Effect of an aromatase inhibitor on bmd and bone turnover markers: 2-year results of the Anastrozole, Tamoxifen, Alone or in Combination (ATAC) trial (18233230)

Diagnostic Approach to Abnormal Alkaline Phosphatase Value

Alkaline phosphatase (ALP) is abundantly represented in nature, being fundamental for a number of processes. In addition to its fundamental function in skeletal mineralization, its roles in the pathogenesis of other diseases are being explored. The measurement of total ALP activity in serum or in plasma is a useful biomarker in clinical practice. Indeed, routine measurement of serum total ALP is a long-standing established part of initial biochemical evaluation of patients both in the hospital setting and on an ambulatory basis. Raised or reduced values of this enzyme activity are indicative of a number of diseases, most commonly affecting the skeleton and the biliary tract. Electrophoretic assays are preferable for visualizing and investigating the cause of increased serum total ALP activities, and bone ALP immunoassays are preferable for investigating and monitoring individuals with bone and mineral metabolic abnormalities. Here, we give a holistic vision of this fundamental enzyme, suggesting a clinical approach to the identification of diseases causing abnormal values. Finally, a therapeutic role has emerged as substitutive therapy in patients with hypophosphatasia, even though ongoing and future studies are exploring its role in other therapeutic areas. This narrative review was based on articles found by searching PubMed from its inception until July 2024 for the terms alkaline phosphatases, isozymes, isoforms, bone alkaline phosphatase, liver alkaline phosphatase, intestinal alkaline phosphatase, placental alkaline phosphatase, liver function tests, γ-glutamyltransferase, skeletal diseases, and liver diseases. We limited our research to papers published in the English language, with emphasis placed on those describing differential diagnosis whenever available.

Bone Health for Gynaecologists

Osteoporosis, the most common bone disorder, profoundly impacts women's health, especially during postmenopausal phases. Characterised by diminished bone mineral density (BMD), it increases the risk of fractures, affecting mobility, quality of life, and potentially mortality. The present review analyses the intricate interactions among physiological alterations, diseases, and medications that lead to bone mineral density reduction in women. It underscores the importance of gynaecologists in the prevention, diagnosis, and management of osteoporosis via early risk assessment, suitable hormone treatment, and lifestyle modifications. Essential considerations encompass the categorisation of osteoporosis into primary (age-related) and secondary (attributable to diseases or pharmacological treatments) types, with particular emphasis on predisposing conditions such as premature menopause, hormone deficits, and cancer therapies. The significance of diagnostic instruments such as DXA and novel methodologies like trabecular bone score and quantitative ultrasonography is emphasised for precise evaluation and surveillance. The review also addresses nutritional methods, physical exercise, and pharmaceutical interventions, including hormone replacement therapy (HRT), selective oestrogen receptor modulators (SERMs), and other anti-resorptive drugs, to preserve bone health. This review highlights the important role of gynaecologists in maintaining women's bone health, promoting a proactive strategy to avert osteoporosis-related complications and enhance long-term results.

Risk factors for and incidence of osteoporosis in patients with breast cancer by gender : a nationwide cohort study

Osteoporosis is common in breast cancer patients, but gender-specific research on its incidence and risk factors is limited. This study examined the incidence and risk of osteoporosis in male and female breast cancer patients and analyzed the risk factors for fractures. This nationwide retrospective cohort study used data from the Korean National Insurance database, identifying invasive breast cancer patients from January 2009 to December 2015.Overall, 80,661 participants (299 males ; 80,362 females) were included. Matching was performed at a 1:5 ratio, based on age, treatment modalities and Charlson Comorbidity Index scores [CCI], resulting in 294 males and 1,470 females.Before and after matching, females consistently showed higher osteoporosis prevalence than males (16.7% vs. 5.0% before, 27.6% vs. 4.8% after, p < 0.001). Before matching, hip or vertebral fractures incidence showed no difference (1.2% vs. 1.3%, p = 0.789), but after matching, a significant difference was observed. (4.0% vs. 1.0%, p = 0.011). Endocrine therapy increased osteoporosis risk, particularly among females (hazard ratio [HR], 6.37; 95% confidence interval [CI], 3.74-10.89; p < 0.001). Age, steroid use, and CCI score were significant risk factors for osteoporosis. Adjusting for other variables, females with osteoporosis had a higher hip or vertebral fracture risk than males (HR, 3.96; 95% CI, 1.24-12.64; p = 0.020). Our study highlights gender-specific risks for osteoporosis and fractures in breast cancer patients, contributing to a comprehensive understanding for improving long-term outcomes and quality of life in survivors.

Effect of bisphosphonate and denosumab treatment on TBS in Japanese breast cancer patients with AIBL

INTRODUCTION

Bisphosphonates and denosumab increase bone mineral density (BMD) for osteoporosis treatment in patients with aromatase inhibitor-associated bone loss (AIBL). This study aimed to directly compare bisphosphonates with denosumab in treating patients with AIBL and to determine the effect of denosumab on the trabecular bone score (TBS).

MATERIALS AND METHODS

Thirty-nine patients with AIBL receiving osteoporosis treatment (21 in the bisphosphonates group and 18 in the denosumab group) were retrospectively evaluated for changes in lumbar spine and femoral BMD, lumbar spine bone quality (assessed by TBS), and blood bone metabolic markers. The Mann-Whitney and Wilcoxon tests were used for statistical evaluation.

RESULTS

After 24 months of treatment, the lumbar spine BMD change rate was 5.82 ± 1.10% with bisphosphonates and 10.49 ± 1.20% with denosumab, with the change rate of denosumab significantly increasing over that of bisphosphonates. The change rate in femoral BMD was 2.69 ± 1.16% with bisphosphonates and 2.95 ± 1.26% with denosumab, with no significant difference between the two groups. The rate of decrease in tartrate-resistant acid phosphatase isoform 5b was significantly higher in the denosumab group. The change rate in TBS at 24 months of treatment was 0.53 ± 1.26% in the bisphosphonates group and 1.08 ± 1.33% in the denosumab group, with no significant difference between the two groups. After 24 months, TBS remained stable.

CONCLUSION

Both bisphosphonates and denosumab may increase BMD, improve bone metabolism, and inhibit bone quality loss in patients with AIBL.

Efficacy of a single 5 mg zoledronic acid infusion in preventing bone loss and fracture in postmenopausal women with breast cancer

INTRODUCTION

Chemotherapy-induced bone loss (CTIBL) is common among breast cancer patients, requiring comprehensive assessment and intervention. Zoledronic acid, a strong inhibitor of bone resorption, is effective in CTIBL management, though information on dosing and intervals, particularly the efficacy of the 5 mg annual dose for osteoporosis in breast cancer patients, is limited.

MATERIALS AND METHODS

In this 12-month prospective observational study, 85 breast cancer patients were divided into three groups: 17 received no treatment, 17 received tamoxifen, and 51 received anastrozole or letrozole (AI). Post-surgery, patients were administered a single 5 mg dose of zoledronic acid and monitored over 12 months for changes in bone mineral density (BMD), fracture rates, and biochemical markers.

RESULTS

Initially, the AI group was the oldest, averaging 59.1 ± 8.7 years. At baseline, no significant differences in variables, except age, were observed. After 12 months, BMD increased in all groups following a single zoledronic acid dose, with the smallest increase in the AI group at the lumbar spine: no treatment (2.4% ± 6.1%), tamoxifen (2.6% ± 3.4%), AI (0.6% ± 14.5%) (p = 0.778). CTx and P1NP levels were consistently suppressed up to 12 months post-treatment, with smaller reductions in the AI group. There were no significant differences in fracture or bone metastasis rates among groups.

CONCLUSION

A single infusion of 5 mg zoledronic acid was effective in increasing bone density in breast cancer patients. However, AI-treated patients showed less improvement in vertebral bone mineral density and biochemical markers. Further long-term studies with larger cohorts are needed.

Endocrine consequences of breast cancer therapy and survivorship

Breast cancer survivorship is increasing, due to earlier diagnosis of the disease and more effective therapies. Long-term endocrine sequelae, including early menopause, bone health, fertility implications and menopausal symptoms, are important survivorship issues. Ovarian failure is common with chemotherapy and options for preserving fertility in young women include ovarian suppression during chemotherapy and oocyte or embryo cryopreservation before chemotherapy. Tamoxifen as adjunct therapy in premenopausal women leads to ovarian stimulation, sometimes ovulation and occasionally pregnancy with important teratogenic implications. Aromatase inhibitor therapy with or without gonadotrophin releasing hormone (GnRH) agonist leads to profound bone loss and anti-resorptive therapy is advised to prevent fracture. Tamoxifen acts to preserve bone in postmenopausal women but not premenopausal women. Pregnancy is not discouraged in young women with early breast cancer, even to the point of pausing adjunct therapy in order to conceive. However, menopausal hormone therapy is discouraged even years later. Non-hormonal therapy for menopausal symptoms in breast cancer survivors is available but, in some cases, estrogen-containing therapy may be worthy of consideration for quality of life in the informed patient.

Osteoporotic fracture risk in women with breast cancer treated with aromatase inhibitors: a health insurance claims database study in Japan

BACKGROUND

Hormone therapy with aromatase inhibitors (AIs) for estrogen receptor-dependent breast cancer may expose patients to an increased osteoporosis risk. This study was performed to estimate fracture risk in women with breast cancer to whom AIs were prescribed in Japan.

METHODS

This retrospective study used data from the Japanese Medical Data Vision database. Women with breast cancer prescribed AIs over a 12-month period were identified and matched to women not prescribed AIs using a propensity score. Fracture rates were estimated by a cumulative incidence function and compared using a cause-specific Cox hazard model. The proportion of women undergoing bone density tests was retrieved.

RESULTS

For all fractures sites combined, cumulative fracture incidence at 10 years was 0.19 [95%CI: 0.16-0.22] in women prescribed AIs and 0.18 [95%CI: 0.15-0.21] without AIs. AI prescription was not associated with any changes in risk (adjusted hazard ratio: 1.08 [95%CI: 0.99-1.17] p = 0.08). Women prescribed AI more frequently underwent bone density testing (31.9% [95% CI: 31.2%; 32.6%] versus 2.2% [95% CI: 2.0%; 2.4%]).

CONCLUSIONS

The anticipated association between AI exposure and osteoporotic fracture risk in Japanese women with breast cancer was not seen clearly.

Molecular and clinical effects of aromatase inhibitor therapy on skeletal muscle function in early-stage breast cancer

We evaluated biochemical changes in skeletal muscle of women with breast cancer initiating aromatase inhibitors (AI), including oxidation of ryanodine receptor RyR1 and loss of stabilizing protein calstabin1, and detailed measures of muscle function. Fifteen postmenopausal women with stage I-III breast cancer planning to initiate AI enrolled. Quadriceps muscle biopsy, dual-energy x-ray absorptiometry, isokinetic dynamometry, Short Physical Performance Battery, grip strength, 6-min walk, patient-reported outcomes, and serologic measures of bone turnover were assessed before and after 6 months of AI. Post-AI exposure, oxidation of RyR1 significantly increased (0.23 ± 0.37 vs. 0.88 ± 0.80, p < 0.001) and RyR1-bound calstabin1 significantly decreased (1.69 ± 1.53 vs. 0.74 ± 0.85, p < 0.001), consistent with dysfunctional calcium channels in skeletal muscle. Grip strength significantly decreased at 6 months. No significant differences were seen in isokinetic dynamometry measures of muscle contractility, fatigue resistance, or muscle recovery post-AI exposure. However, there was significant correlation between oxidation of RyR1 with muscle power (r = 0.60, p = 0.02) and muscle fatigue (r = 0.57, p = 0.03). Estrogen deprivation therapy for breast cancer resulted in maladaptive changes in skeletal muscle, consistent with the biochemical signature of dysfunctional RyR1 calcium channels. Future studies will evaluate longer trajectories of muscle function change and include other high bone turnover states, such as bone metastases.

The recent progress of endocrine therapy-induced osteoporosis in estrogen-positive breast cancer therapy

Breast cancer is a significant global health concern, and the discovery of endocrine therapy has played a crucial role in the treatment of estrogen-positive breast cancer. However, these therapies are often associated with osteoporosis-related adverse events, which increase the risk of fractures in breast cancer patients and can result in limited mobility and reduced quality of life. Previous studies have shown that osteoporosis is essential side effects of the breast cancer therapy, although the exact mechanisms remain mostly unclear. Current clinical treatments, such as bisphosphonates, cause side effects and may impact the therapeutic response to endocrine drugs. In this review, we explore the likelihood of endocrine therapy-induced osteoporosis in estrogen-positive breast cancer therapy and discuss the involved mechanisms as well as the therapeutic potential of drugs and drug combination strategies.

Denosumab effect on bone mineral density and urinary-NTX in breast cancer patients receiving aromatase inhibitors

INTRODUCTION

Aromatase inhibitors are used post-surgical intervention in postmenopausal patients with breast cancer. However, these drugs accelerate decline in bone mineral density (BMD), which is countered by use of denosumab, and the efficacy of the drug can be assessed by bone turnover markers. We investigated the effects of denosumab administration for 2 years on BMD and urinary N-telopeptide of type I collagen (u-NTX) levels in breast cancer patients treated with aromatase inhibitors.

MATERIALS AND METHODS

This was a single-center retrospective study. Postoperative hormone receptor-positive breast cancer patients with low T-scores biannually received denosumab from the time of initiation of aromatase inhibitor therapy for 2 years. BMD was measured every 6 months, and u-NTX levels were assessed after 1 month and thereby every 3 months.

RESULTS

The median patient age of the 55 patients included in this study was 69 (range: 51-90) years. BMD gradually increased in the lumbar spine and femoral neck and u-NTX levels were lowest at 3 months post-initiation of therapy. Patients were divided into two groups based on the change ratio of u-NTX 3 months post-denosumab administration. Of these, the group with higher change ratio showed a higher degree of BMD restoration in the lumbar spine and femoral neck 6 months post-denosumab treatment.

CONCLUSION

Denosumab increased BMD in patients treated with aromatase inhibitors. The u-NTX level decreased soon after start of denosumab treatment, and its change ratio is predictive of improvement in BMD.

Bone health in breast cancer

Early breast cancer is among the most common cancers worldwide. Recent advances continue to improve outcomes and increase long-term survivorship. However, therapeutic modalities are deleterious for patients' bone health. While antiresorptive therapy may partially negate this, consequent reduction in rates of fragility fractures remains unproven. Selective prescription of bisphosphonates or denosumab may be an amicable middle ground. Recent evidence also suggests a possible role of osteoclast inhibitors as adjuvant therapy, but the evidence is modest at best. In this narrative clinical review, we explore the impact of various adjuvant modalities on bone mineral density and fragility fracture rates of early breast cancer survivors. We also review optimal patient selection for antiresorptive agents, their impact on rates of fragility fractures, and the possible role of these agents as adjuvant therapy.

Initiation of Antiresorptive Drug Treatment during Endocrine Therapy for Breast Cancer-A Retrospective Cohort Study of 161,492 Patients in Germany

BACKGROUND

The aim of this retrospective cohort study was to measure the proportion of women with an initial prescription of an antiresorptive drug (bisphosphonates or denosumab) during five years of endocrine breast cancer therapy.

METHODS

The study included women with an initial prescription of tamoxifen (TAM) or aromatase inhibitors (AIs) between January 2016 and December 2020. Kaplan-Meier analyses were performed to show the cumulative incidence of antiresorptive drug prescription for TAM and AIs separately for four age groups. A univariable Cox proportional hazards regression model was also used to estimate the relationship between initial endocrine drug (AIs vs. TAM) and antiresorptive drug prescription.

RESULTS

Within 5 years, 14.1% of patients on AI and 6.1% on TAM received their first prescription for an antiresorptive drug (p < 0.001). The difference between AI and TAM was greatest in women ≤50 years (12.9% of AI and 2.8% of patients on TAM), and smallest in women >80 years (14.5% of AI and 10.3% of patients on TAM). The proportion of denosumab was 46.2% among AI patients vs. 29.1% among patients on TAM (p < 0.001) as alendronate was prescribed to 36.9% of AI vs. 50.0% of patients on TAM.

CONCLUSIONS

Across all age groups, the cumulative incidence of antiresorptive drug prescriptions was higher in patients with BC treated with AI than those receiving TAM. Denosumab was most frequently used as an antiresorptive drug in patients treated with AI, while alendronate was administered more often in patients treated with TAM.

Bone Turnover Markers: Basic Biology to Clinical Applications

Bone turnover markers (BTMs) are used widely, in both research and clinical practice. In the last 20 years, much experience has been gained in measurement and interpretation of these markers, which include commonly used bone formation markers bone alkaline phosphatase, osteocalcin, and procollagen I N-propeptide; and commonly used resorption markers serum C-telopeptides of type I collagen, urinary N-telopeptides of type I collagen and tartrate resistant acid phosphatase type 5b. BTMs are usually measured by enzyme-linked immunosorbent assay or automated immunoassay. Sources contributing to BTM variability include uncontrollable components (e.g., age, gender, ethnicity) and controllable components, particularly relating to collection conditions (e.g., fasting/feeding state, and timing relative to circadian rhythms, menstrual cycling, and exercise). Pregnancy, season, drugs, and recent fracture(s) can also affect BTMs. BTMs correlate with other methods of assessing bone turnover, such as bone biopsies and radiotracer kinetics; and can usefully contribute to diagnosis and management of several diseases such as osteoporosis, osteomalacia, Paget's disease, fibrous dysplasia, hypophosphatasia, primary hyperparathyroidism, and chronic kidney disease-mineral bone disorder.

The bone-muscle connection in breast cancer: implications and therapeutic strategies to preserve musculoskeletal health

Breast cancer and its therapies frequently result in significant musculoskeletal morbidity. Skeletal complications include bone metastases, pain, bone loss, osteoporosis, and fracture. In addition, muscle loss or weakness occurring in both the metastatic and curative setting is becoming increasingly recognized as systemic complications of disease and treatment, impacting quality of life, responsiveness to therapy, and survival. While the anatomical relationship between bone and muscle is well established, emerging research has led to new insights into the biochemical and molecular crosstalk between the skeletal and muscular systems. Here, we review the importance of both skeletal and muscular health in breast cancer, the significance of crosstalk between bone and muscle, and the influence of mechanical signals on this relationship. Therapeutic exploitation of signaling between bone and muscle has great potential to prevent the full spectrum of musculoskeletal complications across the continuum of breast cancer.

Bone mineral density, osteopenia and osteoporosis among US adults with cancer

BACKGROUND

Bone mineral deficits are one of the most common complications in cancer survivors. However, there are no studies evaluating bone mineral density (BMD) and the prevalence of osteopenia and osteoporosis among patients with different types of cancers.

AIM

The objective was to assess BMD and evaluate the prevalence of osteopenia and osteoporosis among US adults with cancer.

DESIGN

A cross-section propensity score matching study.

METHODS

We extracted data from National Health and Nutrition Examination Survey database from 2005 to 2018. We compared BMD in participants with and without cancer which was further analyzed according to cancer type. We conducted logistic regression to evaluate adjusted odds ratios of osteopenia and osteoporosis and determine risk factors for their development.

RESULTS

We found that BMD was significantly higher in participants without cancer than cancer patients. Furthermore, the median BMD of patients with breast cancer or skin cancer (including melanoma) was significantly lower than participants without cancer. People with breast, lung, genitourinary and skin cancers were more likely to incur osteopenia/osteoporosis than those without cancer.

CONCLUSIONS

BMD differs depending upon type in survivors. Individuals with a history of cancer have a poor understanding of osteoporosis and its risk factors. Understanding risk factors in patients with cancers identified in our study may be helpful for preventing osteoporosis and fractures and the development of screening guidelines.

Covalent ERα Antagonist H3B-6545 Demonstrates Encouraging Preclinical Activity in Therapy-Resistant Breast Cancer

Nearly 30% of patients with relapsed breast cancer present activating mutations in estrogen receptor alpha (ERα) that confer partial resistance to existing endocrine-based therapies. We previously reported the development of H3B-5942, a covalent ERα antagonist that engages cysteine-530 (C530) to achieve potency against both wild-type (ERαWT) and mutant ERα (ERαMUT). Anticipating that the emergence of C530 mutations could promote resistance to H3B-5942, we applied structure-based drug design to improve the potency of the core scaffold to further enhance the antagonistic activity in addition to covalent engagement. This effort led to the development of the clinical candidate H3B-6545, a covalent antagonist that is potent against both  ERαWT/MUT, and maintains potency even in the context of ERα C530 mutations. H3B-6545 demonstrates significant activity and superiority over standard-of-care fulvestrant across a panel of ERαWT and ERαMUT palbociclib sensitive and resistant models. In summary, the compelling preclinical activity of H3B-6545 supports its further development for the potential treatment of endocrine therapy-resistant ERα+ breast cancer harboring wild-type or mutant ESR1, as demonstrated by the ongoing clinical trials (NCT03250676, NCT04568902, NCT04288089).

SUMMARY

H3B-6545 is an ERα covalent antagonist that exhibits encouraging preclinical activity against CDK4/6i naïve and resistant ERαWT and ERαMUT tumors.

Secondary Osteoporosis and Metabolic Bone Diseases

Fragility fracture is a worldwide problem and a main cause of disability and impaired quality of life. It is primarily caused by osteoporosis, characterized by impaired bone quantity and or quality. Proper diagnosis of osteoporosis is essential for prevention of fragility fractures. Osteoporosis can be primary in postmenopausal women because of estrogen deficiency. Secondary forms of osteoporosis are not uncommon in both men and women. Most systemic illnesses and organ dysfunction can lead to osteoporosis. The kidney plays a crucial role in maintaining physiological bone homeostasis by controlling minerals, electrolytes, acid-base, vitamin D and parathyroid function. Chronic kidney disease with its uremic milieu disturbs this balance, leading to renal osteodystrophy. Diabetes mellitus represents the most common secondary cause of osteoporosis. Thyroid and parathyroid disorders can dysregulate the osteoblast/osteoclast functions. Gastrointestinal disorders, malnutrition and malabsorption can result in mineral and vitamin D deficiencies and bone loss. Patients with chronic liver disease have a higher risk of fracture due to hepatic osteodystrophy. Proinflammatory cytokines in infectious, autoimmune, and hematological disorders can stimulate osteoclastogenesis, leading to osteoporosis. Moreover, drug-induced osteoporosis is not uncommon. In this review, we focus on causes, pathogenesis, and management of secondary osteoporosis.

Secondary Osteoporosis

Osteoporosis is a global public health problem, with fractures contributing to significant morbidity and mortality. Although postmenopausal osteoporosis is most common, up to 30% of postmenopausal women, > 50% of premenopausal women, and between 50% and 80% of men have secondary osteoporosis. Exclusion of secondary causes is important, as treatment of such patients often commences by treating the underlying condition. These are varied but often neglected, ranging from endocrine to chronic inflammatory and genetic conditions. General screening is recommended for all patients with osteoporosis, with advanced investigations reserved for premenopausal women and men aged < 50 years, for older patients in whom classical risk factors for osteoporosis are absent, and for all patients with the lowest bone mass (Z-score ≤ -2). The response of secondary osteoporosis to conventional anti-osteoporosis therapy may be inadequate if the underlying condition is unrecognized and untreated. Bone densitometry, using dual-energy x-ray absorptiometry, may underestimate fracture risk in some chronic diseases, including glucocorticoid-induced osteoporosis, type 2 diabetes, and obesity, and may overestimate fracture risk in others (eg, Turner syndrome). FRAX and trabecular bone score may provide additional information regarding fracture risk in secondary osteoporosis, but their use is limited to adults aged ≥ 40 years and ≥ 50 years, respectively. In addition, FRAX requires adjustment in some chronic conditions, such as glucocorticoid use, type 2 diabetes, and HIV. In most conditions, evidence for antiresorptive or anabolic therapy is limited to increases in bone mass. Current osteoporosis management guidelines also neglect secondary osteoporosis and these existing evidence gaps are discussed.

Breast cancer therapy and bone

Breast cancer is the most common cancer in women and the leading cause of cancer-associated mortality. The estrogen deprivation associated with therapies used to treat this disease may result in significant loss of bone density and a consequent increase in fracture risk. Anti-resorptive osteoporosis therapies (bisphosphonates and the inhibitor of receptor activator of nuclear factor-κB ligand [RANKL] denosumab) play an important role in the mitigation of cancer therapy-induced bone loss (CTIBL), and may function as adjuvant therapy in moderate to high-risk breast cancer to prevent disease recurrence. Various international guidelines have delineated treatment thresholds based on both bone density assessment and clinical risk factors for CTIBL. The role of these bone-targeted therapies as adjuvant anti-cancer treatment is evolving. Currently, evidence supports the use of the bisphosphonates, zoledronic acid and clodronate, in this setting. Unfortunately, a focus on bone health in women with breast cancer is often not prioritized, leaving this group vulnerable to significant bone loss and subsequent fracture.

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.

The role of illicit drugs in developing medication-related osteonecrosis (MRONJ): a systematic review

Medication-related osteonecrosis of the jaw (MRONJ) is a challenging condition to treat. It has primarily been associated with anti-resorptive and anti-angiogenic drugs, which are increasingly being used to prevent adverse skeletally-related complications in patients with cancer and bone pathologies. Although these medications have been proven to cause osteonecrosis of the jaws (ONJ) there are also a number of other drugs that could potentially cause this condition. The aim of this systematic review is to ascertain whether there is an associated risk of osteonecrosis of the jaw (ONJ) in recreational drug users (RDU). Three authors independently searched PubMed, MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials for published reports of osteonecrosis of the jaw (ONJ) in recreational drug users (RDU) or illicit drug users (IDU) who had no history of treatment with anti-angiogenic or anti-resorptive agents. Only 30 studies were eligible for analysis, and all were independently assessed for risk of bias. There was a total of 101 patients with ONJ attributed solely to illicit drug consumption. The most common site of ONJ was the maxilla (n=54). The most common illicit drug related to ONJ was desmorphine, known as 'Krokodil', this was followed by cocaine, methamphetamine, anabolic steroids, and hydrocodone/acetaminophen. In 52 of the cases, the ONJ resolved following treatment, however, eight showed a recurrence. Although all the studies were judged to be at a high risk of bias, the limited data suggest that some patients are at risk of developing ONJ as a result of illicit drug usage. Studies of higher quality are needed to establish the relative risk of ONJ in this patient group.

CYP19A1 rs10046 Pharmacogenetics in Postmenopausal Breast Cancer Patients Treated with Aromatase Inhibitors: One-year Follow-up

BACKGROUND

Significant individual variation in bone loss associated with aromatase inhibitors (AIs) emphasizes the importance of identifying postmenopausal breast cancer patients at high risk for this adverse effect. The study explores the clinical relevance of genetic variation in the Cytochrome P450 19A1 (CYP19A1) gene in a subset of South African patients during the first year of taking AIs for estrogen receptor (ER)-positive breast cancer.

METHODS

The study population consisted of ER-positive breast cancer patients on AIs, followed in real-life clinical practice. Body mass index was measured and bone mineral density (BMD) was determined at baseline and at month 12. CYP19A1 genotyping was performed using real-time polymerase chain reaction analysis of rs10046, extended to Sanger sequencing and whole exome sequencing in 10 patients with more than 5% bone loss at month 12 at the lumbar spine.

RESULTS

After 12 months of AI treatment, 72 patients had completed BMD and were successfully genotyped. Ten patients (14%) experienced more than 5% bone loss at the lumbar spine over the study period. Genotyping for CYP19A1 rs10046 revealed that patients with two copies of the A-allele were 10.79 times more likely to have an ordinal category change of having an increased percentage of bone loss or no increase at the lumbar spine, compared to patients with the GA or GG genotypes (CI of 1.771- 65.830, p=0.01). None of the 34 patients without lumbar spine bone loss at month 12 were homozygous for the functional CYP19A1 polymorphism. At the total hip region, patients with the AA genotype were 7. 37 times more likely to have an ordinal category change of having an increased percentage of bone loss or no increase (CI of 1.101- 49.336, p=0.04).

CONCLUSION

Homozygosity for the CYP19A1 rs10046 A-allele may provide information, in addition to clinical and biochemical factors that may be considered in risk stratification to optimize bone health in postmenopausal breast cancer women on AIs. Further investigation is required to place the clinical effect observed for a single CYP19A1 gene variant in a genomic context.

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.

Intramedullary rod failure in metastatic breast cancer: Do triple negative cancer patients have more revision surgery?

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Intramedullary rodding can be considered for bone lesions in breast cancer.

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No difference in revision rate among patients with different receptor-status.

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Mean intramedullary rod revision time was 19 months.

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Revision cumulative incidence: 6% at 12 months and 20% at 60 months.

Background

Breast cancer is the most common cancer and second cause of death in women worldwide. Patients with breast cancer are classified into subgroups based on the presence or absence of hormone receptors and the human epidermal growth factor 2-neu (HER-2) marker, the different molecular profiles come with an associated prognosis and variety of possible treatment options. Patients with triple negative cancer have a worse prognosis, a more aggressive behavior, higher likelihood of spreading, a higher risk of recurrence and a poorer outcome overall. Intramedullary rod fixation has proven to provide a good outcome and function in patients with metastatic breast cancer, but no study has addressed the receptor-status potential outcome differences that may affect disease progression at an orthopaedic surgery site.

Questions/Purposes

(1) Do patients with triple negative breast cancer have a higher revision rate of intramedullary rod fixation of bone metastases? (2) Do patients with metastatic triple negative breast cancer have a higher revision rate of intramedullary rod fixation due to local disease progression?

Methods

This was a single-center, observational, retrospective cohort study. Fifty-seven patients with a diagnosis of breast cancer metastatic to long bones who underwent surgical fixation with an intramedullary rod for a pathological fracture or an impending fracture due to a bone metastasis with a Mirels’ score equal or above 8 between January 2004 and December 2016 at our institution were included. All implants used were from the same manufacturer (Stryker Corp., Mahwah, NJ, USA). Patients were divided into two groups based on the receptor status of the tumor and were classified either as triple negative, when the tumor lacked progesterone, estrogen and HER-2 receptors, or as receptor-positive when the presence of one or a combination of either three was proven. In the triple-negative tumor group the mean follow up time was 26 months (SD 29) and median follow up time was 16 months. In the receptor-positive tumor group mean follow up was 27 months (SD 24) with a median follow up of 19 months. To assess possible associations between different factors and the outcomes of interest, we used either the chi-square test or Fisher’s exact test for categorical variables and the ANOVA test for continuous variables. For the survival assessment, a Kaplan-Meier analysis was performed and for the cumulative incidence a competing risk analysis was utilized.

Results

The intramedullary rod revision rate for patients in the triple-negative tumor group was 17%, while for the receptor-positive group it was 12%, this was not statistically different for our sample size. The mean time for revision of the intramedullary rod in the whole sample was 19 months (SD 11, range 6–40). The causes of revision were disease progression (43%), nonunion (29%) and surgeon error (29%). The cumulative incidence of revision surgery was 6% (CI 95%, 2–14%) at 12 months and 20% (CI 95%, 8–36%) at 60 months.

Conclusions

Intramedullary rodding can be considered for the treatment of long bones metastases in breast cancer patients for an impending or actual pathological fracture. There is no difference in the intramedullary rod revision rate among patients with different receptor-status when comparing triple-negative tumor patients and receptor-positive ones.

Level of Evidence

Level III, therapeutic study.

The effect of denosumab in breast cancer patients receiving adjuvant aromatase inhibitors: 36-month results

INTRODUCTION

Aromatase inhibitor (AI)-associated bone loss increases the risk of bone fracture and reduces patients' quality of life, making it a critical issue worldwide. We conducted a prospective non-randomized clinical trial (UMIN-CTR, UMIN 000016173) to assess the effect of denosumab on bone loss in patients treated with adjuvant AI and have previously reported the results at 12 and 24 months. This study aimed to present the results at 36 months of treatment with denosumab for osteopenia in breast cancer patients who were undergoing treatment with adjuvant AI; 36 months is the longest denosumab treatment period reported so far.

MATERIALS AND METHODS

Patients received 60-mg denosumab subcutaneously every 6 months. Daily supplements containing 500-mg elemental calcium and at least 400 international units of vitamin D were highly recommended throughout the study period. The levels of bone mineral density (BMD) and bone turnover markers, serum tartrate-resistant acid phosphatase isoform 5b, and bone alkaline phosphatase were determined at baseline and 6, 12, 18, 24, and 36 months.

RESULTS

At 36 months, the bone mineral density of the lumbar spine, right femoral neck, and left femoral neck were found to increase by 8.8% (95% confidence interval CI 7.6-10.1), 4.3% (95% CI 3.0-5.5), and 3.1% (95% CI 2.1-4.1), respectively. No non-traumatic clinical fractures occurred in patients receiving AI and denosumab.

CONCLUSION

Twice-yearly administration of denosumab to the breast cancer patients treated with adjuvant AI, regardless of the skeletal site, resulted in consistent increases in BMD without severe adverse events at 36 months.

Proton Pump Inhibitors and Oncologic Treatment Efficacy: A Practical Review of the Literature for Oncologists

Proton pump inhibitors (PPIs) are the most commonly used anti-acid drugs worldwide, including among cancer patients. However, drug-drug interactions between PPIs and other agents may lead to decreased drug absorption with possible reduced therapeutic benefit, or even increased toxicity. Unfortunately, only scarce data exist regarding the safety of concomitant PPI use with anti-cancer agents. We aim at reviewing current evidence on this possible interaction by dividing anti-cancer agents by class. Until further data is available, we encourage healthcare providers to limit unnecessary PPI overuse.

The Evolving Complexity of Treating Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor-2 (HER2)-Negative Breast Cancer: Special Considerations in Older Breast Cancer Patients-Part I: Early-Stage Disease

The median age for breast cancer diagnosis is 62 years, but a disproportionate number of patients are over the age of 75 years and the majority of those have hormone receptor-positive, human epidermal growth factor receptor-2 (HER2)-negative cancers. This review provides a logical algorithm to guide providers through the many complicated issues involved in adjuvant systemic therapy decisions in older patients with hormone receptor-positive, HER2-negative breast cancer. For this subtype of breast cancer, the mainstay of treatment is surgery and adjuvant endocrine therapy with tamoxifen or an aromatase inhibitor (AI). Adjuvant chemotherapy is added to the treatment regimen when the benefits of treatment are deemed to outweigh the risks, making the risk-benefit discussion particularly important in older women. Traditional tools for cancer risk assessment and genomic expression profiles (GEPs) are under-utilized in older patients, but yield equally useful information about cancer prognosis as they do in younger patients. Additionally, there are tools that estimate life-limiting toxicity risk from chemotherapy and life expectancy, which are both important issues in the risk-benefit discussion. For very low-risk cancers, such as non-invasive and small lymph node (LN)-negative cancers, the benefits of any adjuvant therapy is likely outweighed by the risks, but endocrine therapy might be considered to prevent future new breast cancers. For invasive tumors that are > 5 mm (T1b or larger) or involve LNs, adjuvant endocrine therapy is recommended. Generally, AIs should be included, though tamoxifen is effective and should be offered when AIs are not tolerated. Bone-preserving agents and high-dose vitamin D are options to preserve bone density or treat osteoporosis, especially in older women who are taking AIs. Where the risk-reducing benefit from adjuvant chemotherapy outweighs the toxicity risk, adjuvant chemotherapy should be considered. Adjuvant chemotherapy has similar benefits in older and younger patients and standard regimens are preferred. Several exciting clinic trials are underway and have included older patients, including those adding molecularly targeted agents, cyclin-dependent kinase (CDK) 4/6 inhibitors and everolimus, to endocrine therapy in the adjuvant setting. The high incidence of breast cancer in older women should drive us to design clinical trials for this population and emphasize their inclusion in ongoing trials as much as possible.

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.

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.

Serum bone markers and risk of osteoporosis and fragility fractures in women who received endocrine therapy for breast cancer: a prospective study

PURPOSE

Osteoporosis and fragility fracture are major bone toxicities of aromatase inhibitors (AIs) for postmenopausal hormone receptor-positive breast cancer. Except for a few small studies on bone turnover markers and reduced bone mineral density after AI treatment, data on the associations of bone markers and risk of osteoporosis or fracture from prospective studies are lacking.

METHODS

In a prospective study of 1709 women on AIs, two bone turnover markers, BALP and TRACP, and two bone regulatory markers, RANKL and OPG, were measured and examined in relation to risk of osteoporosis and fragility fractures during a median follow-up time of 6.1 years.

RESULTS

Higher levels of BALP and TRACP were both associated with increased risk of osteoporosis and higher BALP/TRACP ratios were associated with lower risk of osteoporosis, but no associations were observed for fracture risk. Higher levels of OPG were associated with increased risk of fracture, whereas higher levels of RANKL were associated with lower risk. As a result, OPG/RANKL ratios were positively associated with fracture risk [hazard ratio (HR) = 2.49, 95% confidence interval (CI) 1.34-4.61]. After controlling for age and fracture history, the associations became non-significant but a suggestive trend remained (HR = 1.80, 95% CI 0.96-3.37).

CONCLUSION

Our study provides suggestive evidence for the potential utility of OPG/RANKL ratios in predicting risk of fracture in women treated with AIs for breast cancer. Further validation may be warranted.

Fracture Risk in Women with Breast Cancer Initiating Aromatase Inhibitor Therapy: A Registry-Based Cohort Study

BACKGROUND

Aromatase inhibitors (AIs) used in breast cancer induce loss in bone mineral density (BMD) and are reported to increase fracture risk.

MATERIALS AND METHODS

Using a population-based BMD registry, we identified women aged at least 40 years initiating AIs for breast cancer with at least 12 months of AI exposure (n = 1,775), women with breast cancer not receiving AIs (n = 1,016), and women from the general population (n = 34,205). Fracture outcomes were assessed to March 31, 2017 (mean, 6.2 years for AI users).

RESULTS

At baseline, AI users had higher body mass index (BMI), higher BMD, lower osteoporosis prevalence, and fewer prior fractures than women from the general population or women with breast cancer without AI use (all p < .001). After adjusting for all covariates, AI users were not at significantly greater risk for major osteoporotic fractures (hazard ratio [HR], 1.15; 95% confidence interval [CI], 0.93-1.42), hip fracture (HR, 0.90; 95% CI, 0.56-1.43), or any fracture (HR, 1.06; 95% CI, 0.88-1.28) compared with the general population.

CONCLUSION

Higher baseline BMI, BMD, and lower prevalence of prior fracture at baseline may offset the adverse effects of AI exposure. Although confirmatory data from large cohort studies are required, our findings challenge the view that all women with breast cancer initiating AI therapy should be considered at high risk for fractures.

IMPLICATIONS FOR PRACTICE

In a population-based observational registry that included 1,775 patients initiating long-term aromatase inhibitor therapy, risk for major osteoporotic fracture, hip fracture, or any fracture was similar to the general population. Higher baseline body mass index, bone mineral density, and lower prevalence of prior fracture at baseline may offset the adverse effects of aromatase inhibitor exposure.

Female sex is associated with a lower risk of bone metastases and favourable prognosis in non-sex-specific cancers

Background

The objectives were to investigate the disparity in the prevalence of bone metastases (BM) between the sexes and to assess the effect of female sex on the development and prognosis of BM.

Methods

Cases of invasive non-sex-specific cancers diagnosed between 2010 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) program were used. The prevalence of BM was calculated by combining the prevalence of BM among different cancers. Multivariable logistic regression and proportion hazard regression were conducted to investigate the effect of female sex, and the results were pooled by meta-analysis.

Results

The pooled prevalence of BM among male and female patients was 2.3% (95% CI: 1.6–3.2%) and 1.8% (95% CI: 1.2–2.6%), respectively. The pooled prevalence of BM dramatically decreased for patients aged 11–40 years old, plateaued for patients aged 41–90 years old and increased for patients aged > 90 years old in both male and female patients. Meta-analysis suggested that female sex had a protective effect on the development of BM (pooled OR = 0.80; 95% CI: 0.75–0.84; p < .001) and a favourable prognosis for respiratory system cancers (pooled HR = 0.81; 95% CI: 0.71–0.92; p < .001). However, no significant associations existed for other cancers. Male non-sex-specific cancer patients and those with male-leaning genetic variations or hormonal status have a greater likelihood of developing BM than female patients.

Conclusions

Female sex was associated with fewer BM in various non-sex-specific cancers, and the effect was constant with changes in age. Female sex showed a protective effect exclusively on the prognosis of respiratory system cancers.

Bone-Targeted Agents in Breast Cancer: Do We Now Have All the Answers?

The bone-targeted agents (BTAs), bisphosphonates and denosumab, have an established role in the treatment of metastatic breast cancer bone disease and the prevention of cancer-treatment-induced bone loss. Evidence in support of their ability to improve survival in early breast cancer now indicates that the bisphosphonates are effective in postmenopausal women (naturally or chemically induced), but denosumab does not have similar benefits when added to standard adjuvant therapy. In postmenopausal women with early breast cancer, the choice of BTA may differ depending on the indication for treatment; for fracture prevention in low disease recurrence risk patients, denosumab may be favoured (in comparison with placebo) to maintain bone health, and when disease recurrence prevention is a priority in higher risk patients, bisphosphonates may be favoured. The reason for the lack of efficacy of BTAs in premenopausal/perimenopausal patients still remains unanswered and will need preclinical research to evaluate novel treatment combinations with BTAs in this patient group. This review covers the past, present, and future indications for BTAs in both metastatic and early breast cancer.

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.

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.

Comparison of risedronate versus placebo in preventing anastrozole-induced bone loss in women at high risk of developing breast cancer with osteopenia

Anastrozole has been shown to prevent breast cancer in postmenopausal women at high risk of the disease, but has been associated with substantial accelerated loss of bone mineral density (BMD) and increased fractures. Here, we investigate the effect of risedronate on BMD after 5 years of follow-up in the IBIS-II prevention trial. 1410 women were enrolled in the bone sub-study and stratified into three strata according to the lowest baseline T-score at spine or femoral neck. The objective was to compare the effect of oral risedronate (35 mg weekly) versus placebo in osteopenic women in stratum II who were randomised to anastrozole in the main study. 258 osteopenic, postmenopausal women at high risk of developing breast cancer for whom baseline and follow-up bone mineral density measurements were available. 5-year mean BMD change at the lumbar spine for osteopenic women randomised to anastrozole and risedronate was -0.4% compared to -4.2% for those not on risedronate (P < 0.0001) but not significantly different between risedronate users and non-users at the hip (P = 0.2). 5-year mean PINP change was -20% for those randomised to anastrozole and risedronate compared to 3% for those not on risedronate but on anastrozole (P < 0.0001). Our results confirm the bone loss associated with the use of anastrozole and show that anastrozole-induced BMD loss in the spine can be controlled with risedronate treatment. However, our results suggest that weekly oral risedronate is unable to completely prevent anastrozole induced bone loss at the hip.

Random forest classifiers aid in the detection of incidental osteoblastic osseous metastases in DEXA studies

PURPOSE

Dual-energy X-ray absorptiometry (DEXA) studies are used for screening patients for low bone mineral density (BMD). Patients with breast and prostate cancer are often treated with hormone-altering drugs that result in low BMD. These patients may have incidental osteoblastic metastases of the spine that may be detected on screening DEXA studies. The aim of this pilot study is to assess whether random forest classifiers or support vector machines can identify patients with incidental osteoblastic metastases of the spine from screening DEXA studies and to evaluate which technique is better.

METHODS

We retrospectively reviewed the DEXA studies from 200 patients (155 normal control patients and 45 patients with osteoblastic metastases of one or more lumbar vertebral bodies from L1 to L4). The dataset was split into training (80%) and validation (20%) datasets. The optimal random forest (RF) and support vector machine (SVM) classifiers were obtained. Receiver-operator-characteristic curves were compared with DeLong's test.

RESULTS

The sensitivity, specificity, accuracy and area under the curve (AUC) of the optimal RF classifier were 77.8%, 100.0%, 98.0% and 0.889, respectively, in the validation dataset. The sensitivity, specificity, accuracy and AUC of the optimal SVM classifier were 33.3%, 96.8%, 82.5% and 0.651 in the validation dataset. The RF classifier was significantly better than the SVM classifier (P = 0.008). Only 7 of the 45 patients with osteoblastic metastases (15.6%) were prospectively identified by the radiologist interpreting the study.

CONCLUSIONS

RF classifiers can be used as a useful adjunct to identify incidental lumbar spine osteoblastic metastases in screening DEXA studies.

Use of bone turnover markers in the management of osteoporosis

PURPOSE OF REVIEW

Osteoporosis is a common public health problem that is often undertreated and underdiagnosed. The clinical management of osteoporosis is often reactionary to devastating fracture events. Bone turnover markers may improve the ease and rapidity at which osteoporosis is monitored and treated. Bone turnover markers are biochemical byproducts of bone formation or bone resorption. The clinical use of bone turnover markers is limited by significant preanalytical variability. Effective interpretation of bone turnover markers requires a detailed understanding of the variables that can affect their responses to osteoporosis treatment and monitoring.

RECENT FINDINGS

Progress is continuously being made on the standardization of bone turnover markers. The literature on the response of bone turnover markers to unique clinical situations is expanding. Data for evidence-based reference intervals for bone turnover markers has increased. Variables that affect the appropriate timing of lab draws like diurnal variation, postprandial status, exercise and alcohol use have been described. Studies examining the expected response of bone turnover markers to treatments of osteoporosis and other medications that affect bone health continue to increase.

SUMMARY

Bone turnover markers have clinical utility in the comprehensive evaluation of osteoporosis. When interpreted with caution and with a good understanding of their natural variability, bone turnover markers provide information that supplements osteoporosis management and provides useful clinical information about conditions that alter bone turnover.

Survivorship issues in older breast cancer survivors

PURPOSE

Almost half of breast cancer survivors are aged ≥ 65 years and the proportion is likely to increase due to the aging of the population. The objectives of this article were to review studies of health outcomes among older breast cancer survivors ≥ 65 years to identify gaps in the published literature and offer suggestions for future research.

METHODS

The present review is based upon bibliographic searches in PubMed and CINAHL and relevant search terms. Articles published in English from January 1, 1970 through October 1, 2018 were identified using the following MeSH search terms and Boolean algebra commands.

RESULTS

This review has revealed that older breast cancer survivors cope with health issues related to cancer treatment and the aging process, including comorbidities, osteoporosis, symptoms, physical functioning, cognitive functioning, nutrition, and physical activity.

CONCLUSIONS

Additional research is needed to examine therapeutic interventions to address the health conditions older breast cancer survivors are coping with. Particular focus of further research should be on the nutritional status and physical activity levels of older breast cancer survivors. Individualized nutrition plans and tailored physical activity programs for older survivors are needed that meet people where they are and that form habits.

Evaluation of osteopenia and osteoporosis in younger breast cancer survivors compared with cancer-free women: a prospective cohort study

BACKGROUND

Osteoporosis, an indicator of significant bone loss, has been consistently reported among older breast cancer survivors. Data are limited on the incidence of osteopenia, an earlier indicator of bone loss, and osteoporosis in younger breast cancer survivors compared with cancer-free women.

METHODS

We prospectively examined bone loss in 211 breast cancer survivors (mean age at breast cancer diagnosis = 47 years) compared with 567 cancer-free women in the same cohort with familial risk for breast cancer. Multivariable-adjusted Cox proportional hazards models were used to estimate HRs and 95% CIs of osteopenia and/or osteoporosis incidence based on physician diagnosis.

RESULTS

During a mean follow-up of 5.8 years, 66% of breast cancer survivors and 53% of cancer-free women reported having a bone density examination, and 112 incident cases of osteopenia and/or osteoporosis were identified. Breast cancer survivors had a 68% higher risk of osteopenia and osteoporosis compared to cancer-free women (HR = 1.68, 95% CI = 1.12-2.50). The association was stronger among recent survivors after only 2 years of follow-up (HR = 2.74, 95% CI = 1.37-5.47). A higher risk of osteopenia and osteoporosis was also observed among survivors aged ≤ 50 years, estrogen receptor-positive tumors, and those treated with aromatase inhibitors alone or chemotherapy plus any hormone therapy relative to cancer-free women.

CONCLUSIONS

Younger breast cancer survivors are at higher risk for osteopenia and osteoporosis compared to cancer-free women. Studies are needed to determine effective approaches to minimize bone loss in this population.

The effects of high-dose calcitriol and individualized exercise on bone metabolism in breast cancer survivors on hormonal therapy: a phase II feasibility trial

INTRODUCTION

Cancer treatment-induced bone loss (CTIBL) is a long-term side effect of breast cancer therapy. Both calcitriol and weight-bearing exercise improve bone metabolism for osteoporotic patients, but are unproven in a breast cancer population. We used a novel high-dose calcitriol regimen with an individualized exercise intervention to improve bone metabolism in breast cancer survivors.

METHODS

We accrued 41 subjects to this open label, 2 × 2 factorial, randomized feasibility trial. Breast cancer survivors were randomized to receive the following: (1) calcitriol (45 micrograms/week), (2) individualized exercise with progressive walking and resistance training, (3) both, or (4) a daily multivitamin (control condition) for 12 weeks. Primary outcomes included changes in biomarkers of bone formation, bone resorption, and the bone remodeling index, a composite measure of bone formation and resorption. Safety measures included clinical and biochemical adverse events. A main effect analysis was used for these endpoints.

RESULTS

Hypercalcemia was limited to three grade I cases with no grade ≥ 2 cases. Among exercisers, 100% engaged in the prescribed aerobic training and 44.4% engaged in the prescribed resistance training. Calcitriol significantly improved bone formation (Cohen's d = 0.64; p < 0.01), resulting in a non-significant increase in the bone remodeling index (Cohen's d = 0.21; p = 31). Exercise failed to improve any of the bone biomarkers.

CONCLUSIONS

Both calcitriol and exercise were shown to be feasible and well tolerated. Calcitriol significantly improved bone formation, resulting in a net increase of bone metabolism. Compliance with the exercise intervention was sub-optimal, which may have led to a lack of effect of exercise on bone metabolism.

Osteoporosis and musculoskeletal complications related to therapy of breast cancer

Aromatase inhibitors (AIs) are the treatment of choice for the majority of postmenopausal women with estrogen receptor (ER) positive breast cancers in early and advanced stage settings. One of most frequent side effects of AIs is bone loss that is of sufficient magnitude to increase risk of osteoporotic fractures. Osteoporosis is primarily a complex genetic disease with few modifiable risk factors. As the lifespan increases, and breast mortality decreases, more women with breast cancer will be at risk of osteoporotic fractures, or falls that result in fractures. The screening, prevention, and treatment of osteoporosis do not differ in women with or without breast cancer. Rather, breast cancer treatments, including AIs, chemotherapy-induced ovarian failure, and gonadotropin-releasing hormone (GnRH) agonists, all decrease estrogen, which causes net bone resorption, leading some women to experience fracture. Occurring in about fifty-percent of women, AI-induced arthralgia is one of the most common side effects, and causes of nonadherence and discontinuation. Registry studies show that nonadherence and discontinuation may contribute to higher breast cancer mortality. Thus, understanding the mechanisms, risk factors, and interventions to mitigate symptoms of AI-induced arthralgia is a high priority.

Effect of denosumab on bone mineral density in Japanese women with osteopenia treated with aromatase inhibitors for breast cancer: subgroup analyses of a Phase II study

Background

The aim of the study was to conduct subgroup analyses of therapeutic effects of 12-month denosumab therapy on the percentage change in bone mineral density (BMD) from baseline in the lumber spine and femoral neck.

Materials and methods

We prospectively evaluated the BMD of the lumbar spine and femoral neck of 100 hormone receptor-positive, clinical stage I–IIIA postoperative postmenopausal breast cancer patients, for whom treatment with aromatase inhibitors (AIs) as adjuvant endocrine therapy was scheduled. The primary endpoint was the percent change in lumbar spine BMD from baseline to 12 months. Patient subgroups were analyzed according to baseline variables that are known risk factors for bone loss, including previous AI therapy, age, time since menopause, baseline body mass index (BMI), and baseline BMD T-score.

Results

At 12 months, lumbar spine BMD increased by 4.7%; the patients who were administered AI therapy prior to denosumab (n=70) demonstrated a 4.7% increase in BMD, and the patients who received denosumab at the start of AI therapy (n=30) demonstrated a 4.5% increase in BMD (p=0.8385). Additionally, 2.4% and 1.4% increases in BMD of the right and left femoral neck, respectively, were observed. Initiation of AI (with denosumab, before denosumab), type of AI (non-steroidal, steroidal), age (<65, ≥65 years), time since menopause (≤5, >5 years), BMI (<25, ≥25 kg/m²), and T-score (≤−1.0, >−1.0) of the right femoral neck were as follows: (2.2%, 2.5%, p=0.7773), (2.6%, 0.9%, p=0.1726), (2.5%, 2.3%, p=0.7594), (2.1%, 2.4%, p=0.2034), (2.1%, 2.9%, p=0.2034), and (2.3%, 2.7%, p=0.6823), respectively. Initiation of AI (with denosumab, before denosumab), type of AI (non-steroidal, steroidal), age (<65, ≥65 years), time since menopause (≤5, >5 years), BMI (<25, ≥25 kg/m²), and T-score (≤−1.0, >−1.0) of the left femoral neck were as follows: (1.0%, 1.5%, p=0.1972), (1.2%, 2.7%, p=0.2931), (1.4%, 1.3%, p=0.8817), (−0.1%, 1.6%, p=0.1766), (1.3%, 1.9%, p=0.6465), and (1.5%, 1.1%, p=0.6573), respectively.

Conclusion

Twice-yearly treatment with denosumab was associated with increased BMD among Japanese women receiving adjuvant AI therapy, regardless of the baseline characteristics or skeletal site.

The Cytochrome P450 Enzyme Responsible for the Production of (Z)-Norendoxifen in vitro

Norendoxifen, an active metabolite of tamoxifen, is a potent aromatase inhibitor. Little information is available regarding production of norendoxifen in vitro. Here, we conducted a series of kinetic and inhibition studies in human liver microsomes (HLMs) and expressed P450s to study the metabolic disposition of norendoxifen. To validate that norendoxifen was the metabolite of endoxifen, metabolites in HLMs incubates of endoxifen were measured using a HPLC/MS/MS method. To further probe the specific isoforms involved in the metabolic route, endoxifen was incubated with recombinant P450s (CYP 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 3A4, 3A5 and CYP4A11). Formation rates of norendoxifen were evaluated in the absence and presence of P450 isoform specific inhibitors using HLMs. The peak of norendoxifen was found in the incubations consisting of endoxifen, HLMs, and cofactors. The retention times of norendoxifen, endoxifen, and the internal standard (diphenhydramine) were 7.81, 7.97, and 5.86 min, respectively. The K_m (app) and V_max (app) values of norendoxifen formation from endoxifen in HLM was 47.8 μm and 35.39 pmol min^-1 mg^-1 . The apparent hepatic intrinsic clearances of norendoxifen formation were 0.74 μl mg^-1 min. CYP3A5 and CYP2D6 were the major enzymes capable of norendoxifen formation from endoxifen with the rates of 0.26 and 0.86 pmol pmol^-1 P450 × min. CYP1A2, 3A2, 2C9, and 2C19 also contributed to norendoxifen formation, but the contributions were at least 6-fold lower. One micromolar ketoconazole (CYP3A inhibitor) showed an inhibitory effect on the rates of norendoxifen formation by 45%, but 1 μm quinidine (CYP2D6 inhibitor) does not show any inhibitory effect. Norendoxifen, metabolism from endoxifen by multiple P450s that including CYP3A5.

Postmenopausal Breast Cancer, Aromatase Inhibitors, and Bone Health: What the Surgeon Should Know

Breast cancer, as the most common malignancy in women, remains a major public health issue despite countless advances across decades. Endocrine therapy is the cornerstone of treatment of the hormone-sensitive subtype of breast cancer. The use of aromatase inhibitors (AIs) in the postmenopausal women has extended the survival beyond that of Tamoxifen, but harbors a subset of side effects, most notably accelerated bone loss. This, however, does not occur in all women undergoing treatment. It is vital to identify susceptible patients early, to limit such events, employ early treatment thereof, or alter drug therapy. International trials on AIs, predominantly performed in North American and European females, provide little information on what to expect in women in developing countries. Here, surgeons often prescribe and manage endocrine therapy. The prescribing surgeon should be aware of the adverse effect of the endocrine therapy and be able to attend to side effects. This review highlights clinical and biochemical factors associated with decrease in bone mineral density in an, as yet, unidentified subgroup of postmenopausal women. In the era of personalized medical care, appropriate management of bone health by surgeons based on these factors becomes increasingly important.

Use of bone turnover markers in postmenopausal osteoporosis

Bone turnover comprises two processes: the removal of old bone (resorption) and the laying down of new bone (formation). N-terminal propeptide of type I procollagen (PINP) and C-telopeptide of type I collagen (CTX-I) are markers of bone formation and resorption, respectively, that are recommended for clinical use. Bone turnover markers can be measured on several occasions in one individual with good precision. However, these markers are subject to several sources of variability, including feeding (resorption decreases) and recent fracture (all markers increase for several months). Bone turnover markers are not used for diagnosis of osteoporosis and do not improve prediction of bone loss or fracture within an individual. In untreated women, very high bone turnover marker concentrations suggest secondary causes of high bone turnover (eg, bone metastases or multiple myeloma). In people with osteoporosis, bone turnover markers might be useful to assess the response to anabolic and antiresorptive therapies, to assess compliance to therapy, or to indicate possible secondary osteoporosis. Much remains to be learnt about how bone turnover markers can be used to monitor the effect of stopping bisphosphonate therapy (eg, to identify a threshold above which restarting therapy should be considered). More studies are needed to investigate the use of bone turnover markers for assessment of the bone safety of new medications.

Use of CTX-I and PINP as bone turnover markers: National Bone Health Alliance recommendations to standardize sample handling and patient preparation to reduce pre-analytical variability

The National Bone Health Alliance (NBHA) recommends standardized sample handling and patient preparation for C-terminal telopeptide of type I collagen (CTX-I) and N-terminal propeptide of type I procollagen (PINP) measurements to reduce pre-analytical variability. Controllable and uncontrollable patient-related factors are reviewed to facilitate interpretation and minimize pre-analytical variability.

INTRODUCTION

The IOF and the International Federation of Clinical Chemistry (IFCC) Bone Marker Standards Working Group have identified PINP and CTX-I in blood to be the reference markers of bone turnover for the fracture risk prediction and monitoring of osteoporosis treatment. Although used in clinical research for many years, bone turnover markers (BTM) have not been widely adopted in clinical practice primarily due to their poor within-subject and between-lab reproducibility. The NBHA Bone Turnover Marker Project team aim to reduce pre-analytical variability of CTX-I and PINP measurements through standardized sample handling and patient preparation.

METHODS

Recommendations for sample handling and patient preparations were made based on review of available publications and pragmatic considerations to reduce pre-analytical variability. Controllable and un-controllable patient-related factors were reviewed to facilitate interpretation and sample collection.

RESULTS

Samples for CTX-I must be collected consistently in the morning hours in the fasted state. EDTA plasma is preferred for CTX-I for its greater sample stability. Sample collection conditions for PINP are less critical as PINP has minimal circadian variability and is not affected by food intake. Sample stability limits should be observed. The uncontrollable aspects (age, sex, pregnancy, immobility, recent fracture, co-morbidities, anti-osteoporotic drugs, other medications) should be considered in BTM interpretation.

CONCLUSION

Adopting standardized sample handling and patient preparation procedures will significantly reduce controllable pre-analytical variability. The successful adoption of such recommendations necessitates the close collaboration of various stakeholders at the global stage, including the laboratories, the medical community, the reagent manufacturers and the regulatory agencies.

Sex Differences and Bone Metastases of Breast, Lung, and Prostate Cancers: Do Bone Homing Cancers Favor Feminized Bone Marrow?

Sex-associated differences in bone metastasis formation from breast, lung, and prostate cancer exist in clinical studies, but have not been systematically reviewed. Differences in the bone marrow niche can be attributed to sexual dimorphism, to genetic variations that affect sex hormone levels, or to the direct effects of sex hormones, natural or exogenously delivered. This review describes the present understanding of sex-associated and sex hormone level differences in the marrow niche and in formation of bone metastasis during the transition of these three cancers from treatable disease to an often untreatable, lethal metastatic one. Our purpose is to provide insight into some underlying molecular mechanisms for hormonal influence in bone metastasis formation, and to the potential influence of sexual dimorphism, genetic differences affecting sex assignment, and sex hormone level differences on the bone niche and its favorability for metastasis formation. We reviewed publications in PubMed and EMBASE, including full length manuscripts, case reports, and clinical studies of relevance to our topic. We focused on bone metastasis formation in breast, lung, and prostate cancer because all three commonly present with bone metastases. Several clear observations emerged. For breast cancer bone metastasis formation, estrogen receptor (ER) signaling pathways indicate a role for ER beta (ERβ). Estrogen influences the bone microenvironment, creating and conditioning a favorable niche for colonization and breast cancer progression. For lung cancer, studies support the hypothesis that females have a more favorable bone microenvironment for metastasis formation. For prostate cancer, a decrease in the relative androgen to estrogen balance or a “feminization” of bone marrow favors bone metastasis formation, with a potentially important role for ERβ that may be similar to that in breast cancer. Long-term estrogen administration or androgen blockade in males may feminize the bone marrow niche to one more favorable for bone metastases in prostate cancer. Administration of androgens in females, especially combined with mastectomy, may reduce risk of developing bone metastatic breast cancer. We conclude that it should be considered that females, those with female-leaning genetic variations, or hormonal states that feminize the bone marrow, may offer favorable sites for bone metastases.