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

The impact of bone mineral density screening on incident fractures and healthcare resource utilization among postmenopausal breast cancer survivors treated with aromatase inhibitors

Bone mineral density screening prior to initiating aromatase inhibitor therapy was associated with lower incident bone fractures and healthcare resource utilization among postmenopausal breast cancer survivors.

INTRODUCTION

Postmenopausal women with hormone receptor-positive breast cancer (BC) often receive aromatase inhibitor (AI) therapy. However, AIs induce bone loss and BC survivors are at an increased risk of bone fractures. This study determined whether receipt of baseline dual-energy x-ray absorptiometry (DXA) screening is associated with decreased incident fractures and lower healthcare resource utilization.

METHODS

We retrospectively analyzed 22,713 stage 0-III primary BC survivors who received AI therapy ≤ 1 year prior to BC diagnosis from the Medicare-Linked Surveillance, Epidemiology, and End-Results database. We categorized DXA screening for those who had a procedural claim within 12 months prior through 6 months after first AI claim. We used propensity score methods to assess the association of DXA screening with bone fractures and health resource utilization.

RESULTS

Of the study cohort, 62% received a DXA screening. Women with comorbid dementia, renal disease, and congestive heart failure were less likely to receive a DXA. After adjusting for confounders, BC survivors who received a DXA had a 32% decreased risk of any bone fracture compared to those who did not (hazard ratio (HR): 0.68, 95% confidence interval (CI): 0.60-0.76, p < 0.001). Similarly, those who received a DXA were less likely to be hospitalized (HR 0.73 (0.62-0.86)) or use outpatient services (HR 0.85 (0.74-0.97)).

CONCLUSIONS

Bone density screening is associated with decreased incident bone fractures and a lower likelihood of utilizing healthcare resource for fracture-related events. Postmenopausal BC survivors treated with AIs should undergo appropriate bone density screening to reduce morbidity, mortality, and health care expenses.

Endoxifen, an Estrogen Receptor Targeted Therapy: From Bench to Bedside

The selective estrogen receptor (ER) modulator, tamoxifen, is the only endocrine agent with approvals for both the prevention and treatment of premenopausal and postmenopausal estrogen-receptor positive breast cancer as well as for the treatment of male breast cancer. Endoxifen, a secondary metabolite resulting from CYP2D6-dependent biotransformation of the primary tamoxifen metabolite, N-desmethyltamoxifen (NDT), is a more potent antiestrogen than either NDT or the parent drug, tamoxifen. However, endoxifen's antitumor effects may be related to additional molecular mechanisms of action, apart from its effects on ER. In phase 1/2 clinical studies, the efficacy of Z-endoxifen, the active isomer of endoxifen, was evaluated in patients with endocrine-refractory metastatic breast cancer as well as in patients with gynecologic, desmoid, and hormone-receptor positive solid tumors, and demonstrated substantial oral bioavailability and promising antitumor activity. Apart from its potent anticancer effects, Z-endoxifen appears to result in similar or even greater bone agonistic effects while resulting in little or no endometrial proliferative effects compared with tamoxifen. In this review, we summarize the preclinical and clinical studies evaluating endoxifen in the context of breast and other solid tumors, the potential benefits of endoxifen in bone, as well as its emerging role as an antimanic agent in bipolar disorder. In total, the summarized body of literature provides compelling arguments for the ongoing development of Z-endoxifen as a novel drug for multiple indications.

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

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

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.

Divergence from osteoporosis screening guidelines in older breast cancer patients treated with anti-estrogen therapy: A population-based cohort study

PURPOSE

Older Breast Cancer (BC) survivors are an increased risk of osteoporosis due to natural aging and long-term cancer treatment-related toxicity. It is well known that anti-estrogen therapy (AET), especially aromatase inhibitors (AI), is associated with rapid bone loss and thus increases the risk of osteoporosis. This study characterizes patterns and predictors of receiving guideline-recommended bone densitometry (BD) screening at AET initiation.

METHODS

A retrospective cohort study (1998-2012) of all women ≥65 years of age initiating AET was designed using claims data from Quebec's universal health care. Associations with BD screening were estimated using a generalized estimating equations regression model, adjusting for clustering of patients within physicians.

RESULTS

Among 16,480 women initiating AET, 36.1% received a baseline BD. Among AI users, the rate was 58.4%. In the multivariate analysis, age, lower socioeconomic status, tamoxifen use, lack of periodic health exam and having a general practitioner as the AET prescriber were associated with lower odds of BD screening. In terms of quality of care-related variables, lack of guideline-appropriate radiotherapy (OR: 0.69 (95% CI, 0.57-0.83), or chemotherapy consideration (0.82 (95% CI, 0.71-0.94)) and non-adherence to AET (0.76 (95% CI, 0.68-0.84)) were associated with lower odds of receiving BD screening. Women diagnosed with BC after 2003 had significantly better odds of being screened.

CONCLUSION

Despite an increase in rates since 2003, BD screening remains suboptimal, especially for women at higher risk of osteoporosis. Coordination of health care and service-delivery monitoring can potentially optimize long-term management of treatment-related toxicity in older BC survivors.

Low bone mineral density is associated with breast cancer in postmenopausal women: a case-control study

OBJECTIVE

To evaluate risk factors for low bone mineral density (BMD) in postmenopausal breast cancer survivors compared with postmenopausal women without breast cancer (controls).

METHOD

In this study, 112 breast cancer survivors were compared to 224 women (controls). Inclusion criteria were amenorrhea ≥12 months, age 45-75 years, treated for breast cancer, and metastasis-free for at least 5 years. The control group consisted of women without breast cancer, matched by age and menopause status (in a proportion of 1: 2 as sample calculation). The risk factors for low BMD (osteopenia/osteoporosis) were assessed by interview. BMD was measured by dual-energy X-ray absorptiometry in the lumbar spine (L1-L4) and femoral neck. Logistic regression models (odds ratio, OR) were used to identify factors associated with low BMD.

RESULTS

The mean (standard deviation) age of breast cancer survivors was 61.3 (9.7) years, with a mean follow-up of 10.2 (3.9) years. These women had a higher incidence of osteopenia (45.1%) and osteoporosis (22.3%) in the femoral neck than controls (39.3% and 9.0%, respectively) (p = 0.0005). Lumbar spine BMD did not differ between groups (p = 0.332). Univariate analysis adjusted for age and time since menopause revealed that chemotherapy (OR 6.90; 95% confidence interval (CI) 5.57-9.77) was associated with a higher risk of low BMD. Contrarily, regular physical exercise (OR 0.24; 95% CI 0.06-0.98) and a body mass index ≥30 kg/m² (OR 0.09; 95% CI 0.02-0.37) reduced the risk among breast cancer survivors.

CONCLUSION

Postmenopausal breast cancer survivors had a higher incidence of osteopenia and osteoporosis in the femoral neck than women without breast cancer. A history of chemotherapy was a risk factor for low BMD, whereas regular physical activity and high body mass index reduced the risk among breast cancer survivors.

Bone Density Screening in Postmenopausal Women With Early-Stage Breast Cancer Treated With Aromatase Inhibitors

PURPOSE

In postmenopausal women with breast cancer treated with aromatase inhibitors (AIs), most expert panels advise baseline bone mineral density testing with a dual-energy x-ray absorptiometry (DXA) scan repeated every 1 to 2 years. How often this recommendation is followed is unclear.

METHODS

We performed a retrospective analysis of women with stage I to III breast cancer who started AI therapy from January 1, 2008, to December 31, 2010, with follow-up through December 31, 2012, by using the SEER-Medicare database. Selection criteria included AI use for ≥ 6 months and no recent osteoporosis diagnosis or bisphosphonate use. We used multivariable logistic regression to investigate associations between patient characteristics and receipt of a baseline DXA scan. In patients who continued AI treatment, we assessed rates of follow-up scans.

RESULTS

In the sample of 2,409 patients (median age, 74 years), 51.0% received a baseline DXA scan. Demographic characteristics associated with the absence of a baseline DXA scan were older age (85 to 94 years v 67 to 69 years; odds ratio [OR], 0.62; 95% CI, 0.42 to 0.92) and black v white race (OR, 0.68; 95% CI, 0.47 to 0.97). Among patients who underwent a baseline DXA scan and continued AI for 3 years, 28.0% had a repeat DXA scan within 2 years and 65.9% within 3 years. In aggregate, of the 1,164 patients who continued with AI treatment for 3 years, only 34.5% had both a baseline and at least one DXA scan during the 3-year follow-up period.

CONCLUSION

The majority of older Medicare beneficiaries with breast cancer treated with AIs do not undergo appropriate bone mineral density evaluation.

Emerging drugs for the treatment of bone metastasis

INTRODUCTION

Bone metastases are virtually incurable resulting in significant disease morbidity, reduced quality of life and mortality. Bone provides a unique microenvironment whose local interactions with tumor cells offer novel targets for therapeutic interventions. Increased understanding of the pathogenesis of bone disease has led to the discovery and clinical utility of bone-targeted agents other than bisphosphonates and denosumab, currently, the standard of care in this setting.

AREAS COVERED

In this review, we present the recent advances in molecular targeted therapies focusing on therapies that inhibit bone resorption and/or stimulate bone formation and novel anti-tumoral agents that exerts significant effects on skeletal metastases, nowadays available in clinical practice or in phase of development.

EXPERT OPINION

New emergent bone target therapies radium-223, mTOR inhibitors, anti-androgens have demonstrated the ability to increase overall survival in bone metastatic patients, other compounds, such as ET-1 and SRC inhibitors, up to now failed to clearly confirm in clinical trials their promising preclinical data.

A comprehensive review of metabolic syndrome affecting erectile dysfunction

INTRODUCTION

Metabolic syndrome (MetS) is the most important public health issue threatening the health of men and women all over the world. Its current prevalence (i.e., approximately 30%) is continuously increasing. MetS by itself is considered a risk factor for erectile dysfunction (ED).

AIM

To focus on the definition epidemiology, pathogenesis, and possible mechanistic links between MetS and ED in order to provide guidelines for treating such individuals.

METHODS

The search strategies yielded total records screened from PubMed.

MAIN OUTCOME MEASURES

Regardless of the definition, MetS consists of insulin resistance, hypertension, dyslipidemia, and obesity. MetS is not an end disease but is a disorder of energy utilization and storage.

RESULTS

The prevalence of ED in patients with MetS is almost twice than in those without MetS, and about 40% of patients with ED have MetS. An important mechanism linking MetS and ED is hypogonadism.

CONCLUSIONS

Recognizing through ED, underlying conditions such as hypogonadism, diabetes and MetS might be a useful motivation for men to improve their health-related choices. The clinical management of MetS can be done by therapeutic interventions that include lifestyle modifications, hormone replacement alone or in combination with phosphodiesterase 5 inhibitors, and other pharmacological treatments.

Bone health care for patients with prostate cancer receiving androgen deprivation therapy

Patients with prostate cancer often receive androgen deprivation therapy (ADT) as part of their treatment regimen. However, treatment with ADT causes multiple side effects, including reduced bone mineral density (BMD), lower lean body mass, and a higher risk for fractures. Several organizations provide clinical practice guidelines for osteoporosis screening, prevention, and treatment in this population, but adherence to these guidelines remains low. Areas for improvement in provider adherence include baseline and follow-up BMD testing, as well as counseling regarding healthy bone behaviors such as calcium/vitamin D intake, lifestyle changes, and physical exercise. Comparison of osteoporosis care in breast cancer and non-oncology populations shows that suboptimal bone health care is not isolated to prostate cancer. A summary of the literature examining improvements in patient adherence and provider delivery of bone health care is included in this review, but high-quality studies are lacking. Patients may be the most receptive to written educational information delivered at or near the time of ADT initiation. Involvement of a primary care practitioner and oncologist in care delivery is associated with higher BMD test use. Institution-level programs that automatically initiate osteoporosis screening and management may be effective at reducing the incidence of hip fracture. Lastly, suggestions are provided for future approaches to knowledge translation and quality of care studies to improve bone health.

The effects of a novel hormonal breast cancer therapy, endoxifen, on the mouse skeleton

Endoxifen has recently been identified as the predominant active metabolite of tamoxifen and is currently being developed as a novel hormonal therapy for the treatment of endocrine sensitive breast cancer. Based on past studies in breast cancer cells and model systems, endoxifen classically functions as an anti-estrogenic compound. Since estrogen and estrogen receptors play critical roles in mediating bone homeostasis, and endoxifen is currently being implemented as a novel breast cancer therapy, we sought to comprehensively characterize the in vivo effects of endoxifen on the mouse skeleton. Two month old ovariectomized C57BL/6 mice were treated with vehicle or 50 mg/kg/day endoxifen hydrochloride via oral gavage for 45 days. Animals were analyzed by dual-energy x-ray absorptiometry, peripheral quantitative computed tomography, micro-computed tomography and histomorphometry. Serum from control and endoxifen treated mice was evaluated for bone resorption and bone formation markers. Gene expression changes were monitored in osteoblasts, osteoclasts and the cortical shells of long bones from endoxifen treated mice and in a human fetal osteoblast cell line. Endoxifen treatment led to significantly higher bone mineral density and bone mineral content throughout the skeleton relative to control animals. Endoxifen treatment also resulted in increased numbers of osteoblasts and osteoclasts per tissue area, which was corroborated by increased serum levels of bone formation and resorption markers. Finally, endoxifen induced the expression of osteoblast, osteoclast and osteocyte marker genes. These studies are the first to examine the in vivo and in vitro impacts of endoxifen on bone and our results demonstrate that endoxifen increases cancellous as well as cortical bone mass in ovariectomized mice, effects that may have implications for postmenopausal breast cancer patients.

Aromatase inhibitors for the treatment of endometriosis

OBJECTIVE

To review the use of aromatase inhibitors (AIs) for the treatment of endometriosis.

DESIGN

Literature review.

CONCLUSION(S)

Most studies show that in reproductive-age women, the combination of AI with conventional therapy alleviates endometriosis-related pain. In postmenopausal women, using an AI alone has been shown to be an effective treatment, although more studies are needed in this subgroup. Side effects of using AIs appear to be tolerable in most women, although special consideration should be given to monitoring bone mineral density. More studies need to be done examining pregnancy rates and outcomes after AI treatment for endometriosis. In addition, larger randomized clinical trials using AIs need to be done. In summary, AIs may be effective in treating endometriosis-related chronic pelvic pain in both reproductive-age and postmenopausal women.