Clinical review: Effect of endocrine therapies on bone in breast cancer patients

Epigenetic Landscapes of Aging in Breast Cancer Survivors: Unraveling the Impact of Therapeutic Interventions-A Scoping Review

Breast cancer therapies have dramatically improved survival rates, but their long-term effects, especially on aging survivors, need careful consideration. This review delves into how breast cancer treatments and aging intersect, focusing on the epigenetic changes triggered by chemotherapy, radiation, hormonal treatments, and targeted therapies. Treatments can speed up biological aging by altering DNA methylation, histone modifications, and chromatin remodeling, affecting gene expression without changing the DNA sequence itself. The review explains the double-edged sword effect of therapy-induced epigenetic modifications, which help fight cancer but also accelerate aging. Chemotherapy and targeted therapies, in particular, impact DNA methylation and histone modifications, promoting chronic inflammation and shortening telomeres. These changes increase biological age, as seen in epigenetic clocks and biomarkers like p21, which also play roles in drug resistance and therapeutic decisions. Chronic inflammation, driven by higher levels of inflammatory cytokines such as TNF-α and IL-6 as well as telomere shortening, significantly contributes to the aging characteristics of breast cancer survivors. Non-coding RNAs, including microRNAs and long non-coding RNAs, are crucial in regulating gene expression and aging pathways altered by these treatments. This review explores new therapies targeting these epigenetic changes, like DNA methylation inhibitors, histone deacetylase inhibitors, and microRNA-based treatments, to reduce the aging effects of cancer therapy. Non-drug approaches, such as dietary changes and lifestyle modifications, also show promise in combating therapy-induced aging. It also highlights the clinical signs of aging-related side effects, such as heart and lung problems, endocrine and reproductive issues, and reduced quality of life. The development of comprehensive methods like the CHEMO-RADIAT score to predict major cardiovascular events after therapy is discussed. Understanding the epigenetic changes caused by breast cancer therapies offers valuable insights for creating interventions to enhance the health span and quality of life for survivors. Continued research is crucial to fully understand these epigenetic alterations and their long-term health impacts.

Current and future advances in practice: aromatase inhibitor-induced arthralgia

Aromatase inhibitors (AIs) have shown great success as adjuvant therapy for post-menopausal women with hormone receptor-positive breast cancers. AI-induced arthralgia (AIA) is a frequent AI toxicity contributing to non-adherence and discontinuation. This review aims to understand current knowledge of AIA. The mean incidence of AIA was 39.1% and the mean discontinuation of AI therapy due to AIA was 9.3%. Most of the AIAs were non-inflammatory. A shorter time since the last menstrual period and pre-existing joint pain were risk factors. Vitamin D3 supplementation may be a preventative measure and treatment with duloxetine, acupuncture and/or exercise is supported by large randomized controlled trials. There was consistent improvement in AIAs with switching to an alternate AI, and this could additionally allow continuation of cancer treatment with AI. Further research is needed to identify predictive biomarkers, better characterize AIA subcategories and study more reliable therapeutic options.

Do breast cancer patients have increased risk of complications after primary total hip and total knee arthroplasty?

Aims

Breast cancer survivors have known risk factors that might influence the results of total hip arthroplasty (THA) or total knee arthroplasty (TKA). This study evaluated clinical outcomes of patients with breast cancer history after primary THA and TKA.

Methods

Our total joint registry identified patients with breast cancer history undergoing primary THA (n = 423) and TKA (n = 540). Patients were matched 1:1 based upon age, sex, BMI, procedure (hip or knee), and surgical year to non-breast cancer controls. Mortality, implant survival, and complications were assessed via Kaplan-Meier methods. Clinical outcomes were evaluated via Harris Hip Scores (HHSs) or Knee Society Scores (KSSs). Mean follow-up was six years (2 to 15).

Results

Breast cancer patient survival at five years was 92% (95% confidence interval (CI) 89% to 95%) after THA and 94% (95% CI 92% to 97%) after TKA. Breast and non-breast cancer patients had similar five-year implant survival free of any reoperation or revision after THA (p ≥ 0.412) and TKA (p ≥ 0.271). Breast cancer patients demonstrated significantly lower survival free of any complications after THA (91% vs 96%, respectively; hazard ratio = 2 (95% CI 1.1 to 3.4); p = 0.017). Specifically, the rate of intraoperative fracture was 2.4% vs 1.4%, and venous thromboembolism (VTE) was 1.4% and 0.5% for breast cancer and controls, respectively, after THA. No significant difference was noted in any complications after TKA (p ≥ 0.323). Both breast and non-breast cancer patients experienced similar improvements in HHSs (p = 0.514) and KSSs (p = 0.132).

Conclusion

Breast cancer survivors did not have a significantly increased risk of mortality or reoperation after primary THA and TKA. However, there was a two-fold increased risk of complications after THA, including intraoperative fracture and VTE.

Prevalence and factors associated with the occurrence of pathological fractures and their impact on the overall survival of patients with bone metastases under palliative care

OBJECTIVES

To assess the prevalence and factors associated with the occurrence of pathological fractures and their impact on the overall survival of patients with bone metastases under palliative care.

METHODS

An observational retrospective cohort assessment concerning both male and female patients with cancer presenting with bone metastases referred to a palliative care unit. Sociodemographic and clinical data were obtained before and after care unit referral. Patients were followed up until death or the last follow-up (4 years after referral). Logistic regression models and survival curves employing a log-rank test were applied.

RESULTS

A total of 348 patients were included in the study. Most were <65 years (65%) and female (62%), and the most frequent primary tumour site was the breast (40%). The prevalence of pathological fractures was 28%, more frequent in the axial skeleton (49%), with no association with overall patient survival (p=0.348). Patients with breast cancer exhibited a 2.96-fold higher chance (95% CI: 1.80 to 4.86) of developing a fracture compared with other tumours, and not receiving previous radiotherapy increased the chances of fracture occurrence by 5.60-fold (95% CI: 2.46 to 12.77).

CONCLUSION

A high prevalence of pathological fractures was observed. Presenting with breast cancer and not having undergone previous radiotherapy increase the chances of fracture occurrence, although this is not associated with overall survival in patients under palliative care.

Incidence of Post-denosumab Rebound Hypercalcaemia in Bony-Metastatic Breast Cancer

Denosumab reduces incidence of skeletal related events in patients with bony-metastatic breast cancer, however cessation is associated with a rebound phenomenon which, rarely, has been associated with hypercalcaemia. We aimed to identify the incidence of post-denosumab cessation rebound hypercalcaemia amongst patients with breast cancer-related bony metastases. We performed a single-centre retrospective cohort analysis to determine the incident of rebound hypercalcaemia amongst patients treated with antiresorptive agents for bony metastatic breast cancer between 2016-2020. 22,320 outpatient encounters were reviewed, which identified 97 patients with bonymetastatic disease treated with antiresorptive therapy. Of the 21 patients who had denosumab ceased, six (28.6%) developed hypercalcaemia. Interval between last denosumab dose and onset of hypercalcaemia was a median 7.5 (range 2-13) months. There was a significant difference in both denosumab treatment duration as well as total treatment dose exposure between patients who developed hypercalcaemia post-denosumab cessation (median 41 months, 40 doses) and those who remained normocalcaemic (median 10 months, 5 doses), p = 0.009. In our study, hypercalcaemia occurred between two and thirteen months after denosumab cessation. Greater denosumab treatment duration as well as total denosumab dose exposure was associated with higher risk of hypercalcaemia after denosumab cessation. Hormonal therapy or previous bisphosphonate treatment was not seen to impact upon development of hypercalcaemia. Rebound hypercalcaemia is a rare but important diagnosis to consider in patients experiencing hypercalcaemia after denosumab cessation.

Attitudes and Beliefs of Older Female Breast Cancer Survivors and Providers About Exercise in Cancer Care

OBJECTIVES

To understand breast cancer survivors' and providers' attitudes and beliefs regarding exercise counseling and structured exercise programs within cancer care.

SAMPLE & SETTING

61 female breast cancer survivors and 11 breast cancer providers from a university cancer center in the Pacific Northwest.

METHODS & VARIABLES

Survivors completed anonymous self-report surveys, and providers participated in semistructured interviews. Survey data were analyzed using descriptive statistics, and interview transcripts were analyzed using qualitative content analysis.

RESULTS

Breast cancer survivors and providers believed that including exercise counseling within cancer care was important. More than half of the survivors reported that they would attend structured exercise classes; a majority of providers thought cancer centers should offer exercise programs.

IMPLICATIONS FOR NURSING

Nurses could facilitate exercise counseling within cancer care and advocate for clinic-based exercise programs.

Breast cancer

Breast cancer is the most frequent malignancy in women worldwide and is curable in ~70-80% of patients with early-stage, non-metastatic disease. Advanced breast cancer with distant organ metastases is considered incurable with currently available therapies. On the molecular level, breast cancer is a heterogeneous disease; molecular features include activation of human epidermal growth factor receptor 2 (HER2, encoded by ERBB2), activation of hormone receptors (oestrogen receptor and progesterone receptor) and/or BRCA mutations. Treatment strategies differ according to molecular subtype. Management of breast cancer is multidisciplinary; it includes locoregional (surgery and radiation therapy) and systemic therapy approaches. Systemic therapies include endocrine therapy for hormone receptor-positive disease, chemotherapy, anti-HER2 therapy for HER2-positive disease, bone stabilizing agents, poly(ADP-ribose) polymerase inhibitors for BRCA mutation carriers and, quite recently, immunotherapy. Future therapeutic concepts in breast cancer aim at individualization of therapy as well as at treatment de-escalation and escalation based on tumour biology and early therapy response. Next to further treatment innovations, equal worldwide access to therapeutic advances remains the global challenge in breast cancer care for the future.

Letrozole improves the sensitivity of breast cancer cells overexpressing aromatase to cisplatin via down-regulation of FEN1

PURPOSE

Flap endonuclease 1 (FEN1) is up-regulated by estrogen (17β-estradiol, E2) and related to cisplatin resistance of human breast cancer cells. Letrozole, an aromatase inhibitor, suppresses the change of testosterone into estrogen and is frequently used to treat breast cancer. However, the effects of letrozole on FEN1 expression and cisplatin sensitivity in breast cancer cells overexpressing aromatase have not been revealed.

METHODS

The expression of FEN1 and the proteins in ERK/Elk-1 signaling were evaluated by RT-PCR and Western blot. Cisplatin sensitivity was explored through CCK-8 and flow cytometry analysis, respectively. FEN1 siRNAs and FEN1 expression plasmid were transfected into cells to down-regulate or up-regulate FEN1 expression. The promotor activity of FEN1 was detected using luciferase reporter assay.

RESULTS

FEN1 down-regulation improved cisplatin sensitivity of breast cancer cells overexpressing aromatase. Letrozole down-regulated FEN1 expression and increased cisplatin sensitivity. The sensitizing effect of letrozole to cisplatin was dependent on FEN1 down-regulation. FEN1 overexpression could block the sensitizing effect of letrozole to cisplatin. Testosterone up-regulated the promotor activity, protein expression of FEN1, and phosphorylation of ERK/Elk-1, which could be eliminated by both letrozole and MEK1/2 inhibitor U0126. Letrozole down-regulated FEN1 expression in an ERK/Elk-1-dependent manner.

CONCLUSIONS

Our findings clearly demonstrate that letrozole improves cisplatin sensitivity of breast cancer cells overexpressing aromatase via down-regulation of FEN1 and suggest that a combined use of letrozole and cisplatin may be a potential treatment protocol for relieving cisplatin resistance in human breast cancer.

The Management of Menopausal Symptoms in Women Following Breast Cancer: An Overview

The improved detection and successful treatment of breast cancer, resulting in better survival rates, has led to an increasing number of women living with the effects of treatment modalities and their long-term consequences. Menopausal symptoms following breast cancer can occur at an earlier age, be more severe and significantly influence a woman's overall wellbeing, in particular, sexual function, quality of life and adherence to treatment. There is a dearth of good quality evidence on the safest and most effective treatment options available for these women, and this article aims to summarize the current available treatments. Pertinent to these women is general advice, such as avoidance of triggers, and lifestyle modifications. Following which, non-pharmacological interventions, including cognitive behavior therapy (CBT), hypnosis, acupuncture, stellate ganglion nerve block and complementary agents, are discussed. Pharmacological therapies and their safety profile in these high-risk women are then examined; namely, menopausal hormone therapy, progestogens, antidepressants (selective serotonin reuptake inhibitors and selective noradrenaline reuptake inhibitors), gabapentin, clonidine and intra-vaginal dehydroepiandrosterone (DHEA). Finally, neurokinin 3 receptor antagonists, promising new agents for the treatment of troublesome menopausal vasomotor symptoms, are discussed.

Aerobic and resistance exercise improves physical fitness, bone health, and quality of life in overweight and obese breast cancer survivors: a randomized controlled trial

Background

Exercise is an effective strategy to improve quality of life and physical fitness in breast cancer survivors; however, few studies have focused on the early survivorship period, minorities, physically inactive and obese women, or tested a combined exercise program and measured bone health. Here, we report the effects of a 16-week aerobic and resistance exercise intervention on patient-reported outcomes, physical fitness, and bone health in ethnically diverse, physically inactive, overweight or obese breast cancer survivors.

Methods

One hundred breast cancer survivors within 6 months of completing adjuvant treatment were assessed at baseline, post-intervention, and 3-month follow-up (exercise group only) for physical fitness, bone mineral density, serum concentrations of bone biomarkers, and quality of life. The exercise intervention consisted of moderate-vigorous (65–85% heart rate maximum) aerobic and resistance exercise thrice weekly for 16 weeks. Differences in mean changes for outcomes were evaluated using mixed-model repeated measure analysis.

Results

At post-intervention, the exercise group was superior to usual care for quality of life (between group difference: 14.7, 95% CI: 18.2, 9.7; p < 0.001), fatigue (p < 0.001), depression (p < 0.001), estimated VO_2max (p < 0.001), muscular strength (p < 0.001), osteocalcin (p = 0.01), and BSAP (p = 0.001). At 3-month follow-up, all patient-reported outcomes and physical fitness variables remained significantly improved compared to baseline in the exercise group (p < 0.01).

Conclusions

A 16-week combined aerobic and resistance exercise program designed to address metabolic syndrome in ethnically-diverse overweight or obese breast cancer survivors also significantly improved quality of life and physical fitness. Our findings further support the inclusion of supervised clinical exercise programs into breast cancer treatment and care.

Trial registration

This trial is registered on ClinicalTrials.gov: NCT01140282 as of June 9, 2010.

External Beam Irradiation Preferentially Inhibits the Endochondral Pathway of Fracture Healing: A Rat Model

BACKGROUND

External beam irradiation is an accepted treatment for skeletal malignancies. Radiation acts on both cancerous and normal cells and, depending on the balance of these effects, may promote or impair bone healing after pathologic fracture. Previous studies suggest an adverse effect of radiation on endochondral ossification, but the existence of differential effects of radiation on the two distinct bone healing pathways is unknown.

QUESTIONS/PURPOSES

The purpose of this study was to investigate the differential effects of external beam irradiation on endochondral compared with intramembranous ossification with intramedullary nail and plate fixation of fractures inducing the two respective osseous healing pathways through assessment of (1) bone biology by histomorphometric analysis of cartilage area and micro-CT volumetric assessment of the calcified callus; and (2) mechanical properties of the healing fracture by four-point bending failure analysis of bending stiffness and strength.

METHODS

Thirty-six male Sprague-Dawley rats underwent bilateral iatrogenic femur fracture: one side was repaired with an intramedullary nail and the other with compression plating. Three days postoperatively, half (n = 18) received 8-Gray external beam irradiation to each fracture. Rodents were euthanized at 1, 2, and 4 weeks postoperatively (n = 3/group) for quantitative histomorphometry of cartilage area and micro-CT assessment of callus volume. The remaining rodents were euthanized at 3 months (n = 9/group) and subjected to four-point bending tests to assess stiffness and maximum strength.

RESULTS

Nailed femurs that were irradiated exhibited a reduction in cartilage area at both 2 weeks (1.08 ± 1.13 mm versus 37.32 ± 19.88 mm; 95% confidence interval [CI] of the difference, 4.32-68.16 mm; p = 0.034) and 4 weeks (4.60 ± 3.97 mm versus 39.10 ± 16.28 mm; 95% CI of the difference, 7.64-61.36 mm; p = 0.023) compared with nonirradiated fractures. There was also a decrease in the volume ratio of calcified callus at 4 weeks (0.35 ± 0.08 versus 0.51 ± 0.05; 95% CI of the difference, 0.01-0.31; p = 0.042) compared with nonirradiated fractures. By contrast, there was no difference in cartilage area or calcified callus between irradiated and nonirradiated plated femurs. The stiffness (128.84 ± 76.60 N/mm versus 26.99 ± 26.07 N/mm; 95% CI of the difference, 44.67-159.03 N/mm; p = 0.012) and maximum strength (41.44 ± 22.06 N versus 23.75 ± 11.00 N; 95% CI of the difference, 0.27-35.11 N; p = 0.047) of irradiated plated femurs was greater than the irradiated nailed femurs. However, for nonirradiated femurs, the maximum strength of nailed fractures (36.05 ± 17.34 N versus 15.63 ± 5.19 N; 95% CI of the difference, 3.96-36.88 N; p = 0.022) was greater than plated fractures, and there was no difference in stiffness between the nailed and plated fractures.

CONCLUSIONS

In this model, external beam irradiation was found to preferentially inhibit endochondral over intramembranous ossification with the greatest impairment in healing of radiated fractures repaired with intramedullary nails compared with those fixed with plates. Future work with larger sample sizes might focus on further elucidating the observed differences in mechanical properties.

CLINICAL RELEVANCE

This work suggests that there may be a rationale for compression plating rather than intramedullary nailing of long bone fractures in select circumstances where bony union is desirable, adjunctive radiation treatment is required, and bone stock is sufficient for plate and screw fixation.

Assessment and management of bone health in women with oestrogen receptor-positive breast cancer receiving endocrine therapy: Position statement of the Endocrine Society of Australia, the Australian and New Zealand Bone & Mineral Society, the Australasian Menopause Society and the Clinical Oncology Society of Australia

To formulate clinical consensus recommendations on bone health assessment and management of women with oestrogen receptor-positive early breast cancer receiving endocrine therapy, representatives appointed by relevant Australian Medical Societies used a systematic approach for adaptation of guidelines (ADAPTE) to derive an evidence-informed position statement addressing 5 key questions. Women receiving adjuvant aromatase inhibitors and the subset of premenopausal woman treated with tamoxifen have accelerated bone loss and increased fracture risk. Both bisphosphonates and denosumab prevent bone loss; additionally, denosumab has proven antifracture benefit. Women considering endocrine therapy need fracture risk assessment, including clinical risk factors, biochemistry and bone mineral density (BMD) measurement, with monitoring based on risk factors. Weight-bearing exercise, vitamin D and calcium sufficiency are recommended routinely. Antiresorptive treatment should be considered in women with prevalent or incident clinical or morphometric fractures, a T-score (or Z-scores in women <50 years) of <-2.0 at any site, or if annual bone loss is ≥5%, considering baseline BMD and other fracture risk factors. Duration of antiresorptive treatment can be individualized based on absolute fracture risk. Relative to their skeletal benefits, risks of adverse events with antiresorptive treatments are low. Skeletal health should be considered in the decision-making process regarding choice and duration of endocrine therapy. Before and during endocrine therapy, skeletal health should be assessed regularly, optimized by nonpharmacological intervention and where indicated antiresorptive treatment, in an individualized, multidisciplinary approach. Clinical trials are needed to better delineate long-term fracture risks of adjuvant endocrine therapy and to determine the efficacy of interventions designed to minimize these risks.

Managing Menopausal Symptoms and Associated Clinical Issues in Breast Cancer Survivors

OBJECTIVE

Review evidence to guide management of menopausal signs and symptoms in women after breast cancer and make recommendations accordingly.

EVIDENCE

Randomized controlled clinical trials, observational studies, evidence-based guidelines, and expert opinion from professional societies.

BACKGROUND

Symptoms and clinical problems associated with estrogen depletion-sleep disorders, vulvovaginal atrophy (VVA), vasomotor symptoms (VMS), mood changes, depressive symptoms, cardiovascular disease, osteopenia, and osteoporosis-confront the estimated 9.3 million breast cancer survivors globally.

RECOMMENDATIONS

Following breast cancer, women should not generally be treated with menopausal hormone therapy or tibolone but should optimize lifestyle. Women with moderate to severe symptoms may benefit from mind-brain behavior or nonhormone, pharmacologic therapy. The selective serotonin/noradrenaline reuptake inhibitors and gabapentenoid agents improve VMS and quality of life. For osteoporosis, nonhormonal agents are available. Treatment of VVA remains an area of unmet need. Low-dose vaginal estrogen is absorbed in small amounts with blood levels remaining within the normal postmenopausal range but could potentially stimulate occult breast cancer cells, and although poorly studied, is not generally advised, particularly for those on aromatase inhibitors. Intravaginal dehydroepiandrosterone and oral ospemiphene have been approved to treat dyspareunia, but safety after breast cancer has not been established. Vaginal laser therapy is being used for VVA but efficacy from sham-controlled studies is lacking. Therapies undergoing development include lasofoxifene, neurokinin B inhibitors, stellate ganglion blockade, vaginal testosterone, and estetrol.

CONCLUSIONS

Nonhormone options and therapies are available for treatment of estrogen depletion symptoms and clinical problems after a diagnosis of breast cancer. Individualization of treatment is essential.

Improvement of Bone Physiology and Life Quality Due to Association of Risedronate and Anastrozole

The endocrine therapy is the new frontiers of many breast cancers hormone sensitive. Hormone therapy for treating women with hormone receptor-positive cancer suppresses breast cancer growth either by reducing estrogen synthesis or by interfering with the action of estrogen within tumor cells. In this prospective randomized observational study we investigate the effect of adjuvant anastrozole in monotherapy or associated with risedronate on bone physiology and quality of life in postmenopausal, hormone-sensitive early breast cancer women at mild to moderate risk of fragility fractures.

Methods : 84 women were randomly assigned to receive anastrozole alone (group A) or anastrozole plus oral risedronate (group A+R). At baseline and after 24 months lumbar spine (LS) and femoral neck (FN) BMD were evaluated with dual-energy x-ray absorptiometry and health-related quality of life (HRQoL) was examined using the short-form healthy survey.

Results : After 24 months, the group A+R has showed a significant increase in T-score for LS (p < 0.05) and for FN (p < 0.05) whereas women of group A had a statistically significant rate of bone loss both in LS T-score (p < 0.05) and in FN (p < 0.05). A significant change in T-score BMD was seen for group A+R compared with group A at the LS (p = 0.04) and at FN (p = 0.04). Finally, group A+R showed an overall significant improvement of health profile (SF-36) in group A (p = 0.03).

Conclusion : Postmenopausal breast cancer women with osteopenia during treatment with anastrozole have considerable risk of developing osteoporosis during the first 2 years; preventive measures such as healthy lifestyle and daily supplements of calcium and vitamin D alone seem to be insufficient in holding their bones healthy. Our findings suggest the usefulness of addition of risedronate in order to prevent aromatase inhibitors-related bone loss, not only in case of high-risk of fractures, but also for women at mild-moderate risk. This determines a significant improvement in bone health and a positive impact on HRQoL.

[Synthesis and binding affinity to human steroid hormone receptors of 3-phenoxy-4-hydroxycoumarins and 3-phenoxy-4-phenylcoumarins]

The synthesis and the study of the binding affinity to human receptors of glucocorticoids, mineralcorticoids, androgens, estrogens and progesterone of 3-phenoxy-4-hydroxycoumarins and 3-phenoxy-4-phenylcoumarins were performed. It shows the absence of any binding affinity of all these derivatives to glucocorticoid and mineralcorticoid receptors and a non-selective binding affinity to androgen, oestrogen and progesterone receptors with 3-phenoxy-4-phényl-coumarins.

Risk of hospitalisation and death due to bone fractures after breast cancer: a registry-based cohort study

BACKGROUND

Bone fractures may have an impact on prognosis of breast cancer. The long-term risks of bone fracture in breast cancer patients have not been thoroughly studied.

METHODS

Poisson regression was used to investigate the incidence of hospitalisation due to bone fracture comparing women with and without breast cancer based on Swedish National registers. Cox regression was used to investigate the risk of being hospitalised with bone fracture, and subsequent risk of death, in a regional cohort of breast cancer patients.

RESULTS

For breast cancer patients, the 5-year risk of bone fracture hospitalisation was 4.8% and the 30-day risk of death following a bone fracture hospitalisation was 2.0%. Compared with the general population, breast cancer patients had incidence rate ratios of 1.25 (95% CI: 1.23-1.28) and 1.18 (95% CI: 1.14-1.22) for hospitalisation due to any bone fracture and hip fracture, respectively. These ratios remained significantly increased for 10 years. Comorbidities (Charlson Comorbidity Index ⩾1) were associated with the risk of being hospitalised with bone fracture. Women taking aromatase inhibitors were at an increased risk as compared with women taking tamoxifen (HR=1.48; 95% CI: 0.98-2.22). Breast cancer patients hospitalised for a bone fracture showed a higher risk of death (HR=1.83; 95% CI: 1.50-2.22) compared with those without bone fracture.

CONCLUSIONS

Women with a previous breast cancer diagnosis are at an increased risk of hospitalisation due to a bone fracture, particularly if they have other comorbidities.

How plausible is the use of dietary n-3 PUFA in the adjuvant therapy of cancer?

Considerable debate exists regarding the potential antineoplastic effect of dietary long-chain n-3 PUFA contained in fatty fishes. Since the majority of published data has proven that their intake does not induce toxic or carcinogenic effects in humans, their possible preventive use against cancer has been suggested. On the other hand, it is unlikely that they could be effective in cancer patients as a single therapy. Nevertheless, a considerable effort has been put forth in recent years to evaluate the hypothesis that n-3 PUFA might improve the antineoplastic efficiency of currently used anticancer agents. The rationale for this therapeutic combinatory strategy is trying to increase cancer sensitivity to conventional therapies. This could allow the use of lower drug/radiation doses and, thereby, a reduction in the detrimental health effects associated with these treatments. We will here critically examine the studies that have investigated this possibility, by focusing particularly on the biological and molecular mechanisms underlying the antineoplastic effect of these combined treatments. A possible use of n-3 PUFA in combination with the innovative single-targeted anti-cancer therapies, that often are not completely devoid of dangerous side-effects, is also suggested.

Pharmacologic management of bone-related complications and bone metastases in postmenopausal women with hormone receptor-positive breast cancer

There is a high risk for bone loss and skeletal-related events, including bone metastases, in postmenopausal women with hormone receptor-positive breast cancer. Both the disease itself and its therapeutic treatments can negatively impact bone, resulting in decreases in bone mineral density and increases in bone loss. These negative effects on the bone can significantly impact morbidity and mortality. Effective management and minimization of bone-related complications in postmenopausal women with hormone receptor-positive breast cancer remain essential. This review discusses the current understanding of molecular and biological mechanisms involved in bone turnover and metastases, increased risk for bone-related complications from breast cancer and breast cancer therapy, and current and emerging treatment strategies for managing bone metastases and bone turnover in postmenopausal women with hormone receptor-positive breast cancer.

Bone health in adults treated with endocrine therapy for early breast or prostate cancer

Bone is a hormonally responsive organ. Sex hormones and calcium regulating hormones, including parathyroid hormone, 1-25 dihydroxy vitamin D, and calcitonin, have effects on bone resorption and bone deposition. These hormones affect both bone quality and bone quantity. The sex hormone estrogen inhibits bone resorption, and estrogen therapy has been developed to prevent and treat osteoporosis. Androgens are an important source of estrogen through the action of the enzyme aromatase and may themselves stimulate bone formation. Hence, the sex steroids play a role in bone metabolism. Breast cancer and prostate cancer are frequently hormonally responsive and may be treated with antiestrogens or antiandrogens respectfully. In addition, chemotherapy and supportive medications may alter the patient's endocrine system. In general, the suppression of sex hormones has a predictable affect on bone health, as seen by loss of bone mineral density and increased risk of fragility fractures. The bone toxicity of cancer-directed endocrine therapy can be mitigated through screening, counseling on optimization of calcium and vitamin D intake, exercise, and other lifestyle/behavioral actions, as well as the use of medications when the fracture risk is high. Maintaining bone health in patients who are treated with endocrine therapy for breast and prostate cancer is the focus of this review.

Early-Stage Breast Cancer in the Elderly: Confronting an Old Clinical Problem

Breast cancer generally develops in older women and its incidence is continuing to increase with increasing age of the population. The pathology and biology of breast cancer seem to be different in the elderly, often resulting in the undertreatment of elderly patients and thus in higher rates of recurrence and mortal-ity. The aim of this review is to describe the differences in the biology and treatment of early breast cancer in the elderly as well as the use of geriatric assessment methods that aid decision-making. Provided there are no contraindications, the cornerstone of treatment should be surgery, as the safety and efficacy of surgical resection in elderly women have been well documented. Because most breast cancers in the elderly are hormone responsive, hormonal therapy remains the mainstay of systemic treatment in the adjuvant setting. The role of chemotherapy is limited to patients who test negative for hormone receptors and demonstrate an aggressive tumor profile. Although the prognosis of breast cancer patients has generally improved during the last few decades, there is still a demand for evidence-based optimization of therapeutic interventions in older patients.

RANKL and OPG Polymorphisms Are Associated with Aromatase Inhibitor-Related Musculoskeletal Adverse Events in Chinese Han Breast Cancer Patients

Background

Breast cancer patients treated with aromatase inhibitors (AIs) may experience musculoskeletal adverse events (MS-AEs). Several studies have confirmed that the RANKL/RANK/OPG signaling pathway plays a dominant role in bone health. Therefore, this study aimed to analyze the relationship between the serum levels of RANKL, OPG and their SNPs (single nucleotide polymorphisms) with AI-related MS-AEs.

Methodology and Principal Findings

Patients with early stage, hormone-sensitive breast cancer who were receiving AI therapy were enrolled. We included 208 cases with AI-related MS-AEs and 212 without (controls). The levels of estradiol, bone-turnover markers, multiple inflammatory cytokines, RANKL,OPG and lumbar spine BMD were measured, and questionnaires were completed. We analyzed 29 SNPs of RANKL, RANK and OPG using Sequenom MassARRAY assays and PCR-based TaqMan assays. The levels of bone-turnover markers and RANKL and the ratio of RANKL/OPG were higher in patients with AI-related MS-AEs than controls (all p < 0.05). A genetic assay showed that the RANKL SNP rs7984870 and OPG SNP rs2073618 were associated with AI-related MS-AEs. In patients with AI-related MS-AEs, rs7984870 CC and rs2073618 CC were risk genotypes. Carriers of the rs7984870 CC genotype were more likely to have a higher RANKL level and RANKL/OPG ratio than carriers of the GG genotype, and carriers of the rs2073618 CC genotype were more likely to have a lower OPG level and a higher RANKL/OPG ratio than carriers of the GG genotype (all p < 0.05). Moreover, risk genotypes were associated with higher levels of serum CTX and PINP and a lower lumbar spine BMD (all p < 0.05).

Conclusions and Significance

In conclusion, the RANKL and OPG risk genotypes synergize to negatively impact bone health and predispose breast cancer patients to AI-related MS-AEs.

Everolimus plus exemestane for the treatment of advanced breast cancer: a review of subanalyses from BOLERO-2

Hormone receptor-positive breast cancer is typically managed with endocrine therapies. However, resistance to endocrine therapy results in disease progression in a large proportion of breast cancers. Through the understanding of the mechanisms of endocrine resistance, identification of implicated pathways and targets has led to the development of novel agents targeting these pathways. Phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway aberrations are common in breast cancer, with increased PI3K/AKT/mTOR signaling associated with resistance to endocrine and human epidermal growth factor receptor 2 (HER2)-targeted therapies. The mTOR inhibitor everolimus, in combination with exemestane, has been approved for patients with advanced hormone receptor-positive/HER2-negative breast cancer who progress on prior nonsteroidal aromatase inhibitor therapy based on results reported in the Breast Cancer Trials of Oral Everolimus-2 (BOLERO-2) study. This review will summarize the overall findings from BOLERO-2 and will consider available subanalyses by age, Asian origin, visceral or bone metastases, and prior therapy, with the aim of identifying populations most likely to benefit from everolimus therapy. The review will also summarize safety findings and their management and the effects of everolimus on quality of life.

Considerations for payers in managing hormone receptor-positive advanced breast cancer

Breast cancer (BC) is the second most common cause of death in women. In 2010, the direct cost associated with BC care in the US was $16.5 billion, the highest among all cancers. By the year 2020, at the current rates of incidence and survival, the cost is projected to increase to approximately $20 billion. Although endocrine therapies to manage hormone receptor-positive (HR+) BC are highly effective, endocrine resistance results in disease progression. Increased understanding of endocrine resistance and the mechanisms of disease progression has led to development and subsequent approval of novel targeted treatments, resulting in the expansion of the therapeutic armamentarium to combat HR+ BC. Clear guidelines based on the safety and efficacy of treatment options exist; however, the optimal sequence of therapy is unknown, and providers, payers, and other key players in the health care system are tasked with identifying cost-effective and evidence-based treatment strategies that will improve patient outcomes and, in time, help curb the staggering increase in cost associated with BC care. Safety and efficacy are key considerations, but there is also a need to consider the impact of a given therapy on patient quality of life, treatment adherence, and productivity. To minimize cost associated with overall management, cost-effectiveness, and financial burden that the therapy can impose on patients, caregivers and managed care plans are also important considerations. To help evaluate and identify the optimal choice of therapy for patients with HR+ advanced BC, the available data on endocrine therapies and novel agents are discussed, specifically with respect to the safety, efficacy, financial impact on patients and the managed care plan, impact on quality of life and productivity of patients, and improvement in patient medication adherence.

Managing postmenopausal women with hormone receptor-positive advanced breast cancer who progress on endocrine therapies with inhibitors of the PI3K pathway

Although endocrine therapies that interfere with estrogen receptor (ER)-mediated signaling have revolutionized the management of postmenopausal women with hormone receptor-positive (HR+) breast cancer (BC), long-term management of these patients is suboptimal because of the eventual emergence of endocrine resistance. Intense research has elucidated a number of targets that act downstream or upstream of the ER, as well as those that crosstalk with the ER; however, clinical validation of inhibiting specific targets to overcome endocrine resistance has been lacking. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway has been implicated to mediate endocrine resistance, and a number of novel agents that target this pathway are in early- and late-stage clinical trials. Recently, everolimus, an inhibitor of mTOR, a critical component of the PI3K/AKT/mTOR pathway, in combination with endocrine therapy, was shown to prolong progression-free survival with a manageable adverse-event profile in postmenopausal patients with HR+ BC. Bolstered by the safety and efficacy observed with concomitant inhibition of the ER and the PI3K/mTOR pathway and the validation of dual inhibition approach in managing postmenopausal patients with HR+ BC, a number of novel agents that inhibit PI3K (pan-PI3K inhibitors) or PI3K and mTOR (dual PI3K/mTOR) are being evaluated in clinical trials. Thus, mTOR inhibitors have provided the much-needed ammunition to oncologists who manage postmenopausal women with BC and have paved the way for the development of novel therapies that target the PI3K/mTOR pathway. Use of these novel therapies in managing postmenopausal women with BC, in combination with endocrine therapies, is expected to improve overall outcomes by overcoming endocrine resistance.

Understanding response and resistance to oestrogen deprivation in ER-positive breast cancer

Oestrogens (E) and oestrogen receptor alpha (ERα) play fundamental roles in the development and progression of more than three-quarters of breast cancers (BC). The ability to influence the natural history of BC by hormonal manipulation is well established and endocrine therapies represent the cornerstone of systemic management for women with ERα-positive disease. Endocrine agents abrogate oestrogenic signalling through distinct and incompletely overlapping mechanisms, either impeding the transcriptional activity of ERα or diminishing E-synthesis. In post-menopausal women, E-production is chiefly attributable to the enzymatic conversion of androgens in extra-gonadal tissues by the cytochrome P-450 superfamily member aromatase. Greater understanding of steroid biosynthesis has underpinned rational drug design and pharmacological development of potent and specific aromatase inhibitors (AIs). Contemporary agents induce profound E-suppression in post-menopausal women and are first-line neo-adjuvant, adjuvant and metastatic therapies, with greater efficacy and tolerability than tamoxifen. The principal qualifier for endocrine treatment, including AIs, remains ERα expression. However, it is increasingly apparent that ERα expression is not synonymous with sensitivity to treatment and insufficient to account for the considerable heterogeneity of response. Better predictive biomarkers of de novo resistance are required to improve patient selection and identify those poor-responders who may benefit from alternative or additional systemic treatment from the outset. Among patients who do respond well initially, many relapse during their clinical course and there is also an unmet need for biomarkers of acquired resistance. The majority of women who relapse on AIs continue to express functional ERα which remains a legitimate target for second-line endocrine therapy. Understanding and overcoming acquired resistance to AIs requires a greater appreciation of ERα biology and the mechanisms though which E-dependence can be subverted. In this article, we review the impact of therapeutic E-deprivation on the natural history of ERα-positive breast cancer. Consideration is given to established and emerging biomarkers and/or determinants of response and resistance to E-deprivation. In vitro and in vivo evidence of the molecular mechanisms underpinning the transition from sensitivity to resistance are reviewed in the context of current models of ERα activity and their potential translational relevance.

Influence of weight training on skeletal health of breast cancer survivors with or at risk for breast cancer-related lymphedema

PURPOSE

This study aimed to determine whether the Physical Activity and Lymphedema (PAL) trial weight training program for breast cancer survivors at risk of or with breast cancer-related lymphedema provided skeletal benefits.

METHODS

Of the 295 participants in the randomized controlled PAL trial, 258 (weight training; N = 128; control, N = 130) had complete measures of bone mineral density (BMD (in grams per square centimeter)) of the proximal femur and lumbar spine and were also categorized by T scores. Women in the weight training group performed slowly progressive weight training 2 days/week for 12 months compared to women in the control group who maintained their usual physical activities.

RESULTS

There were no significant differences in the rate of BMD change at any skeletal site between weight training and control groups, regardless of menopausal status. Distribution of bone health categories was not significantly different between groups at baseline, but became different at 12 months (p < 0.03) among postmenopausal women due to an increase in the percentage of controls who became osteopenic (35 to 44%) compared to stable bone health in weight lifters.

CONCLUSIONS

The PAL weight training program that increased muscle strength without exacerbating or causing lymphedema among breast cancer survivors was not as efficacious at improving skeletal health. The skeletal loads produced from the PAL program may be insufficient to notably shift BMD, but may have a subtle osteogenic effect.

IMPLICATIONS FOR CANCER SURVIVORS

The safety and efficacy of rigorous weight training programs for improving skeletal health in women at risk for or with breast cancer-related lymphedema remain to be determined.

Final overall survival: fulvestrant 500 mg vs 250 mg in the randomized CONFIRM trial

Background

At the time of the initial analysis of overall survival (OS) for the Comparison of Faslodex in Recurrent or Metastatic Breast Cancer (CONFIRM) randomized, double-blind, phase III trial, approximately 50% of patients had died. A final analysis of OS was subsequently planned for when 75% of patients had died.

Methods

Patients were randomly assigned 1:1 to fulvestrant 500 mg administered as two 5-mL intramuscular injections on days 0, 14, and 28 and every 28 (±3) days thereafter or fulvestrant 250 mg administered as two 5-mL intramuscular injections (one fulvestrant and one placebo [identical in appearance to study drug]) on days 0, 14 (two placebo injections only), and 28 and every 28 (±3) days thereafter. OS was analyzed using an unadjusted log-rank test. No adjustments were made for multiplicity. Serious adverse events (SAEs) and best response to subsequent therapy were also reported. All statistical tests were two-sided.

Results

In total, 736 women (median age = 61.0 years) were randomly assigned to fulvestrant 500mg (n = 362) or 250mg (n = 374). At the final survival analysis, 554 of 736 (75.3%) patients had died. Median OS was 26.4 months for fulvestrant 500mg and 22.3 months for 250mg (hazard ratio = 0.81; 95% confidence interval = 0.69–0.96; nominal P = .02). There were no clinically important differences in SAE profiles between the treatment groups; no clustering of SAEs could be detected in either treatment group. Type of first subsequent therapy and objective responses to first subsequent therapy were well balanced between the two treatment groups.

Conclusions

In patients with locally advanced or metastatic estrogen receptor–positive breast cancer, fulvestrant 500mg is associated with a 19% reduction in risk of death and a 4.1-month difference in median OS compared with fulvestrant 250mg. Fulvestrant 500mg was well tolerated, and no new safety concerns were identified.

Skeletal manifestations of treatment of breast cancer on premenopausal women

With increasing use of screening mammography and more effective adjuvant systemic therapies, the majority of women diagnosed with early stage breast cancer will be long-term survivors and experience personal cures. Among the common side effects of adjuvant therapies is treatment-related bone loss, primarily as a result of estrogen deprivation. Whereas this occurs in both postmenopausal and premenopausal women, this brief review will focus on pre- or perimenopausal women when initially diagnosed with breast cancer. An important distinction is between those women who retain ovarian function despite cancer or preventative treatments and the more common situation of premenopausal women who as result of cancer treatments undergo ovarian failure or early menopause. Some women with treatment-related ovarian failure will have sufficient treatment-related bone loss to be at increased risks of subsequent nontraumatic fractures and/or osteoporosis and will be candidates for antiresorptive treatments. The noncancer treatment risk factors, screening and treatments for the management of osteopenia and osteoporosis are generally the same in postmenopausal women with and without breast cancer. However, premenopausal women with relatively rapid onset of treatment-related ovarian failure and bone loss pose several challenges. Awareness of treatment-related bone loss and risks of subsequent osteoporosis is a high priority in an ever-increasing population of breast cancer survivors.

High-dose eicosapentaenoic acid and docosahexaenoic acid supplementation reduces bone resorption in postmenopausal breast cancer survivors on aromatase inhibitors: a pilot study

Postmenopausal breast cancer survivors are living longer; however, a common class of drugs, aromatase inhibitors (AI), depletes estrogen levels, promotes bone loss, and heightens fracture risk. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may offset AI effects to bone because of the known effects on cellular processes of bone turnover. Therefore, we hypothesized that 4 g of EPA and DHA daily for 3 mo would decrease bone turnover in postmenopausal breast cancer survivors on AI therapy in a randomized, double-blind, placebo controlled pilot study that included 38 women. At baseline and 3 mo, serum fatty acids, bone turnover, and inflammatory markers were analyzed. Serum EPA and DHA, total and long-chain (LC) omega (n)-3 polyunsaturated fatty acids (PUFA) increased, whereas arachidonic acid, total and LC n-6 PUFA, and the LC n-6:n-3 PUFA ratio decreased compared to placebo (all P < .05). Bone resorption was inhibited in the fish oil responders compared to placebo (P < .05). Inflammatory markers were not altered. This short-term, high-dose fish oil supplementation study's findings demonstrate that fish oil can reduce bone resorption; however, longer-term studies are needed to assess bone density preservation and to explore mechanistic pathways in this population at high risk for bone loss.

Cancer, physical activity, and exercise

This review examines the relationship between physical activity and cancer along the cancer continuum, and serves as a synthesis of systematic and meta-analytic reviews conducted to date. There exists a large body of epidemiologic evidence that conclude those who participate in higher levels of physical activity have a reduced likelihood of developing a variety of cancers compared to those who engage in lower levels of physical activity. Despite this observational evidence, the causal pathway underlying the association between participation in physical activity and cancer risk reduction remains unclear. Physical activity is also a useful adjunct to improve the deleterious sequelae experienced during cancer treatment. These deleterious sequelae may include fatigue, muscular weakness, deteriorated functional capacity, and many others. The benefits of physical activity during cancer treatment are similar to those experienced after treatment. Despite the growing volume of literature examining physical activity and cancer across the cancer continuum, a number of research gaps exist. There is little evidence on the safety of physical activity among all cancer survivors, as most trials have selectively recruited participants. The specific dose of exercise needed to optimize primary cancer prevention or symptom control during and after cancer treatment remains to be elucidated.

Tamoxifen inhibits macrophage FABP4 expression through the combined effects of the GR and PPARγ pathways

Macrophage adipocyte fatty acid-binding protein (FABP4) plays an important role in foam cell formation and development of atherosclerosis. Tamoxifen inhibits this disease process. In the present study, we determined whether the anti-atherogenic property of tamoxifen was related to its inhibition of macrophage FABP4 expression. We initially observed that tamoxifen inhibited macrophage/foam cell formation, but the inhibition was attenuated when FABP4 expression was selectively inhibited by siRNA. We then observed that tamoxifen and 4-hydroxytamoxifen inhibited FABP4 protein expression in primary macrophages isolated from both the male and female wild-type mice, suggesting that the inhibition is sex-independent. Tamoxifen and 4-hydroxytamoxifen inhibited macrophage FABP4 protein expression induced either by activation of GR (glucocorticoid receptor) or PPARγ (peroxisome-proliferator-activated receptor γ). Associated with the decreased protein expression, Fabp4 mRNA expression and promoter activity were also inhibited by tamoxifen and 4-hydroxytamoxifen, indicating transcriptional regulation. Analysis of promoter activity and EMSA/ChIP assays indicated that tamoxifen and 4-hydroxytamoxifen activated the nGRE (negative glucocorticoid regulatory element), but inhibited the PPRE (PPARγ regulatory element) in the Fabp4 gene. In vivo, administration of tamoxifen to ApoE (apolipoprotein E)-deficient (apoE−/−) mice on a high-fat diet decreased FABP4 expression in macrophages and adipose tissues as well as circulating FABP4 levels. Tamoxifen also inhibited FABP4 protein expression by human blood monocyte-derived macrophages. Taken together, the results of the present study show that tamoxifen inhibited FABP4 expression through the combined effects of GR and PPARγ signalling pathways. Our findings suggest that the inhibition of macrophage FABP4 expression can be attributed to the anti-atherogenic properties of tamoxifen.

Impact + resistance training improves bone health and body composition in prematurely menopausal breast cancer survivors: a randomized controlled trial

Our randomized controlled trial in prematurely menopausal breast cancer survivors showed that impact + resistance training prevented increases in percentage of body fat compared with controls and also improved BMD at the hip and prevented BMD loss at the spine among exercise-trained women who were menopausal for >1 year.

INTRODUCTION

Cancer treatment-related menopause worsens bone health and body composition in breast cancer survivors (BCS). We investigated whether impact + resistance training could improve bone mineral density (BMD), reduce bone turnover, build muscle, and decrease fat mass in BCS with premature menopause.

METHODS

We conducted a randomized controlled trial in 71 BCS (mean age, 46.5 years) within 5 years of treatment-related menopause. Women were randomly assigned to one of two groups: (1) impact + resistance training (prevent osteoporosis with impact + resistance (POWIR)) or (2) exercise placebo (FLEX) 3×/week for 1 year. Outcomes were hip and spine BMD (in grams per square centimeter) and body composition (percent body fat (%BF) and lean and fat mass (in kilograms)) by DXA and bone turnover markers (serum osteocalcin (in nanograms per milliliter) and urinary deoxypryrodinoline (in nanomoles per milliliter).

RESULTS

There were no significant group × time interactions for bone outcomes when using an intent-to-treat approach on the full sample. In analyses restricted to BCS who were menopausal for ≥1 year, POWIR increased BMD at the hip and slowed BMD loss at the spine compared with FLEX (femoral neck-POWIR, 0.004 ± 0.093 g/cm(2) vs. FLEX, -0.010 ± 0.089 g/cm(2); p < 0.01; spine-POWIR, -0.003 ± 0.114 g/cm(2) vs. FLEX, -0.020 ± 0.110 g/cm(2); p = 0.03). POWIR prevented increases in %BF (POWIR, 0.01 % vs. FLEX, 1.3 %; p < 0.04). Women with attendance to POWIR at ≥64 % had better improvements in %BF than women attending less often (p < 0.03).

CONCLUSION

Impact + resistance training may effectively combat bone loss and worsening body composition from premature menopause in BCS.

Aromatase inhibitor-induced arthralgia: a review

Though aromatase inhibitors (AIs) are an essential part of estrogen receptor-positive (ER+) breast cancer therapy, many patients discontinue the medicine before their adjuvant therapy is completed because of the arthralgia which often accompanies the medicine. Up to half of women on AI therapy experience joint pain, and up to 20% will become non-compliant with the medicine because of the joint pain. Yet, very little is known about what causes AI-induced arthralgia (AIA), and there is no established, effective treatment for this difficult problem. It compromises survivors' quality of life and leads to non-compliance. This paper will discuss AIA in depth, including potential etiologies, clinical significance, risk factors, and possible management solutions. Of note, this article presents one of the first proposed algorithms which clearly lays out a treatment plan for AIA, incorporating a variety of interventions which have been proven by the available literature.

The development of endocrine therapy for women with breast cancer

The development of endocrine therapies has transformed the treatment of patients with breast cancer. The shift from ablative surgery and aggressive chemotherapies to more targeted, better tolerated therapy has improved both mortality and quality of life for patients with hormone-responsive disease. During the 1970s, the selective oestrogen-receptor modulator, tamoxifen, emerged as a new treatment for women with advanced breast cancer. The subsequent development of numerous and diverse selective endocrine therapies such as luteinising hormone-releasing hormone agonists, aromatase inhibitors and oestrogen-receptor antagonists have added further treatment options. Furthermore, with well-tolerated and effective endocrine therapy, adjuvant treatment became an option for patients with early breast cancer. Tamoxifen emerged as the gold standard adjuvant therapy in the 1980s; however, later trials in postmenopausal women showed the aromatase inhibitors offer advantages over tamoxifen. In addition to AIs being indicated as adjuvant therapy, some are also being evaluated for use as a preventative measure in high-risk women. This chronological account outlines key milestones in the evolution of endocrine therapies over the last 40 years, highlighting each class of agent and the key trials that have led to changes in clinical practice. The advances in endocrine therapies outlined here, coupled with advances in breast cancer management and diagnostics, will likely lead to more patient-tailored therapy, resulting in greater clinical benefits and more cost-effective treatment strategies.

Potential implications of adjuvant endocrine therapy for the oral health of postmenopausal women with breast cancer

Current adjuvant treatment modalities for breast cancer that express the estrogen receptor or progesterone receptor include adjuvant anti-estrogen therapies, and tamoxifen and aromatase inhibitors. Bone, including the jaw, is an endocrine-sensitive organ, as are other oral structures. This review examines the potential links between adjuvant anti-estrogen treatments in postmenopausal women with hormone receptor positive breast cancer and oral health. A search of PubMed, EMBASE, CENTRAL, and the Web of Knowledge was conducted using combinations of key terms "breast," "cancer," "neoplasm," "Tamoxifen," "Aromatase Inhibitor," "chemotherapy," "hormone therapy," "alveolar bone loss," "postmenopausal bone loss," "estrogen," "SERM," "hormone replacement therapy," and "quality of life." We selected articles published in peer-reviewed journals in the English. The authors found no studies reporting on periodontal diseases, alveolar bone loss, oral health, or oral health-related quality of life in association with anti-estrogen breast cancer treatments in postmenopausal women. Periodontal diseases, alveolar bone density, tooth loss, and conditions of the soft tissues of the mouth have all been associated with menopausal status supporting the hypothesis that the soft tissues and bone of the oral cavity could be negatively affected by anti-estrogen therapy. As a conclusion, the impact of adjuvant endocrine breast cancer therapy on the oral health of postmenopausal women is undefined. The structures of the oral cavity are influenced by estrogen; therefore, anti-estrogen therapies may carry the risk of oral toxicities. Oral health care for breast cancer patients is an important but understudied aspect of cancer survivorship.

Changes in bone biomarker concentrations and musculoskeletal symptoms among breast cancer patients initiating aromatase inhibitor therapy and women without a history of cancer

The objectives of this study were to examine: (1) changes in bone formation (osteocalcin) and bone resorption (cross-linked N-telopeptides of bone type I collagen [NTXs]) markers, as well as calcium, phosphorus, and intact parathyroid hormone, over the first 6 months of aromatase inhibitor (AI) therapy among a cohort of breast cancer patients compared with a group of unexposed women without a history of cancer; and (2) whether bone marker changes were associated with musculoskeletal pain. Eligible breast cancer patients (n = 49) and postmenopausal women without a history of cancer (n = 117) were recruited and followed for 6 months. At baseline, 3 months, and 6 months, a questionnaire was administered to assess pain and medication use, and a blood sample was drawn. Results showed that, among the breast cancer patients, calcium concentrations decreased significantly (-7.8% change; p = 0.013) and concentrations of NTXs increased significantly from baseline to 6 months (9.6% change; p = 0.012). Changes were not observed for women in the comparison group. Statistically significant differences in percent change between the breast cancer patients and the women in the comparison group were observed for calcium at 6 months (-7.8% versus 0.0%; p = 0.025), phosphorus at 6 months (-5.1% versus 16.7%; p = 0.003), NTXs at 6 months (9.6% versus -0.7%; p = 0.017), and osteocalcin at 6 months (11.5% versus -3.6%; p = 0.016). No statistically significant associations were observed between bone turnover marker changes and musculoskeletal pain among the breast cancer patients, although baseline NTXs were higher among women with onset or increase in pain compared with those reporting no pain (p = 0.08). Findings from this study suggest that AIs cause changes in bone turnover during the first 6 months of treatment; however, these changes are not associated with musculoskeletal pain. Breast cancer patients initiating AI therapy should be assessed and monitored for fracture risk using known clinical risk factors, including bone density, and managed appropriately.

Patterns of bone density evaluation in a community population treated with aromatase inhibitors

Aromatase inhibitors (AIs) increase the risk of bone loss and fracture. Guidelines recommend routine bone density screening for women on AIs, but there are few data regarding the incorporation of these guidelines into clinical practice. We assessed bone density testing in a community-based cohort of breast cancer patients treated with AIs. By means of encounter and pharmacy data from WellPoint plans in the HealthCore Integrated Research Database, we assessed bone density testing among 9,138 women aged ≥50 years with breast cancer who were treated with AIs between 2002 and 2008. We used multivariable logistic regression to identify factors associated with baseline bone density testing in women initiating an AI, and among a subset of 2,086 women treated with AIs for at least 2 years, with testing during the first 2 years of therapy. Only 41.6 % of women underwent bone density testing when initiating AI therapy. Rates of bone density testing increased over time, but were lower for women who were older, lived in the Northeast (vs. other regions), had been treated with prior proton pump inhibitor or tamoxifen therapy, lived in areas with lower educational attainment, or were enrolled in a health maintenance organization (vs. other insurance types) (all P < 0.05). Among women treated with AIs for at least 2 years, 59.9 % of women underwent bone density testing during the first 2 years of AI therapy. Rates of testing were lower for women living in the Midwest or West (vs. Northeast), living in areas with lower education levels, enrolled in health maintenance organizations (vs. other insurance types), and with prior tamoxifen use. In conclusion, most women initiating AI therapy, and 40 % of those on long-term therapy, did not undergo recommended bone density evaluation in this community-based population. Attention is needed to insure that unnecessary fractures are avoided in breast cancer patients taking AIs.

Potential role of odanacatib in the treatment of osteoporosis

Cathepsin K is a key enzyme involved in the degradation of organic bone matrix by osteoclasts. Inhibition of bone resorption observed in human and animal models deficient for cathepsin K has identified this enzyme as a suitable target for intervention by small molecules with the potential to be used as therapeutic agents in the treatment of osteoporosis. Odanacatib (ODN) is a nonbasic selective cathepsin K inhibitor with good pharmacokinetic parameters such as minimal in vitro metabolism, long half-life, and oral bioavailability. In preclinical studies, ovariectomized monkeys and rabbits treated with ODN showed substantial inhibition of bone resorption markers along with increases in bone mineral density (BMD). Significant differences were observed in the effects of ODN treatment compared with those of other antiresorptive agents such as bisphosphonates and denosumab. ODN displayed compartment-specific effects on trabecular versus cortical bone formation, with treatment resulting in marked increases in periosteal bone formation and cortical thickness in ovariectomized monkeys whereas trabecular bone formation was reduced. Furthermore, osteoclasts remained viable. Phase I and II studies conducted in postmenopausal women showed ODN to be safe and well tolerated. After 5 years, women who received ODN 50 mg weekly continuously from year 1 (n = 13), showed BMD increases from baseline of 11.9% at the lumbar spine, 9.8% at the femoral neck, 10.9% at the hip trochanter, and 8.5% at the total hip. Additionally, these subjects maintained a low level of the urine bone resorption marker N-terminal telopeptide/creatinine (−67.4% from baseline) through 5 years of treatment, while levels of serum bone-specific alkaline phosphatase remained only slightly reduced relative to baseline (−15.3%). In women who were switched from ODN to placebo after 2 years, bone turnover markers were transiently increased and BMD gains reversed after 12 months off medication. Adverse experiences in the ODN-treated group were not significantly different from the placebo group. In conclusion, available data suggests that cathepsin K inhibition could be a promising intervention with which to treat osteoporosis. Ongoing studies are expected to provide information on the long-term efficacy in fracture reduction and safety of prolonged treatment with ODN.

Heel ultrasound can assess maintenance of bone mass in women with breast cancer

Postmenopausal women with early stage breast cancer are at increased risk for bone loss and fractures. Bisphosphonates can prevent bone loss, but little data are available on changes in bone mass assessed by heel quantitative ultrasound (QUS). Our objectives were to determine if (1) heel QUS would provide a reliable and accessible method for evaluation of changes in bone mass in women with breast cancer when compared with the current standard of bone mass measurement, dual-energy X-ray absorptiometry (DXA) and (2) oral risedronate could affect these changes. Eighty-six newly postmenopausal (up to 8 yr) women with nonmetastatic breast cancer were randomized to risedronate, 35 mg once weekly or placebo. Outcomes were changes in heel QUS bone mass measurements and conventional DXA-derived bone mineral density (BMD). Over 2 yr, bone mass assessed by heel QUS remained stable in women on risedronate, whereas women on placebo had a 5.2% decrease (p ≤ 0.05) in heel QUS bone mass. Both total hip BMD and femoral neck BMD assessed by DXA decreased by 1.6% (p ≤ 0.05) in the placebo group and remained stable with risedronate. Spine BMD remained stable in both groups. Heel QUS was moderately associated with BMD measured by DXA at the total hip (r=0.50), femoral neck (r=0.40), and spine (r=0.46) at baseline (all p ≤ 0.001). In conclusion, risedronate helps to maintain skeletal integrity as assessed by heel QUS for women with early stage breast cancer. Heel QUS is associated with DXA-derived BMD at other major axial sites and may be used to follow skeletal health and bone mass changes in these women.

Bisphosphonates: prevention of bone metastases in breast cancer

Disease recurrence and distant metastases remain challenging for patients with breast cancer despite advances in early diagnosis, surgical expertise, and adjuvant therapy. Bone is the most common site for breast cancer metastasis, and the bone microenvironment plays a crucial role in harboring disseminated tumor cells (DTCs), a putative source of late relapse in and outside bone. Therefore, agents that affect bone metabolism might not only prevent the development of bone lesions but also provide meaningful reductions in the risk of relapse both in bone and beyond. Bisphosphonates bind to mineralized bone surfaces and are ingested by osteoclasts, wherein they inhibit osteolysis, thereby preventing the release of growth factors from the bone matrix. Therefore, the bone microenvironment becomes less conducive to survival and growth of DTCs and bone lesion formation. Recent trials of zoledronic acid in the adjuvant setting in breast cancer have demonstrated reduced disease recurrence in bone and other sites in premenopausal and postmenopausal women with early 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.

Prevention of chemotherapy-induced osteoporosis by cyclophosphamide with a long-acting form of parathyroid hormone

BACKGROUND

Most chemotherapeutics reduce bone mineral density (BMD) and increase risk for fractures by causing gonadal suppression, which in turn increases bone removal. Cyclophosphamide (CYP) also has a direct effect of inhibiting bone formation and removal, making the resulting bone loss particularly difficult to treat with antiresorptive therapy.

AIM

We tested whether a single dose of the anabolic agent PTH linked to a collagen binding domain (PTHCBD) could prevent the effects of CYP-induced bone loss.

METHODS

Mice received either buffer alone, CYP, or CYP+ PTH-CBD. BMD and alkaline phosphatase were measured every 2 weeks for a total of 8 weeks.

RESULTS

After 6 weeks, mice treated with CYP showed expected reductions in BMD (increase from baseline: 7.4 ± 6.9 vs 24.35 ± 4.86% in mice without chemotherapy, p<0.05) and decrease in alkaline phosphatase levels (42.78 ± 6.06 vs 60.62 ± 6.23 IU/l in mice without chemotherapy, p<0.05), consistent with osteoporosis from impaired bone formation. Administration of a single dose of PTH-CBD (320 μg/kg ip) prior to CYP treatment improved BMD (change from baseline: 23.4 ± 5.4 vs 7.4 ± 6.9%, CYP treatment alone, p<0.05) and increased alkaline phosphatase levels (50.14 ± 4.86 vs 42.78 ± 6.06 IU/l in CYP treatment alone, p<0.05). BMD values and alkaline phosphatase levels were restored to those seen in mice not receiving chemotherapy.

CONCLUSIONS

A single dose of PTHCBD prior to chemotherapy reversed CYP-induced suppression of bone formation and prevented CYP-induced bone loss in mice.

Breast cancer medications and vision: effects of treatments for early-stage disease

This review concerns the effects on vision and the eye of medications prescribed at three phases of treatment for women with early-stage breast cancer (BC): (1) adjuvant cytotoxic chemotherapy, (2) adjuvant endocrine therapy, and (3) symptomatic relief. The most common side effects of cytotoxic chemotherapy are epiphora and ocular surface irritation, which can be caused by any of several different regimens. Most notably, the taxane docetaxel can lead to epiphora by inducing canalicular stenosis. The selective-estrogen-receptor-modulator (SERM) tamoxifen, long the gold-standard adjuvant-endocrine-therapy for women with hormone-receptor-positive BC, increases the risk of posterior subcapsular cataract. Tamoxifen also affects the optic nerve head more often than previously thought, apparently by causing subclinical swelling within the first 2 years of use for women older than ∼50 years. Tamoxifen retinopathy is rare, but it can cause foveal cystoid spaces that are revealed with spectral-domain optical coherence tomography (OCT) and that may increase the risk for macular holes. Tamoxifen often alters the perceived color of flashed lights detected via short-wavelength-sensitive (SWS) cone response isolated psychophysically; these altered perceptions may reflect a neural-response sluggishness that becomes evident at ∼2 years of use. The aromatase inhibitor (AI) anastrozole affects perception similarly, but in an age-dependent manner suggesting that the change of estrogen activity towards lower levels is more important than the low estrogen activity itself. Based on analysis of OCT retinal thickness data, it is likely that anastrozole increases the tractional force between the vitreous and retina. Consequently, AI users, myopic AI users particularly, might be at increased risk for traction-related vision loss. Because bisphosphonates are sometimes prescribed to redress AI-induced bone loss, clinicians should be aware of their potential to cause scleritis and uveitis occasionally. We conclude by suggesting some avenues for future research into the visual and ocular effects of AIs, particularly as relates to assessment of cognitive function.