cell populations in the bone marrow, including a rich vascular network, immune cells, adipocytes, and nerves. We discuss metabolic programs that tumor cells could engage with to specifically grow in bone. We also describe the progress and future directions of existing bone-targeted agents and report emerging therapies that have arisen from recent advances in our understanding of the pathophysiology of bone metastases. Finally, we discuss the value of bone turnover biomarkers in detection and monitoring of progression and therapeutic effects in patients with bone metastasis.

Feasibility outcomes of a randomised, multicentre, pilot trial comparing standard 6-monthly dosing of adjuvant zoledronate with a single one-time dose in patients with early stage breast cancer

•

Adjuvant bisphosphonates are an established standard in postmenopausal breast cancer.

•

Guidelines note the need to explore different agents, doses, and intervals of bisphosphonates.

•

Feasibility of randomizing to 6-monthly vs one dose of IV zoledronate was demonstrated.

Background

Adjuvant zoledronate is widely used in patients with early stage breast cancer (EBC), but its optimal duration and dosing interval is still unknown. While a single-dose of zoledronate can improve bone density for many years, a proper evaluation of its effects on breast cancer-related outcomes would require a large trial. In this pilot study we evaluated the feasibility of performing such a trial.

Methods

Eligible patients with EBC were randomised to receive either one dose of zoledronate or 7 doses (6-monthly dosing for 3 years). Feasibility was assessed by a combination of primary outcomes including: activation of at least 6 Ontario sites within a year, active participation (i.e. approaching eligible patients for study participation) of at least half of the medical oncologists, and enrolment of at least 100 patients across all sites within 9 months of the sixth site being activated.

Results

All 6 sites were activated within 1 year and of 47 medical oncologists, 27 (57%) approached patients. Between November 2018 and April 2020, 211 eligible patients were randomised, 106 (50.2%) to a single dose of zoledronate and 105 (49.8%) to 6-monthly dosing. Baseline characteristics of randomised patients included; median age 59 (range 36–88), ER and/or PR positive (85%), Her2 positive (23%), menopausal status (premenopausal [19%], perimenopausal [6.7%] and postmenopausal [74%]) and 74% received neo/adjuvant chemotherapy.

Conclusions

All study feasibility endpoints were met in this trial comparing alternative schedules for adjuvant zoledronate. We will now seek funding for performing a larger efficacy trial.

Trial registration: NCT03664687.

Bisphosphonates and breast cancer - From cautious palliation to saving lives

Bone metastases are common in breast cancer and may cause considerable morbidity including fractures, severe pain, nerve compression and hypercalcaemia. Alongside developments in the multidisciplinary management for patients with metastatic breast cancer, the use of bisphosphonates, and more recently denosumab, has transformed the course of advanced breast cancer for many patients resulting in a major reduction in skeletal complications, reduced bone pain and improved quality of life. Additionally, because the bone marrow microenvironment is so intimately involved in the metastatic processes required for cancer dissemination, the use of adjuvant bisphosphonates has been studied extensively over the past 25 years in many randomised trials. We now have clear evidence that bisphosphonates significantly reduce both metastasis to bone and mortality in postmenopausal women with early breast cancer. Efficacy seems similar across different biological subgroups of postmenopausal breast cancer with the use of either a nitrogen-containing bisphosphonate such as intravenous zoledronate or daily oral ibandronate as well as the non-nitrogen containing agent, daily oral clodronate. In this overview of evolving role of bisphosphonates in breast cancer, focussing particularly on pamidronate and zoledronate, the long winding development road from the 1970s through to the present day is described and some of the serendipitous findings, "lucky breaks" and regulatory decisions along the way outlined.

Osteoporosis: A Long-Term and Late-Effect of Breast Cancer Treatments

Simple Summary

Osteoporosis is a prevalent condition affecting 200 million individuals world-wide. Estimates are about one in three women will experience a fragility fracture of hip, spine or wrist. Common breast cancer treatments, such as aromatase inhibitors in postmenopausal women and chemotherapy-induced ovarian failure in premenopausal women, cause bone loss that in some women will lead to osteoporosis and fragility fractures. Fragility fractures cause morbidity and mortality and are entirely preventable. Prevention or treatment of osteoporosis includes lifestyle modifications (e.g., reducing smoking and excessive alcohol consumption, and increasing physical activity), taking calcium and vitamin D3, screening for osteoporosis with dual-energy absorptiometry, and treatment, if clinically indicated, with ether oral bisphosphonates, intravenous zoledronic acid, or subcutaneous denosumab. This chapter reviews the pathogenesis of osteoporosis, the magnitude of bone loss related to common breast cancer treatments, osteoporosis risk factor assessment and screening, and the specific drugs to treat or prevent osteoporosis.

Abstract

Osteoporosis is both a long-term effect (occurs during treatment and extends after treatment) and a late-effect (occurs after treatment ends) of breast cancer treatments. The worldwide prevalence of osteoporosis is estimated to be some 200 million patients. About one in three postmenopausal women will experience an osteoporotic (or fragility) fracture of the hip, spine, or wrist. breast cancer treatments, including gonadotropin-releasing hormone (GnRH) agonists, chemotherapy-induced ovarian failure (CIOF), and aromatase inhibitors (AIs), cause bone loss and increase the risks of osteoporosis. Also, breast cancer is a disease of aging, and most of the “one in eight” lifetime risks of breast cancer are in women in their sixth, seventh, and eighth decades. The majority of women diagnosed with breast cancers today will be long-term survivors and experience personal cures. It is the coalescence of osteoporosis with breast cancer, two common and age-related conditions that make osteoporosis relevant in women with breast cancer throughout the continuum from diagnosis, treatment, and survivorship. It is critical to remember that women (and men) will lose bone after age thirty years. However, only certain women will lose bone of sufficient magnitude to merit treatment with anti-osteoporosis drugs. The narrative review is intended for medical, surgical, radiation oncologists, and other mid-level providers, and provides an overview of bone loss and the prevention and treatment of osteoporosis.

Molecular mechanisms of action of bisphosphonates and new insights into their effects outside the skeleton

Bisphosphonates (BP) are a class of calcium-binding drug used to prevent bone resorption in skeletal disorders such as osteoporosis and metastatic bone disease. They act by selectively targeting bone-resorbing osteoclasts and can be grouped into two classes depending on their intracellular mechanisms of action. Simple BPs cause osteoclast apoptosis after cytoplasmic conversion into toxic ATP analogues. In contrast, nitrogen-containing BPs potently inhibit FPP synthase, an enzyme of the mevalonate (cholesterol biosynthesis) pathway. This results in production of a toxic metabolite (ApppI) and the loss of long-chain isoprenoid lipids required for protein prenylation, a process necessary for the function of small GTPase proteins essential for the survival and activity of osteoclasts. In this review we provide a state-of-the-art overview of these mechanisms of action and a historical perspective of how they were discovered. Finally, we challenge the long-held dogma that BPs act only in the skeleton and highlight recent studies that reveal insights into hitherto unknown effects on tumour-associated and tissue-resident macrophages.

Challenges in Preventing Bone Loss Induced by Aromatase Inhibitors

CONTEXT

Aromatase inhibitors have become a mainstay in the adjuvant treatment regimen in postmenopausal women with hormone receptor-positive breast cancer. While many of these patients have an excellent long-term prognosis, adverse effects on bone represent an emerging complication of aromatase inhibitor treatment, resulting in substantial bone loss and fragility fractures. Treatment approaches to prevent aromatase inhibitor-induced bone loss typically consist of an antiresorptive approach with bisphosphonates or the RANKL antibody denosumab. However, different guidelines vary with respect to treatment thresholds, duration, and dosing. The choice of antiresorptive regime is further complicated by comorbidities and potential disease-modifying effects of individual agents.

OBJECTIVE

This review summarizes the evidence of how aromatase inhibitors affect bone health and provides an update of clinical approaches to preserve bone strength in affected women. (J Clin Endocrinol Metab XX: 0-0, 2020).

Eight pillars of oncorheumatology: Crossroads between malignancies and musculoskeletal diseases

ONCORHEUMATOLOGY

RELATIONSHIP BETWEEN MALIGNANCIES AND MUSCULOSKELETAL DISEASES: Oncorheumatology is the meeting point of tumor formation and rheumatic musculoskeletal diseases (RMD). Multiple interactions exist between these two medical specialties. One major field is the topic of malignancies associated with rheumatic diseases, while the other topic covers the development of musculoskeletal disease in cancer patients. Within the first group, secondary malignancies may be associated with rheumatic diseases. Mostly sustained inflammation is responsible for transition into cancer. Tumor-associated antigens (TAA) with adhesive properties are present on tumor cells. These molecules may also be expressed by inflammatory leukocytes and soluble TAA levels may be elevated in RMDs. There has been continuous debate with respect to the possible carcinogenicity of conventional and targeted antirheumatic drugs. Very recent data from registries suggest that neither biologics, nor JAK inhibitors increase cancer risk in arthritis patients. The issue of physiotherapy in rheumatic patients with recent or current cancer has also been controversial. Some modalities, primarily exercise, may be safely applied to patients with RMD and cancer. The second large topic includes paraneoplastic syndromes. Musculoskeletal paraneoplasias are triggered by tumor-derived mediators. These syndromes are sometimes slightly different from the classical RMDs. Various chemotherapies may also be associated with autoimmune side effects. Recently, these immune-related complications have also been observed in cancer patients treated with immune-checkpoint inhibitors. Sex hormone-deprivation therapies, such as aromatase inhibitors and anti-androgens are widely used for the treatment of breast and prostate cancer, respectively. These compounds may induce bone loss and lead to osteoporosis. Finally, primary and secondary malignancies of the musculoskeletal system may also interest rheumatologists. In this review, the clinical, practical aspects of these eight pillars of oncorheumatology will be discussed.

Extra-skeletal effects of bisphosphonates

Bisphosphonates (BPs) are pyrophosphate analogues widely used in diseases related to bone loss and increased bone turnover. Their high affinity for bone hydroxyapatite makes them ideal agents for bone diseases, while preventing them from reaching other cells and tissues. Data of the last decade, however, have demonstrated extra-skeletal tissue deposition and a variety of non-skeletal effects have been recently recognized. As such, BPs have been shown to exert anti-tumor, immunomodulatory, anti-inflammatory and anti-diabetic effects. In addition, new delivery systems (liposomes, nanoparticles, hydrogels) are being developed in an effort to expand BPs clinical application to extra-skeletal tissues and enhance their overall therapeutic spectrum and effectiveness. In the present review, we outline current data on extra-skeletal actions of bisphosphonates and attempt to unravel the underlying pathophysiological mechanisms.

Physiopathological roles of vesicular nucleotide transporter (VNUT), an essential component for vesicular ATP release

Vesicular nucleotide transporter (VNUT) is the last identified member of the SLC17 organic anion transporter family, which plays a central role in vesicular storage in ATP-secreting cells. The discovery of VNUT demonstrated that, despite having been neglected for a long time, vesicular ATP release represents a major pathway for purinergic chemical transmission, which had been mainly attributed to ATP permeation channels. This article summarizes recent advances in our understanding of the mechanism of VNUT and its physiopathological roles as well as the development of inhibitors. Regulating the activity and/or the expression of VNUT represents a new and promising therapeutic strategy for the treatment of multiple diseases.

Survival in older women with early stage breast cancer receiving low-dose bisphosphonates or denosumab

BACKGROUND

Bisphosphonates and denosumab, as adjuvant therapy in breast cancer, have been associated in some studies with improved cancer outcomes. The potential benefits of these drugs used at the lower doses commonly given for osteoporosis have not been established. The objective of this study was to investigate the association between therapy with bone-modifying agents (BMAs) and survival in older women with early breast cancer.

METHODS

The authors conducted a retrospective cohort study of women aged ≥66 years with breast cancer who were included in the Surveillance, Epidemiology, and End Results and Texas Cancer Registry Medicare-linked databases. Associations were examined between the receipt of BMAs at dosages indicated for osteoporosis within 2 years after diagnosis and overall and breast cancer-specific survival. Cox proportional hazards models and propensity score adjustment and matching were used for the analyses.

RESULTS

Of the 37,724 women included, 7925 (21%) received at least 6 months of a BMA within the first 2 years of breast cancer diagnosis, including bisphosphonates only in 6898 women (80.7%), denosumab only in 1204 (15.2%), and both classes of BMAs in 323 (4.1%). The median follow-up was 64 months. The receipt of a bisphosphonate was associated with improved overall survival (hazard ratio [HR], 0.87; 95% CI, 0.82-0.93) and breast cancer-specific survival (HR, 0.77; 95% CI, 0.64-0.92) after multivariable adjustment. Benefits were primarily seen for patients who had stage II and III disease. No benefits were observed with denosumab (stage II: HR, 1.05 [95% CI, 0.90-1.22]; stage III: HR, 1.09 [95% CI, 0.66-1.82]).

CONCLUSIONS

Bisphosphonates at the doses recommended for osteoporosis are associated with improved survival in older postmenopausal women with early breast cancer.

Current and Emerging Biomarkers Predicting Bone Metastasis Development

Bone is one of the preferential sites of distant metastases from malignant tumors, with the highest prevalence observed in breast and prostate cancers. Patients with bone metastases (BMs) may experience skeletal-related events, such as severe bone pain, pathological fractures, spinal cord compression, and hypercalcemia, with negative effects on the quality of life. In the last decades, a deeper understanding of the molecular mechanisms underlying the BM onset has been gained, leading to the development of bone-targeting agents. So far, most of the research has been focused on the pathophysiology and treatment of BM, with only relatively few studies investigating potential predictors of risk for BM development. The ability to select such "high-risk" patients could allow early identification of those most likely to benefit from interventions to prevent or delay BM. This review summarizes several evidences for the potential use of specific biomarkers able to predict early the BM development.

Bone health care in women with breast cancer

The aim of this article is to analyze and critically appraise the literature regarding optimal bone health care in women with breast cancer and, more specifically, to present (1) the causes of bone loss in breast cancer patients, (2) the appropriate screening for osteoporosis and fracture risk estimation, (3) optimal prevention and therapeutic strategies for osteoporosis and fractures, (4) the role of antiresorptive agents as adjuvant therapy for the prevention of bone metastases and increase of overall survival, and (5) current data on the possible use of menopausal hormone therapy (MHT) in these patients. The objective is to provide a sound pathophysiological background along with evidence-based and practical recommendations for physicians managing such women.

Management of osteoporosis in women with breast cancer

The screening, prevention and treatment of osteoporosis are similar in women with or without breast cancer. Breast cancer treatments, such as aromatase inhibitors, chemotherapy-induced ovarian failure and gonadotropin-releasing hormone antagonists all decrease estrogen levels, which in turn causes net bone resorption and bone loss. Bone loss over time will be of sufficient magnitude to cause some women to experience fractures. Thus, osteoporosis is an equation; the peak bone mass achieved by age 30 years minus the age-related and menopausal bone loss. Women should have their bone density measured by dual x-ray absorptiometry scans every 2 years. As clinically indicated, women should receive anti-osteoporosis drugs such as zoledronic acid, denosumab or oral bisphosphonates.

Clinical benefits of bone targeted agents in early breast cancer

Through their profound effects on the bone microenvironment, bone targeted treatments can potentially modify the process of metastasis and have important effects on disease outcomes as well as on bone health. The Early Breast Cancer Trialists Collaborative Group (EBCTCG) evaluated the effect of adjuvant bisphosphonates in early breast cancer by performing a meta-analysis of individual patient data (n = 18,766) from all available randomized trials initiated between the early 1990s until 2006. In postmenopausal women, bisphosphonates reduced bone recurrence (RR = 0.72; 95%CI 0.60-0.86, 2p = 0.0002) and breast cancer mortality (0.82; 95%CI 0.73-0.93, 2p = 0.002); no effects on disease outcomes could be identified in premenopausal women. Somewhat surprisingly, these effects could not be reproduced in the large adjuvant trial of denosumab (DCARE). In this study, neither bone metastasis free survival (the primary endpoint) or disease-free survival were improved by the addition of this targeted antibody inhibitor of osteoclast activity. Efforts are ongoing to try to understand the biologic implications of these results. For now, the use of denosumab in early cancers is limited to its use for fracture prevention using the 60mg every 6 months dosing schedule.

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.

Aromatase inhibitor therapy in recurrent, estrogen-receptor positive uterine serous carcinoma: A case report

•

There is a critical need for therapeutic options in uterine serous carcinoma (USC).

•

A substantial proportion of USC cases express estrogen receptors (ER).

•

This report describes use of letrozole therapy in recurrent, ER-positive USC.

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Zoledronic acid may enhance letrozole efficacy against hormone-sensitive tumors.

•

Aromatase inhibitors could be a potential treatment option in ER-positive USC.

Breast cancer outcome in relation to bone mineral density and bisphosphonate use: a sub-study of the DATA trial

Purpose

The phase III DATA study compared 6 and 3 years of adjuvant anastrozole following 2–3 years of tamoxifen in postmenopausal breast cancer patients. This pre-planned side-study assessed the relationship between a reduced bone mineral density (BMD) and distant recurrence-free survival (DRFS), and evaluated the effect of bisphosphonates on DRFS.

Methods

We selected all patients with a BMD measurement within 3 years after randomisation (landmark) without any DRFS events. Kaplan–Meier methods and Cox proportional hazards models were used for analyses.

Results

Of 1860 eligible patients, 1142 had a DEXA scan before the landmark. The BMD was normal in 436 (38.2%) and showed osteopenia in 565 (49.5%) and osteoporosis in 141 (12.3%) patients. After a median follow-up of 5.0 years from the landmark, neither osteopenia nor osteoporosis (compared with normal BMD) were associated with DRFS in both the 6-year [osteopenia HR 0.82 (95% CI 0.45–1.49), osteoporosis HR 1.10 (95% CI 0.26–4.67)] and the 3-year arm [osteopenia HR 0.75 (95% CI 0.40–1.42), osteoporosis HR 1.86 (95% CI 0.43–8.01)]. Moreover, bisphosphonate use did not impact DRFS.

Conclusion

No association was observed between a reduced BMD and DRFS. Neither did we observe an impact of bisphosphonates on DRFS.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05567-9) contains supplementary material, which is available to authorized users.

Management manual for cancer treatment-induced bone loss (CTIBL): position statement of the JSBMR

Androgen deprivation therapy and aromatase inhibitors are known to cause a decrease in bone mineral density and an increase in fractures. Patients receiving these treatments have been shown to have a fracture risk equal to or greater than that of patients with osteoporosis with prevalent fractures. This manual was created to prevent fractures in patients with cancer treatment-induced bone loss with high fracture risks who cannot be treated under the current Japanese guideline for the prevention and treatment of osteoporosis. This manual recommends drug treatment for patients with BMD - 2.0 ≤ T score < - 1.5 with the family history of hip fracture or 15% or more 10-year probability of major osteoporotic fractures by FRAX^®; or in patients with BMD T score < - 2.0. It is important to verify whether the use of this manual can reduce fractures and improve the quality of life of patients with cancer treatment-induced bone loss by prospective studies.

Endocrine Therapy-related Endocrinopathies-Biology, Prevalence and Implications for the Management of Breast Cancer

Nearly 270,000 new breast cancer cases are predicted to be diagnosed in the USA in 2019 with more than 70% being estrogen receptor positive and treated using endocrine therapy. The suppression of estrogen biosynthesis or action via the use of ovarian suppression, aromatase inhibitors and selective estrogen receptor modulators/degraders, respectively, is effective in approximately 70% of women. The systemic inhibition of estrogen during breast cancer treatment is also associated with side effects due to the important endocrine functions of this steroid hormone, including its role in the maintenance of energy homeostasis and bone health. The current work will present perspectives of the impact of endocrine therapy from the point of view of breast medical oncology, endocrinology, and basic science.

Tumor dormancy in bone

Background

Bone marrow is a common site of metastasis for a number of tumor types, including breast, prostate, and lung cancer, but the mechanisms controlling tumor dormancy in bone are poorly understood. In breast cancer, while advances in drug development, screening practices, and surgical techniques have dramatically improved survival rates in recent decades, metastatic recurrence in the bone remains common and can develop years or decades after elimination of the primary tumor.

Recent Findings

It is now understood that tumor cells disseminate to distant metastatic sites at early stages of tumor progression, leaving cancer survivors at a high risk of recurrence. This review will discuss mechanisms of bone lesion development and current theories of how dormant cancer cells behave in bone, as well as a number of processes suspected to be involved in the maintenance of and exit from dormancy in the bone microenvironment.

Conclusions

The bone is a complex microenvironment with a multitude of cell types and processes. Many of these factors, including angiogenesis, immune surveillance, and hypoxia, are thought to regulate tumor cell entry and exit from dormancy in different bone marrow niches.

Disseminated Tumor Cells and Dormancy in Breast Cancer Progression

Hematogenous dissemination of single cancer cells is a common phenomenon in patients with solid tumors. These cells may experience different fates: most will die during the process; some will grow into metastasis and some will persist in secondary homing sites for many years in a state referred to as dormancy. The mechanisms of this state are still not clear; single cancer cells can survive either by completely withdrawing from the cell cycle or by continuing to proliferate at a slow rate that is counterbalanced by cell death. Another hypothesis assumes that at least some of dormant tumor cells feature stem cell-like characteristics that may contribute to their extremely long half-lives and enhance chemotherapy resistance. Breast cancer is particularly known for prolonged periods of clinical freedom of disease (sometimes up to 20-30 years), followed by a distant relapse. In this chapter, we explore the relationship between the clinical phenomenon of tumor dormancy and the disseminated tumor cells and discuss the potential implications for treatment.

Dichotomic effects of clinically used drugs on tumor growth, bone remodeling and pain management

Improvements in the survival of breast cancer patients have led to the emergence of bone health and pain management as key aspects of patient’s quality of life. Here, we used a female rat MRMT-1 model of breast cancer-induced bone pain to compare the effects of three drugs used clinically morphine, nabilone and zoledronate on tumor progression, bone remodeling and pain relief. We found that chronic morphine reduced the mechanical hypersensitivity induced by the proliferation of the luminal B aggressive breast cancer cells in the tumor-bearing femur and prevented spinal neuronal and astrocyte activation. Using MTT cell viability assay and MRI coupled to ¹⁸FDG PET imaging followed by ex vivo 3D µCT, we further demonstrated that morphine did not directly exert tumor growth promoting or inhibiting effects on MRMT-1 cancer cells but induced detrimental effects on bone healing by disturbing the balance between bone formation and breakdown. In sharp contrast, both the FDA-approved bisphosphonate zoledronate and the synthetic cannabinoid nabilone prescribed as antiemetics to patients receiving chemotherapy were effective in limiting the osteolytic bone destruction, thus preserving the bone architecture. The protective effect of nabilone on bone metabolism was further accompanied by a direct inhibition of tumor growth. As opposed to zoledronate, nabilone was however not able to manage bone tumor-induced pain and reactive gliosis. Altogether, our results revealed that morphine, nabilone and zoledronate exert disparate effects on tumor growth, bone metabolism and pain control. These findings also support the use of nabilone as an adjuvant therapy for bone metastases.

Adjuvant bisphosphonate therapy in early-stage breast cancer-Treating the soil to kill the seed

Bisphosphonates alter the tumor microenvironment, possibly preventing cancer cell growth in the bone. Analyses of data from numerous clinical trials and a large individual patient-level data meta-analysis have suggested an anti-tumor effect for bisphosphonates in patients with early-stage breast cancer who are postmenopausal. The absolute benefit from the use of bisphosphonates on breast cancer-related mortality reduction mirrors that seen with the use of anthracycline-based chemotherapy versus a first-generation chemotherapy regimen (CMF). In this review, we discuss the evidence base for the use of adjuvant bisphosphonates in early-stage breast cancer and provide recommendations for clinical use.

Adjuvant denosumab in early breast cancer (D-CARE): an international, multicentre, randomised, controlled, phase 3 trial

BACKGROUND

Denosumab is a fully human monoclonal antibody that binds to, and inhibits, the receptor activator of RANKL (TNFSF11) and might affect breast cancer biology, as shown by preclinical evidence. We aimed to assess whether denosumab combined with standard-of-care adjuvant or neoadjuvant systemic therapy and locoregional treatments would increase bone metastasis-free survival in women with breast cancer.

METHOD

In this international, double-blind, randomised, placebo-controlled, phase 3 study (D-CARE), patients were recruited from 389 centres in 39 countries. We enrolled women (aged ≥ 18 years) with histologically confirmed stage II or III breast cancer and an Eastern Cooperative Oncology Group performance status of 0 or 1. On eligibility confirmation, investigators at each site telephoned an interactive voice response system to centrally randomly assign patients (1:1) based on a fixed stratified permuted block randomisation list (block size 4) to receive either denosumab (120 mg) or matching placebo subcutaneously every 3-4 weeks, starting with neoadjuvant or adjuvant chemotherapy, for about 6 months and then every 12 weeks for a total duration of 5 years. Stratification factors were breast cancer therapy, lymph node status, hormone receptor and HER2 status, age, and geographical region. The primary endpoint was the composite endpoint of bone metastasis-free survival. This trial is registered with ClinicalTrials.gov, NCT01077154.

FINDINGS

Between June 2, 2010, and Aug 24, 2012, 4509 women were randomly assigned to receive denosumab (n=2256) or placebo (n=2253) and included in the intention-to-treat analysis. The primary analysis of the study was done when all patients had the opportunity to complete 5 years of follow-up with an analysis data cutoff date of Aug 31, 2017. The primary endpoint of bone metastasis-free survival was not significantly different between the groups (median not reached in either group; hazard ratio 0·97, 95% CI 0·82-1·14; p=0·70). The most common grade 3 or worse treatment-emergent adverse events, reported in patients who had at least one dose of the investigational product (2241 patients with denosumab vs 2218 patients with placebo), were neutropenia (340 [15%] vs 328 [15%]), febrile neutropenia (112 [5%] vs 142 [6%]), and leucopenia (62 [3%] vs 61 [3%]). Positively adjudicated osteonecrosis of the jaw occurred in 122 (5%) of 2241 patients treated with denosumab versus four (<1%) of 2218 patients treated with placebo; treatment-emergent hypocalcaemia occurred in 152 (7%) versus 82 (4%). Two treatment-related deaths occurred in the placebo group due to acute myeloid leukaemia and depressed level of consciousness.

INTERPRETATION

Despite preclinical evidence suggesting RANKL inhibition might delay bone metastasis or disease recurrence in patients with early-stage breast cancer, in this study, denosumab did not improve disease-related outcomes for women with high-risk early breast cancer.

FUNDING

Amgen.

Chirality-Driven Mode of Binding of α-Aminophosphonic Acid-Based Allosteric Inhibitors of the Human Farnesyl Pyrophosphate Synthase (hFPPS)

Thienopyrimidine-based allosteric inhibitors of the human farnesyl pyrophosphate synthase (hFPPS), characterized by a chiral α-aminophosphonic acid moiety, were synthesized as enantiomerically enriched pairs, and their binding mode was investigated by X-ray crystallography. A general consensus in the binding orientation of all (R)- and (S)-enantiomers was revealed. This finding is a prerequisite for establishing a reliable structure-activity relationship (SAR) model.

Preventive drug therapy and contralateral breast cancer: summary of the evidence of clinical trials and observational studies

Background: Breast cancer patients have a lifelong 2-4-fold increased risk of developing a second primary tumor in the contralateral breast compared with the risk for a first primary breast cancer in the general female population. Prevention of contralateral breast cancer (CBC) has received increased attention during recent decades. Here, we summarize and discuss the available literature on drug preventive therapy and CBC.Results: The endocrine-targetting drugs, tamoxifen and aromatase inhibitors are used as standard adjuvant treatment for estrogen receptor (ER)-positive breast cancer. Both are associated with relative risk reductions of CBC of up to 50%, but incur serious side effects. Several prescription drugs originally developed for other purposes, including bisphosphonates, statins, non-steroidal anti-inflammatory drugs, metformin, anti-hypertensives and retinoids, have shown anti-cancer activity in preclinical models. However, results of observational studies on CBC are sparse and inconsistent, with only statins demonstrating promise as preventive agents and a potential treatment option for ER-negative breast cancer patients.Conclusion: Future studies are needed to assess the effect of statins in risk reduction and to identify other drugs with chemopreventive potential against CBC. Eventually, efforts must be directed towards identifying those breast cancer patients likely to benefit most from specific preventive therapies.

Management of Osteoporosis in Survivors of Adult Cancers With Nonmetastatic Disease: ASCO Clinical Practice Guideline

PURPOSE

The aim of this work is to provide evidence-based guidance on the management of osteoporosis in survivors of adult cancer.

METHODS

ASCO convened a multidisciplinary Expert Panel to develop guideline recommendations based on a systematic review of the literature.

RESULTS

The literature search of the 2018 systematic review by the US Preventive Services Task Force in the noncancer population was used as the evidentiary base upon which the Expert Panel based many of its recommendations. A total of 61 additional studies on topics and populations not covered in the US Preventive Services Task Force review were also included. Patients with cancer with metastatic disease and cancer survival outcomes related to bone-modifying agents are not included in this guideline.

RECOMMENDATIONS

Patients with nonmetastatic cancer may be at risk for osteoporotic fractures due to baseline risks or due to the added risks that are associated with their cancer therapy. Clinicians are advised to assess fracture risk using established tools. For those patients with substantial risk of osteoporotic fracture, the clinician should obtain a bone mineral density test. The bone health of all patients may benefit from optimizing nutrition, exercise, and lifestyle. When a pharmacologic agent is indicated, bisphosphonates or denosumab at osteoporosis-indicated dosages are the preferred interventions.

Development and validation of a novel nomogram for predicting distant metastasis-free survival among breast cancer patients

Background

Distant metastasis (DM) from breast cancer has a poor prognosis. Our objective was to develop and validate a nomogram to predict individual distant metastasis-free survival (DMFS) and risk stratification in non-metastatic breast cancer patients.

Methods

A nomogram was based on an analysis of 1,201 breast cancer patients treated at Sun Yat-sen Memorial Hospital from 2001 to 2014. Using univariate and multivariate analyses to identify the predictors, this model was externally validated in an independent cohort of 538 patients from the Guangdong General Hospital between 2004 and 2012. The predictive discrimination and calibration ability of this nomogram were assessed using concordance index (C-index), risk group stratification, and calibration curve.

Results

The 5-year DMFS in the training and validation cohorts were 95.74% and 91.02%, respectively. On multivariable analysis of training cohort, the prognostic factors in the nomogram comprised age, tumor size, lymph node status, molecular subtype, and lymphovascular invasion (LVI). The C-index of our model was 0.75 [95% confidence interval (CI): 0.67-0.83] for the training cohort and 0.71 (95% CI: 0.64-0.78) for the validation cohort. The calibration curves for 5-year DMFS showed good agreement between the model prediction and actual observation. Based on the risk stratification, Kaplan-Meier curves indicated that the low-risk group had significantly better prognosis than the high-risk group (P<0.001).

Conclusions

Our nomogram can provide an individual prediction of 5-year DMFS in non-metastatic breast cancer patients. This prognostic tool may help clinicians to make appropriate treatment regimens and optimal surveillance plans.

Retrospective study on the efficacy of bisphosphonates in tyrosine kinase inhibitor-treated patients with non-small cell lung cancer exhibiting bone metastasis

Bisphosphonates (Bps) inhibit the maturation of osteoclasts and suppress the adhesion of cancer cells to the bone matrix. They are recommended as the standard treatment for tumors exhibiting bone metastasis (BM). However, whether Bps can improve the prognosis of patients with tyrosine kinase inhibitor (TKI)-treated non-small cell lung cancer (NSCLC) exhibiting BM remains unclear. A total of 129 patients with NSCLC initially diagnosed with BM at The First Affiliated Hospital of Sun Yat-Sen University (Guangzhou, China) between January 2005 and December 2017 were analyzed in the present retrospective study. Median progression free survival (mPFS) time, median bone metastasis overall survival (mBM-OS) time and bone-associated progression-free survival were analyzed. Among the 129 patients, patients treated with Bps experienced significantly prolonged PFS time [mPFS: 7.1 vs. 5.1 months; hazard ratio (HR), 0.51; confidence interval (CI), 0.30-0.87; P=0.0114] in comparison with patients not treated with Bps. Of the 49 patients treated with frontline TKIs (EGFR TKIs or ALK TKI), 32 received Bps at the same time, while 17 patients received TKIs alone. The results revealed that mPFS time was significantly greater in the TKIs plus Bps group than in the TKIs alone group (mPFS: 11.2 vs. 6.9 months; HR, 0.13; CI, 0.05-0.35; P<0.0001). Significantly prolonged BM-OS time was also observed in the combination group in comparison with the TKIs alone group (mBM-OS: 31 vs. 22 months; HR, 0.31; CI, 0.10-0.96; P=0.0413). The present study demonstrated that among the patients who received TKIs (EGFR TKIs or ALK TKIs), those who also received Bps experienced significantly longer PFS time and tended to exhibit significantly improved BM-OS time, which indicated that Bps should be added to the treatment regimen of patients with NSCLC exhibiting genetic mutations and bone metastasis who have been prescribed TKIs (EGFR TKIs or ALK TKIs).

Assessment and management of bone health in women with early breast cancer receiving endocrine treatment in the DATA study

The phase III DATA study investigates the efficacy of adjuvant anastrozole (6 vs. 3 year) in postmenopausal women with breast cancer previously treated with 2-3 years of tamoxifen. This planned side-study assessed patterns of care regarding detection and treatment of osteopenia/osteoporosis, and trends in bone mineral density (BMD) during and after therapy. We registered all BMD measurements and bisphosphonate-use. Time to osteopenia/osteoporosis was analysed by Kaplan Meier methodology. For the trend in T-scores we used linear mixed models with random patients effects. Of 1860 eligible DATA patients, 910 (48.9%) had a baseline BMD measurement. Among patients with a normal baseline BMD (n = 417), osteopenia was observed in 53.5% and 55.4% in the 6- and 3-year group respectively (p = 0.18), during follow-up. Only two patients (3-year group) developed osteoporosis. Of the patients with osteopenia at baseline (n = 408), 24.4% and 20.4% developed osteoporosis respectively (p = 0.89). Three years after randomisation 18.3% and 18.2% used bisphosphonates in the 6- and 3-year groups respectively and 6 years after randomisation this was 23.7% and 20.9% respectively (p = 0.90) of which the majority used oral bisphosphonates. The yearly mean BMD-change during anastrozole in the lumbar spine showed a T-score decline of 0.075. After bisphosphonate addition the decline became less prominent (0.047 (p < 0.001)) and after anastrozole cessation, while continuing bisphosphonates, the mean BMD yearly increased (0.047 (p < 0.001)). In conclusion, extended anastrozole therapy was not associated with a higher incidence of osteoporosis. Anastrozole-use was associated with a BMD decrease; however, the decline was modest and partially reversible after anastrozole cessation.

How do skeletal morbidity rate and special toxicities affect 12-week versus 4-week schedule zoledronic acid efficacy? A systematic review and a meta-analysis of randomized trials

BACKGROUND

Zoledronic Acid is a bisphosphonate used in a 4-week schedule for the treatment of bone metastases. Some randomized trials supported its role also when administered every 12 weeks.

METHODS

we performed a systematic review and a meta-analysis in order to evaluate the two different schedules in terms of skeletal morbidity rate (SMR), skeletal related events (SRE) and adverse events (AEs).

RESULTS

our results showed a clinical difference favouring the 12-week schedule in terms of AEs (RR 1.17, 95% CI 1.06-1.29). No signifcant differences were found for SMR (RR 0.97, 95% CI 0.84-1.13) and SRE (RR 1.02, 95% CI 0.89-1.16).

CONCLUSIONS

Our findings support in clinical practice the 12-week schedule an alternative to the standard 4-week schedule in advanced breast and prostate cancer, in particular when the clinical comorbidities of the patients suggest a higher risk of renal failure or hypocalcaemia.

French recommendations on strategies for preventing and treating osteoporosis induced by adjuvant breast cancer therapies

Standard adjuvant therapies for breast cancer such as chemotherapy or aromatase inhibitor and LH-RH agonist hormone therapy are associated with significant survival gains but also induce bone loss by aggravating the estrogen deprivation. The bone loss may be substantial, notably during early treatment, and occurs regardless of the baseline bone mineral density values. The objective of developing these recommendations was to achieve a practical consensus among various scientific societies, based on literature review, about osteoporosis prevention and treatment in these patients. The following scientific societies contributed to the work: Société Française de Rhumatologie (SFR), Groupe de Recherche et d'Information sur les Ostéoporoses (GRIO), Groupe Européen d'Etudes des Métastases Osseuses (GEMO), Association Francophone pour les Soins Oncologiques de Support (AFSOS), Société Française de Sénologie et de Pathologie Mammaire (SFSPM), Société Française de Radiothérapie Oncologique (SFRO). Drug prescription and reimbursement modalities in France were taken into account. These recommendations apply to postmenopausal women taking systemic chemotherapy and/or aromatase inhibitor therapy, non-postmenopausal women taking LH-RH agonist therapy, and non-postmenopausal women with persistent amenorrhea 1 year after chemotherapy completion. All women in these three categories should undergo an evaluation of bone health and receive interventions to combat risk factors for bone loss. Patients with a history of severe osteoporotic fracture and/or a T-score value <-2.5 should receive osteoporosis drug therapy. The FRAX® score should be used to guide treatment decisions in patients whose T-score is between -1 and -2.5. General osteoporosis prevention measures should be applied in patients without criteria for osteoporosis drug therapy, who should undergo bone mineral density measurements 18-24 months later if the baseline T-score is<-1 and 3-5 years later if the baseline T-score is>-1. The anti-tumor effect of bisphosphonates and denosumab was not considered when establishing these recommendations.