Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX

A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX.

INTRODUCTION

The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD).

METHODS

We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted β-coefficients.

RESULTS

A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination.

CONCLUSION

A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.

Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan

We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures.

INTRODUCTION

The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors.

METHODS

A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible.

RESULTS

Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed.

CONCLUSIONS

These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).

Zoledronic acid reduces the rate of clinical fractures after surgical repair of a hip fracture regardless of the Pretreatment bone mineral density

In patients with surgical repair of a low-trauma hip fracture, zoledronic acid (ZA) reduced the risk of subsequent fractures regardless of pretreatment femoral neck and total hip bone mineral density (BMD).

INTRODUCTION

Zoledronic acid reduces the risk of subsequent fractures after repair of a hip fracture. It is still unclear whether the benefits in fracture reduction with ZA depend upon hip bone mineral density at the time of fracture.

METHODS

We preformed additional post hoc analyses of data from the HORIZON Recurrent Fracture Trial to determine if ZA treatment reduced the risk of new clinical fractures regardless of pretreatment BMD. We modeled femoral neck and total hip BMD as both continuous and dichotomous variables (BMD T-score above and below -2.5).

RESULTS

There are no evidence that baseline femoral neck and total hip BMD modified the anti-fracture efficacy of ZA when pretreatment BMD was analyzed as a continuous or a dichotomous variable (interaction p-values > 0.20). The clinical fracture efficacy of ZA was similar among patients with pretreatment femoral neck BMD values above and below -2.5 (relative hazards = 0.60 and 0.67, respectively, interaction p-value = 0.95). A similar result was obtained using pretreatment total hip BMD values (relative hazards = 0.72 and 0.57, respectively, interaction p-value = 0.41).

CONCLUSION

There data should provide more comfort in prescribing ZA after surgical repair of a hip fracture, regardless of pretreatment BMD.

Osteoporosis case ascertainment strategies in European and Asian countries: a comparative review

While many clinical guidelines recommend screening for osteoporosis for early detection and treatment, there is great diversity in the case-finding strategies globally. We sought to compare case-finding strategies, focusing on the approaches used in European and Asian countries. This article provides an overview of the current case-finding strategies in the UK, Germany (including Austria and German-speaking regions of Switzerland), China, Japan, and Korea. We conducted a review of current treatment guidelines in each country and included expert opinions from key opinion leaders. Most countries define osteoporosis among patients with a radiographically identified fracture of the hip or the vertebrae. However, for other types of fractures, or in the absence of a fracture, varying combinations of risk-factor assessment and areal bone mineral density (aBMD) assessed by dual X-ray absorptiometry are used to define osteoporosis cases. A T-score ≤ - 2.5 is accepted to identify osteoporosis in the absence of a fracture; however, not all countries accept DXA alone as the sole criteria. Additionally, the critera for requiring clinical risk factors in addition to aBMD differ across countries. In most Asian countries, aBMD scanning is only provided beyond a particular age threshold. However, all guidelines recommend fracture risk assessment in younger ages if risk factors are present. Our review identified that strategies for case-finding differ regionally, particularly among patients without a fracture. More homogenized ways of identifying osteoporosis cases are needed, in both the Eastern and the Western countries, to improve osteoporosis case-finding before a fracture occurs.Case-finding in osteoporosis is essential to initiate treatment and minimize fracture risk. We identified differences in case-finding strategies between Eastern and Western countries. In the absence of a diagnosed fracture, varying combinations of risk factors and bone density measurements are used. Standardized case-finding strategies may help improve treatment rates.

Genome-wide meta-analysis of variant-by-diuretic interactions as modulators of lipid traits in persons of European and African ancestry

Hypertension (HTN) is a significant risk factor for cardiovascular morbidity and mortality. Metabolic abnormalities, including adverse cholesterol and triglycerides (TG) profiles, are frequent comorbid findings with HTN and contribute to cardiovascular disease. Diuretics, which are used to treat HTN and heart failure, have been associated with worsening of fasting lipid concentrations. Genome-wide meta-analyses with 39,710 European-ancestry (EA) individuals and 9,925 African-ancestry (AA) individuals were performed to identify genetic variants that modify the effect of loop or thiazide diuretic use on blood lipid concentrations. Both longitudinal and cross-sectional data were used to compute cohort-specific interaction results, which were then combined through meta-analysis in each ancestry. These ancestry-specific results were further combined through trans-ancestry meta-analysis. Analysis of EA data identified two genome-wide significant (p < 5×10⁻⁸) loci with single nucleotide variant (SNV)-loop diuretic interaction on TG concentrations (including COL11A1). Analysis of AA data identified one genome-wide significant locus adjacent to BMP2 with SNV-loop diuretic interaction on TG concentrations. Trans-ancestry analysis strengthened evidence of association for SNV-loop diuretic interaction at two loci (KIAA1217 and BAALC). There were few significant SNV-thiazide diuretic interaction associations on TG concentrations and for either diuretic on cholesterol concentrations. Several promising loci were identified that may implicate biologic pathways that contribute to adverse metabolic side effects from diuretic therapy.

B-49 Family Expectations regarding Functional Disability following Moderate/Severe Traumatic Brain Injury

Objective

The present study explored self-concept and treatment motivation in individuals with traumatic brain injury (TBI) based on what their family members recalled having been told by health care professionals to expect about functional changes following brain injury.

Method

Adult family members (76% female) of nineteen individuals with moderate/severe TBI (mean age 38; 4 yrs post) were asked about expected functional changes. Patients completed the Tennessee Self-Concept Scale (TSCS:2) and Motivation for Rehabilitation Treatment Questionnaire. Patients and families completed the Neurobehavioral Functioning Inventory (NFI). Results of point biserial correlational analyses (p < .05) are reported.

Results

NFI and TSCS:2 results placed within the average range. Patients expressed stronger interest in rehabilitation when their families had been told that they might not have survived or that they would not recover to their premorbid levels (r = .43-.47). When families had not been told to expect changes, patients were more self-critical and evidenced lower personal self-concept if not warned specifically about cognitive problems (r =.44 ). When families were told not to expect recovery, patients acknowledged lower family and personal self-concept (r = .53-.64) and poorer self-satisfaction (r = .66).

Conclusions

Key findings underscore detrimental impact on TBI patients when their families did not expect functional changes during recovery. Patients expressed greater interest in rehabilitation when their families had been told they would not recover to their premorbid baseline. Results suggest that health professionals should inform families about potential physical, cognitive, and emotional changes following moderate/severe TBI; negative residua of not doing so may persist in patients for years into recovery.

Abstract P1-10-01: Defining the spectrum of germline variants among African American patients with triple negative breast cancer

Background: African American (AA) women are more likely to have breast cancer at a younger age and be diagnosed with triple negative breast cancer (TNBC), which is as yet unexplained. We examined results of multi-gene panel testing in AA women with TNBC tested at a large commercial laboratory to assess the utility of gene panels and findings in this group.

Methods: We assessed individuals who had clinical hereditary cancer testing with a multi-gene panel between September 2013 and May 2018. Women were included for analysis if they had a personal history of TNBC and self-identified as having any AA ancestry (n=3,268) or only Caucasian (CA) ancestry (n=8,953). Clinical data was collected from provider-completed test request forms. Comparisons were performed using descriptive statistics, t-tests (continuous variables), and chi-square tests (categorical variables) adjusting for multiple testing when necessary.

Results: In this cohort, AA women were significantly more likely than CA women to meet NCCN guidelines (97.5% vs. 96.6%, p=0.010) and significantly less likely to have an additional personal (16.2% vs. 21.8%, p&lt;0.001) or family (79.3% vs. 86.3%, p&lt;0.001) history of cancer. Overall, 11.5% of AA women were found to carry a pathogenic variant (PV) compared to 13.4% of CA women (p=0.004; Table 1). Compared to CA women, AA women with a PV were significantly younger at diagnosis (46.7 vs. 49.5 years of age; p&lt;0.001). The prevalence of PVs in BRCA1, CHEK2 and the Lynch syndrome genes was higher in CA women, whereas the prevalence of BRCA2 PVs was higher in AA women. While the prevalence of PVs in individual genes was not significantly different according to ancestry after adjusting for multiple comparisons, AA women were significantly less likely to have a PV in any breast cancer-related gene compared to CA women (p=0.048). AA women were significantly more likely to have a Variant of Uncertain Significance (VUS; 35.6% vs. 20.9%; p&lt;0.001) and to have &gt;1 VUS (8.6% vs. 2.6%, p&lt;0.001). Regardless of ancestry, patients diagnosed before age 40 were more likely to carry a PV (19.7% AA, 22.2% CA). However, the prevalence of PVs among patients diagnosed after age 60 was still striking (8.9% AA, 10.9% CA) and was similar to the PV prevalence among patients diagnosed between 40-60 (10.1% AA, 12.3% CA).

Conclusions: In the era of multi-gene panel testing, this large cohort of patients with TNBC supports the use of panel testing in AA women with TNBC regardless of age or additional personal/family history of cancer. While additional research to the rate and pathogenicity of VUS in AA women is needed, genetic counseling is necessary to explain the possibility and meaning of a VUS in this group.

Table 1.Distribution of PVs in BC-related genes according to ancestry AA WomenCA WomenGeneN (%)N (%)Any Breast Cancer-Related Gene347 (10.6)1104 (12.3)BRCA1132 (4.0)496 (5.5)BRCA297 (3.0)236 (2.6)ATM6 (0.2)25 (0.3)BARD119 (0.6)67 (0.7)BRIP120 (0.6)46 (0.5)CDH11 (&lt;0.1)1 (&lt;0.1)CHEK22 (0.1)33 (0.4)NBN2 (0.1)10 (0.1)PALB244 (1.3)138 (1.5)PTEN2 (0.1)4 (&lt;0.1)RAD51C20 (0.6)41 (0.5)STK1101 (&lt;0.1)TP532 (0.1)6 (0.1)Lynch Syndrome Genes10 (0.3)46 (0.5)Other Genes12 (0.4)24 (0.3)Multiple PVs6 (0.2)28 (0.3)Total (Any Gene)375 (11.5)1202 (13.4)

Citation Format: Pederson HJ, Heald B, Budd GT, Bernhisel R, Cummings S, Saam JR, Lancaster JM, Grobmyer SR, Eng C. Defining the spectrum of germline variants among African American patients with triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-10-01.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Pharmacogenomics study of thiazide diuretics and QT interval in multi-ethnic populations: the cohorts for heart and aging research in genomic epidemiology

Thiazide diuretics, commonly used antihypertensives, may cause QT interval (QT) prolongation, a risk factor for highly fatal and difficult to predict ventricular arrhythmias. We examined whether common single-nucleotide polymorphisms (SNPs) modified the association between thiazide use and QT or its component parts (QRS interval, JT interval) by performing ancestry-specific, trans-ethnic and cross-phenotype genome-wide analyses of European (66%), African American (15%) and Hispanic (19%) populations (N=78 199), leveraging longitudinal data, incorporating corrected standard errors to account for underestimation of interaction estimate variances and evaluating evidence for pathway enrichment. Although no loci achieved genome-wide significance (P<5 × 10-8), we found suggestive evidence (P<5 × 10-6) for SNPs modifying the thiazide-QT association at 22 loci, including ion transport loci (for example, NELL1, KCNQ3). The biologic plausibility of our suggestive results and simulations demonstrating modest power to detect interaction effects at genome-wide significant levels indicate that larger studies and innovative statistical methods are warranted in future efforts evaluating thiazide-SNP interactions.

Abstract OT3-02-01: Development of cell-free nucleic acid-based tests for early detection of breast cancer: The STRIVE study

Background:

Mammography (digital 2D or digital 3D/tomosynthesis) is the cornerstone of current screening strategies for breast cancer, but new approaches are needed to further reduce the proportion of cancers diagnosed at advanced stages and more effectively identify those women in need of additional testing and biopsies. Circulating cell-free nucleic acids (cfNAs) shed from tumors, isolated from peripheral blood, and analyzed with ultra-deep and broad sequencing of cancer-associated genes, have great potential for early cancer detection. The ultimate goal is to develop blood cfNA cancer screening tests for use in conjunction with established risk factors and/or radiographic features for improved cancer detection. Development of these tests requires large, well-annotated cohorts of asymptomatic participants with adequate volumes of prediagnostic blood. The STRIVE Study cohort was recently established to train and validate cfNA-based tests for early detection of breast cancer.

Eligibility criteria and trial design: The STRIVE Study is a new prospective, multi-ethnic mammography cohort that will recruit 120,000 subjects from 15+ US breast cancer screening centers (including Mayo Clinic and Sutter Health sites). Eligibility criteria require only that a participant has a scheduled routine screening mammogram at a participating center and has not received a biopsy prior to the research blood draw. Participants are recruited within 28 days of screening mammography (digital or tomosynthesis), consent electronically, provide blood samples, and complete an on-line risk factor questionnaire. Participants will be followed for all cancer diagnoses, cancer recurrences, and death for at least 5 years. Pertinent medical record information, imaging findings (including breast density), and follow-up data will be transferred electronically to a central database throughout the study period. Additional blood samples will be collected from participants with abnormal mammogram results, or who are diagnosed with cancer, to document and better understand the evolution of cfNA signals. Recruitment began in February 2017.

Primary Aims: To train and validate a cfNA blood-based test to identify breast cancer overall in a cohort of women undergoing screening mammography.

Statistical Methods: The study will be divided into a training phase (1/3 of participants) and an independent clinical validation phase (remaining 2/3 of participants). In the training phase, statistical machine learning techniques will be used to develop algorithms incorporating cfNA signals, clinical characteristics, or radiological features. In the validation phase, the prespecified locked algorithm developed from the training phase will be clinically validated in an independent group of women.

Contact information for people with a specific interest in the trial: Additional details regarding the STRIVE Study are available on the ClinicalTrials.gov website (NCT03085888). For site-specific questions, please call 844-366-9738 for the Mayo Clinic and 1-855-578-7483 for Sutter Health.

Citation Format: Liu MC, Cummings S, Vachon CM, Kerlikowske K, Couch FJ, Morris EA, Olson JE, Polley EC, Conners AL, Ellis RL, Patel B, Maimone IV S, Zhang N, Hamilton S, Clarke CA, Allen BA, Maddala T, Hartman A-R. Development of cell-free nucleic acid-based tests for early detection of breast cancer: The STRIVE study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT3-02-01.

Effect of high-fat diet on secreted milk transcriptome in midlactation mice

High-fat diet (HFD) during lactation alters milk composition and is associated with development of metabolic diseases in the offspring. We hypothesized that HFD affects milk microRNA (miRNA) and mRNA content, which potentially impact offspring development. Our objective was to determine the effect of maternal HFD on secreted milk transcriptome. To meet this objective, 4 wk old female ICR mice were divided into two treatments: control diet containing 10% kcal fat and HFD containing 60% kcal fat. After 4 wk on CD or HFD, mice were bred while continuously fed the same diets. On postnatal day 2 (P2), litters were normalized to 10 pups, and half the pups in each litter were cross-fostered between treatments. Milk was collected from dams on P10 and P12. Total RNA was isolated from milk fat fraction of P10 samples and used for mRNA-Seq and small RNA-Seq. P12 milk was used to determine macronutrient composition. After 4 wk of prepregnancy feeding HFD mice weighed significantly more than did the control mice. Lactose and fat concentration were significantly ( P < 0.05) higher in milk of HFD dams. Pup weight was significantly greater ( P < 0.05) in groups suckled by HFD vs. control dams. There were 25 miRNA and over 1,500 mRNA differentially expressed (DE) in milk of HFD vs. control dams. DE mRNA and target genes of DE miRNA enriched categories that were primarily related to multicellular organismal development. Maternal HFD impacts mRNA and miRNA content of milk, if bioactive nucleic acids are absorbed by neonate differences may affect development.

Vertebral fracture in postmenopausal Chinese women: a population-based study

In a random sample of postmenopausal Chinese women, the prevalence of radiographic vertebral fractures increased from 13% between ages 50 and 59 to over 50% after age 80 years. A model with seven clinical risk factors predicted the probability of vertebral fractures as well with as without BMD and better than a model with only three risk factors. More than half an hour of outdoor activity per day might correlate with lower risk of vertebral fracture in this population.

INTRODUCTION

We aimed to describe the prevalence and develop a model for prediction of radiographic vertebral fractures in a large random sample of postmenopausal Chinese women.

METHODS

We enrolled 1760 women from an age-stratified random sample of postmenopausal women in Beijing, China. The presence of vertebral fracture was assessed by semi-quantitative grading of lateral thoracolumbar radiographs, risk factors by interview, bone mineral density (BMD) of the proximal femur and lumbar spine by dual x-ray absorptiometry (DXA), and markers of bone turnover from a fasting blood sample. Associations of these factors were analyzed in logistic models and discrimination by areas of receiver operating characteristics curves (AUC).

RESULTS

The prevalence of vertebral fracture, ranged from 13.4% ages 50 to 59 years old to 58.1% at age 80 years or older. Older age, a history of non-vertebral fracture, lower femoral neck BMD T-score, body mass index (BMI), height loss, housework, and less than half an hour of outdoor activity were significantly associated with increased probability of having a vertebral fracture. A model with those seven factors had a similar AUC with or without BMD and performed better than a simple model with three factors.

CONCLUSION

This study is from a true random sample of postmenopausal women in urban China with high response rate. The prevalence of vertebral fractures in postmenopausal women in Beijing increases from 13% under age 60 to over 50% by age 80 years. A model with seven clinical risk factors with or without BMD is better than simple models and may guide the use of spine x-rays to identify women with vertebral fractures. More than half an hour of outdoor activity might correlate with lower risk of vertebral fracture in this population.

Spinal radiographs in those with back pain-when are they appropriate to diagnose vertebral fractures?

The presence of an osteoporotic vertebral fracture improves fracture risk assessment and may change management, so it is vital for healthcare professionals to assess patients for the presence or absence of these fractures. This may be particularly important in the presence of back pain. However, the correlation between low back symptoms and spinal imaging results is poor and the pathophysiology of most low back pain is not known, leading to a common conclusion that spinal radiographs are not appropriate for the assessment of back pain. For individual patients with back pain, spinal radiographs should be considered if they have certain features in the history and examination. As well as the traditional risk factors for osteoporosis, self-reported descriptives of back pain and novel physical examination findings have been shown to make the presence of vertebral fractures more likely. Systematic approaches have the potential to improve bone health across the population but need to be targeted to be cost-effective. Spinal radiographs should be considered for individual older patients with back pain if they have certain additional features in the history and examination.

Abstract P5-09-05: A model with polygenic risk score and mammographic density predicts interval cancers

Introduction:

Interval breast cancers present with clinical symptoms following a normal screening mammogram. They are associated with unfavorable biological features and with dense breasts. Models predictive of aggressive phenotypes may facilitate tailored screening for women at elevated risk of interval cancers. Polygenic risk scores (PRS) represent the cumulative effects of multiple single nucleotide polymorphisms (SNPs) and can be used to risk-stratify women. In prior reports, PRS is preferentially associated with screen-detected rather than interval cancers. We investigated methods to refine the PRS to preferentially predict interval cancers, and tested the performance of the PRS in joint models with mammographic breast density (MBD).

Methods:

We used data from 1058 breast cancer cases from The Cancer Genome Atlas (TCGA) as the discovery set for our PRS. We selected 107 SNPs from genomewide association studies of breast cancer risk for testing against tumor status at last follow-up in TCGA. Presence of tumor indicated recurrence, progression, or positive margins after resection. Women with tumor present at &lt;100 days of follow-up were excluded. Suggestive associations (p&lt;0.2) were used to construct a PRS, calculated as the sum across all SNPs of the per-allele log-odds ratio multiplied by the number of risk alleles for each SNP. We tested the performance of the PRS in a nested case-control dataset with 471 cases (102 interval cancers, 369 screen detected) and 496 controls from the California Pacific Medical Center Research Institute cohort. Logistic regression was used to evaluate the association between PRS, MBD and interval cancers. Area under the receiver operating characteristic (AUROC) curve was used to measure discrimination.

Results:

Of 107 SNPs, 23 had suggestive associations with presence of tumor at last follow-up in TCGA. The 23-SNP PRS discriminated between women with interval cancers and controls, with AUROC 0.57 (95% CI 0.51-0.63). With the inclusion of MBD in the model, the AUROC was 0.68 (95% CI 0.62-0.74). Women in the highest PRS quintile had an unadjusted 2.07-fold odds (95% CI 1.05-4.07) of developing interval cancers compared with women in the lowest quintile; adjustment for MBD did not change the point estimate. The PRS also discriminated between women with interval and screen-detected cancers, although the findings did not reach statistical significance (AUROC 0.55, 95% CI 0.48-0.61). With the inclusion of MBD in the model, the AUROC was 0.63 (95% CI 0.57-0.69).

Discussion:

A PRS associated with presence of tumor at last follow-up was independently predictive of interval cancers relative to controls. Models with PRS and MBD discriminated between interval and screen-detected cancers, although MBD provided most of the predictive power. Our findings are limited by the size and low number of recurrences in TCGA. It is possible that tumor status largely reflects treatment received, and may only partially represent the biological pathways of interval cancers. Our results suggest that SNPs may potentially identify women at risk for developing interval breast cancer, although further validation is required.

Citation Format: Shieh Y, Hu D, Huntsman S, Ma L, Gard CC, Leung JWT, Tice JA, Cummings SR, Kerlikowske K, Ziv E. A model with polygenic risk score and mammographic density predicts interval cancers [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-09-05.

Denosumab or Zoledronic Acid in Postmenopausal Women With Osteoporosis Previously Treated With Oral Bisphosphonates

CONTEXT

Denosumab and zoledronic acid (ZOL) are parenteral treatments for patients with osteoporosis.

OBJECTIVE

The objective of the study was to compare the effect of transitioning from oral bisphosphonates to denosumab or ZOL on bone mineral density (BMD) and bone turnover.

DESIGN AND SETTING

This was an international, multicenter, randomized, double-blind trial.

PARTICIPANTS

A total of 643 postmenopausal women with osteoporosis previously treated with oral bisphosphonates participated in the study.

INTERVENTIONS

Subjects were randomized 1:1 to sc denosumab 60 mg every 6 months plus iv placebo once or ZOL 5 mg iv once plus sc placebo every 6 months for 12 months.

MAIN OUTCOME MEASURES

Changes in BMD and bone turnover markers were measured.

RESULTS

BMD change from baseline at month 12 was significantly greater with denosumab compared with ZOL at the lumbar spine (primary end point; 3.2% vs 1.1%; P < .0001), total hip (1.9% vs 0.6%; P < .0001), femoral neck (1.2% vs -0.1%; P < .0001), and one-third radius (0.6% vs 0.0%; P < .05). The median decrease from baseline was greater with denosumab than ZOL for serum C-telopeptide of type 1 collagen at all time points after day 10 and for serum procollagen type 1 N-terminal propeptide at month 1 and at all time points after month 3 (all P < .05). Median percentage changes from baseline in serum intact PTH were significantly greater at months 3 and 9 with denosumab compared with ZOL (all P < .05). Adverse events were similar between groups. Three events consistent with the definition of atypical femoral fracture were observed (two denosumab and one ZOL).

CONCLUSIONS

In postmenopausal women with osteoporosis previously treated with oral bisphosphonates, denosumab was associated with greater BMD increases at all measured skeletal sites and greater inhibition of bone remodeling compared with ZOL.

Osteoporosis: the evolution of a diagnosis

The global trend towards increased longevity has resulted in ageing populations and a rise in diseases or conditions that primarily affect older persons. One such condition is osteoporosis (fragile or porous bones), which causes an increased fracture risk. Vertebral and hip fractures lead to increased morbidity and mortality and result in enormous healthcare costs. Here, we review the evolution of the diagnosis of osteoporosis. In an attempt to separate patients with normal bones from those with osteoporosis and to define the osteoporosis diagnosis, multiple factors and characteristics have been considered. These include pathology and histology of the disease, the endocrine regulation of bone metabolism, bone mineral density (BMD), fracture type or trauma severity, risk models for fracture prediction, and thresholds for pharmacological intervention. The femoral neck BMD -2.5 SDs cut-off for the diagnosis of osteoporosis is arbitrarily chosen, and there is no evidence to support the notion that fracture location (except vertebral fractures) or severity is useful to discriminate osteoporotic from normal bones. Fracture risk models (including factors unrelated to bone) dissociate bone strength from the diagnosis, and treatment thresholds are often based on health-economic considerations rather than bone properties. Vertebral fractures are a primary feature of osteoporosis, characterized by decreased bone mass, strength and quality, and a high risk of another such fracture that can be considerably reduced by treatment. We believe that the 2001 definition of osteoporosis by the National Institutes of Health Consensus Development Panel on Osteoporosis is still valid and useful: 'Osteoporosis is defined as a skeletal disorder characterized by compromised bone strength predisposing a person to an increased risk of fracture'.

Arterialized venous bicarbonate is associated with lower bone mineral density and an increased rate of bone loss in older men and women

CONTEXT

Higher dietary net acid loads have been associated with increased bone resorption, reduced bone mineral density (BMD), and increased fracture risk.

OBJECTIVE

The objective was to compare bicarbonate (HCO3) measured in arterialized venous blood samples to skeletal outcomes.

DESIGN

Arterialized venous samples collected from participants in the Health, Aging and Body Composition (Health ABC) Study were compared to BMD and rate of bone loss.

SETTING

The setting was a community-based observational cohort.

PARTICIPANTS

A total of 2287 men and women age 74 ± 3 years participated.

INTERVENTION

Arterialized venous blood was obtained at the year 3 study visit and analyzed for pH and pCO2. HCO3 was determined using the Henderson-Hasselbalch equation.

MAIN OUTCOME MEASURE

BMD was measured at the hip by dual-energy x-ray absorptiometry at the year 1 (baseline) and year 3 study visits.

RESULTS

Plasma HCO3 was positively associated with BMD at both year 1 (P = .001) and year 3 (P = .001) in models adjusted for age, race, sex, clinic site, smoking, weight, and estimated glomerular filtration rate. Plasma HCO3 was inversely associated with rate of bone loss at the total hip over the 2.1 ± 0.3 (mean ± SD) years between the two bone density measurements (P < .001). Across quartiles of plasma HCO3, the rate of change in BMD over the 2.1 years ranged from a loss of 0.72%/y in the lowest quartile to a gain of 0.15%/y in the highest quartile of HCO3.

CONCLUSIONS

Arterialized plasma HCO3 was associated positively with cross-sectional BMD and inversely with the rate of bone loss, implying that systemic acid-base status is an important determinant of skeletal health during aging. Ongoing bone loss was linearly related to arterialized HCO3, even after adjustment for age and renal function. Further research in this area may have major public health implications because reducing dietary net acid load is possible through dietary intervention or through supplementation with alkaline potassium compounds.

Bone-muscle indices as risk factors for fractures in men: the Osteoporotic Fractures in Men (MrOS) Study

OBJECTIVE

To assess bone-muscle (B-M) indices as risk factors for incident fractures in men.

METHODS

Participants of the Osteoporotic Fractures in Men (MrOS) Study completed a peripheral quantitative computed tomography scan at 66% of their tibial length. Bone macrostructure, estimates of bone strength, and muscle area were computed. Areal bone mineral density (aBMD) and body composition were assessed with dual-energy X-ray absorptiometry. Four year incident non-spine and clinical vertebral fractures were ascertained. B-M indices were expressed as bone-to-muscle ratios for: strength, mass and area. Discriminative power and hazards ratios (HR) for fractures were reported.

RESULTS

In 1163 men (age: 77.2±5.2 years, body mass index (BMI): 28.0±4.0 kg/m(2), 4.1±0.9 follow-up years, 7.7% of men ⋝1 fracture), B-M indices were smaller in fractured men except for bending and areal indices. Smaller B-M indices were associated with increased fracture risk (HR: 1.30 to 1.74) independent of age and BMI. Strength and mass indices remained significant after accounting for lumbar spine but not total hip aBMD. However, aBMD correlated significantly with B-M indices.

CONCLUSION

Mass and bending B-M indices are risk factors for fractures in men, but may not improve fracture risk prediction beyond that provided by total hip aBMD.

Low holotranscobalamin and cobalamins predict incident fractures in elderly men: the MrOS Sweden

In a population-based study on cobalamin status and incident fractures in elderly men (n = 790) with an average follow-up of 5.9 years, we found that low levels of metabolically active and total cobalamins predict incident fractures, independently of body mass index (BMI), bone mineral density (BMD), plasma total homocysteine (tHcy), and cystatin C.

INTRODUCTION

Cobalamin deficiency in elderlies may affect bone metabolism. This study aims to determine whether serum cobalamins or holotranscobalamin (holoTC; the metabolic active cobalamin) predict incident fractures in old men.

METHODS

Men participating in the Gothenburg part of the population-based Osteoporotic Fractures in Men (MrOS) Sweden cohort and without ongoing vitamin B medication were included in the present study (n = 790; age range, 70-81 years).

RESULTS

During an average follow-up of 5.9 years, 110 men sustained X-ray-verified fractures including 45 men with clinical vertebral fractures. The risk of fracture (adjusted for age, smoking, BMI, BMD, falls, prevalent fracture, tHcy, cystatin C, 25-OH-vitamin D, intake of calcium, and physical activity (fully adjusted)), increased per each standard deviation decrease in cobalamins (hazard ratio (HR), 1.38; 95% confidence intervals (CI), 1.11-1.72) and holoTC (HR, 1.26; 95% CI, 1.03-1.54), respectively. Men in the lowest quartile of cobalamins and holoTC (fully adjusted) had an increased risk of all fracture (cobalamins, HR = 1.67 (95% CI, 1.06-2.62); holoTC, HR = 1.74 (95% CI, 1.12-2.69)) compared with quartiles 2-4. No associations between folate or tHcy and incident fractures were seen.

CONCLUSIONS

We present novel data showing that low levels of holoTC and cobalamins predicting incident fracture in elderly men. This association remained after adjustment for BMI, BMD, tHcy, and cystatin C. However, any causal relationship between low cobalamin status and fractures should be explored in a prospective treatment study.

Standardising the descriptive epidemiology of osteoporosis: recommendations from the Epidemiology and Quality of Life Working Group of IOF

The Committee of Scientific Advisors of International Osteoporosis Foundation (IOF) recommends that papers describing the descriptive epidemiology of osteoporosis using bone mineral density (BMD) at the femoral neck include T-scores derived from an international reference standard.

INTRODUCTION

The prevalence of osteoporosis as defined by the T-score is inconsistently reported in the literature which makes comparisons between studies problematic.

METHODS

The Epidemiology and Quality of Life Working Group of IOF convened to make its recommendations and endorsement sought thereafter from the Committee of Scientific Advisors of IOF.

RESULTS

The Committee of Scientific Advisors of IOF recommends that papers describing the descriptive epidemiology of osteoporosis using BMD at the femoral neck include T-scores derived from the National Health and Nutrition Examination Survey III reference database for femoral neck measurements in Caucasian women aged 20-29 years.

CONCLUSIONS

It is expected that the use of the reference standard will help resolve difficulties in the comparison of results between studies and the comparative assessment of new technologies.

Evaluation of movement and physiological demands of rugby league referees using global positioning systems tracking

The use of global positioning systems (GPS) technology within referees of any sport is limited. Therefore, the purpose of the current study was to evaluate the movement and physiological demands of professional rugby league referees using GPS tracking analysis. Time-motion analysis was undertaken on 8 referees using 5-Hz GPS devices and heart rate monitors throughout a series of Super League matches. 44 data sets were obtained with results identifying similar total distance covered between first and second half periods with a significant (P=0.004) reduction in the number of high velocity efforts performed between 5.51-7.0 m.s-1 (1st=21±8, 2nd=18±8). Mean distance covered from greatest to least distance, was 3 717±432 m, 3 009±402 m, 1 411±231 m, 395±133 m and 120±97 m for the following 5 absolute velocity classifications, respectively; 0.51-2.0 m.s-1; 2.1-4.0 m.s-1: 4.01-5.5 m.s-1; 5.51-7.0 m.s-1; <7.01 m.s-1. Heart rate was significantly (P<0.001) greater in the first (85.5±3.4% maxHR) compared to the second (82.9±3.8% maxHR) half. This highlights the intermittent nature of rugby league refereeing, consisting of low velocity activity interspersed with high velocity efforts and frequent changes of velocity. Training should incorporate interval training interspersing high velocity efforts of varying distances with low velocity activity while trying to achieve average heart rates of ~ 84% maxHR to replicate the physiological demands.

Cost-effectiveness of bone densitometry among Caucasian women and men without a prior fracture according to age and body weight

We used a microsimulation model to estimate the threshold body weights at which screening bone densitometry is cost-effective. Among women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to identify those for whom bone densitometry is cost-effective.

INTRODUCTION

Bone densitometry may be more cost-effective for those with lower body weight since the prevalence of osteoporosis is higher for those with low body weight. Our purpose was to estimate weight thresholds below which bone densitometry is cost-effective for women and men without a prior clinical fracture at ages 55, 60, 65, 75, and 80 years.

METHODS

We used a microsimulation model to estimate the costs and health benefits of bone densitometry and 5 years of fracture prevention therapy for those without prior fracture but with femoral neck osteoporosis (T-score ≤ -2.5) and a 10-year hip fracture risk of ≥3%. Threshold pre-test probabilities of low BMD warranting drug therapy at which bone densitometry is cost-effective were calculated. Corresponding body weight thresholds were estimated using data from the Study of Osteoporotic Fractures (SOF), the Osteoporotic Fractures in Men (MrOS) study, and the National Health and Nutrition Examination Survey (NHANES) for 2005-2006.

RESULTS

Assuming a willingness to pay of $75,000 per quality adjusted life year (QALY) and drug cost of $500/year, body weight thresholds below which bone densitometry is cost-effective for those without a prior fracture were 74, 90, and 100 kg, respectively, for women aged 55, 65, and 80 years; and were 67, 101, and 108 kg, respectively, for men aged 55, 75, and 80 years.

CONCLUSIONS

For women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to select those for whom bone densitometry is cost-effective.

Treatment failure in osteoporosis

Guidelines concerning the definition of failure of therapies used to reduce the risk of fracture are provided.

INTRODUCTION

This study aims to provide guidelines concerning the definition of failure of therapies used to reduce the risk of fracture.

METHODS

A working group of the Committee of Scientific Advisors of the International Osteoporosis Foundation was convened to define outcome variables that may assist clinicians in decision making.

RESULTS

In the face of limited evidence, failure of treatment may be inferred when two or more incident fractures have occurred during treatment, when serial measurements of bone remodelling markers are not suppressed by anti-resorptive therapy and where bone mineral density continues to decrease.

CONCLUSION

The provision of pragmatic criteria to define failure to respond to treatment provides an unmet clinical need and may stimulate research into an important issue.

Common genetic variation near the connexin-43 gene is associated with resting heart rate in African Americans: a genome-wide association study of 13,372 participants

BACKGROUND

Genome-wide association studies have identified several genetic loci associated with variation in resting heart rate in European and Asian populations. No study has evaluated genetic variants associated with heart rate in African Americans.

OBJECTIVE

To identify novel genetic variants associated with resting heart rate in African Americans.

METHODS

Ten cohort studies participating in the Candidate-gene Association Resource and Continental Origins and Genetic Epidemiology Network consortia performed genome-wide genotyping of single nucleotide polymorphisms (SNPs) and imputed 2,954,965 SNPs using HapMap YRI and CEU panels in 13,372 participants of African ancestry. Each study measured the RR interval (ms) from 10-second resting 12-lead electrocardiograms and estimated RR-SNP associations using covariate-adjusted linear regression. Random-effects meta-analysis was used to combine cohort-specific measures of association and identify genome-wide significant loci (P≤2.5×10(-8)).

RESULTS

Fourteen SNPs on chromosome 6q22 exceeded the genome-wide significance threshold. The most significant association was for rs9320841 (+13 ms per minor allele; P = 4.98×10(-15)). This SNP was approximately 350 kb downstream of GJA1, a locus previously identified as harboring SNPs associated with heart rate in Europeans. Adjustment for rs9320841 also attenuated the association between the remaining 13 SNPs in this region and heart rate. In addition, SNPs in MYH6, which have been identified in European genome-wide association study, were associated with similar changes in the resting heart rate as this population of African Americans.

CONCLUSIONS

An intergenic region downstream of GJA1 (the gene encoding connexin 43, the major protein of the human myocardial gap junction) and an intragenic region within MYH6 are associated with variation in resting heart rate in African Americans as well as in populations of European and Asian origin.

Risk factors for nonvertebral fracture in obese older women

CONTEXT

A high prevalence of obesity has recently been reported in postmenopausal women with low trauma fracture, suggesting that higher bone mineral density (BMD) in obese individuals may not be protective against fracture.

OBJECTIVE

The aim of this study was to compare BMD and other risk factors for nonvertebral fracture in 1377 obese postmenopausal women.

DESIGN

Characteristics of obese women with and without incident nonvertebral fracture were investigated among the prospective cohort in the Study of Osteoporotic Fractures.

SETTING

The Study of Osteoporotic Fractures is a multicenter study of 9704 women (>99% Caucasian) aged 65 yr and over who were recruited between September 1986 and October 1988 from population-based listings at four U.S. clinical centers.

MAIN OUTCOME MEASURE

The main outcome measure was nonvertebral fracture.

RESULTS

BMD T-scores in the spine, femoral neck, and total hip were significantly lower in obese women who experienced fractures than in obese women without fracture: mean differences, -0.56 [95% confidence interval (CI) = -0.73 to -0.39], -0.46 (95% CI = -0.57 to -0.36), and -0.51 (95% CI = -0.62 to -0.39), respectively (P < 0.0001 for all). A previous history of fracture [odds ratio = 1.69 (95% CI = 1.33-2.14); P < 0.0001] and femoral neck BMD [1.62 (95% CI = 1.42-1.85) per sd decrease in BMD; P < 0.0001] were independently associated with incident nonvertebral fracture.

CONCLUSIONS

Obese postmenopausal women who sustain nonvertebral fractures have significantly lower BMD on average than obese women without fracture and are more likely to have a past history of fracture. Fractures in obese postmenopausal women thus exhibit some characteristics of fragility fractures.

Treatment with denosumab reduces the incidence of new vertebral and hip fractures in postmenopausal women at high risk

CONTEXT

The FREEDOM (Fracture REduction Evaluation of Denosumab in Osteoporosis every 6 Months) trial showed denosumab significantly reduced the risk of fractures in postmenopausal women with osteoporosis.

OBJECTIVE

We evaluated the effect of denosumab on the incidence of new vertebral and hip fractures in subgroups of women at higher risk for these fractures.

DESIGN

FREEDOM was a 3-yr, randomized, double-blind, placebo-controlled, phase 3 trial.

PARTICIPANTS AND SETTING

Postmenopausal women (N = 7808) with osteoporosis were enrolled at 213 study sites worldwide.

INTERVENTIONS

Subjects received s.c. denosumab (60 mg) or placebo every 6 months and daily supplements of calcium (≥1000 mg) and vitamin D (≥400 IU).

MAIN OUTCOME MEASURES

This post hoc analysis evaluated fracture incidence in women with known risk factors for fractures including multiple and/or moderate or severe prevalent vertebral fractures, aged 75 yr or older, and/or femoral neck bone mineral density T-score of -2.5 or less.

RESULTS

Compared with placebo, denosumab significantly reduced the risk of new vertebral fractures in women with multiple and/or severe prevalent vertebral fractures (16.6% placebo vs. 7.5% denosumab; P < 0.001). Similarly, denosumab significantly reduced the risk of hip fractures in subjects aged 75 yr or older (2.3% placebo vs. 0.9% denosumab; P < 0.01) or with a baseline femoral neck bone mineral density T-score of -2.5 or less (2.8% placebo vs. 1.4% denosumab; P = 0.02). These risk reductions in higher-risk individuals were consistent with those seen in patients at lower risk of fracture.

CONCLUSIONS

Denosumab reduced the incidence of new vertebral and hip fractures in postmenopausal women with osteoporosis at higher risk for fracture. These results highlight the consistent antifracture efficacy of denosumab in patients with varying degrees of fracture risk.

Genetics of cardiac arrhythmias

Continued research into the identification of mutated genes that cause inherited arrhythmogenic diseases has helped forward understanding into their pathophysiology. Over the last two decades the progress that has been made in the realm of genetic arrhythmias has made it possible not only for symptomatic patients to improve their outcomes, but also family members to better understand their risks and allow them in conjunction with their care providers to make the best decisions for their care. With this continued progress, significant changes will continue to occur in clinical practice. The advances in technology coupled with the improving understanding of genetically determined arrhythmias assists in earlier recognition of potentially fatal diseases, which leads to earlier implementation of treatment. It is the aim of this article to abridge the current knowledge of the genetic background of inherited arrhythmogenic diseases, namely long QT syndrome, short QT syndrome, Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia. Pathogenesis and genotype-phenotype correlations are also discussed.

Secular trends in the incidence of hip and other osteoporotic fractures

Osteoporosis constitutes a major public health problem through its association with age-related fractures, most notably those of the proximal femur. Substantial geographic variation has been noted in the incidence of hip fracture throughout the world, and estimates of recent incidence trends have varied widely. Studies in the published literature have reported an increase, plateau, and decrease in age-adjusted incidence rates for hip fracture among both men and women. Accurate characterisation of these temporal trends is important in predicting the health care burden attributable to hip fracture in future decades. We therefore conducted a review of studies worldwide, addressing secular trends in the incidence of hip and other fractures. Studies in western populations, whether in North America, Europe or Oceania, have generally reported increases in hip fracture incidence through the second half of the last century, but those continuing to follow trends over the last two decades have found that rates stabilise with age-adjusted decreases being observed in certain centres. In contrast, some studies suggest that the rate is rising in Asia. This synthesis of temporal trends in the published literature will provide an important resource for preventing fractures. Understanding the reasons for the recent declines in rates of hip fracture may help understand ways to reduce rates of hip fracture worldwide.

Effect of once-yearly zoledronic acid on the spine and hip as measured by quantitative computed tomography: results of the HORIZON Pivotal Fracture Trial

Changes in bone mineral density and bone strength following treatment with zoledronic acid (ZOL) were measured by quantitative computed analysis (QCT) or dual-energy X-ray absorptiometry (DXA). ZOL treatment increased spine and hip BMD vs placebo, assessed by QCT and DXA. Changes in trabecular bone resulted in increased bone strength.

INTRODUCTION

To investigate bone mineral density (BMD) changes in trabecular and cortical bone, estimated by quantitative computed analysis (QCT) or dual-energy X-ray absorptiometry (DXA), and whether zoledronic acid 5 mg (ZOL) affects bone strength.

METHODS

In 233 women from a randomized, controlled trial of once-yearly ZOL, lumbar spine, total hip, femoral neck, and trochanter were assessed by DXA and QCT (baseline, Month 36). Mean percentage changes from baseline and between-treatment differences (ZOL vs placebo, t-test) were evaluated.

RESULTS

Mean between-treatment differences for lumbar spine BMD were significant by DXA (7.0%, p < 0.01) and QCT (5.7%, p < 0.0001). Between-treatment differences were significant for trabecular spine (p = 0.0017) [non-parametric test], trabecular trochanter (10.7%, p < 0.0001), total hip (10.8%, p < 0.0001), and compressive strength indices at femoral neck (8.6%, p = 0.0001), and trochanter (14.1%, p < 0.0001).

CONCLUSIONS

Once-yearly ZOL increased hip and spine BMD vs placebo, assessed by QCT vs DXA. Changes in trabecular bone resulted in increased indices of compressive strength.

Application of the National Osteoporosis Foundation Guidelines to postmenopausal women and men: the Framingham Osteoporosis Study

We applied the 2008 National Osteoporosis Foundation (NOF) Guidelines to Framingham Osteoporosis Study participants and found nearly one half of Caucasian postmenopausal women and one sixth of men aged 50 years and older would be recommended for osteoporosis treatment. Given the high proportion of persons recommended for treatment, NOF Guidelines may need to be re-evaluated with respect to budget impact.

INTRODUCTION

Little is known about the public health impact of the NOF Guidelines. Therefore, we determined the proportion of US Caucasians recommended for treatment of osteoporosis according to NOF Guidelines (2003 and 2008).

METHODS

One thousand nine hundred and forty-six postmenopausal women and 1,681 men aged > or =50 years from the Framingham Study with information on bone mineral density (1987-2001) were included. Information on clinical predictors was used to estimate the 10-year probability of hip and major osteoporotic fracture by FRAX (version 3.0).

RESULTS

Overall proportion of women meeting treatment criterion was less when the 2008 NOF Guidelines were applied (41.1%) compared with 2003 Guidelines (47.8%). The proportion of women aged <65 years meeting treatment criterion was much less when applying 2008 Guidelines (23.1% in 2003, 8.3% in 2008), whereas the proportion of women aged >75 years increased slightly (78.3% in 2003, 86.0% in 2008). Seventeen percent of men aged > or =50 years met treatment criterion (2.5% aged 50-64 years, 49.8% aged >75 years).

CONCLUSIONS

Nearly one half of Caucasian postmenopausal women and one sixth of men aged 50 years and older would be recommended for osteoporosis treatment according to 2008 NOF Guidelines. Given the high proportion of persons recommended for treatment, NOF Guidelines may need to be re-evaluated with respect to budget impact.

Baseline serum estradiol and fracture reduction during treatment with hormone therapy: the Women's Health Initiative randomized trial

INTRODUCTION

The purpose of the study was to test the hypothesis that the reduction in fractures with hormone therapy (HT) is greater in women with lower estradiol levels.

METHODS

We conducted a nested case-control study within the Women's Health Initiative HT Trials. The sample included 231 hip fracture case-control pairs and a random sample of 519 all fracture case-control pairs. Cases and controls were matched for age, ethnicity, randomization date, fracture history, and hysterectomy status. Hormones were measured prior to randomization. Incident cases of fracture were identified over an average follow-up of 6.53 years.

RESULTS

There was no evidence that the effect of HT on fracture differed by baseline estradiol (E2) or sex hormone binding globulin (SHBG). Across all quartiles of E2 and SHBG, women randomized to HT had about a 50% lower risk of fracture, including hip fracture, compared to placebo.

CONCLUSION

The effect of HT on fracture reduction is independent of estradiol and SHBG levels.

Baseline Endogenous Estradiol and the Association of Hormone Therapy with Breast Cancer Risk, the Women's Health Initiative Clinical Trials

Background: The effect of exogenous hormones on breast cancer risk may depend on baseline endogenous levels of estradiol (E2). We investigated whether women with lower E2 levels will have the greatest increase in breast cancer risk during treatment with estrogen plus progestin ((E+P); combined conjugated equine estrogens (CEE) plus medroxyprogesterone acetate) or estrogen-alone ((E-alone); CEE) therapy. Additionally, we examined whether the risk of breast cancer varies by untreated levels of endogenous E2.Methods: We performed an ancillary study within the Women's Health Initiative E+P and E-alone clinical trials. We used a case-only design to test for interactions between untreated levels of E2 and hormone therapy (E+P or E-alone) on breast cancer risk. We measured baseline levels of bioavailable E2 in 346 cases of invasive breast cancer from the E+P trial and 231 cases from the E-alone trial. To estimate the risk of breast cancer by endogenous E2 levels (expressed as quartiles), we used a case-cohort design which included the cases described above in addition to a randomly selected comparison group (N=387; 203 from the E+P and 184 from the E-alone trial). Incident breast cancer cases were identified over an average follow-up of 4.1 years in the E+P trial and 5.4 years in the E-alone trial. All analyses were performed separately for the E+P and the E-alone trials.Results: In the case-only study, the effect of E+P therapy on breast cancer risk did not seem to vary by endogenous E2 quartiles (p-heterogeneity= 0.16). Breast cancer risk associated with E-alone treatment tended to be greater among women with the lowest E2 levels; however this association was not significant (hazard ratio (HR)= 1.44, 95% confidence interval (CI)= 0.79-2.59).Table 1. Effects of E+P and E-alone treatments on breast cancer risk (HR (95% CI)) by quartiles of baseline estradiol: case-only results E+PE-aloneEstradiol  Quartile 11.20 (0.80-1.80)1.44 (0.79-2.59)Quartile 20.88 (0.58-1.34)0.98 (0.58-1.67)Quartile 31.27 (0.81-2.00)0.79 (0.47-1.33)Quartile 40.67 (0.43-1.06)0.92 (0.57-1.49)P-heterogeneity0.160.51P-trend0.160.20 In the case-cohort analysis, higher endogenous E2 levels were associated with increased breast cancer risk (p-trend= 0.01), independent of hormone therapy.Table 2. Effects of baseline estradiol and hormone therapy (E+P vs. E-alone) on breast cancer risk (HR (95% CI)): case-cohort results E+PE-aloneHormone therapy treatment (Reference= placebo group)1.01 (0.96-1.07)0.84 (0.56-1.26)   Estradiol  Quartile 1 (Reference)1.001.00Quartile 21.22 (0.75-2.00)1.30 (0.77-2.17)Quartile 31.41 (0.87-2.32)1.32 (0.77-2.27)Quartile 41.85 (1.12-3.03)2.38 (1.32-4.35)P-trend0.010.01 Conclusion: The risk of breast cancer increases with higher levels of untreated endogenous E2. However, untreated E2 level does not modify the effect of E+P or E-alone therapy on breast cancer risk. Estradiol measurement is unlikely to identify women where hormone therapy may substantially increase the risk of breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 906.

Sex Hormones and Risk of Estrogen Receptor (ER)-Positive and ER-Negative Breast Cancer

Background: There is a need for improved breast cancer risk prediction by tumor estrogen receptor (ER) status. Endogenous sex hormone levels are associated with risk of overall breast cancer and the ER-positive subtype. However, the role of estradiol (E2) and testosterone (T) in the development of ER-negative tumors remains unclear. We investigated the associations of circulating levels of endogenous E2 and T with the risk of ER-positive as well as ER-negative breast cancer in postmenopausal women.Methods: We performed a case-cohort study within the Women's Health Initiative- Observational Study of postmenopausal women not taking exogenous hormones (age range: 50-79 years). Baseline endogenous levels of bioavailable E2 and T were measured using radioimmunoassays (University of Southern California, LA, CA) in 196 cases of invasive ER-positive breast cancer, 107 cases of invasive ER-negative cancer, and 560 randomly selected controls. The average follow-up time was 7.3 years.Results: After adjustment for putative risk factors, women with E2 levels in the upper three quartiles had an approximately 2-fold increased risk of ER-positive breast cancer, compared to those with E2 in the lowest quartile. These associations were only modestly decreased after adjustment for T. Higher T levels also indicated increased risk of ER-positive breast cancer; women in the third quartile of T had a 1.7-fold significantly higher risk, compared to those in the first quartile. However, this association was substantially diminished and not significant after controlling for E2.No association was observed between E2 levels and ER-negative cancer. However, women with T levels in the second, third, and fourth quartiles had lower risks of ER-negative cancer in the order of 54% (p= 0.018), 38% (p= 0.13), and 46% (p= 0.05), respectively, compared to women with T in the lowest quartile. These associations did not change materially after adjusting for E2.Table 1. Risk (Hazard Ratio (HR) and 95% CI) of ER-positive and ER-negative breast cancer by E2 and T quartiles ER-positive (HR (95% CI))ER-negative (HR (95% CI)) Model 1*Model 2**Model 1*Model 2*E2    Q11.001.001.001.00Q22.19 (1.25-3.84)2.12 (1.16-3.87)0.57 (0.29-1.12)0.72 (0.34-1.53)Q31.92 (1.10-3.35)1.74 (0.92-3.33)0.75 (0.40-1.42)1.09 (0.51-2.3)Q42.11 (1.21-3.68)1.86 (0.97-3.56)0.88 (0.48-1.62)1.36 (0.60-3.08)P for trend0.020.150.840.44T    Q11.001.001.001.00Q21.01 (0.57-1.78)0.82 (0.44-1.53)0.46 (0.24-0.88)0.45 (0.22-0.92)Q31.72 (1.04-2.84)1.36 (0.75-2.48)0.62 (0.34-1.15)0.56 (0.27-1.18)Q41.45 (0.85-2.46)1.16 (0.62-2.17)0.54 (0.29-1.00)0.44 (0.20-1.00)P for trend0.050.280.100.09*Model1: adjusted for age, race, age at menopause, alcohol use, physical activity, history of needle aspiration, lifetime use of estrogen+progestin, and time since quitting hormone therapy use. **Model2: adjusted for Model1 + sex hormones.Conclusion: Higher endogenous E2 levels were associated with increased risk of ER-positive breast cancer, independent of risk factors and T. In contrast, higher concentrations of endogenous T were related to lower risk of ER-negative breast cancer, independent of risk factors and E2. This is the first study to report an association of testosterone with ER-negative breast cancer. Further studies are needed to confirm this association.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 907.

Effects of Arzoxifene on Breast Cancer Incidence in Postmenopausal Women with Osteoporosis or with Low Bone Mass

Precinical and early clinical data indicate that arzoxifene, a third generation SERM, is more potent and bioavailable than raloxifene. Here we report the results of the phase 3, multicenter, placebo-controlled, double-blind GENERATIONS trial of 9354 postmenopausal women with osteoporosis (N=5252) or low bone mineral density (BMD) (N=4102), randomly assigned to arzoxifene 20mg/d (N=4676) or placebo (N=4678). The primary endpoints were the incidences of radiographic vertebral fracture in the osteoporotic population (at 36 months) and invasive breast cancer in all study participants (after all participants had completed 48 months of treatment). Breast cancers were detected by annual mammograms and/or clinical breast examination and adjudicated centrally by an independent committee. The primary analysis compared the incidence of adjudicated invasive breast cancer between treatment groups using a log-rank test. Both treatment groups were evenly balanced for risk of breast cancer including age, previous benign breast biopsies, family history of breast cancer, estimated Gail risk and BMD. The trial met both primary endpoints with a 41% reduction in the incidence of vertebral fractures (p&lt;0.001) and 56% percent reduction in incidence of invasive breast cancer (p=0.002). Table 1 summarizes the breast cancer findings after the 48 month follow-up. The incidence of invasive breast cancer in the placebo group was higher in the women who had a Gail score &gt; 1.66 compared to ≤ 1.66 (1.5% vs. 0.6%) and in those with low bone mass versus osteoporosis (1.2% vs. 0.7%), but the risk reduction with arzoxifene was similar between Gail risk groups (HR 0.32 vs 0.57. p-value for interaction=0.31) and between low bone mass and osteoporosis groups (HR 0.34 vs 0.57. p-value for interaction=0.35). Other findings included no significant reduction in non-vertebral fractures or cardiovascular events. Generally, arzoxifene was well tolerated, although there was a significant increase in venous thromboembolism, gall bladder disease, pulmonary obstructive/infective disorders, hot flushes, muscle cramps and gynecological-related events in the arzoxifene group. We conclude that arzoxifene reduces the incidence of invasive breast cancer as well as vertebral fracture. The results of the GENERATIONS trial provide further support for a significant risk reduction of invasive breast cancer by SERMs in post menopausal women.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 51.