Fracture risk in women with breast cancer: a population-based study

Influence of the anchor system on body sway in women affected and not affected by lymphedema secondary to breast cancer: A cross-sectional study

BACKGROUND

Postural control is an essential ability for functional independence modified by therapeutic approaches and morbidities secondary to breast cancer. The anchor system enables additional haptic perception of body position in front of the support base and can be used alone or in conjunction with sensorimotor training.

RESEARCH QUESTION

What is the influence of the anchor system, through different manual contacts on the upper limb, on body sway in women affected and not affected by lymphedema secondary to breast cancer treatment?

METHODS

Cross-sectional study involving 60 women homogeneously distributed to the group affected by lymphedema (GAL), with a mean age of 62.53 (SD = 12.54) years and upper limb volume difference (ULVD = Ipsilateral - Contralateral) of 636.21 (SD = 387.94) cm3, and group not affected by lymphedema (GNAL), with a mean age of 57.24 (SD = 11.43) years and ULVD of -8.91 (SD = 121.72) cm3. Baropodometry was used to assess body sway, through the presence and absence of the visual sense, associated with different manual contacts of the anchor system designated absence, simulation of use, unilateral and bilateral contact. The Shapiro-Wilk and Student's T-tests with Bonferroni Post-Hoc were used in the statistical analysis (p ≤ 0.05).

RESULTS

The GAL expressed non-significant values compared to the GNAL in the absence of visual sense and non-use of the anchor system. The unilateral contact of the anchor system on the preferred upper limb in the presence of the visual sense, and bilateral contact of the anchor system in the presence and absence of the visual sense promoted a significant reduction of body sway in both groups.

SIGNIFICANCE

In breast cancer survivors, the anchor system with bilateral contact effectively maintains postural control, regardless of the visual sense and the volume of the upper limb.

Association between tamoxifen and incidence of osteoporosis in Korean patients with ductal carcinoma in situ

Introduction

The partial estrogen-agonist action of tamoxifen on bone receptors has beneficial effects on bone mineral density. However, in premenopausal women, the use of tamoxifen causes systemic estrogen depletion, which has detrimental effects on bone health. We aim to investigate the association between tamoxifen and osteoporosis in the real world using data from a longitudinal nationwide cohort of Korean patients.

Methods

Data were collected from the National Health Insurance claims database in South Korea. Osteoporosis was defined by diagnostic codes accompanying prescription data for osteoporosis. The cumulative incidence was analyzed by Kaplan-Meier survival curves and the risk factors were analyzed using a multivariable Cox proportional hazard regression model.

Results

Between 2009 and 2015, of the 4,654 women with ductal carcinoma in situ (DCIS) without prior osteoporosis, 2,970 were prescribed tamoxifen and 1,684 were not. A total of 356 DCIS survivors were later diagnosed with osteoporosis during a median follow-up period of 84 months. In the overall population, tamoxifen was associated with a low risk of osteoporosis, before and after propensity matching adjusted for age, operation type, and comorbidities (before matching, hazard ratio [HR]=0.69, 95% confidence interval [CI]=0.559-0.851, p<0.001; after matching, HR=0.664, 95% CI=0.513-0.858, p=0.002). In the subgroup analysis, findings were consistent in postmenopausal women but were not evident in the younger age group.

Conclusion

In a nationwide cohort study, a low risk of osteoporosis was associated with the use of tamoxifen. The protective effect of tamoxifen was more profound in older women and was not related to the incidence of osteoporosis in younger women.

Fracture risk among patients with cancer compared to individuals without cancer: a population-based study

BACKGROUND

Patients with cancer may be at increased risk of osteoporosis and fracture; however, gaps exist in the existing literature and the association between cancer and fracture requires further examination.

METHODS

We conducted a population-based cohort study of Ontario patients with cancer (breast, prostate, lung, gastrointestinal, haematologic) diagnosed between January 2007 to December 2018 and 1:1 matched non-cancer controls. The primary outcome was incident fracture (end of follow-up December 2019). Multivariable Cox regression analysis was used to estimate the relative fracture risk with sensitivity analysis accounting for competing risk of death.

RESULTS

Among 172,963 cancer patients with non-cancer controls, 70.6% of patients with cancer were <65 years old, 58% were female, and 9375 and 8141 fracture events were observed in the cancer and non-cancer group, respectively (median follow-up 6.5 years). Compared to non-cancer controls, patients with cancer had higher risk of fracture (adjusted HR [aHR] 1.10, 95% CI 1.07-1.14, p < 0.0001), which was also observed for both solid (aHR 1.09, 95% CI 1.05-1.13, p < 0.0001) and haematologic cancers (aHR 1.20, 95% CI 1.10-1.31, p < 0.0001). Sensitivity analysis accounting for competing risk of death did not change these findings.

CONCLUSIONS

Our study indicates that patients with cancer are at modest risk of fractures compared to non-cancer controls.

Is there an association between breast cancer and incident adhesive capsulitis of the shoulder? A retrospective cohort study from Germany

PURPOSE

Preliminary data suggest that women with breast cancer are at particularly high risk of adhesive capsulitis of the shoulder. Therefore, this study aimed to investigate the potential association between breast cancer and adhesive capsulitis in adults from Germany.

METHODS

This retrospective cohort study included all women aged ≥ 18 years who were diagnosed for the first time with breast cancer in one of 1,274 general practices in Germany between January 2000 and December 2018 (index date). Women without breast cancer were matched (1:1) to those with breast cancer using a propensity score based on age at the index date, index year, and the average number of medical consultations per year during the follow-up. In women without breast cancer, the index date was a randomly selected visit date between 2000 and 2018. The association between breast cancer and the 10-year incidence of adhesive capsulitis was studied using Kaplan-Meier curves and a Cox regression model adjusted for age and several comorbidities.

RESULTS

There were 52,524 women included in this study (mean [SD] age 64.2 [12.9] years). The 10-year incidence of adhesive capsulitis was 3.6% in both the group with and the group without breast cancer (log-rank p-value = 0.317). The Cox regression analysis further showed no significant association between breast cancer and adhesive capsulitis (HR = 0.96, 95% CI = 0.86-1.08).

CONCLUSION

In this sample of women from Germany, breast cancer was not significantly associated with adhesive capsulitis. Although the present preliminary findings are reassuring, general practitioners should regularly assess shoulder function in breast cancer survivors.

Fracture risk and assessment in adults with cancer

Individuals with cancer face unique risk factors for osteoporosis and fractures. Clinicians must consider the additive effects of cancer-specific factors, including treatment-induced bone loss, and premorbid fracture risk, utilizing FRAX score and bone mineral densitometry when available. Pharmacologic therapy should be offered as per cancer-specific guidelines, when available, or local general osteoporosis guidelines informed by clinical judgment and patient preferences. Our objective was to review and summarize the epidemiologic burden of osteoporotic fracture risk and fracture risk assessment in adults with cancer, and recommended treatment thresholds for cancer treatment-induced bone loss, with specific focus on breast, prostate, thyroid, gynecological, multiple myeloma, and hematopoietic stem cell transplant. This narrative review was informed by PubMed searches to July 25, 2022, that combined terms for cancer, stem cell transplantation, fracture, bone mineral density (BMD), trabecular bone score, FRAX, Garvan nomogram or fracture risk calculator, QFracture, prediction, and risk factors. The literature informs that cancer can impact bone health in numerous ways, leading to both systemic and localized decreases in BMD. Many cancer treatments can have detrimental effects on bone health. In particular, hormone deprivation therapies for hormone-responsive cancers such as breast cancer and prostate cancer, and hematopoietic stem cell transplant for hematologic malignancies, adversely affect bone turnover, resulting in osteoporosis and fractures. Surgical treatments such as hysterectomy with bilateral salpingo-oophorectomy for gynecological cancers can also lead to deleterious effects on bone health. Radiation therapy is well documented to cause localized bone loss and fractures. Few studies have validated the use of fracture risk prediction tools in the cancer population. Guidelines on cancer-specific treatment thresholds are limited, and major knowledge gaps still exist in fracture risk and fracture risk assessment in patients with cancer. Despite the limitations of current knowledge on fracture risk assessment and treatment thresholds in patients with cancer, clinicians must consider the additive effects of bone damaging factors to which these patients are exposed and their premorbid fracture risk profile. Pharmacologic treatment should be offered as per cancer-specific guidelines when available, or per local general osteoporosis guidelines, in accordance with clinical judgment and patient preferences.

Fracture risk in breast cancer: Does obesity have an effect? A scoping review

Background

Metastasis from breast cancer (BC) has a predilection for the skeleton. Due to its osteolytic nature, breast cancer bone metastasis (BCBM) appears to increase fracture risk. The association between obesity and its effect on bone seems to be skeletal site-specific. The incidence of pathological fractures often involves the axial skeleton even though the most debilitating effects of fractures are caused in the appendicular skeleton. Whether obesity increases fracture risk in BCBM remains inconclusive, however. At present, there is no literature that examines the effects of obesity on BCBM, and fracture risk are as such we sought to determine the effect of obesity on fracture risk in BC. This is the focus of the review.

Objectives

This scoping review aims to examine the link between fracture outcomes of women with BC and obesity as reported by Body Mass Index (BMI). The purpose of this study is to determine if current literature suggests obesity increases fracture risk in women with BC.

Design

We conducted a comprehensive literature search for breast cancer bone metastasis, obesity, and fracture risk in PubMed, Cochrane Library, NIH Clinical Trials, and OpenGrey. Articles that included BC, obesity, and fracture risk were included for analysis. Data were pooled, charted, analysed, and reported according to PRISMA-ScR standards.

Data synthesis and results

Each outcome was stratified by BMI (obese or non-obese) status in women with breast cancer. Five studies were eligible for analysis and relevant data was charted to allow results to be synthesised. We found four out of five studies reported a positive association between BMI and fracture risk in females with breast cancer.

Conclusions

We found a potential association of obesity and fracture risk in breast cancer. However, as we conducted this study it was evident that there is limited literature available on this topic and none for breast cancer bone metastasis. This poses an important direction for future research. Larger and robust pre-clinical and clinical randomized control trials are needed to better understand the relation between obesity and metastatic breast cancer.

Analyses of the association between breast cancer and osteoporosis/fracture history: a cross-sectional study using KoGES HEXA data

We performed a nationwide, population-based cohort study to evaluate the risk of osteoporosis and osteoporotic fracture in patients with breast cancer using the data from Korean Genome and Epidemiology Study (KoGES) and concluded that Korean women with breast cancer had a higher risk of osteoporosis than healthy women, regardless of age.

PURPOSE

This study aimed to evaluate the association between breast cancer and the occurrence of osteoporosis and osteoporotic fracture using data from the Korean Genome and Epidemiology Study (KoGES).

METHODS

Using the national KoGES health examinee (HEXA) data consisting of data from urban resident participants ≥ 40 years old, we extracted data for patients with breast cancer (n = 1080) and for control participants (n = 106,993); we then analyzed the occurrence of osteoporosis and osteoporotic fracture at baseline from 2004 to 2013 and during follow-up from 2012 to 2016. A logistic regression model was used to analyze the odds ratios (ORs) and the 95% confidence intervals (CIs). Subgroup analysis was performed based on age (younger group aged ≤ 51 years old; older group aged ≥ 52 years old).

RESULTS

The ORs (95% CIs) for osteoporosis and osteoporotic fracture were 1.54 (95% CI = 1.28-1.84, P < 0.001) and 1.01 (95% CI = 0.82-1.23, P = 0.949), respectively, in the breast cancer group. In the subgroup analysis based on age, the ORs (95% CIs) for osteoporosis were 2.41 (95% CI = 1.70-3.43, P < 0.001) in the younger group and 1.33 (95% CI = 1.08-1.64, P = 0.007) in the older group of breast cancer patients. The ORs (95% CIs) for osteoporotic fracture were 1.15 (95% CI = 0.81-1.63, P = 0.441) in the younger group and 0.95 (95% CI = 0.74-1.21, P = 0.661) in the older group of breast cancer patients.

CONCLUSION

We concluded that Korean women with breast cancer had a higher risk of osteoporosis than healthy women, but the same finding was not observed for osteoporotic fracture, regardless of age.

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.

Osteoporotic Fractures of the Spine, Hip, and Other Locations after Adjuvant Endocrine Therapy with Aromatase Inhibitors in Breast Cancer Patients: a Meta-analysis

BACKGROUND

Aromatase inhibitors (AIs) play an important role in the endocrine therapy of postmenopausal breast cancer patients, with a recent tendency to extend the duration of their use. However, AIs may increase the risk of osteoporotic bone fractures. This meta-analysis evaluated the risk of osteoporotic fractures of the hip, spine, and other locations in breast cancer patients using AIs.

METHODS

We performed a systematic search to identify randomized controlled clinical trials that investigated osteoporotic fractures in breast cancer patients on AI therapy. The main outcomes were the incidence and risk of osteoporotic fractures in general and of hip, vertebral, and non-vertebral fractures in AI users and controls.

RESULTS

The systematic review found a total of 30 randomized controlled trials including 117,974 participants. The meta-analysis showed a higher incidence of osteoporotic fracture in AI users: The crude risk ratio for all osteoporotic fractures was 1.35 (95% confidence interval [CI], 1.29-1.42; P < 0.001), for hip fractures 1.18 (95% CI, 1.02-1.35; P < 0.001), for vertebral fractures 1.84 (95% CI, 1.36-2.49; P < 0.001), and for non-vertebral fractures 1.18 (95% CI, 1.02-1.35; P < 0.001), respectively, compared to the controls.

CONCLUSION

Our meta-analysis suggested an increased risk of osteoporotic fractures for AI therapy in patients with breast cancer that was most expressed for vertebral fractures. Breast cancer patients on AIs need to be monitored for osteoporosis and osteoporotic fractures, and active prevention measures should be implemented.

The impact of arm lymphedema on healthcare utilization during long-term breast cancer survivorship: a population-based cohort study

PURPOSE

Cancer treatment-related late effects degrade survivors' quality of life, independence, and societal integration, yet may be ameliorated, or even reversed, with effective care. Unfortunately, survivors inconsistently receive this care and the impact on their healthcare utilization is unknown. We sought to estimate differences in utilization between breast cancer (BC) survivors with and without upper extremity lymphedema; a common, remediable late effect.

METHODS

We conducted a population-based, retrospective longitudinal cohort study of survivors with incident BC diagnosed from January 1, 1990, through December 31, 2010. HC utilization was characterized using the Berenson-Eggers Type of Service (BETOS) categories. Outcomes included overall healthcare utilization as well as its compartmentalization into the BETOS categories of (1) Evaluation and management, (2) Procedures, (3) Imaging, (4) Tests, (5) Durable medical equipment, (6) Physical/occupational therapy, (7) Other, and (8) Exceptions/Unclassified.

RESULTS

The cohort included 1906 subjects of which 94% (1800) had records meeting the inclusion criteria. Mean follow-up per survivor was 12.8 years (mean, 11, range 1-25 years). Analysis revealed that (1) survivors with BC-associated lymphedema used > 30% more services annually; (2) their increased utilization lessened but persisted for at least 10 years after diagnosis; and (3) this finding of increased utilization extends across all BETOS categories, is further amplified as BMI increases, and cannot be explained solely by lymphedema-directed care.

CONCLUSIONS

BC-related lymphedema appears to be an important driver of survivors' healthcare utilization and guideline-concordant activities to reduce its incidence and severity may be cost neutral or saving.

IMPLICATIONS FOR CANCER SURVIVORS

Early detection and effective management of cancer-related late effects like lymphedema may reduce survivors' healthcare needs in the decades that follow their cancer treatment.

Risk of Osteoporotic Fracture in Patients with Breast Cancer: Meta-Analysis

Background

The fracture risk induced by anti-estrogen therapy in patients with breast cancer remains controversial. The aim of this study was to perform a meta-analysis and systematic review to evaluate the risk of osteoporotic fracture in patients with breast cancer.

Methods

A systematic search was performed to identify studies that included any osteoporotic fracture (hip fracture and vertebral fracture) in patients breast cancer. Main outcome measures were occurrence and risk of osteoporotic fractures including hip and vertebral fractures in patients and controls.

Results

A systematic search yielded a total of 4 studies that included osteoporotic fracture outcomes in patients with breast cancer. Meta-analysis showed a higher risk of osteoporotic fracture in patients with breast cancer. Analysis of these 4 studies involving a total of 127,722 (23,821 cases and 103,901 controls) patients showed that the incidence of osteoporotic fractures was higher in the breast cancer group than in the control group. The pooled estimate of crude relative risk for osteoporotic fracture was 1.35 (95% confidence interval, 1.29-1.42; P<0.001).

Conclusions

Although studies were limited by a small number, results suggested a possible association between anti-estrogen therapy and increased risk of osteoporotic fractures in patients with breast cancer.

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

PURPOSE

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

METHODS

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

RESULTS

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

RECOMMENDATIONS

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

Long-Term Endocrine and Metabolic Consequences of Cancer Treatment: A Systematic Review

The number of patients surviving ≥5 years after initial cancer diagnosis has significantly increased during the last decades due to considerable improvements in the treatment of many cancer entities. A negative consequence of this is that the emergence of long-term sequelae and endocrine disorders account for a high proportion of these. These late effects can occur decades after cancer treatment and affect up to 50% of childhood cancer survivors. Multiple predisposing factors for endocrine late effects have been identified, including radiation, sex, and age at the time of diagnosis. A systematic literature search has been conducted using the PubMed database to offer a detailed overview of the spectrum of late endocrine disorders following oncological treatment. Most data are based on late effects of treatment in former childhood cancer patients for whom specific guidelines and recommendations already exist, whereas current knowledge concerning late effects in adult-onset cancer survivors is much less clear. Endocrine sequelae of cancer therapy include functional alterations in hypothalamic-pituitary, thyroid, parathyroid, adrenal, and gonadal regulation as well as bone and metabolic complications. Surgery, radiotherapy, chemotherapy, and immunotherapy all contribute to these sequelae. Following irradiation, endocrine organs such as the thyroid are also at risk for subsequent malignancies. Although diagnosis and management of functional and neoplastic long-term consequences of cancer therapy are comparable to other causes of endocrine disorders, cancer survivors need individually structured follow-up care in specialized surveillance centers to improve care for this rapidly growing group of patients.

The tamoxifen paradox-influence of adjuvant tamoxifen on fracture risk in pre- and postmenopausal women with breast cancer

Our data demonstrate that tamoxifen does not reduce fracture risk. Close surveillance is necessary to prevent bone loss in premenopausal women with breast cancer upon treatment initiation.

INTRODUCTION

Endocrine treatment of breast cancer may interfere with bone turnover and influence fracture risk.

METHODS

Out of a cohort of almost 5 million patients in total, we identified 5520 women between 18 and 90 years of age with breast cancer receiving tamoxifen, matched them with 5520 healthy controls using the Disease Analyzer Database, and investigated the fracture risk.

RESULTS

We found a cumulative incidence of fractures of 6.3% in patients aged between 18 and 50 years (n = 3634) treated with tamoxifen versus a cumulative incidence of 3.6% in the control group (p < 0.001). As such, the risk of fracture was 75% higher for patients receiving tamoxifen than that for healthy controls (HR 1.75; 95% CI 1.25-2.48). With regard to patients aged between 55 and 90 years (n = 7406), the cumulative incidence of fractures in patients treated with tamoxifen was 10.1% compared to 9.3% in the control group (p = 0.740), i.e., there was no significant difference between the two groups (HR 0.97; 95% CI 0.81-1.16).

CONCLUSIONS

Compared to healthy controls, premenopausal women with breast cancer treated with tamoxifen showed an increased risk of fracture, while postmenopausal women on tamoxifen did not show any risk reduction.

Increased risk of fractures in patients with polycystic ovary syndrome: a nationwide population-based retrospective cohort study

Polycystic ovary syndrome (PCOS) is a complex disorder; various features of this disorder may influence bone metabolism and skeletal mass. The contribution of PCOS to lower bone mineral density has been recognized. However, the impact of PCOS on the long-term risks for fractures remains inconclusive. The aim of this study was to determine the risk of overall fracture and fractures at different anatomic sites in patients with PCOS. Using a nationwide health insurance claims database, we included 11,106 subjects, aged 15-80 years, with newly diagnosed PCOS (ICD-9-CM: 254.4X) during 2000-2012. Patients with PCOS and respective age-matched (1:4) controls without PCOS were enrolled. The occurrence of fracture was monitored until the end of 2013. Cox regression and computed hazard ratios (HR) with 95% confidence intervals (95% CI) were used to determine the risk of PCOS among women with fractures. The PCOS and non-PCOS groups were comprised of 11,106 patients with PCOS and 44,424 participants without PCOS, respectively. Patients with PCOS had a higher incidence of any fractures compared with non-PCOS group (10.16 versus 8.07 per 1000 person-years) and a greater risk of any fractures [adjusted hazard ratio (aHR) = 1.23, 95% CI = 1.13-1.33], osteoporotic fractures (aHR = 1.33, 95% CI = 1.15-1.54), spine fractures (aHR = 1.36, 95% CI = 1.11-1.66) and forearm fractures (aHR = 1.39, 95% CI = 1.07-1.80), but the risk for femur or hip fracture, humerus, wrist and non-osteoporotic fractures were not increased. In conclusion, the PCOS group had a higher occurrence rate of fractures than the non-PCOS group. These results provide evidence for the adverse effects of PCOS on the risk of fractures.

Risk of fractures at different anatomic sites in patients with irritable bowel syndrome: a nationwide population-based cohort study

This study was to investigate the fracture risk of irritable bowel syndrome (IBS) in comparison with non-IBS group. Our results found that IBS group has increased risk for fracture, in particular of the spine, forearm, hip, and hand.

INTRODUCTION

Patients with IBS might also be at increased risk of osteoporosis and osteoporotic fractures. Up to now, the association between IBS and the risk of fractures at different anatomic sites occurrences is not completely clear. We conducted a population-based cohort analysis to investigate the fracture risk of IBS in comparison with non-IBS group.

METHODS

We identified 29,505 adults aged ≥ 20 years with newly diagnosed IBS using the Taiwan National Health Insurance Research Database in 2000-2012. A comparison group was constructed of patients without IBS who were matched according to gender and age. The occurrence of fracture was monitored until the end of 2013. We analyzed the risk of fracture events to occur in IBS by using Cox proportional hazards regression models.

RESULTS

Patients with IBS had a higher incidence of osteoporotic fractures compared with the non-IBS group (12.34 versus 9.45 per 1000 person-years) and an increased risk of osteoporotic fractures (adjusted hazard ratio [aHR] = 1.27, 95% confidence interval [CI] = 1.20-1.35). Site-specific analysis showed that the IBS group had a higher risk of fractures for spine, forearm, hip, and hand than did the non-IBS group. With further stratification for gender and age, a higher aHR value for osteoporotic fractures in the IBS group was seen across all age groups in males, but seen in elderly females. In addition, female, elderly, low income, hypertension, coronary artery disease, cerebrovascular disease, and depressive disorders as independent osteoporotic fracture risk factors in IBS patients.

CONCLUSIONS

The IBS is considered as a risk factor for osteoporotic fractures, particularly in female individuals and fracture sites located at the spine, forearm, hip, and hand.

Vertebral fractures among breast cancer survivors in China: a cross-sectional study of prevalence and health services gaps

BACKGROUND

Breast cancer survivors are at high risk for fracture due to cancer treatment-induced bone loss, however, data is scarce regarding the scope of this problem from an epidemiologic and health services perspective among Chinese women with breast cancer.

METHODS

We designed a cross-sectional study comparing prevalence of vertebral fractures among age- and BMI-matched women from two cohorts. Women in the Breast Cancer Survivors cohort were enrolled from a large cancer hospital in Beijing. Eligibility criteria included age 50-70 years, initiation of treatment for breast cancer at least 5 years prior to enrollment, and no history of metabolic bone disease or bone metastases. Data collected included sociodemographic characteristics; fracture-related risk factors, screening and preventive measures; breast cancer history; and thoracolumbar x-ray. The matched comparator group was selected from participants enrolled in the Peking Vertebral Fracture Study, an independent cohort of healthy community-dwelling postmenopausal women from Beijing.

RESULTS

Two hundred breast cancer survivors were enrolled (mean age 57.5 ± 4.9 years), and compared with 200 matched healthy women. Twenty-two (11%) vertebral fractures were identified among breast cancer survivors compared with 7 (3.5%) vertebral fractures in the comparison group, yielding an adjusted odds ratio for vertebral fracture of 4.16 (95%CI 1.69-10.21, p < 0.01). The majority had early stage (85.3%) and estrogen and/or progesterone receptor positive (84.6%) breast cancer. Approximately half of breast cancer survivors reported taking calcium supplements, 6.1% reported taking vitamin D supplements, and only 27% reported having a bone density scan since being diagnosed with breast cancer.

CONCLUSIONS

Despite a four-fold increased odds of prevalent vertebral fracture among Chinese breast cancer survivors in our study, rates of screening for osteoporosis and fracture risk were low reflecting a lack of standardization of care regarding cancer-treatment induced bone loss.

Incidence and predictors of osteoporotic fractures in patients with Barrett's oesophagus: a population-based nested case-control study

BACKGROUND

Proton pump inhibitors (PPI) are inconsistently associated with osteoporotic fractures. Barrett's oesophagus (BO) patients are treated with high PPI doses for prolonged periods, but there are limited data on the incidence of osteoporosis and fractures in this group pf patients.

AIM

To estimate the incidence of (and risk factors for) low bone mass (osteoporosis and/or osteopenia) related fractures in a population-based BO cohort.

METHODS

All subjects with BO and a diagnosis of osteoporosis and fractures were identified using Rochester Epidemiology Project resources. The incidence rates of all and osteoporotic fractures in these subjects were compared to an age- and gender similar population in Olmsted County to determine standardised incidence ratios (SIR). Predictors were assessed using Cox proportional hazards models.

RESULTS

Five hundred and twenty-one patients were included (median [IQR] age 61 [52, 72] years; 398 [76%] men) of whom 113 (21.7%) had fractures, and 46 (8.8%) had osteoporotic fractures. The incidence of all fractures and osteoporotic fractures was comparable to that of an age- and gender-matched population (SIR 1.09; 95% CI 0.92-1.29: SIR 1.05; 95% CI 0.85-1.29). PPI use, dose or duration of use was not associated with osteoporotic fracture risk (HR 0.87; 95% CI 0.12-6.39). Independent risk factors for osteoporotic fractures included older age, female gender and higher co-morbidity index.

CONCLUSIONS

The incidence of osteoporotic fractures was not increased in BO patients compared to the general population. In addition, PPI use was not associated with increased fracture risk regardless of the duration of therapy or dose.

Skeletal health in breast cancer survivors

Although some risk factors for breast cancer might be protective for osteoporosis, several cross-sectional studies have reported, nevertheless, that patients with breast cancer have a lower bone mass and potentially a higher incidence of fractures than expected. In any case, it appears that patients with breast cancer are not protected from osteoporosis, which provides further support for the recommendation that bone health is assessed after a diagnosis of breast cancer. Most adjuvant therapies will lead to increased bone loss and a higher fracture rate. Among the adjuvant therapy options for premenopausal patients with breast cancer, endocrine therapy (ovarian suppression) and chemotherapy can result in cancer treatment-induced bone loss (CTIBL) of up to 10% at the lumbar spine after one year. Antiresorptive therapies prevent CTIBL in premenopausal women with breast cancer. Most of the evidence demonstrating the efficacy of bisphosphonates in the prevention of CTIBL is derived from clinical trials with zoledronic acid. The addition of zoledronic acid 4mg per six months to adjuvant endocrine therapy maintained and even increased bone mass during a 3-year treatment period and significantly improved disease-free survival in a population of young women who underwent menopause due to the adjuvant treatment. The major contributor to bone loss in the adjuvant treatment of breast cancer in postmenopausal women is the use of aromatase inhibitors (AIs). Oncology trials have underestimated the fracture risk in the setting of AI-induced bone loss. In the ABCSG-18 study, the only trial in which fracture incidence was the primary endpoint, the rate of clinical fractures was close to 10% after 3 years in the placebo group on AIs only. Bisphosphonates and denosumab at osteoporosis treatment doses can counteract AI-induced bone loss. In the ABCSG-18 trial, treatment with denosumab 60mg injection every 6 months reduced the risk of first clinical fracture relative to placebo by 50%. Current guidelines recommend antiresorptive therapy in patients with a baseline T score of <-2.0 or with two or more clinical risk factors for fracture. These recent guidelines will need to be updated, as similar significant protective effects were seen in women with either normal or low bone mass. Moreover, a formal meta-analysis of individual patient data from more than 18,000 women in 26 randomized trials of adjuvant zoledronic acid or clodronate treatment for early breast cancer revealed that bisphosphonates significantly reduced the risk of first distant recurrence in bone and the risk of breast cancer mortality, at least in postmenopausal women. Even though the increased risk of fracture during adjuvant treatment for breast cancer in postmenopausal women is notable, an enhanced risk of fracture in long-term survivors of breast cancer remains under debate. The most recent studies suggest that Caucasian breast cancer survivors do not have a significantly increased risk of osteoporotic fracture over the long term.

Management of Aromatase Inhibitor-Associated Bone Loss (AIBL) in postmenopausal women with hormone sensitive breast cancer: Joint position statement of the IOF, CABS, ECTS, IEG, ESCEO IMS, and SIOG

BACKGROUND

Several guidelines have been reported for bone-directed treatment in women with early breast cancer (EBC) for averting fractures, particularly during aromatase inhibitor (AI) therapy. Recently, a number of studies on additional fracture related risk factors, new treatment options as well as real world studies demonstrating a much higher fracture rate than suggested by randomized clinical controlled trials (RCTs). Therefore, this updated algorithm was developed to better assess fracture risk and direct treatment as a position statement of several interdisciplinary cancer and bone societies involved in the management of AI-associated bone loss (AIBL).

PATIENTS AND METHODS

A systematic literature review identified recent advances in the management of AIBL. Results with individual agents were assessed based on trial design, size, follow-up, and safety.

RESULTS

Several fracture related risk factors in patients with EBC were identified. Although, the FRAX algorithm includes fracture risk factors (RF) in addition to BMD, it does not seem to adequately address the effects of AIBL. Several antiresorptive agents can prevent and treat AIBL. However, concerns regarding compliance and long-term safety remain. Overall, the evidence for fracture prevention is strongest for denosumab 60 mg s.c. every 6 months. Additionally, recent studies as well as an individual patient data meta-analysis of all available randomized trial data support additional anticancer benefits from adjuvant bisphosphonate treatment in postmenopausal women with a 34% relative risk reduction in bone metastasis and 17% relative risk decrease in breast cancer mortality that needs to be taken into account when advising on management of AIBL.

CONCLUSIONS

In all patients initiating AI treatment, fracture risk should be assessed and recommendation with regard to exercise and calcium/vitamin D supplementation given. Bone-directed therapy should be given to all patients with a T-score<-2.0 or with a T-score of <-1.5 SD with one additional RF, or with ≥2 risk factors (without BMD) for the duration of AI treatment. Patients with T-score>-1.5 SD and no risk factors should be managed based on BMD loss during the first year and the local guidelines for postmenopausal osteoporosis. Compliance should be regularly assessed as well as BMD on treatment after 12 - 24 months. Furthermore, because of the decreased incidence of bone recurrence and breast cancer specific mortality, adjuvant bisphosphonates are recommended for all postmenopausal women at significant risk of disease recurrence.

Long-term effect of aromatase inhibitors on bone microarchitecture and macroarchitecture in non-osteoporotic postmenopausal women with breast cancer

In non-osteoporotic postmenopausal women with breast cancer, aromatase inhibitors (AIs) negatively affected bone mineral density (BMD), lumbar spine trabecular bone score (TBS) as a bone microarchitecture index, and hip geometry as a bone macroarchitecture index.

INTRODUCTION

AIs increase the risk of fracture in patients with breast cancer. Therefore, we aimed to evaluate the long-term skeletal effects of AIs in postmenopausal women with primary breast cancer.

METHODS

We performed a retrospective longitudinal observational study in non-osteoporotic patients with breast cancer who were treated with AIs for ≥3 years (T-score >-2.5). Patients with previous anti-osteoporosis treatment or those who were given bisphosphonate during AI treatment were excluded from the analysis. We serially assessed BMD, lumbar spine TBS, and hip geometry using dual-energy X-ray absorptiometry.

RESULTS

BMD significantly decreased from baseline to 5 years at the lumbar spine (-6.15%), femur neck (-7.12%), and total hip (-6.35%). Lumbar spine TBS also significantly decreased from baseline to 5 years (-2.12%); this change remained significant after adjusting for lumbar spine BMD. The annual loss of lumbar spine BMD and TBS slowed after 3 and 1 year of treatment, respectively, although there was a relatively constant loss of BMD at the femur neck and total hip for up to 4 years. The cross-sectional area, cross-sectional moment of inertia, minimal neck width, femur strength index, and section modulus significantly decreased, although the buckling ratio increased over the treatment period (all P < 0.001); these changes were independent of total hip BMD.

CONCLUSIONS

Long-term adjuvant AI treatment negatively influenced bone quality in addition to BMD in patients with breast cancer. This study suggests that early monitoring and management are needed in non-osteoporotic patients with breast cancer who are starting AIs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Differentiating the Causes of Spontaneous Rib Fracture After Breast Cancer

Spontaneous rib fracture after treatment for primary breast cancer is not uncommon. Although metastatic disease accounts for about 30% of spontaneous rib fractures and should constitute the first line of diagnostic investigation, other possible contributors include primary osteoporosis or secondary osteoporosis resulting from cancer treatments. Chemotherapy-induced menopause, aromatase inhibitors, radiation therapy, and long-term bisphosphonate use can all contribute to bone fragility, including spontaneous rib fractures in the latter 3. Drawing on recent breast cancer practice guidelines as well as population-based studies of fracture risk for women with a history of breast cancer and systematic reviews, this Perspective will provide an update on recent developments in understanding how to differentiate the possible reasons for non-traumatic rib fracture in women treated for breast cancer. In addition to describing the various possible causes of spontaneous rib fracture, the recommended medical and imaging procedures for differentiating among the potential causes will be presented.

Negative Impact of Aromatase Inhibitors on Proximal Femoral Bone Mass and Geometry in Postmenopausal Women with Breast Cancer

Aromatase inhibitors (AIs), the standard therapy for estrogen receptor- or progesterone receptor-positive breast cancer in postmenopausal women, lead to increased hip fractures in breast cancer patients. To investigate the mechanism of increased incidence of hip fractures in breast cancer patients treated with AIs, we evaluated bone mineral density (BMD) in the cortical and trabecular compartments and assessed femoral geometry using quantitative computed tomography (QCT) in breast cancer patients. In total, 249 early breast cancer patients who underwent QCT in their fifties (mean age 54.3 years) were retrospectively analyzed. Proximal femoral BMD and geometrical parameters were compared. In all regions of the proximal femur, cortical areal BMDs were lower in the AI group than in the non-AI group (p < 0.05). Cortical thickness of the femoral neck, trochanter, and total hip was significantly lower in the AI group compared with the non-AI group (p < 0.05). Analysis of the narrowest section of the femoral neck showed significantly thinner cortical bone and smaller cortical area in the AI group than in the non-AI group (p < 0.05), especially in the superoposterior quadrant. Bone strength parameters in the femoral neck, such as the section modulus and cross-sectional moment of inertia, were significantly lower in the AI group than in the non-AI group (p < 0.05). In conclusion, AI treatment in breast cancer patients is associated with deterioration of femoral cortical BMD and geometry, which could contribute in site-specific weakened bone strength and increased incidence of hip fractures.

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

Background

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

Methodology and Principal Findings

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

Conclusions and Significance

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

Breast cancer survivors are at an increased risk for osteoporotic fractures not explained by lower BMD: a retrospective analysis

Background:

An association between higher bone mineral density (BMD) and the diagnosis of breast cancer (BC) has been reported. Data on the risk of osteoporotic fractures in women with BC are conflicting.

Aims:

The objective of this study was to assess fracture risk adjusted for BMD in women with and without BC, and to assess whether fracture risk in BC patients is attributed to BMD or BC characteristics.

Methods:

Using electronic medical records of patients who underwent dual energy X-ray absorptiometry BMD studies at Soroka University Medical Center between February 2003 and March 2011, we identified women with subsequent diagnosis of osteoporotic fractures. BC status, demographic, health characteristics, BMD, and other laboratory findings were assessed. In BC patients data on grade, stage, and treatment were collected. Primary outcome was osteoporotic fracture, analyzed by Cox proportional hazards regression models.

Results:

During a median follow-up of 4.9 years in 17,110 women with BMD testing (658 BC patients), 1,193 women experienced an osteoporotic fracture (62 in BC and 1,131 in no-BC groups). In multivariate analysis adjusted for age, body mass index (BMI) and BMD, hazard ratio (HR) for any osteoporotic fracture in women with BC was 1.34 (P=0.026). BMD was similar among women with and without BC who fractured. BC patients who experienced an osteoporotic fracture had a trend for less-advanced BC, lower rates of chemotherapy treatment, and higher rates of tamoxifen treatment.

Conclusions:

BC survivors are at increased risk of an osteoporotic fracture, which is not explained by worse BMD. Chemotherapy or aromatase inhibitors did not contribute substantially to fracture risk among our BC survivors.

Minimal-trauma fracture in women with breast cancer surviving for at least 5 years from diagnosis

SUMMARY

Minimal-trauma fracture is an important issue in breast cancer survivors, especially rib fracture. The likelihood of fracture is affected by menopausal status and a diagnosis of osteoporosis prior to breast cancer. Most women reported at least one assessment of bone mineral density.

INTRODUCTION

We have investigated the self-reported frequency and pattern of minimal-trauma fracture (MTF) in breast cancer (BC) survivors at least 5 years from diagnosis, along with the use of bone mineral density (BMD) assessment.

METHODS

This study was carried out within the Bupa Health Foundation Health and Wellbeing After Breast Cancer Study which is a questionnaire-based prospective cohort study of 1683 women diagnosed with their first invasive breast cancer between 2004 and 2006 and followed for at least 5 years.

RESULTS

One thousand two hundred and five women, who remained free of recurrence or new breast cancer, completed the fifth annual follow-up. One hundred sixty-four (13.6%) reported at least one MTF. Rib fracture was the most common (52 fractures in 46 women). Compared with women who remained pre-/peri-menopausal, either being postmenopausal at diagnosis (OR 3.53, 95% Confidence Interval (CI) 1.09-11.44, p=0.036) or changing from pre- to postmenopausal during follow-up (OR 3.97, 95% CI 1.21-13.10, p=0.023) was associated with a higher likelihood of fracture, as was having a diagnosis of osteoporosis at the time of diagnosis (OR 1.74, 95% CI 1.00-2.99, p=0.047). Most women (64.9%) reported at least one BMD assessment.

CONCLUSIONS

Overall MTF is a problem for breast cancer survivors, with rib fracture a particular issue for women in our study. Both pre-existing osteoporosis and being postmenopausal are risk factors for subsequent MTF in women treated for breast cancer. Clinicians need to be mindful of fracture prevention medication in these groups.

Screening for osteoporosis after breast cancer: for whom, why and when

Osteoporosis and breast cancer are common diseases in postmenopausal women. Bone and the breast are both estrogenic dependent tissues and different surrogate markers for osteoporosis are opposite of those for the risk of breast cancer. In particular, numerous studies have reported a positive relationship between high bone mineral density (BMD) and a greater risk of breast cancer. On the other hand, most treatments in early breast cancer women including ovarian suppression treatments (chemotherapy, surgery or GnRH agonists) and aromatase inhibitor (AI) therapy induce a profound and rapid suppression of estrogen levels thereby increasing the rate of bone loss. Nevertheless, their impact on the risk of fracture is still questionable, especially in postmenopausal women with no osteoporosis at baseline. The purpose of this minireview is to examine the relationship between breast cancer and the risk of fracture and to discuss a screening strategy for osteoporosis after breast cancer.

Blood clot formation does not affect metastasis formation or tumor growth in a murine model of breast cancer

Cancer is associated with increased fracture risk, due either to metastasis or associated osteoporosis. After a fracture, blood clots form. Because proteins of the coagulation cascade and activated platelets promote cancer development, a fracture in patients with cancer often raises the question whether it is a pathologic fracture or whether the fracture itself might promote the formation of metastatic lesions. We therefore examined whether blood clot formation results in increased metastasis in a murine model of experimental breast cancer metastasis. For this purpose, a clot was surgically induced in the bone marrow of the left tibia of immundeficient mice. Either one minute prior to or five minutes after clot induction, human cancer cells were introduced in the circulation by intracardiac injection. The number of cancer cells that homed to the intervention site was determined by quantitative real-time PCR and flow cytometry. Metastasis formation and longitudinal growth were evaluated by bioluminescence imaging. The number of cancer cells that homed to the intervention site after 24 hours was similar to the number of cells in the opposite tibia that did not undergo clot induction. This effect was confirmed using two more cancer cell lines. Furthermore, no difference in the number of macroscopic lesions or their growth could be detected. In the control group 72% developed a lesion in the left tibia. In the experimental groups with clot formation 79% and 65% developed lesions in the left tibia (p = ns when comparing each experimental group with the controls). Survival was similar too. In summary, the growth factors accumulating in a clot/hematoma are neither enough to promote cancer cell homing nor support growth in an experimental model of breast cancer bone metastasis. This suggests that blood clot formation, as occurs in traumatic fractures, surgical interventions, and bruises, does not increase the risk of metastasis formation.

Femur fracture classification in women with a history of breast cancer

Purpose

Women with breast cancer are at increased risk for femur fracture. Contributing factors include estrogen deficiency, cancer-related therapies, or direct bone involvement. This study examines fracture subtypes in women with prior breast cancer experiencing a femur fracture.

Methods

Women age ≥50 years old with a history of invasive breast cancer who experienced a femur fracture were identified during 2005–2012. Fracture site was classified by hospital diagnosis (for hip) and/or radiologic findings (for femoral diaphysis), with subtype classification as pathologic, atypical or fragility fracture. Clinical characteristics were ascertained using health plan databases and disease registries.

Results

There were 802 women with prior breast cancer who experienced a femur fracture. The mean age at fracture was 80.5±9.6 years, with most fractures (93.8%) occurring in the hip and only 6.2% in the femoral diaphysis. However, diaphyseal fractures accounted for 23.6% of fractures in younger women (age ≤65 years). Pathologic fractures comprised 9.6% of total fractures (56.0% of diaphyseal fractures) and accounted for half the fractures in younger women. An atypical fracture pattern was seen in 1% of all femur fractures and 16.0% of diaphyseal fractures, with prior bisphosphonate exposure in all atypical fracture cases.

Conclusion

Most femur fractures in women with prior breast cancer occurred in the hip. Among younger women and those experiencing diaphyseal fractures, a larger proportion were pathologic and some were found to be atypical. Further studies should examine risk factors for femur fracture in women with breast cancer with specific attention to fracture subtype and pharmacologic exposures.

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This study examines femur fracture subtypes in women with prior breast cancer.

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Most fractures occurred in the hip, with fewer occurring in the femoral diaphysis.

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Fractures occurring in the femoral diaphysis were more likely to be pathologic.

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Fractures were also more likely to be pathologic in younger women.

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One in six diaphyseal femur fractures was classified as an atypical femur fracture.

Effects of adjuvant exemestane versus anastrozole on bone mineral density for women with early breast cancer (MA.27B): a companion analysis of a randomised controlled trial

BACKGROUND

Treatment of breast cancer with aromatase inhibitors is associated with damage to bones. NCIC CTG MA.27 was an open-label, phase 3, randomised controlled trial in which women with breast cancer were assigned to one of two adjuvant oral aromatase inhibitors-exemestane or anastrozole. We postulated that exemestane-a mildly androgenic steroid-might have a less detrimental effect on bone than non-steroidal anastrozole. In this companion study to MA.27, we compared changes in bone mineral density (BMD) in the lumbar spine and total hip between patients treated with exemestane and patients treated with anastrozole.

METHODS

In MA.27, postmenopausal women with early stage hormone (oestrogen) receptor-positive invasive breast cancer were randomly assigned to exemestane 25 mg versus anastrozole 1 mg, daily. MA.27B recruited two groups of women from MA.27: those with BMD T-scores of -2·0 or more (up to 2 SDs below sex-matched, young adult mean) and those with at least one T-score (hip or spine) less than -2·0. Both groups received vitamin D and calcium; those with baseline T-scores of less than -2·0 also received bisphosphonates. The primary endpoints were percent change of BMD at 2 years in lumbar spine and total hip for both groups. We analysed patients according to which aromatase inhibitor and T-score groups they were allocated to but BMD assessments ceased if patients deviated from protocol. This study is registered with ClinicalTrials.gov, NCT00354302.

FINDINGS

Between April 24, 2006, and May 30, 2008, 300 patients with baseline T-scores of -2·0 or more were accrued (147 allocated exemestane, 153 anastrozole); and 197 patients with baseline T-scores of less than -2·0 (101 exemestane, 96 anastrozole). For patients with T-scores greater than -2·0 at baseline, mean change of bone mineral density in the spine at 2 years did not differ significantly between patients taking exemestane and patients taking anastrozole (-0·92%, 95% CI -2·35 to 0·50 vs -2·39%, 95% CI -3·77 to -1·01; p=0·08). Respective mean loss in the hip was -1·93% (95% CI -2·93 to -0·93) versus -2·71% (95% CI -4·32 to -1·11; p=0·10). Likewise for those who started with T-scores of less than -2·0, mean change of spine bone mineral density at 2 years did not differ significantly between the exemestane and anastrozole treatment groups (2·11%, 95% CI -0·84 to 5·06 vs 3·72%, 95% CI 1·54 to 5·89; p=0·26), nor did hip bone mineral density (2·09%, 95% CI -1·45 to 5·63 vs 0·0%, 95% CI -3·67 to 3·66; p=0·28). Patients with baseline T-score of -2·0 or more taking exemestane had two fragility fractures and two other fractures, those taking anastrozole had three fragility fractures and five other fractures. For patients who had baseline T-scores of less than -2·0 taking exemestane, one had a fragility fracture and four had other fractures, whereas those taking anastrozole had five fragility fractures and one other fracture.

INTERPRETATION

Our results demonstrate that adjuvant treatment with aromatase inhibitors can be considered for breast cancer patients who have T-scores less than -2·0.

FUNDING

Canadian Cancer Society Research Institute, Pfizer, Canadian Institutes of Health Research.

Fracture risk in older, long-term survivors of early-stage breast cancer

OBJECTIVES

To examine the effect of breast cancer and its treatment on fracture risk in older breast cancer survivors.

DESIGN

A 10-year prospective cohort study beginning 5 years after a diagnosis of breast cancer for survivors and match date for comparison women.

SETTING

Six integrated healthcare systems.

PARTICIPANTS

Women aged 65 and older (1,286 survivors, 1,286 comparison women, mean age 77.7 in both groups, white, non-Hispanic: survivors, 81.6%; comparison women, 85.2%) who were alive and recurrence free 5 years after a diagnosis of early-stage breast cancer and matched on age, study site, and enrollment year to a comparison cohort without breast cancer.

MEASUREMENTS

Cox proportional hazards models were used to estimate the association between fracture risk and survivor-comparison status, adjusting for drugs and risk factors associated with bone health. A subanalysis was used to evaluate the association between tamoxifen exposure and fracture risk.

RESULTS

No difference was observed in fracture rates between groups (hazard ratio (HR) = 1.1, 95% confidence interval (CI) = 0.9-1.3). The protective effect of tamoxifen was not statistically significant (HR = 0.9, 95% CI = 0.6-1.2).

CONCLUSION

Long-term survivors of early-stage breast cancer diagnosed at age 65 and older are not at greater risk of osteoporotic fractures than age-matched women without breast cancer. There appears to be no long-term protection from fractures with tamoxifen use.