Performance of FRAX in Women with Breast Cancer Initiating Aromatase Inhibitor Therapy: A Registry-Based Cohort Study

Management of cancer treatment-induced bone loss in patients with breast and hormone sensitive prostate cancer: AIOM survey

PURPOSE

Cancer treatment-induced bone loss is a side effect of hormonal therapy that can severely affect patients' quality of life. The aim of this survey was to obtain an updated picture of management of bone health in patients with breast cancer undergoing adjuvant hormonal therapy and in patients with hormone sensitive prostate cancer according to Italian oncologists.

METHODS

Our survey was made up of 21 multiple-choice questions: the first part dealt with the respondents' characteristics, while the second with management of bone health in the described setting. An invitation to complete the survey was sent by e-mail to 2336 oncologists, members of Italian Association of Medical Oncology, in October 2022.

RESULTS

Overall, 121 (5.2%) Italian oncologists completed the survey. In most cases (57%) the oncologist personally took charge of the management of bone health in patients at risk for cancer treatment-induced bone loss. At the beginning of hormonal therapy, most respondents reported to require bone health diagnostic exams, such as dual-energy X-ray absorptiometry (89%), repeated with different timing. Main reported reasons (not mutually exclusive) for prescribing antiresorptive drugs were modifying fracture risk (87%), densitometry values (75%) or prognosis (34%). Answers about the management of antiresorptive therapy were heterogeneous.

CONCLUSION

A heterogeneous approach on the management of cancer treatment-induced bone loss in Italy arises from this survey. This scenario highlights the need for a major consensus of the Italian scientific community on the diagnostic and therapeutic approach of cancer treatment-induced bone loss and for a greater awareness of this topic among Italian oncologists.

Ovarian Suppression: Early Menopause, Late Effects

PURPOSE OF REVIEW

Pre-menopausal women diagnosed with hormone receptor (HR) breast cancer are candidates for prolonged hypoestrogenism to improve cancer outcomes. However, the disease benefit eclipses the toxicities associated with ovarian function suppression (OFS), which are often under-reported.

RECENT FINDINGS

Increased risk of mortality from cardiovascular disease, bone disorders, and metabolic disorders is well reported in women with no history of cancer, after surgical oophorectomy or premature ovarian failure. Vasomotor symptoms, urogenital atrophy, weight gain, sexual dysfunction, cognitive decline, and sleep disturbances contribute to the increased non-compliance associated with OFS, especially in younger women. Balancing the toxicities of prolonged OFS with its benefits should be critically analyzed by providers when making recommendations for their patients. Supportive care to manage multi-system toxicities and to counteract the long-term impact on all-cause mortality should be emphasized by every cancer program. Future studies with OFS should incorporate patient outcomes and strategies for symptom management in addition to focusing on improving disease outcomes.

Probability of the 10-year Risk of Hip and Major Osteoporotic Fracture in Non-radiographic Axial Spondyloarthritis

BACKGROUND

Fracture risk in non-radiographic spondyloarthritis is underestimated. A reliable tool such as the Fracture Risk Assessment tool (FRAX) may assess this risk probability. This study aimed to assess the fracture risk by the FRAX score in patients with nr-axSpA and to determine factors associated with high fracture risk.

METHODS

We conducted a retrospective study of nr-axSpA patients meeting the Assessment of SpondyloArthritis International Society (ASAS) classification criteria for spondyloarthritis. All patients had Bone Mineral Density (BMD) by dual-energy X-ray absorptiometry (DEXA). The 10- year probability of major osteoporotic fracture (MOF) and hip fracture (HF) was calculated using the Fracture Risk Assessment Tool (FRAX).

RESULTS

Among 40 patients with nr-axSpA, 27 were women (67.5%). Their mean age was 43.7 ± 12.1 years. The mean disease duration was 3.15 ± 2.7 years. Eighteen patients (45%) had osteopenia, and 12 patients (30%) had osteoporosis. The median HF FRAX was 0% [0-1.2]. The median MOF FRAX was 0.5% [0.3-1.8]. MOF FRAX was positively correlated with age (p = 0.002), disease onset age (p = 0.006), disease duration (p = 0.024), and the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) (p < 0.0001), and negatively correlated with daily calcium intake (p < 0.0001). HF FRAX was positively correlated with mSASSS (p < 0.0001) and negatively correlated with daily calcium intake (p = 0.005).

CONCLUSION

Our study confirmed the frequency of bone loss during nr-axSpA and showed that osteoporotic risk fracture was related not only to traditional risk factors for osteoporosis but also to disease-related factors.

Effect of BMI-Discordant Abdominal Tissue Thickness on Fracture Probability: A Registry-Based Study

FRAX, which is used to assess fracture probability, considers body mass index (BMI), but BMI may not reflect individual variation in body composition and distribution. We examined the effect of BMI-discordant abdominal thickness on FRAX-derived fracture probability for major osteoporotic fracture (MOF) and hip fracture. We studied 73,105 individuals, mean age 64.2 years. During mean 8.7 years, 7048 (9.6%) individuals sustained incident MOF, including 2155 (3.0%) hip fractures. We defined abdominal thickness index (ATI) as the difference between abdominal thickness measured by dual-energy X-ray absorptiometry (DXA) and thickness predicted by BMI using sex-stratified regression. ATI was categorized from lower (<-2 cm, -2 to -1 cm) to higher (1-2 cm, >+2 cm) with referent around zero (-1 to +1 cm). Adjusted for FRAX probability, increasing ATI was associated with incident MOF and hip fracture (p < 0.001). For the highest ATI category, MOF risk was increased (hazard ratio [HR] = 1.23, 95% confidence interval [CI] 1.12-1.35) independent of FRAX probability. Similar findings were noted for hip fracture probability (HR = 1.28, 95% CI 1.09-1.51). There was significant age-interaction with much larger effects before age 65 years (HR = 1.44, 95% CI 1.23-1.69 for MOF; 2.29, 95% CI 1.65-3.18 for hip fracture). In contrast, for the subset of individuals with diabetes, there was also increased risk for those in the lowest ATI category (HR = 1.73, 95% CI 1.12-2.65 for MOF; 2.81, 95% CI 1.59-4.97 for hip fracture). Calibration plots across ATI categories demonstrated deviation from the line of identity in women (calibration slope 2.26 for MOF, 2.83 for hip fracture). An effect of ATI was not found in men, but this was inconclusive as the sex-interaction terms did not show significant effect modification. In conclusion, these data support the need to investigate increased abdominal thickness beyond that predicted by BMI and sex as a FRAX-independent risk factor for fracture. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Effect of Race/Ethnicity on United States FRAX Calculations and Treatment Qualification: A Registry-Based Study

Since 2008. the United States has had four race/ethnic fracture risk assessment tool (FRAX) calculators: White ("Caucasian"), Black, Asian, and Hispanic. The American Society for Bone and Mineral Research Task Force on Clinical Algorithms for Fracture Risk has been examining the implications of retaining race/ethnicity in the US FRAX calculators. To inform the Task Force, we computed FRAX scores according to each US calculator in 114,942 White, 485 Black, and 2816 Asian women (self-reported race/ethnicity) aged 50 years and older. We estimated treatment qualification based upon FRAX thresholds (3% for hip fracture, 20% for major osteoporotic fracture [MOF]). Finally, we examined measures for a hypothetical population-based FRAX calculator derived as the weighted mean for the US population based upon US Census Bureau statistics. With identical inputs, the highest FRAX measurements were found with the White FRAX calculator, lowest measurements with the Black calculator, and intermediate measurements for the Asian and Hispanic calculators. The percentage of women with FRAX scores exceeding the hip fracture treatment threshold was 32.0% for White, 1.9% for Black, and 19.7% for Asian women; the MOF treatment threshold was exceeded for 14.9% of White, 0.0% of Black, and 3.5% of Asian women. Disparities in treatment qualification were reduced after considering additional criteria (fracture history and dual-energy X-ray absorptiometry [DXA] T-score -2.5 or lower). When fracture risk was recalculated for non-White women using the White FRAX calculator, mean values for Asian women slightly exceeded those for White women but for Black women remained substantially below those for White women. When using a single population-based FRAX calculator, the mean probability of fracture and treatment qualification increased for non-White women across the age range. In summary, use of a single population-based FRAX calculator, rather than existing US race/ethnic FRAX calculators, will reduce differences in treatment qualification and may ultimately enhance equity and access to osteoporosis treatment. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

A Population-Based Registry Study of Extended Bisphosphonate Use: Minimal Shift After Landmark Publications About Shorter Treatment Duration

Optimal duration of bisphosphonate therapy was unknown until the FLEX study was published in 2006 showing a 5-year course to be adequate for most women. In 2008, a link between long-term bisphosphonate and atypical femoral fractures was reported and confirmed in later studies. We hypothesized these landmark observations should have led to a decrease in use of bisphosphonates for >5 or 10 years, from 2010 onward. The Manitoba Bone Mineral Density (BMD) Registry with linkage to provincial pharmacy data was used to determine the percentage of long- and very long-term bisphosphonate users from therapy start. The cohort comprised women aged >50 years with BMD between 1995 and 2018 with oral bisphosphonate first prescribed for >90 days with adherence >75% in the first year. For each calendar year of continued therapy, the percentage of patients and medication possession rate was tabulated. The percentage of users beyond 5 years was compared among patients who started therapy in 1998-2004 (those taking 5 years of therapy still finish before 2010) versus 2005-2012 (all new therapy starts overlap 2010 in those taking ≥5 years of treatment). The cohort included 2991 women with mean follow-up 8.8 (1.3) years, 64.9% of whom took continuous oral bisphosphonate for >5 years and 41.9% for >10 years. In the earlier versus later era, there were 74.4% versus 70.2% who completed 5 years. With respect to longer treatment, there were 68.0% and 60.5% of patients treated for 6 or more years (p < 0.0001) and 46.6% versus 33.5% treated for >10 years (p = 0.08). Medication possession rate was >79% in every year of therapy. Landmark studies leading to more limited bisphosphonate courses may have slightly reduced longer-term treatment, but up to one-third of adherent patients in the modern era still receive continuous bisphosphonate therapy for >10 years. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

FRAX Adjustment by Trabecular Bone Score with or Without Bone Mineral Density: The Manitoba BMD Registry

Trabecular bone score (TBS), a texture measure derived from spine dual-energy x-ray absorptiometry (DXA) images, is a FRAX®-independent risk factor for fracture. The TBS adjustment to FRAX assumes the presence of femoral neck BMD in the calculation. However, there are many individuals in whom hip DXA cannot be acquired. Whether the TBS-adjustment would apply to FRAX probabilities calculated without BMD has not been studied. The current analysis was performed to evaluate major osteoporotic fracture (MOF) and hip fracture risk adjusted for FRAX with and without femoral neck BMD. The study cohort consisted of 71,209 individuals (89.8% female, mean age 64.0 years). During mean follow-up 8.7 years, 6743 (9.5%) individuals sustained one or more incident MOF, of which 2037 (2.9%) sustained a hip fracture. Lower TBS was significantly associated with increased fracture risk when adjusted for FRAX probabilities, with a slightly larger effect when BMD was not included. Inclusion of TBS in the risk calculation gave a small but significant increase in stratification for fracture probabilities estimated with and without BMD. Calibration plots showed very minor deviations from the line of identity, indicating overall good calibration. In conclusion, the existing equations for incorporating TBS in FRAX estimates of fracture probability work similarly when femoral neck BMD is not used in the calculation. This potentially extends the range of situations where TBS can be used clinically to those individuals in whom lumbar spine TBS is available but femoral neck BMD is not available.

Fracture risk gradient assessed by categories of bone mineral density and trabecular bone score: the Manitoba BMD Registry

Trabecular bonescore (TBS) helps to predict fracture risk in older adults. In this registry-based cohort study of patients aged 40 years and older, reduction in bone mineral density (BMD) and TBS are complementary for fracture risk prediction enhancement with lower BMD imparting greater risk than reduction in TBS.

PURPOSE

Trabecular bone score (TBS) enhances fracture risk prediction independent of bone mineral density (BMD) in older adults. The purpose of this study was to further evaluate the gradient of fracture risk based on TBS tertile categories and WHO BMD categories, adjusted for other risk factors.

METHODS

Using the Manitoba DXA registry, patients aged 40 years and older with spine/hip DXA and L1-L4 TBS were identified. Any incident fractures, major osteoporotic fractures (MOF), and hip fractures were identified. Cox regression models were used to estimate unadjusted and covariate-adjusted hazard ratios (HR, 95%CI) for incident fracture by BMD and TBS category and for each SD decrease in BMD and TBS.

RESULTS

The study population included 73,108 individuals, 90% female with mean age 64 years. Mean (SD) minimum T-score was - 1.8 (1.1), and mean L1-L4 TBS was 1.257 (0.123). Lower BMD and TBS, both per SD, by WHO BMD category and by TBS tertile category, were significantly associated with MOF, hip, and any fracture (all HRs p < 0.001). However, the quantum of risk was consistently greater for BMD than TBS, with HRs showing non-overlapping CIs.

CONCLUSION

TBS is complementary to BMD in prediction of incident major, hip, and any osteoporosis-related fracture, but reductions in BMD impart greater risk than reductions in TBS on both continuous and categorical scales.

Bone health in breast cancer

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

Management of cancer treatment-induced bone loss (CTIBL) in patients with breast cancer or prostate cancer

Breast cancer and prostate cancer are sex hormone-dependent cancers, and estrogen or androgen suppression therapy is the standard treatment. Cancer treatment-induced bone loss (CTIBL): bone loss and osteoporosis have become important side effects of these therapies. To summarize the current evidences, (1) Endocrine therapy for breast cancer and prostate cancer is associated with a significant decrease in bone mineral density. (2) Aromatase inhibitors (AI) for breast cancer are associated with a significant increase in fractures, and androgen deprivation therapy (ADT) for prostate cancer is likely to be associated with an increase in fractures. (3) Administration of bisphosphonates and denosumab increases bone mass in patients undergoing endocrine therapy for breast cancer. Administration of bisphosphonates, denosumab, and SERMs increased bone mass in patients undergoing ADT therapy for prostate cancer. (4) Bisphosphonates and denosumab reduce fracture risk in patients on AI for breast cancer, and toremifene and denosumab in patients on ADT for prostate cancer.

Contributions of Clinical and Technical Factors to Longitudinal Change in Trabecular Bone Score and Bone Density: A Registry-Based Individual-Level Analysis

Lumbar spine trabecular bone score (TBS), a gray-level texture measure derived from spine dual-energy X-ray absorptiometry (DXA) images, is a bone mineral density (BMD)-independent risk factor for fracture. An unresolved question is whether TBS is sufficiently responsive to change over time or in response to widely used osteoporosis therapy at the individual level to serve as a useful biomarker. Using the Manitoba DXA Registry, we identified 11,643 individuals age 40 years and older with two fan-beam DXA scans performed on the same instrument within 5 years (mean interval 3.2 years), of whom 6985 (60.0%) received antiresorptive osteoporosis medication (majority oral bisphosphonate) between the scans. We examined factors that were associated with a change in lumbar spine TBS, lumbar spine BMD, and total hip BMD exceeding the 95% least significant change (LSC). Change exceeding the LSC was identified in 23.0% (9.3% increase, 13.8% decrease) of lumbar spine TBS, 38.2% (22.1% increase, 16.1% decrease) lumbar spine BMD, and 42.5% (17.6% increase, 24.9% decrease) total hip BMD measurement pairs. From regression models, the variables most strongly associated with significant change in TBS (decreasing order) were tissue thickness change, acquisition mode change, weight change, and spine percent fat change. Consistent with the insensitivity of TBS to oral antiresorptive therapies, use of these agents showed very little effect on TBS change. In contrast, for both spine BMD change and total hip BMD change, osteoporosis medication use was the most significant variable, whereas tissue thickness change, acquisition mode change, and weight change had relatively weak effects. In summary, change in spine TBS using the present algorithm appears to be strongly affected by technical factors. This suggests a limited role, if any, for using TBS change in untreated individuals or for monitoring response to antiresorptive treatment in routine clinical practice with the current version of the TBS algorithm. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Bone density and trabecular bone score to predict fractures in adults aged 20-39 years: a registry-based study

Trabecular bone score (TBS) enhances fracture risk assessment in older adults; whether this is true in younger people is uncertain. In this registry-based study of adults aged 20-39 years, low BMD, but not low TBS, predicted fracture.

PURPOSE

Trabecular bone score (TBS), a bone texture measurement, is associated with fracture risk independent of bone mineral density (BMD) in older adults. In adults aged 20-40 years, TBS remains stable and its role in fracture risk assessment is unclear. We utilized the Manitoba Bone Density Registry to explore the relationship of fracture risk with BMD and TBS in younger adults.

METHODS

Women and men aged 20-39 years referred for DXA testing were studied. Incident major and any fractures were captured from health records. Categories based on WHO BMD T-score classification and TBS tertile were considered using Cox regression models to estimate covariate-adjusted (including sex) hazard ratios (aHR, 95%CI) for incident fracture by category, and each SD decrement in BMD and TBS.

RESULTS

The study included 2799 individuals (77% female, mean age 32 years). Mean (SD) minimum T-score was - 0.9 (1.1) and TBS 1.355 (0.114); 7% had osteoporosis and 13% were in the lowest TBS tertile. Incident major osteoporotic fracture (MOF) and any fracture risk was elevated in those with osteopenia (aHRs 1.20/1.45) and osteoporosis (aHRs 4.60/5.16). Fracture risk was unrelated to TBS tertile. Each SD decrement in BMD was associated with increased MOF risk (aHR 1.64) and any fracture (aHR 1.71); lower TBS was unrelated to fractures.

CONCLUSION

In young adults, low BMD, but not low TBS, was predictive of MOF and any fracture. Routine clinical TBS measurement is not recommended for young adults. Further study is indicated to evaluate whether TBS is beneficial in subsets of younger adults.

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.

Performance of FRAX in Men With Prostate Cancer: A Registry-Based Cohort Study

The Fracture Risk Assessment Tool (FRAX®) was created to predict major osteoporotic fractures (MOF) and hip fractures in the general population. Whether FRAX accurately predicts fractures in men with prostate cancer is unknown. Our objective was to assess the performance of FRAX for predicting incident fractures in men with prostate cancer. Men from the Manitoba Bone Mineral Density (BMD) Registry (1996-2018) with prostate cancer diagnoses in the 3 years prior to dual-energy X-ray absorptiometry (DXA) were identified. FRAX scores with and without BMD were calculated. From population-based healthcare data we identified incident MOF, hip fracture, any osteoporotic fracture and death from the date of BMD testing to March 31, 2018. Cox regression was performed to estimate hazard ratios (HRs) with 95% confidence intervals (95% CIs) per standard deviation increase in FRAX score. Observed 10-year probability (estimated with competing risk of mortality) was compared with 10-year FRAX-predicted fracture probability to assess calibration. The study population included 684 men with prostate cancer (mean age 74.6 years) and 8608 men without prostate cancer (mean age 65.5 years). FRAX stratified risk for MOF (HR 1.91, 95% CI 1.48-2.45 with BMD; HR 1.96, 95% CI 1.43-2.69 without BMD) and hip fracture (HR 3.37, 95% CI 1.90-6.01 with BMD; HR 4.58, 95% CI 2.17-9.67 without BMD) in men with prostate cancer. There was no effect modification observed with prostate cancer status or current androgen deprivation therapy. Observed 10-year fracture probability in men with prostate cancer showed good agreement with FRAX with and without BMD included in the calculation (observed/predicted calibration ratios MOF 0.97, hip 1.00 with BMD; MOF 0.92, hip 0.93 with BMD). In conclusion, FRAX reliably predicts incident fractures in men with prostate cancer. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Prevention of aromatase inhibitor-induced bone loss with anti-resorptive therapy in post-menopausal women with early-stage breast cancer

We assessed if antiresorptive treatment can prevent aromatase inhibitor-induced bone loss in patients with early breast cancer. We observed that patients who did not receive antiresorptive treatment had a 20.8-fold increase in risk of bone loss after 24 months of aromatase inhibitors therapy.

PURPOSE

This study aimed to describe changes in femoral and lumbar bone mineral density (BMD) after 24 months of aromatase inhibitors (AIs) and antiresorptive treatment in postmenopausal women with estrogen receptor-positive breast cancer.

METHODS

Prospective, longitudinal study in a real-life setting with a 2-year follow-up. Patients underwent a complete baseline bone assessment including clinical assessment, biological evaluation, BMD measurement, and spine X-ray. Antiresorptive treatment was prescribed to patients with a T-score <  - 2 or a T-score <  - 1.5 SD with additional osteoporosis risk factors. A follow-up bone assessment was carried out after 24 months.

RESULTS

Among 328 patients referred to our center, 168 patients (67.7 ± 10.6 years) were included in our study, and 144 were eligible for antiresorptive treatment. After 24 months, patients receiving antiresorptive treatment experienced a significant increase of + 6.28% in femoral-BMD (F-BMD) and + 7.79% in lumbar-BMD (L-BMD). This increase was not significantly different between osteoporotic and osteopenic patients. Conversely, patients not receiving antiresorptive treatment presented significant F-BMD and L-BMD loss regardless of the baseline BMD. In the multivariate logistic model, the lack of antiresorptive treatment was the only predictive factor for major femoral bone loss with a 20.83 odds ratio (CI95%:4.2-100, p < 0.001).

CONCLUSION

This real-life study confirmed that antiresorptive treatment significantly increases femoral and lumbar BMD regardless of the baseline BMD in postmenopausal patients receiving AIs for early breast cancer. Patients who did not receive antiresorptive treatment had a 20.8-fold increased risk of major bone loss. Nevertheless, the best threshold to adopt for starting antiresorptive agents remains undetermined.

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

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

Construction and validation of a risk prediction model for aromatase inhibitor-associated bone loss

Purpose

To establish a high-risk prediction model for aromatase inhibitor-associated bone loss (AIBL) in patients with hormone receptor-positive breast cancer.

Methods

The study included breast cancer patients who received aromatase inhibitor (AI) treatment. Univariate analysis was performed to identify risk factors associated with AIBL. The dataset was randomly divided into a training set (70%) and a test set (30%). The identified risk factors were used to construct a prediction model using the eXtreme gradient boosting (XGBoost) machine learning method. Logistic regression and least absolute shrinkage and selection operator (LASSO) regression methods were used for comparison. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of the model in the test dataset.

Results

A total of 113 subjects were included in the study. Duration of breast cancer, duration of aromatase inhibitor therapy, hip fracture index, major osteoporotic fracture index, prolactin (PRL), and osteocalcin (OC) were found to be independent risk factors for AIBL (p < 0.05). The XGBoost model had a higher AUC compared to the logistic model and LASSO model (0.761 vs. 0.716, 0.691).

Conclusion

The XGBoost model outperformed the logistic and LASSO models in predicting the occurrence of AIBL in patients with hormone receptor-positive breast cancer receiving aromatase inhibitors.

Fracture Prediction from Trabecular Bone Score is Unaffected by Anti-Resorptive Treatment: A Registry-Based Cohort Study

Trabecular bone score (TBS) predicts osteoporotic fractures independent of bone mineral density (BMD) and clinical risk factors. The aim of this study was to explore whether anti-resorptive treatment affects fracture risk prediction from TBS using a large clinical registry that includes all dual-energy X-ray absorptiometry (DXA) tests for the Province of Manitoba, Canada. Cohort 1 included 53,863 individuals aged ≥ 40 years (11.4% men; mean age 64.1 years) who had not received any anti-resorptive therapy in the year prior the baseline DXA. Cohort 2 comprised 22,917 individuals aged ≥ 40 years (6% men, mean age 66.7 years) undergoing a second DXA visit. Anti-resorptive medication was initiated in the first year after DXA in 13,439 (25%) individuals from Cohort 1 (87.9% bisphosphonates); among Cohort 2 8,864 (38.7%) had received anti-resorptive medication in the year before DXA (77.8% bisphosphonates). Incident major osteoporotic fracture (MOF), hip fracture and any fracture were identified over mean follow up 8.6 and 7.0 years for Cohorts 1 and 2, respectively. Area under the curve showed significant risk stratification for all fracture types and treatment levels, whether treatment was initiated after TBS measurement (Cohort 1) or prior to TBS measurement (Cohort 2). In Cox regression models, without and with covariate adjustment, fracture prediction from TBS was unaffected by anti-resorptive medication use (p-interaction >0.5 for all analyses). In conclusion, TBS was a robust predictor of fracture in models adjusted for clinical risk factors and BMD. The use of anti-resorptive therapy, either in the year before or following TBS measurement, did not attenuate fracture risk prediction by TBS compared to untreated individuals.

External validation of FRISBEE 5-year fracture prediction models: a registry-based cohort study

Five-year fracture risk prediction from the Fracture Risk Brussels Epidemiological Enquiry (FRISBEE) models was externally tested in 9716 Canadian women and demonstrated good discrimination but consistently overestimated risk.

INTRODUCTION

Five-year risk prediction models for all fractures, major osteoporotic fractures (MOFs) and central fractures (proximal to forearm and ankle) from the FRISBEE cohort demonstrated good performance in the original derivation cohort. Our aim was to externally validate the FRISBEE-based 5-year prediction models in routine practice.

METHODS

Using the population-based Manitoba Bone Mineral Density (BMD) registry, we identified women aged 60-85 years undergoing baseline BMD assessment from September 1, 2012 to March 31, 2018. Five-year probabilities of all fractures, MOFs and central fractures were calculated using the FRISBEE prediction models. We identified incident non-traumatic fractures up to 5 years from population-based healthcare data sources. Performance characteristics included area under the receiver operating characteristic curve (AUROC), gradient of risk (hazard ratio [HR] per SD increase and across risk tertiles) from Cox regression analysis, and calibration (ratio 5-year observed cumulative incidence to predicted fracture probability).

RESULTS

We included 9716 women (mean age 70.7 + / - SD 5.3 years). During a mean observation time of 2.5 years, all fractures, MOFs and central fractures were identified in 377 (3.9%), 264 (2.7%) and 259 (2.7%) of the women. AUROC showed significant fracture risk stratification with the FRISBEE models (all fractures 0.69 [95%CI 0.67-0.72], MOFs 0.71 [95%CI 0.68-0.74], central fractures 0.72 [95%CI 0.69-0.75]). There was a strong gradient of risk for predicting fracture outcomes per SD increase (HRs from 1.98 to 2.26) and across risk tertiles (HRs for middle vs lowest from 2.25 to 2.41, HRs for highest vs lowest from 4.70 to 6.50). However, risk was overestimated for all fractures (calibration-in-the-large 0.63, calibration slope 0.63), MOF (calibration-in-the-large 0.51, calibration slope 0.57) and central fractures (calibration-in-the-large 0.55, calibration slope 0.60).

CONCLUSIONS

FRISBEE 5-year prediction models were externally validated to stratify fracture risk similar to the derivation cohort, but would need recalibration for Canada as risk was overestimated.

Muscle strength is associated with fracture risk obtained by fracture risk assessment tool (FRAX) in women with breast cancer

Background

Women with breast cancer are at risk for the development of sarcopenia and occurrence of fractures. The initial and periodic screening of these conditions can prevent the risks of disability, poor quality of life, and death. The present study investigated the association between sarcopenia phenotypes and fracture risk, assessed by the Fracture Risk Assessment Tool (FRAX) in women with breast cancer.

Methods

Cross-sectional study. It included women aged between 40 and 80 years, diagnosed with Luminal subtype breast cancer, with time of diagnosis ≤ 12 months, who had not started endocrine therapy, did not have metastasis, had not been treated for another malignancy, and had no recurrences. Sociodemographic, habits and lifestyle, clinical, anthropometric, and body composition variables were considered. Muscle strength, skeletal muscle mass, and physical performance were investigated using handgrip strength (HGS), appendicular skeletal muscle mass index (ASMI), and Timed Up and Go test (TUGT), respectively. Fracture risk was assessed using FRAX. Multiple linear regression models were conducted to verify the association between exposure variables and sarcopenia phenotypes. A significance level of p < 0.05 was adopted for all tests using the SPPS 25.0 program.

Results

Sixty-two women with a mean age of 58.1 ± 10.4 years were evaluated. Of these, 66.1% self-declared to be non-white, 41.9% and 71.0% did not consume alcohol or smoke, respectively, and 61.3% were insufficiently active. A total of 45.2% had clinical stage II carcinoma and 65.5% had the invasive breast carcinoma histological subtype. There was a predominance of adequacy of HGS (88.7%), ASMI (94.5%), and TUGT (96.8%), as well as low risk of hip fractures (85.5%) and major fractures (82.3%). HGS remained associated with FRAX hip fractures (p = 0.007) and FRAX major fractures (p = 0.007) in the adjusted models, while ASMI was associated with body mass (p < 0.001).

Conclusions

Low muscle strength was the sarcopenia phenotype that remained associated with fracture risk in women with breast cancer, independently of sociodemographic factors, level of physical activity, and clinical factors. In addition to the assessment of probable sarcopenia, this measurement may point out the risk of fractures.

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

BACKGROUND

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

AIM

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

DESIGN

A cross-section propensity score matching study.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of Discordant Hip Bone Density on Incident Fracture Risk: A Registry-Based Cohort Study

The Fracture Risk Assessment Tool (FRAX®) combines clinical risk factors and optionally femoral neck bone density to estimate major osteoporotic fracture (MOF) and hip fracture probability. Hip dual-energy X-ray absorptiometry (DXA) simultaneously measures the trochanter and total hip, but these regions are not considered by FRAX. Our aim was to determine whether discordance in trochanter and total hip bone density (defined as ≥1 T-score difference from the femoral neck) affects fracture risk adjusted for fracture probability. Using the Manitoba bone density registry, we identified 84,773 women and men age 40 years or older undergoing baseline hip DXA. The outcomes were incident MOF and hip fracture. Cox regression hazard ratios (HRs) with 95% confidence intervals (CIs) adjusted for baseline fracture probability were used to test the association between hip T-score discordance and incident fractures. Hip T-score discordance affected more than one in five subjects (trochanter lower in 3.9%, higher in 14.2%; total hip lower in 0.3%, higher in 14.9%). After mean 8.8 years there were 8444 incident MOF including 2664 hip fractures. Discordantly lower trochanter and lower total hip T-score (≥1 below femoral neck) was associated with increased risk for MOF (adjusted HRs 1.47 and 1.60) and hip fracture (HRs 1.85 and 2.12), while discordantly higher trochanter and total hip T-score (≥1 above femoral neck) was associated with lower risk for MOF (HRs 0.83 and 0.71) and hip fracture (HRs 0.79 and 0.68). In models that examined the trochanter and total hip simultaneously, discordantly lower trochanter T-score was associated with increased incident MOF and hip fracture risk (HRs 1.43 and 1.79) whereas discordantly higher total hip T-score was associated with lower risk (HRs 0.73 and 0.75). In conclusion, trochanter and total hip regions frequently show T-scores that are discordant with the femoral neck. This information strongly affects incident fracture risk independent of fracture probability scores computed with femoral neck bone density. © 2022 American Society for Bone and Mineral Research (ASBMR).

Performance of the Garvan Fracture Risk Calculator in Individuals with Diabetes: A Registry-Based Cohort Study

Diabetes increases fracture and falls risks. We evaluated the performance of the Garvan fracture risk calculator (FRC) in individuals with versus without diabetes. Using the population-based Manitoba bone mineral density (BMD) registry, we identified individuals aged 50-95 years undergoing baseline BMD assessment from 1 September 2012, onwards with diabetes and self-reported falls in the prior 12 months. Five-year Garvan FRC predictions were generated from clinical risk factors, with and without femoral neck BMD. We identified non-traumatic osteoporotic fractures (OF) and hip fractures (HF) from population-based data to 31 March 2018. Fracture risk stratification was assessed from area under the receiver operating characteristic curves (AUROC). Cox regression analysis was performed to examine the effect of diabetes on fractures, adjusted for Garvan FRC predictions. The study population consisted of 2618 women with and 14,064 without diabetes, and 636 and 2201 men with and without the same, respectively. The Garvan FRC provided significant OF and HF risk stratification in women with diabetes, similar to those without diabetes. Analyses of OF in men were limited by smaller numbers; no significant difference was evident by diabetes status. Cox regression showed that OF risk was 23% greater in women with diabetes adjusted for Garvan FRC including BMD (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.01-1.49), suggesting it slightly underestimated risk; a non-significant increase in diabetes-related HF risk was noted (HR 1.37, 95% CI 0.88-2.15). Garvan FRC shows similar fracture risk stratification in individuals with versus without diabetes, but may underestimate this risk.

Reverse engineering the FRAX algorithm: Clinical insights and systematic analysis of fracture risk

The Fracture Risk Assessment Tool (FRAX) is a computational tool developed to predict the 10-year probability of hip fracture and major osteoporotic fracture based on inputs of patient characteristics, bone mineral density (BMD), and a set of seven clinical risk factors. While the FRAX tool is widely available and clinically validated, its underlying algorithm is not public. The relative contribution and necessity of each input parameter to the final FRAX score is unknown. We systematically collected hip fracture risk scores from the online FRAX calculator for osteopenic Caucasian women across 473,088 unique inputs. This dataset was used to dissect the FRAX algorithm and construct a reverse-engineered fracture risk model to assess the relative contribution of each input variable. Within the reverse-engineered model, age and T-Score were the strongest contributors to hip fracture risk, while BMI had marginal contribution. Of the clinical risk factors, parent history of fracture and ongoing glucocorticoid treatment had the largest additive effect on risk score. A generalized linear model largely recapitulated the FRAX tool with an R2 of 0.91. Observed effect sizes were then compared to a true patient population by creating a logistic regression model of the Study of Osteoporotic Fractures (SOF) cohort, which closely paralleled the effect sizes seen in the reverse-engineered fracture risk model. Analysis identified several clinically relevant observations of interest to FRAX users. The role of major osteoporotic fracture risk prediction in contributing to an indication of treatment need is very narrow, as the hip fracture risk prediction accounted for 98% of treatment indications for the SOF cohort. Removing any risk factor from the model substantially decreased its accuracy and confirmed that more parsimonious models are not ideal for fracture prediction. For women 65 years and older with a previous fracture, 98% of FRAX combinations exceeded the treatment threshold, regardless of T-score or other factors. For women age 70+ with a parent history of fracture, 99% of FRAX combinations exceed the treatment threshold. Based on these analyses, we re-affirm the efficacy of the FRAX as the best tool for fracture risk assessment and provide deep insight into the interplay between risk factors.

The Effect of Fracture Recency on Observed 10-Year Fracture Probability: A Registry-Based Cohort Study

FRAX estimates 10-year fracture major osteoporotic fracture (MOF) and hip fracture probability from multiple risk factors. FRAX does not consider prior fracture site or time since fracture. Fracture risk is greater in the initial 2-year post-fracture period (imminent risk), implying that FRAX may underestimate risk in this setting. We used the population-based Manitoba Bone Mineral Density (BMD) Program registry to examine the effect of fracture recency and site on incident fracture risk predictions using FRAX. We identified women aged 40 years or older with baseline BMD and FRAX scores. Observed fracture outcomes to 10 years were compared with predicted 10-year fracture probability stratified by prior fracture status: none, recent (<2 years [median 0.3 years]), and remote (≥2 years [median 10.6 years]). For women with recent fractures, we also examined proposed multipliers to adjust FRAX for the effect of fracture recency and site. The cohort comprised 33,465 women aged 40 to 64 years (1897 recent fracture, 2120 remote fracture) and 33,806 women aged ≥65 years (2365 fracture, 4135 remote fracture). Observed fracture probability was consistent with predicted probability in most analyses. In women aged 40 to 64 years, there was a significant effect of recent vertebral and humerus fracture on MOF (observed to predicted 1.61 and 1.48, respectively), but these effects were still lower than the proposed multipliers (2.32 and 1.67, respectively). No significant effect of fracture recency was found after hip or forearm fracture in either age group. Our findings contribute to accumulating evidence of the importance of recent fracture. The effect of fracture recency was not consistent across fracture sites and with a lower magnitude than previously reported. Further quantification of effect size and specificity in additional independent cohorts is warranted to validate and refine recent-fracture multipliers in fracture risk assessment. © 2022 American Society for Bone and Mineral Research (ASBMR).

Prediction of vertebral fractures in cancer patients undergoing hormone deprivation therapies: reliability of who fracture risk assessment tool (frax) and bone mineral density in real-life clinical practice

•

In females under estrogen-deprivation therapies, risk of vertebral fractures was associated with FRAX score for major fractures, with the best therapeutic threshold of 6.5%.

•

In males under androgen-deprivation therapy, risk of vertebral fractures was high when BMD T-score was lower than −1.0 SD or when subjects were treated with abiraterone.

•

High body mass index was an independent risk factor for vertebral fractures in males exposed to androgen-deprivation therapy.

•

In the setting of hormonal deprivation therapies, FRAX and BMD thresholds were lower than those used in post-menopausal osteoporosis and primary male osteoporosis.

Background and Objective

Prediction of fractures in cancer survivors exposed to hormone-deprivation therapies (HDTs) is a challenge since bone loss is rapid and severe, and determinants of fractures in this setting are still largely unknown. In this study we investigated reliability of the WHO Fracture Risk Assessment Tool (FRAX) and bone mineral density (BMD) to identify subjects developing vertebral fractures during HDTs.

Design

Five-hundred-twenty-seven consecutive subjects (429 females with breast cancer, 98 males with prostate cancer; median age 61 years), under HDTs for at least 6 months, were evaluated for vertebral fractures by a radiological and morphometric approach, in relationship with FRAX score, body mass index (BMI), BMD, age and duration of HDTs.

Results

Vertebral fractures were found in 140 subjects (26.6%) and spine deformity index was significantly associated with duration of HDTs (rho 0.38; p < 0.001). Only in females, vertebral fractures were significantly associated with FRAX score for major fractures [OR 1.08; P < 0.001]. The best cut-off of FRAX score for major fractures, as calculated by receiving operating characteristic (ROC) analysis was 6.35%. In males, however, vertebral fractures were significantly and independently associated with BMI ≥ 25 Kg/m² (OR 17.63; P < 0.001), BMD T-score below −1.0 SD at any skeletal site (OR 7.79; P < 0.001) and gonadotropin-releasing hormone agonists (GnRHa) plus abiraterone treatment (OR 11.51; P = 0.001).

Conclusions

FRAX and BMD may be useful for predicting vertebral fractures in subjects undergoing HDTs, but the thresholds seem to be lower than those used in the general population. High BMI is a determinant of vertebral fractures in males under HDT.

Predictive performance of the Garvan Fracture Risk Calculator: a registry-based cohort study

The G arvan Fracture Risk Calculator predicts risk of osteoporotic fractures. We evaluated its predictive performance in 16,682 women and 2839 men from Manitoba, Canada, and found significant risk stratification, with a strong gradient across scores. The tool outperformed clinical risk factors and bone mineral density for fracture risk stratification.

INTRODUCTION

The optimal model for fracture risk estimation to guide treatment decision-making remains controversial. Our objective was to evaluate the predictive performance of the Garvan Fracture Risk Calculator (FRC) in a large clinical registry from Manitoba, Canada.

METHODS

Using the population-based Manitoba Bone Mineral Density (BMD) registry, we identified women and men aged 50-95 years undergoing baseline BMD assessment from September 1, 2012, onwards. Five-year Garvan FRC predictions were generated from clinical risk factors (CRFs) with and without femoral neck BMD. We identified incident non-traumatic osteoporotic fractures (OFs) and hip fractures (HFs) from population-based healthcare data sources to March 31, 2018. Fracture risk was assessed from area under the receiver operating characteristic curve (AUROC). Cox regression analysis and calibration ratios (5-year observed/predicted) were assessed for risk quintiles. All analyses were sex stratified.

RESULTS

We included 16,682 women (mean age 66.6 + / - SD 8.7 years) and 2839 men (mean age 68.7 + / - SD 10.2 years). During a mean observation time of 2.6 years, incident OFs were identified in 681 women and 140 men and HFs in 199 women and 22 men. AUROC showed significant fracture risk stratification with the Garvan FRC. Tool predictions without BMD were better than from age or decreasing weight, and the tool with BMD performed better than BMD alone. Garvan FRC with BMD performed better than without BMD, especially for HF prediction (AUROC 0.86 in women, 0.82 in men). There was a strong gradient of increasing risk across Garvan FRC quintiles (highest versus lowest, hazard ratios women 5.75 and men 3.43 for any OF; women 101.6 for HF). Calibration differences were noted, with both over- and underestimation in risk.

CONCLUSIONS

Garvan FRC outperformed CRFs and BMD alone for fracture risk stratification, particularly for HF, but may require recalibration for accurate predictions in this population.

Updated guidance on the management of cancer treatment-induced bone loss (CTIBL) in pre- and postmenopausal women with early-stage breast cancer

INTRODUCTION

Adjuvant endocrine therapy induces bone loss and increases fracture risk in women with hormone-receptor positive, early-stage breast cancer (EBC). We aimed to update a previous position statement on the management of aromatase inhibitors (AIs) induced bone loss and now included premenopausal women.

METHODS

We conducted a systematic literature search of the medical databases from January 2017 to May 2020 and assessed 144 new studies.

RESULTS

Extended use of AIs beyond 5 years leads to persistent bone loss in breast cancer extended adjuvant trials and meta-analyses. In addition to bone mineral density (BMD), vertebral fracture assessment (VFA) and trabecular bone score (TBS) were shown to independently predict fracture risk in real life prospective studies. FRAX® tool does not seem to be reliable for assessing fracture risk in CTIBL. In premenopausal women, there is strong evidence that intravenous zoledronate prevents bone loss but weak conflicting evidence on reducing disease recurrence from independent randomised controlled trials (RCTs). In postmenopausal women, the strongest evidence for fracture prevention is for denosumab based on a well-powered RCT while there is strong evidence for bisphosphonates (BPs) to prevent and reduce CTIBL but no convincing data on fractures. Adjuvant denosumab has failed to show anticancer benefits in a large, well-designed RCT.

DISCUSSION AND CONCLUSIONS

Extended use of AIs and persistent bone loss from recent data reinforce the need to evaluate fracture risk in EBC women initiated on AIs. Fracture risk should be assessed with clinical risk factors and BMD along with VFA, but FRAX is not adapted to CTIBL. Anti-resorptive therapy should be considered in those with a BMD T-score < -2.0 SD or with ≥ 2 clinical risk factors including a BMD T-score < -1.0 SD. In premenopausal women, intravenous zoledronate is the only drug reported to prevent bone loss and may have additional anticancer benefits. In postmenopausal women, either denosumab or BPs can be prescribed for fracture prevention with pertinent attention to the rebound phenomenon after stopping denosumab. Adjuvant BPs, in contrast to denosumab, have shown high level evidence for reducing breast cancer recurrence in high-risk post-MP women which should be taken into account when choosing between these two.

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

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

Osteoporosis epidemiology using international cohorts

PURPOSE OF REVIEW

The field of osteoporosis research has been active for the past 20 years and has allowed significant advancement in the management of osteoporosis. This review will give an overview of the latest data from international cohorts that relate to current and recent osteoporosis research.

RECENT FINDINGS

The clinical diagnosis of osteoporosis relies heavily on bone mineral density (BMD) measured at femoral neck or spine and although BMD has excellent predictive value for future fractures, fracture risk assessment has evolved over the years, resulting in the birth of fracture prediction tools. Fracture risk factors not currently featured in these tools are being considered for inclusion, including imminent risk fracture following a sentinel fracture, number of falls, and previous vertebral fractures. Data from groups with comorbidities such as chronic obstructive pulmonary disease are helping us understand how to best manage patients with multiple comorbidities. Finally, the prevalence of vertebral fracture in the older general population and other selected populations has been explored, alongside the global burden of osteoporosis and its consequences.

SUMMARY

Our understanding of osteoporosis continues to expand, but knowledge gaps remain.

Bone-modifying Agents (BMAs) in Breast Cancer

Bone-modifying agents (BMAs) are mainstays in breast cancer and prevent and treat osteoporosis in early-stage disease and reduce skeletal metastases complications in advanced disease. There is some evidence to support that BMA also prevents skeletal metastases and improves overall survival. Bone loss occurs with chemotherapy-induced ovarian failure, gonadotrophin-releasing hormone (GnRH) agonists, and aromatase inhibitors. In some women, the bone loss will be of sufficient magnitude to increase the risks of osteoporosis or fractures. Recommended steps in osteoporosis prevention or treatment include risk factor assessment, taking adequate amounts of calcium and vitamin D3, and periodic evaluations with dual-energy x-ray absorptiometry scanning. If clinically indicated by the T-scores and fracture-risk prediction algorithms treat with oral, IV bisphosphonates or subcutaneous denosumab (DEN). Zoledronic acid (ZA) or DEN reduces skeletal metastases complications, including pathological fracture, spinal cord compression, or the necessity for radiation or surgery to bone. Also, both of these drugs have the side-effect of osteonecrosis at a similar incidence. Monthly administration of ZA or DEN is standard, but several recent randomized trials show noninferiority between ZA monthly and every 3-month ZA. Every 3-month ZA is a new standard of care. Similar trials of the schedule of DEN are ongoing. ZA anticancer effect is only in postmenopausal women or premenopausal women rendered postmenopausal by GnRH agonists or bilateral oopherectomy. High-risk women, either postmenopausal or premenopausal, receiving GnRH/oopherctomy should consider adjuvant ZA. There are insufficient data to support DEN in this setting. Herein, this narrative review covers the mechanism of action of BMA, randomized clinical trials, and adverse events, both common and rare.

Cancer Treatment-Induced Bone Loss (CTIBL): State of the Art and Proper Management in Breast Cancer Patients on Endocrine Therapy

OPINION STATEMENT

About 70-80% of early breast cancer (BC) patients receive adjuvant endocrine therapy (ET) for at least 5 years. ET includes in the majority of cases the use of aromatase inhibitors, as upfront or switch strategy, that lead to impaired bone health. Given the high incidence and also the high prevalence of BC, cancer treatment-induced bone loss (CTIBL) represents the most common long-term adverse event experimented by patients with hormone receptor positive tumours. CTIBL is responsible for osteoporosis occurrence and, as a consequence, fragility fractures that may negatively affect quality of life and survival expectancy. As recommended by main international guidelines, BC women on aromatase inhibitors should be carefully assessed for their fracture risk at baseline and periodically reassessed during adjuvant ET in order to early detect significant worsening in terms of bone health. Antiresorptive agents, together with adequate intake of calcium and vitamin D, should be administered in BC patients during all course of ET, especially in those at high risk of osteoporotic fractures, as calculated by tools available for clinicians. Bisphosphonates, such as zoledronate or pamidronate, and anti-RANKL antibody, denosumab, are the two classes of antiresorptive drugs used in clinical practice with similar efficacy in preventing bone loss induced by aromatase inhibitor therapy. The choice between them, in the absence of direct comparison, should be based on patients' preference and compliance; the different safety profile is mainly related to the route of administration, although both types of drugs are manageable with due care, since most of the adverse events are predictable and preventable. Despite advances in management of CTIBL, several issues such as the optimal time of starting antiresorptive agents and the duration of treatment remain unanswered. Future clinical trials as well as increased awareness of bone health are needed to improve prevention, assessment and treatment of CTIBL in these long-term survivor patients.

Bone densitometry categories as a salient distracting feature in the modern clinical pathways of osteoporosis care: A retrospective 20-year cohort study

BACKGROUND

It is unknown as to what factors typically drive osteoporosis therapy decisions in real-world practice.

METHODS

Retrospective, 20-year cohort study within the government health system of Manitoba including all women having bone densitometry (BMD) tests between 1996 and 2017. Osteoporosis prescription data was linked to registry data on fractures, clinical risk factors and BMD tests. We defined 6 possible treatment decisions by prescription data: no treatment, starting, stopping, continuing, drug hiatus and re-starting. For each decision, we tested the association between salient patient factors (age, glucocorticoid use, recent fracture, BMD hip or spine T-score ≤ -2.5, FRAX major osteoporotic fracture probability ≥20%) using multivariable logistic regression. The factors were rank-ordered by decreasing Wald χ² statistic to determine the relative importance.

RESULTS

There were 64,181 women, 33.8% of whom started osteoporosis therapy. For patients who begin therapy after a first BMD, the rank-ordered multivariable logistic regression factor most strongly associated was the T-score ≤ -2.5 [OR of 7.59(95%CI 7.19-8.01, p < 0.001)]. This was followed by glucocorticoid use [OR 2.89(95%CI 2.59-3.22, p < 0.001)]. Increasing age and recent fracture (within 2 years) were weak predictors of therapy and high FRAX score associated with reduced odds of therapy [OR 0.80 (95%CI 0.74-0.88, p < 0.001)]. T-scores were the strongest factor predicting therapy stop/continuation/re-starting; age and prior fracture had weak or no associations.

CONCLUSIONS

Despite recommendations for fracture-risk-based approach to osteoporosis therapy, BMD T-score continues to be the dominant factor in actual practice. Age, prior fracture or global fracture risk are much less associated; it is possible that BMD T-score categories are therefore acting as a clinically salient distracting factor.

Fracture prediction from FRAX for Canadian ethnic groups: a registry-based cohort study

We identified large between-ethnicity calibration differences in the Canadian FRAX® tool which substantially overestimated the major osteoporotic fracture (MOF) risk in Asian women and Black women, and overestimated hip fracture risk in Asian women.

PURPOSE

FRAX® is calibrated using population-specific fracture and mortality data. The need for FRAX to accommodate ethnic diversity within a country is uncertain. We addressed this question using the population-based Manitoba Bone Mineral Density (BMD) Program registry and self-reported ethnicity.

METHODS

The study population was women aged 40 years or older with baseline FRAX assessments (Canadian and other ethnic calculators), fracture outcomes, and self-reported ethnicity (White N = 68,907 [referent], Asian N = 1910, Black N = 356). Adjusted hazard ratios (HR) with 95% confidence intervals (CI) for time to MOF and hip fracture were estimated. We examined candidate variables from DXA that might contribute to ethnic differences including skeletal size, hip axis length (HAL), trabecular bone score (TBS), and estimated body composition.

RESULTS

Adjusted for baseline risk using the Canadian FRAX tool with BMD, Asian women compared with White women were at much lower risk for MOF (HR 0.46, 95% CI 0.35-0.59) and hip fracture (0.16, 95% CI 0.08-0.34). Black women were also at lower MOF risk (HR 0.58, 95% CI 0.32-1.00); there were no hip fractures. The US ethnic-specific FRAX calculators accounted for most of the between-ethnicity differences in MOF risk (86% for Asian, 92% for Black) but only partially accounted for lower hip fracture risk in Asian women (40%). The candidate variables explained only a minority of the effect of ethnicity. Gradient of risk in analyses was similar (p-interactions ethnicity*FRAX non-significant).

CONCLUSIONS

We identified significant ethnic differences in performance of the Canadian FRAX tool with fracture probability overestimated among Asian and Black women. The US ethnic calculators helped to address this discrepancy for MOF risk assessment, but not for hip fracture risk among Asian women.

Osteoporosis: A Long-Term and Late-Effect of Breast Cancer Treatments

Simple Summary

Osteoporosis is a prevalent condition affecting 200 million individuals world-wide. Estimates are about one in three women will experience a fragility fracture of hip, spine or wrist. Common breast cancer treatments, such as aromatase inhibitors in postmenopausal women and chemotherapy-induced ovarian failure in premenopausal women, cause bone loss that in some women will lead to osteoporosis and fragility fractures. Fragility fractures cause morbidity and mortality and are entirely preventable. Prevention or treatment of osteoporosis includes lifestyle modifications (e.g., reducing smoking and excessive alcohol consumption, and increasing physical activity), taking calcium and vitamin D3, screening for osteoporosis with dual-energy absorptiometry, and treatment, if clinically indicated, with ether oral bisphosphonates, intravenous zoledronic acid, or subcutaneous denosumab. This chapter reviews the pathogenesis of osteoporosis, the magnitude of bone loss related to common breast cancer treatments, osteoporosis risk factor assessment and screening, and the specific drugs to treat or prevent osteoporosis.

Abstract

Osteoporosis is both a long-term effect (occurs during treatment and extends after treatment) and a late-effect (occurs after treatment ends) of breast cancer treatments. The worldwide prevalence of osteoporosis is estimated to be some 200 million patients. About one in three postmenopausal women will experience an osteoporotic (or fragility) fracture of the hip, spine, or wrist. breast cancer treatments, including gonadotropin-releasing hormone (GnRH) agonists, chemotherapy-induced ovarian failure (CIOF), and aromatase inhibitors (AIs), cause bone loss and increase the risks of osteoporosis. Also, breast cancer is a disease of aging, and most of the “one in eight” lifetime risks of breast cancer are in women in their sixth, seventh, and eighth decades. The majority of women diagnosed with breast cancers today will be long-term survivors and experience personal cures. It is the coalescence of osteoporosis with breast cancer, two common and age-related conditions that make osteoporosis relevant in women with breast cancer throughout the continuum from diagnosis, treatment, and survivorship. It is critical to remember that women (and men) will lose bone after age thirty years. However, only certain women will lose bone of sufficient magnitude to merit treatment with anti-osteoporosis drugs. The narrative review is intended for medical, surgical, radiation oncologists, and other mid-level providers, and provides an overview of bone loss and the prevention and treatment of osteoporosis.

Targeted bone density testing for optimizing fracture prevention in Canada

The Canadian FRAX® tool used without bone mineral density (BMD) is highly sensitive for identifying individuals qualifying for pharmacotherapy based upon an intervention threshold of 20% for major osteoporotic fracture risk (MOF) computed with BMD.

INTRODUCTION

This analysis was performed to inform initial BMD testing as part of Osteoporosis Canada's Guidelines Update for women and men at average risk, assuming a pharmacotherapy intervention threshold of 20% for FRAX® MOF computed with BMD.

METHODS

Women and men age 50 + without previous low-trauma fracture or high-risk medication use were identified in a BMD registry for the province of Manitoba, Canada. Fracture probability assessments with the Canadian FRAX® tool were computed without and with BMD (denoted MOF-clinical and MOF-BMD, respectively).

RESULTS

The study population consisted of 50,700 women (mean age 65.5 ± 9.4 years) and 4152 men (69.2 ± 10.0 years). FRAX MOF-clinical score was > 10% in 33.8% of women and 13.3% of men (P < 0.001). The median (interquartile range [IQR]) age for MOF-clinical to reach 10% in women was 70 (69-72) and 65 years (62-67) years in the absence and presence of additional FRAX clinical risk factors, respectively. In men, comparable ages were 83 years [82-86] and 76 [70-78] years. Using MOF-BMD of 20% as the intervention threshold, 4.3% of women and 0.7% of men qualified for treatment. MOF-clinical > 10% had high sensitivity to identify those qualifying for treatment (99.3% in women and 99.1% in men). An age-based rule ("BMD testing is indicated at age 70 if no additional FRAX clinical risk factors are present, or at age 65 if one or more clinical risk factors exists") gave similarly high sensitivity (women 99.9% and men > 99.9%).

CONCLUSIONS

FRAX without BMD offers an effective strategy to identify individuals meeting the current Canadian treatment threshold based upon FRAX® with BMD (≥ 20%). Moreover, this can be operationalized using simple age cutoffs of 70 years in the absence of additional clinical risk factors and 65 years in the presence of additional clinical risk factors.

Management of osteoporosis in women with breast cancer

The screening, prevention and treatment of osteoporosis are similar in women with or without breast cancer. Breast cancer treatments, such as aromatase inhibitors, chemotherapy-induced ovarian failure and gonadotropin-releasing hormone antagonists all decrease estrogen levels, which in turn causes net bone resorption and bone loss. Bone loss over time will be of sufficient magnitude to cause some women to experience fractures. Thus, osteoporosis is an equation; the peak bone mass achieved by age 30 years minus the age-related and menopausal bone loss. Women should have their bone density measured by dual x-ray absorptiometry scans every 2 years. As clinically indicated, women should receive anti-osteoporosis drugs such as zoledronic acid, denosumab or oral bisphosphonates.

Evaluating the Performance of the WHO International Reference Standard for Osteoporosis Diagnosis in Postmenopausal Women of Varied Polygenic Score and Race

BACKGROUND

Whether the bone mineral density (BMD) T-score performs differently in osteoporosis classification in women of different genetic profiling and race background remains unclear.

METHODS

The genomic data in the Women's Health Initiative study was analyzed (n = 2417). The polygenic score (PGS) was calculated from 63 BMD-associated single nucleotide polymorphisms (SNPs) for each participant. The World Health Organization's (WHO) definition of osteoporosis (BMD T-score ≤-2.5) was used to estimate the cumulative incidence of fracture.

RESULTS

T-score classification significantly underestimated the risk of major osteoporotic fracture (MOF) in the WHI study. An enormous underestimation was observed in African American women (POR: 0.52, 95% CI: 0.30-0.83) and in women with low PGS (predicted/observed ratio [POR]: 0.43, 95% CI: 0.28-0.64). Compared to Caucasian women, African American, African Indian, and Hispanic women respectively had a 59%, 41%, and 55% lower hazard of MOF after the T-score was adjusted for. The results were similar when used for any fractures.

CONCLUSIONS

Our study suggested the BMD T-score performance varies significantly by race in postmenopausal women.

A decade of FRAX: how has it changed the management of osteoporosis?

The fracture risk assessment tool, FRAX^®, was released in 2008 and provides country-specific algorithms for estimating individualized 10-year probability of hip and major osteoporotic fracture (hip, clinical spine, distal forearm, and proximal humerus). Since its release, 71 models have been made available for 66 countries covering more than 80% of the world population. The website receives approximately 3 million visits annually. Following independent validation, FRAX has been incorporated into more than 80 guidelines worldwide. The application of FRAX in assessment guidelines has been heterogeneous with the adoption of several different approaches in setting intervention thresholds. Whereas most guidelines adopt a case-finding strategy, the case for FRAX-based community screening in the elderly is increasing. The relationship between FRAX and efficacy of intervention has been explored and is expected to influence treatment guidelines in the future.

Performance of FRAX in Predicting Fractures in US Postmenopausal Women with Varied Race and Genetic Profiles

BACKGROUND

Whether the Fracture Risk Assessment Tool (FRAX) performed differently in estimating the 10-year fracture probability in women of different genetic profiling and race remained unclear.

METHODS

The genomic data in the Women's Health Initiative (WHI) study was analyzed (n = 23,981). The genetic risk score (GRS) was calculated from 14 fracture-associated single nucleotide polymorphisms (SNPs) for each participant. FRAX without bone mineral density (BMD) was used to estimate fracture probability.

RESULTS

FRAX significantly overestimated the risk of major osteoporotic fracture (MOF) in the WHI study. The most significant overestimation was observed in women with low GRS (predicted/observed ratio (POR): 1.61, 95% CI: 1.45-1.79) specifically Asian women (POR: 3.5, 95% CI 2.48-4.81) and in African American women (POR: 2.59, 95% CI: 2.33-2.87). Compared to the low GRS group, the 10-year probability of MOF adjusted for the FRAX score was 21% and 30% higher in the median GRS group and high GRS group, respectively. Asian, African American, and Hispanic women respectively had a 78%, 76%, and 56% lower hazard than Caucasian women after the FRAX score was adjusted. The results were similar for hip fractures.

CONCLUSIONS

Our study suggested the FRAX performance varies significantly by both genetic profile and race in postmenopausal women.

Reassessment Intervals for Transition From Low to High Fracture Risk Among Adults Older Than 50 Years

IMPORTANCE

Fracture risk scores are used to identify individuals at high risk of major osteoporotic fracture or hip fracture for antiosteoporosis treatment. For those not meeting treatment thresholds at baseline, the optimal interval for reassessing fracture risk is uncertain.

OBJECTIVE

To examine reassessment intervals for transition from low to high fracture risk under guidelines-defined treatment thresholds.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included persons aged 50 years or older with fracture risk below treatment thresholds at baseline who had fracture risk reassessed at least 1 year later. Data were obtained from a population-based bone mineral density registry (baseline assessment during 1996-2015; reassessment to 2016) in the Province of Manitoba, Canada. Primary analysis was performed from May to June 2019. Analysis for the revision was performed in October 2019.

MAIN OUTCOMES AND MEASURES

The primary outcome was time to transition from low (below the treatment threshold) to high fracture risk (treatment-qualifying risk score using osteoporosis clinical practice guidelines strategies for Canada, the United States, and the United Kingdom).

RESULTS

The study population consisted of 10 564 individuals (94.1% women; mean [SD] age at baseline, 63.2 [8.2] years). At the time of reassessment (a mean [SD] interval of 5.2 [2.9] years between initial and subsequent fracture risk assessment), 690 (6.6%) had reached the fixed major osteoporotic fracture treatment threshold of 20%, 1546 (16.2%) had reached the fixed hip treatment threshold of 3%, and 932 (9.4%) had reached the age-dependent major osteoporotic fracture treatment threshold. Among those below 25% of the treatment threshold at baseline for each guideline, few (0%-3.0%) reached guidelines-defined high fracture risk at follow-up. In contrast, among those at the upper end of the scale for each guideline (75%-99% of the treatment threshold at baseline), 30.6% to 74.4% reached guidelines-defined high fracture risk. An increased number of clinical risk factors was associated with increased likelihood of reaching guidelines-defined high fracture risk (range for 3 guidelines, 17.1%-28.2%) compared with unchanged or decreased clinical risk factors (range for 3 guidelines, 3.3%-12.8%) (P < .001). Estimated time for 10% of the population to reach treatment-qualifying high fracture risk ranged from fewer than 3 years to more than 15 years.

CONCLUSIONS AND RELEVANCE

The findings suggest that baseline fracture risk (as a fraction of the treatment threshold) and change in clinical risk factors can identify individuals with low and high probability of guidelines-defined high fracture risk during follow-up, thereby potentially helping to inform the reassessment interval.

Comparison of treatment strategies and thresholds for optimizing fracture prevention in Canada: a simulation analysis

This comparison of osteoporosis treatment strategies and intervention thresholds highlights tradeoffs in terms of number of individuals qualifying for treatment and estimated fractures prevented.

PURPOSE

The current analysis was performed to inform the following key question as part of the Osteoporosis Canada's Osteoporosis Guidelines Update: "What is the best strategy to identify those at high fracture risk for pharmacotherapy in order to prevent the most fractures, considering both population and patient perspectives?"

METHODS

The study population consisted of 66,878 women age 50 years and older (mean age 66.0 ± 9.7 years) with documented fracture probability assessment (FRAX) and fracture outcomes. Fractures over the next 5 years were identified through linked administrative healthcare data. We estimated the fraction of the population that would warrant treatment and the number of fractures avoided per 1000 person-years according to multiple strategies and thresholds. Strategies were then rank ordered using 19 metrics.

RESULTS

During mean 4.4 years, 863 (3.5%) sustained one or more major osteoporotic fractures (MOF), 212 (0.8%) sustained a hip fracture, and 1210 (4.9%) sustained any incident fracture. For woman age 50-64 years, the highest ranked strategy was treatment based upon total hip T score ≤ -2.5, but several other strategies fell within 0.5 overall ranking. For women age 65 years and older, MOF > 20% was the highest ranked strategy with no closely ranked strategies. Pooling both age subgroups gave MOF > 20% as the highest ranked strategy, with several other strategies within 0.5 overall ranking.

CONCLUSIONS

Choice of treatment strategy and threshold for osteoporosis management strongly influences the number of individuals for whom pharmacologic treatment would be recommended and on estimated fracture rates in the population. This evidence-based approach to comparing these strategies will help to inform guidelines development in Canada and may be on interest elsewhere.

Fracture prediction from self-reported falls in routine clinical practice: a registry-based cohort study

A simple question construct regarding number of falls in the previous year, ascertained by a single question, was strongly associated with incident fractures in routine clinical practice using a population-based dual-energy X-ray absorptiometry (DXA) registry.

INTRODUCTION

There is conflicting evidence from research cohorts that falls independently increase fracture risk. We examined the independent effects of falls on subsequent fractures in a large clinical registry of bone mineral density (BMD) results for the Province of Manitoba, Canada that has been systematically collecting self-reported falls information since September 1, 2012.

METHODS

The study population consisted of 24,943 women and men aged 40 years and older (mean age 65.5 ± 10.2 years) with fracture probability assessment (FRAX), self-reported falls for the previous year (categorized as none, 1, 2, or > 3) and fracture outcomes. Adjusted hazard ratios (HR) with 95 confidence intervals (CI) for time to fracture were estimated using Cox proportional hazards models.

RESULTS

During mean observation time of 2.7 ± 1.0 years, 863 (3.5%) sustained one or more major osteoporotic fractures (MOF), 212 (0.8%) sustained a hip fracture, and 1210 (4.9%) sustained any incident fracture. Compared with no falls in the previous year (referent), there was a gradient of increasing risk for fracture with increasing number of falls (all P < 0.001). Results showed minimal attenuation with covariate adjustment. When adjusted for baseline fracture probability (FRAX score with BMD) the HR for MOF increased from 1.49 (95% CI 1.25-1.78) for one fall to 1.74 (1.33-2.27) for two falls to 2.62 (2.06-3.34) for ≥ 3 falls. HRs were similar for any incident fracture and slightly greater for prediction of hip fracture, reaching 3.41 (95% CI 2.19-5.31) for ≥ 3 previous falls.

CONCLUSIONS

Self-report number of falls in the previous year is strongly associated with incident fracture risk in the routine clinical practice setting, and this risk is independent of age, sex, BMD, and baseline fracture probability. Moreover, there is dose-response with multiple falls (up to a maximum of 3) conferring greater risk than a single fall.