Premenopausal women with early breast cancer treated with estradiol suppression have severely deteriorated bone microstructure

Aromatase inhibitors, bone microstructure, and estimated bone strength in postmenopausal women with breast cancer: a 5-year prospective study

INTRODUCTION

Aromatase inhibitors (AIs) are the standard treatment for early breast cancer (EBC) and are typical causative agents of cancer treatment-induced bone loss. However, the effects of long-term treatment with these drugs on bone microstructure remain unclear.

MATERIALS AND METHODS

This prospective, single-arm observational study included postmenopausal, non-osteoporotic women with hormone receptor-positive EBC. Patients who underwent dual-energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HR-pQCT), and tartrate-resistant acid phosphatase-5b (TRACP-5b) or procollagen type I N-terminal propeptide levels were compared at baseline and at 60 months after commencing AI treatment.

RESULTS

Fifteen women were included in the study, with a median age of 58 years and a quartile range of 56.5-62.5 years. At 60 months, HR-pQCT revealed that the cortical area and thickness decreased with increased cortical porosity in the cortical bone. In addition, the number of trabeculae decreased and trabecular separation increased trabecular bones decreases, and trabecular bone separation opens, resulting in a decrease in the trabecular bone volume fraction. Total bone mineral density (BMD), trabecular volumetric BMD, and cortical volumetric BMD, and estimated bone strength significantly decreased. DXA BMD values significantly decreased in the total hip and femoral neck but not the lumbar spine. TRACP-5b values after 5 years of AI treatment showed a significant negative correlation with the rate of change in the total volumetric BMD in the distal tibia.

CONCLUSION

Postmenopausal women who received AIs for 5 years for EBC experienced significant deterioration in the bone microstructure, BMD, and estimated bone strength.

Denosumab Prevents Bone Loss and Microarchitectural Deterioration in Premenopausal Women With Breast Cancer Receiving Estradiol Suppression Therapy: A Randomized Controlled Trial

PURPOSE

Suppression of ovarian function and aromatase inhibition (AI) increases disease-free survival in premenopausal women with estrogen receptor (ER)-positive early-stage breast cancer but accelerates bone loss. We therefore hypothesized that suppressing bone remodeling using denosumab (DMAB) would prevent bone loss in these women.

METHODS

In a 12-month double-blind randomized trial, 68 women with ER-positive early-stage breast cancer commencing ovarian function suppression and AI were randomly assigned to 60 mg DMAB (n = 34) or placebo (PBO; n = 34) once every 6 months (at 0 and 6 months). Volumetric bone mineral density (BMD), microarchitecture, and estimated bone strength of the distal tibia and distal radius were measured using high-resolution peripheral quantitative computed tomography, and spine and hip BMD were measured using dual-energy X-ray absorptiometry at 0, 6, and 12 months. The primary end point and treatment effect was the mean adjusted between group difference (MAD; [95% CI]) in distal tibial total volumetric BMD over 12 months, with a single P value tested over all time points. The study is registered with the Australian New Zealand Clinical Trials Registry (anzctr.org.au; identifier: ACTRN12616001051437).

RESULTS

Intention-to-treat analysis included all 68 randomly assigned women. Over 12 months, compared with PBO, DMAB prevented the decrease in distal tibial total BMD (MAD, 20.8 mg HA/cm3 [95% CI, 17.3 to 24.2]), cortical BMD (42.9 mg HA/cm3 [95% CI, 32.1 to 53.9]), trabecular BMD (3.32 mg HA/cm3 [95% CI, 1.45 to 5.20], P = .004), estimated stiffness (11.6 kN/m [95% CI, 7.6 to 15.6]), and failure load (563 N [95% CI, 388 to 736]). Findings were similar at the distal radius. Decreases in BMD at the lumbar spine (MAD, 0.13 g/cm2 [95% CI, 0.11 to 0.15]), total hip (0.08 g/cm2 [95% CI, 0.07 to 0.09], and femoral neck (0.06 g/cm2 [95% CI, 0.05 to 0.07]) were also prevented. All P < .001 unless otherwise noted.

CONCLUSION

Treatment with DMAB at commencement of estradiol suppression therapy preserves BMD, bone microarchitecture, and estimated strength, and is likely to increase fracture-free survival.

Systemic Therapy of Premenopausal Patients with Early Stage Hormone Receptor-Positive, HER2-Negative Breast Cancer - Controversies and Standards in Healthcare

In patients with existing ovarian function, there are some special aspects to adjuvant endocrine therapy in premenopausal patients with hormone receptor-positive, HER2-negative (HR pos./HER2 neg.) breast cancer. Treatment options include tamoxifen with or without a GnRH analog, and aromatase inhibitors with a GnRH analog. Furthermore, ovarian function is affected by previous chemotherapy. Both aromatase inhibitors (+GnRH analogs) and GnRH analogs in combination with tamoxifen are supposed to be indicated for patients at increased risk of recurrence. However, national and international guidelines and therapy recommendations do not provide a clear definition of intermediate or high risk; as a result, therapy decisions are often made for each patient on an individual basis. This is also reflected in the considerable variability at national and international levels, e.g., with regard to the use of aromatase inhibitors + GnRH analogs. This review summarizes the data on completed studies (e.g., SOFT, TEXT, EBCTCG meta-analyses) and the current multigene testing studies (TailorX, RxPonder, ADAPT), discusses the rationale for current studies (e.g., CLEAR-B), and looks ahead to future questions.

Role of Ovarian Suppression in Early Premenopausal Breast Cancer

The benefit from removing ovaries to control premenopausal breast cancer growth was identified more than 100 years ago. Subsequent identification of estrogen receptor (ER) enabled targeting of this approach. Development of gonadotropin-releasing hormone agonists facilitated a reversible method of ovarian function suppression, suitable for young women with early breast cancer. Clinical trials have established the value of including ovarian suppression to reduce recurrence of ER-positive premenopausal early breast cancer. Ovarian suppression administered with chemotherapy can reduce the risk of premature menopause in ER-negative cancer, and increase the prospect of future pregnancy in premenopausal women, regardless of tumor hormone receptor status.

Review of bone health in women with estrogen receptor-positive breast cancer receiving endocrine therapy

In estrogen-receptor-positive tumors, adjuvant endocrine therapy has been shown to be highly beneficial for both overall and disease-free survival. Estradiol is key in regulating bone and mineral physiology, and several studies found a strong correlation between these therapies and the risk of fractures. Since these therapies are often given for 5 through 10 years, the timing for bisphosphonates or denosumab initiation seems essential to managing bone metabolism. However, gray zones and discrepancies between guidelines remain as to the best threshold when to start antiresorptive treatment, or whether antiresorptive treatment should be administered to every woman undergoing adjuvant endocrine therapy, independent of their risk factors for fractures. Treatment options and strategies should be discussed at the start of hormone adjuvant therapy to come to a shared decision with the patient, with the final aim of reducing the risk of future fractures as much as possible. This review will cover present guidelines and literature on antiresorptive treatment in this setting, to provide clinicians with useful clues for managing these patients.

Adjuvant endocrine therapy effects on bone mineral density and microstructure in women with breast cancer

INTRODUCTION

Although aromatase inhibitors (AIs) are typical drugs for cancer treatment-induced bone loss, their effects on the bone microstructure remain unclear. In this study, we evaluated changes in the bone mineral density (BMD) and bone microstructure associated with AI treatment using high-resolution peripheral quantitative computed tomography (HR-pQCT) in patients with early breast cancer.

MATERIALS AND METHODS

This prospective, single-arm, observational study included non-osteoporotic, postmenopausal women with hormone receptor-positive breast cancer. Patients underwent dual-energy X-ray absorptiometry (DXA), HR-pQCT, and tartrate-resistant acid phosphatase-5b (TRACP-5b) or procollagen type-I N-terminal propeptide measurements at baseline and 6 and 12 months after AI therapy. The primary endpoint was changes in the total volumetric BMD (Tt.vBMD), trabecular vBMD (Tb.vBMD), and cortical vBMD (Ct.vBMD) longitudinally at the distal radius and tibia.

RESULTS

Twenty women were included (median age 57.5 years; range 55-72 years). At 12 months, HR-pQCT indicated a significant decrease in the Tt.vBMD (median distal radius - 5.3%, p < 0.01; distal tibia - 3.2%, p < 0.01), Tb.vBMD (- 3.2%, p < 0.01; - 1.0%, p < 0.05, respectively), and Ct.vBMD (- 3.2%, p < 0.01; - 2.7%, p < 0.01, respectively). Estimated bone strength was also significantly decreased. The DXA BMD value in the total hip (p < 0.01) and femoral neck (p = 0.03), but not in the lumbar spine, was significantly decreased. The TRACP-5b levels was significantly negatively associated with changes in the Tt.vBMD in both the distal radius and tibia (r =  - 0.53, r =  - 0.47, respectively) CONCLUSION: Postmenopausal women who received AIs for early breast cancer experienced significant trabecular and cortical bone deterioration and a decrease in estimated bone strength within only 1 year.

Effect of tamoxifen with or without gonadotropin-releasing hormone analog on DXA values in women with breast cancer

The purpose of this study was to compare the changes in DXA values including trabecular bone score (TBS) and bone mineral density (BMD) of lumbar spine (LS) and femur according to the hormone therapies including tamoxifen (TMXF) treatment with or without gonadotropin releasing hormone analog (GnRH analog) in women with breast cancer. We enrolled 119 women with breast cancer who had undergone breast-conserving surgery or mastectomy followed by TMXF treatment for postmenopausal women (TMXF group, n = 63, 52.9%) or by combination therapy of TMXF combined with GnRH analog for premenopausal women (TMXF + GnRH group, n = 56, 47.1%) from December 2013 to December 2017. The median follow-up period was 13 months (interquartile range [IQR], 12.0–14.75) for TMXF group and 13.5 months (IQR, 12.00–16.00) for TMXF + GnRH group, respectively. Patients did not receive bone-modifying therapy. The baseline dual-energy X-ray absorptiometry (DXA) scan before breast cancer surgery and follow-up DXA during hormone therapy. Comparing the first and follow-up DXA results, BMD in LS were significantly decreased in both TMXF (P < 0.001, mean difference: − 0.06) and TMXF + GnRH (P < 0.001, mean difference: − 0.09) groups. BMD values of femoral neck (P = 0.0011, mean difference: − 0.01) and total femur (P < 0.001, mean difference: − 0.03) was significantly changed between the baseline and follow-up DXA in TMXF + RnRH group. In the TMX group, a significant changed occurred in the BMD in total femur (P < 0.001, mean difference: − 0.030) but not the BMD of femoral neck (P = 0.095, mean difference: − 0.007). Regarding TBS, no significant change was found in the TMXF (P = 0.574, mean difference: − 0.004) group, whereas there was a significant decrease in TBS in the TMXF + GnRH (P < 0.001, mean difference: − 0.02) group during follow-up. TBS is more sensitive in reflecting the bone microarchitecture changes by TMXF or GnRH agonist in breast cancer patients than BMD. This finding demonstrates that TBS can be a useful parameter to detect bone microarchitectural changes in clinical applications.

Challenges in Preventing Bone Loss Induced by Aromatase Inhibitors

CONTEXT

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

OBJECTIVE

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

Osteoporosis in Premenopausal Women: A Clinical Narrative Review by the ECTS and the IOF

CONTEXT

Consensus regarding diagnosis and management of osteoporosis in premenopausal women (PW) is still lacking due to few studies carried out in this population.

DESIGN

The European Calcified Tissue Society and the International Osteoporosis Foundation convened a working group to produce an updated review of literature published after 2017 on this topic.

RESULTS

Fragility fractures in PW are rare and mostly due to secondary osteoporosis (ie, in presence of an underlying disease such as hormonal, inflammatory, or digestive disorders). In absence of another disorder, low bone mineral density (BMD) together with fragility fractures qualifies as idiopathic osteoporosis. In contrast, low BMD alone does not necessarily represent osteoporosis in absence of bone microarchitectural abnormalities. BMD increases in PW with osteoporosis when the underlying disease is treated. For example, in celiac disease, an increase of 9% in radius trabecular volumetric density was achieved after 1 year of gluten-free diet, while anti-tumor necrosis factor alpha improved BMD in PW with inflammatory bowel diseases. In amenorrhea, including anorexia nervosa, appropriately delivered estrogen replacement therapy can also improve BMD. Alternatively, antiresorptive or anabolic therapy has been shown to improve BMD in a variety of conditions, the range of improvement (3%-16%) depending on skeletal site and the nature of the secondary cause. No studies were powered to demonstrate fracture reduction. The effects of bisphosphonates in childbearing women have been scantly studied and caution is needed.

CONCLUSION

The majority of PW with osteoporosis have an underlying disease. Specific therapy of these diseases, as well as antiresorptive and anabolic drugs, improve BMD, but without evidence of fracture reduction.

Characterization of serum metabolites as biomarkers of carbon black nanoparticles-induced subchronic toxicity in rats by hybrid triple quadrupole time-of-flight mass spectrometry with non-targeted metabolomics strategy

Carbon black nanoparticles (CBNPs) are one of atmospheric particles components and have been closely related with a series of lung diseases. It can reach the depths of the respiratory tract or even alveolar more easily than those micro-particles. Although some of its toxicities have been confirmed in animals or human bodies, the subchronic toxicity mechanism of CBNPs has been uncertain so far. Therefore, it is very necessary to establish a novel method and clarify the mechanism of subchronic toxicity caused by concentration adjustments of small molecule metabolites in vivo. In animal experiments, CB exposure, recovery and control group were set up. The concentration of CBNPs in chamber was 30.06 ± 4.42 mg/m³. We developed a UHPLC-Q-TOF-MS/MS-based non-targeted metabolomic analysis strategy to analyze serum samples of rats. Then, differential metabolites in serum were found by multivariate data analysis and 39 potential biomarkers were identified. It was showed that main metabolic pathways associated with CBNPs exposure were hormones metabolism, amino acid metabolism, nucleotide metabolism and lipid metabolism. It is worth noting that long-term exposure to CBNPs had the greatest impact on steroid hormones biosynthesis so that the risk of infertility could increase. The results provided a new mechanistic insight into the metabolic alterations owing to CBNPs induced subchronic toxicity.

The effects of adjuvant endocrine therapy on bone health in women with breast cancer

In women with oestrogen receptor (ER)-positive early breast cancer, oestradiol is important for breast cancer development and progression. Endocrine therapy prevents the deleterious effects of oestradiol in breast tissue by systemically depleting oestradiol concentration (aromatase inhibitors) or preventing its local action in breast tissue (selective oestrogen receptor modulators i.e. tamoxifen), thereby improving oncological outcomes. Use of aromatase inhibitors in postmenopausal women and ovarian function suppression with either tamoxifen or aromatase inhibition in premenopausal women, consequent to systemic oestradiol depletion, exerts detrimental effects on skeletal health. The oestradiol-deficient state causes increased bone remodelling and a negative bone balance. This results in bone loss, microstructural deterioration and bone fragility predisposing to fractures. Similar effects are also seen with tamoxifen in premenopausal women. In contrast, use of tamoxifen in postmenopausal women appears to exert protective effects on bone but studies on fracture risk are inconclusive. The longevity of women with ER-positive breast cancer treated with adjuvant endocrine therapy emphasises the need to mitigate the adverse skeletal effects of these therapies in order to maximise benefit. In general, fractures are associated with increased morbidity, mortality and are a high socioeconomic burden. Whilst the efficacy of antiresorptive therapy in preventing bone mineral density loss in postmenopausal women has been established, further clinical trial evidence is required to provide guidance regarding fracture risk reduction, when to initiate and stop treatment, choice of agent and optimal management of bone health in premenopausal women receiving endocrine therapy. In addition, potential oncological benefits of antiresorptive therapies will also need to be considered.

DIAGNOSIS OF ENDOCRINE DISEASE: Evaluation of bone fragility in endocrine disorders

An underlying disease affecting bone health is present in up to 40% and 60% of osteoporotic post-menopausal women and men respectively. Among the disorders leading to a secondary form of osteoporosis, the endocrine diseases are highly represented. A frequent finding in patients affected with an endocrine-related forms of bone disease is that the skeletal fragility is partially independent of the bone density, since the fracture risk in these patients is related more to a reduction of bone quality than to a decrease of bone mass. As a consequence, bone mineral density evaluation by dual-X-ray Absorptiometry may be inadequate for establishing the risk of fracture in the setting of the endocrine-related forms of osteoporosis. In the recent years several attempts to non-invasively estimating bone quality have been done. Nowadys, some new tools are available in the clinical practice for optimizing the fracture risk estimation in patients with endocrine disorders. The aim of this review is to summarise the evidences regarding the role of the different imaging tools for evaluating bone density and bone quality in the most frequent forms of endocrine-related osteoporosis, such as obesity, diabetes, acromegaly, thyrotoxicosis, primary hyperparathyroidism, hypercortisolism and hypogonadism. For each of these disorders, data regarding both the current available tools and the future possible new techniques for assessing bone fragility in patients with endocrine diseases are reported.

Bone health in women with breast cancer

Women with early, estrogen receptor-positive breast cancer are treated with adjuvant endocrine therapy, using aromatase inhibitors or selective estradiol receptor modulators such as tamoxifen, to deprive breast tissue from the deleterious effects of estradiol action, hence improving long-term prognosis. Aromatase inhibitors and, in premenopausal women, tamoxifen accelerate bone loss and increase fracture risk. Therefore, all women commencing endocrine therapy need a targeted work-up to assess the baseline fracture risk, and monitoring of bone health during endocrine therapy should be individualized based on this baseline risk. While high-level evidence specific to early breast cancer is lacking, non-pharmacologic measures to maintain optimal bone health such as weight-bearing exercise and calcium and vitamin D sufficiency should be implemented in all women. Antiresorptive treatment should be initiated in all women with preexisting fragility fractures (including vertebral morphometric fractures) and should be considered in women with areal bone mineral density (BMD) T-scores < -2.0 (or Z-scores in women aged <50 years) or those experiencing rapid bone loss (≥5% per year), taking into consideration the baseline BMD and other risk factors for fracture. Further clinical trial evidence is required to provide definitive guidance regarding criteria to initiate antiresorptive treatment, choice of agents, and duration of treatment, taking into account potential oncologic benefits of antiresorptive therapy on breast cancer-related outcomes.

The skeletal impact of cancer therapies

Both cancer and therapies used in the treatment of cancer can have significant deleterious effects on the skeleton, increasing the risks for both bone loss and fracture development. While advancements in cancer therapies have resulted in enhanced cancer survivorship for patients with many types of malignancies, it is increasingly recognized that efforts to reduce bone loss and limit fractures must be considered for nearly all patients undergoing cancer therapy in order to diminish the anticipated future skeletal consequences. To date, most studies examining the impact of cancer therapies on skeletal outcomes have focused on endocrine-associated cancers of the breast and prostate, with more recent advances in our understanding of bone loss and fracture risk in other malignancies. Pharmacologic efforts to limit the adverse effects of cancer therapies on bone have nearly universally employed anti-resorptive approaches, although studies have frequently relied on surrogate outcomes such as changes in bone mineral density or bone turnover markers, rather than on fractures or other skeletal-related events, as primary study endpoints. Compounding current deficiencies for the provision of optimal care is the recognition that despite clearly written and straightforward society-based guidelines, vulnerable eligible patients are very often neither identified nor provided with appropriate treatments to limit the skeletal impact of their cancer therapies.

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.