Selection for treatment of patients at high risk of fracture by the short versus long term prediction models - data from the Belgian FRISBEE cohort

Our imminent model was less sensitive but more selective than FRAX® in the choice of treatment to prevent imminent fractures. This new model decreased NNT by 30%, which could reduce the treatment costs. In the Belgian FRISBEE cohort, the effect of recency further decreased the selectivity of FRAX®.

PURPOSE

We analyzed the selection for treatment of patients at high risk of fracture by the Belgian FRISBEE imminent model and the FRAX® tool.

METHODS

We identified in the FRISBEE cohort subjects who sustained an incident MOF (mean age 76.5 ± 6.8 years). We calculated their estimated 10-year risk of fracture using FRAX® before and after adjustment for recency and the 2-year probability of fracture using the FRISBEE model.

RESULTS

After 6.8 years of follow-up, we validated 480 incident and 54 imminent MOFs. Of the subjects who had an imminent fracture, 94.0% had a fracture risk estimated above 20% by the FRAX® before correction for recency and 98.1% after adjustment, with a specificity of 20.2% and 5.9%, respectively. The sensitivity and specificity of the FRISBEE model at 2 years were 72.2% and 55.4%, respectively, for a threshold of 10%. For these thresholds, 47.3% of the patients were identified at high risk in both models before the correction, and 17.2% of them had an imminent MOF. The adjustment for recency did not change this selection. Before the correction, 34.2% of patients were selected for treatment by FRAX® only, and 18.8% would have had an imminent MOF. This percentage increased to 47% after the adjustment for recency, but only 6% of those would suffer a MOF within 2 years.

CONCLUSION

In our Belgian FRISBEE cohort, the imminent model was less sensitive but more selective in the selection of subjects in whom an imminent fracture should be prevented, resulting in a lower NNT. The correction for recency in this elderly population further decreased the selectivity of FRAX®. These data should be validated in additional cohorts before using them in everyday practice.

Are there specific clinical risk factors for the occurrence of multiple fractures? The FRISBEE study

This study showed additional clinical risk factors for the occurrence of multiple fractures with regards to a single fracture, with often higher hazard ratios. It would be important to include the risk of the occurrence of multiple fractures in future prediction models.

PURPOSE

To identify clinical risk factors (CRFs) which would specifically increase the risk of multiple fractures.

METHODS

Data of the 3560 postmenopausal women of the FRISBEE study were analysed. The CRFs and the fractures are collected annually. The cohort was divided into three groups: those who had no incident fracture, those who had a single incident fracture and those who had 2 two or more incident fractures (i.e. multiple fractures). Statistical analyses were performed using Cox proportional hazards models.

RESULTS

Among the 3560 subjects (followed for 9.1 (7.2-10.6) years), 261 subjects had two or more validated fractures during follow-up (146 were major osteoporotic fractures (MOFs)), 628 had one fracture (435 MOFs), 2671 had no fracture (2979 had no MOF); 157 subjects had two or more central fractures, 389 had only one and 3014 had none. The risk factors for those with multiple fractures at any site were age, history of fracture, history of fall, total hip bone mineral density (BMD), spine BMD and rheumatoid arthritis. For those with multiple MOFs, significant CRFs were age, history of fracture, parental hip fracture, total hip BMD and rheumatoid arthritis.

CONCLUSION

We found in a prospective cohort study that there were more CRFs and higher hazard ratios for the occurrence of multiple fractures than for a single fracture.

Distribution of Fracture Sites in Postmenopausal Overweight and Obese Women: The FRISBEE Study

The association between obesity and fracture sites in postmenopausal women has been little studied. We examined the most common types of fractures in obese and overweight postmenopausal women compared to subjects with a normal BMI in the FRISBEE study, a cohort of postmenopausal women followed since 9.1 (7.2-10.6) years. Chi-squared tests and logistic regressions were used to compare the percentages of fracture sites in overweight/obese subjects to subjects with a normal BMI. Their mean (± SD) age was 76.7 ± 6.9 years and their mean BMI was 26.4 ± 4.4. Seven hundred seventy-seven subjects suffered at least one validated fragility fracture with a total of 964 fractures in the whole cohort. Subjects with a BMI higher than 25 had significantly more ankle fractures and less pelvic fractures than subjects with a normal BMI (OR 1.63, 95% CI 1.02-2.56, P = 0.04 and OR 0.55, 95% CI 0.34-0.89, P = 0.01, respectively). There were no significant differences between overweight and obese subjects. Among those older than 75, there were significantly fewer pelvic fractures in overweight/obese subjects (OR 0.49, 95% CI 0.27-0.87, P = 0.01), but before 75, ankle fractures were significantly more frequent in overweight/obese subjects than in subjects with a normal BMI (OR 1.89, 95% CI 1.01-3.57, P = 0.04). In conclusion, the proportion of ankle and pelvic fractures in obese and overweight subjects differs from that in subjects with a normal BMI, but these differences are age dependent. Fracture prevention strategies should take into account the differential effects of excess weight according to age and the site of fracture.

MOF/Hip Fracture Ratio in a Belgian Cohort of Post-menopausal Women (FRISBEE): Potential Impact on the FRAX® Score

The ratio between major osteoporotic fractures (MOFs) and hip fractures in the Belgian FRAX® tool to predict fractures is currently based on Swedish data. We determined these ratios in a prospective cohort of Belgian postmenopausal women. 3560 women, aged 60-85 years (70.1 ± 6.4 years), were included in a prospective study from 2007 to 2013 and surveyed yearly (FRISBEE). We analyzed the number of validated incident fractures until October 2020 by age and sites and compared the MOFs/hip ratios in this cohort with those from the Swedish databases. We registered 1336 fractures (mean follow-up of 9.1 years). The MOFs/hip ratios extracted from the FRISBEE cohort were 10.7 [95% CI: (5.6-20.5)], 6.4 [4.7-8.7], and 5.0 [3.9-6.5] for women of 60-69, 70-79, and 80-89 years old, respectively. These ratios were 1.7-1.8 times higher for all age groups than those from the Swedish data, which decreased from 6.5 (60-64 years group) down to 1.8 (85-89 age group). The overall MOFs/hip ratio in Frisbee was 6.0 [5.9-6.1], which was higher than any Swedish ratio between 65 and 85 years. Nevertheless, the decrease of the ratios with age paralleled that observed in Sweden. In this Brussels prospective cohort, MOFs/hip ratios were 1.7-1.8 times those observed in Sweden currently used for MOFs prediction in the Belgian FRAX® version. This discrepancy can greatly modify the estimation of the risk of MOFs, which is among the main criteria used to recommend a pharmacological treatment for osteoporosis in several countries.

Impact of non-hip fractures in elderly women: a narrative review

The association of hip fractures with adverse outcomes is well established, but for non-hip fractures this association still needs to be further investigated. The objective of this narrative review is to describe the state of the art with regards to the health impact of clinically relevant non-hip fracture locations in postmenopausal women. PubMed and Scopus databases were searched from January 2010 until December 2020. Studies were included when the crude rates and/or relative risk of 1-year subsequent fractures and/or mortality were reported as well as the precise fracture site. Twenty-three studies met the inclusion criteria. Regarding mortality rates, there was a high variability between studies, with higher rates for vertebral, proximal humerus and pelvic fractures. There was a small or no impact of wrist, ankle or tibia fractures. The mortality rate increased with age after vertebral, proximal humerus and wrist fractures. Moreover, proximal humerus and vertebral fractures were associated with a higher mortality risk. This narrative review indicates that, besides fractures of the hip, fractures of the vertebrae, proximal humerus or pelvis deserve more attention when trying to prevent adverse outcomes of osteoporosis. More studies on the topic of non-hip fractures are urgently needed.

Risk factors for imminent fractures: a substudy of the FRISBEE cohort

Multiple factors increase the risk of an imminent fracture, including a recent fracture, older age, osteoporosis, comorbidities, and the fracture site. These findings could be a first step in the development of a model to predict an imminent fracture and select patients most at need of immediate treatment.

INTRODUCTION

The risk of a recurrent fragility fracture is maximal during the first 2 years following an incident fracture. In this prospective cohort study, we looked at the incidence of recurrent fractures within 2 years after a first incident fracture and we assessed independent clinical risk factors (CRFs) increasing this imminent fracture risk.

METHODS

A total of 3560 postmenopausal women recruited from 2007 to 2013 were surveyed yearly for the occurrence of fragility fractures. We identified patients who sustained a fracture during the first 2 years following a first incident fragility fracture. We quantified the risk of a new fracture and assessed independent CRFs, associated with an imminent fracture at various sites.

RESULTS

A recent fracture was a significant CRF for an imminent fracture (OR (95% CI): 3.7 (2.4-5.7) [p < 0.0001]). The incidence of an imminent fracture was higher in subjects above 80 years (p < 0.001). Other CRFs highly predictive in a multivariate analysis were osteoporosis diagnosis (p < 0.01), a central fracture as the index fracture (p < 0.01), and the presence of comorbidities (p < 0.05), with likelihood ratios of 1.9, 1.9, and 2.2, respectively. An imminent fracture was better predicted by a central fracture (p < 0.01) than by a major osteoporotic fracture. The hazard ratio was the highest for a central fracture.

CONCLUSION

In patients with a recent fracture, older age, osteoporosis, comorbidities, and fracture site were associated with an imminent fracture risk. These findings could be a first step in the development of a model to predict an imminent fracture and select patients most at need of immediate and most appropriate treatment.

Osteoporosis management in hematologic stem cell transplant recipients: Executive summary

•

Hematopoietic stem cell transplant (HSCT) patients are living longer.

•

Bone health is an important long-term comorbidity post-HSCT.

•

HSCT patients are at high risk of bone loss and fragility fracture.

•

HSCT patients are at high risk of bone loss and fragility fracture.

•

Recommendations are provided for better monitoring of bone health.

•

Recommendations include bone assessment, dietary advice and osteoporosis medication.

Background

Treatment advances have reduced the adverse events associated with hematopoietic stem cell transplant (HSCT) and led to an increased number of transplants performed. HSCT patients are living longer with concerns on long-term outcomes. Bone fragility and fracture are at the forefront for long-term morbidities post-HSCT.

Results

In HSCT recipients, evidence has accumulated to support recommendations for more extensive monitoring of bone fragility and more appropriate administration of osteoporosis pharmacotherapies for patients at high risk of bone loss and/or fracture.

Conclusion

This executive summary reports and summarizes the main recommendations published previously, including bone assessment, dietary and lifestyle recommendations and osteoporosis medication.

Discriminating value of HR-pQCT for fractures in women with similar FRAX scores: A substudy of the FRISBEE cohort

Areal bone mineral density (aBMD) has a low sensitivity to identify women at high fracture risk. The FRAX algorithm, by combining several clinical risk factors, might improve fracture prediction compared to aBMD alone. Several micro-architectural and biomechanical parameters which can be measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) are associated with fracture risk. HR-pQCT in combination or not with finite element analysis (FEA) may be used to improve bone strength prediction. Our aim was to assess whether HR-pQCT measurements (densities, cortical and trabecular microarchitecture, biomechanical proprieties assessed by FEA) had an added value in predicting fractures in a subgroup of women belonging to the Belgian FRISBEE cohort. One hundred nineteen women who sustained a fracture (aged 60 to 85 years) during the initial follow-up of our cohort had a radius and tibia examination by HR-pQCT and were compared with controls matched for their FRAX score at baseline. We found that low distal radius total (OR = 1.41 [1.07-1.86] per SD, p < 0.05) and trabecular densities (OR = 1.45 [1.10-1.90], p < 0.01), trabecular number (OR = 1.32 [1.01-1.72], p < 0.05), intra individual distribution of separation (OR = 0.73 [0.54-0.99], p < 0.05) as several FEA parameters were significantly associated with fractures. At the distal tibia, impaired cortical density (OR = 1.32 [1.03-1.70] per SD, p < 0.05) and thickness (OR = 1.29 [1.01-1.63], p < 0.05) and apparent modulus (OR = 1.30 [1.01-1.66], p < 0.05) were significantly correlated with fractures. A low ultra distal radial aBMD (UDR) measured at the time of HR-pQCT was significantly associated with fractures (OR = 1.67 [1.22-2.28], p < 0.01). Women from both groups were followed further after the realization of the HR-pQCT and 46 new fractures were registered. In this second part of the study, low UDR aBMD (OR = 1.66 [1.18-2.35], p < 0.01), total (OR = 1.48 [1.08-2.03], p < 0.05), cortical (OR = 1.40 [1.04-1.87], p < 0.05) and trabecular (OR = 1.37 [1.01-1.85], p < 0.05) densities or apparent modulus (OR = 1.49 [1.07-2.05], p < 0.05) at the radius were associated with a significant increase of fracture risk. At the tibia, only the cortical density was significantly associated with the fracture risk (OR = 1.34 [1.02-2.76], p < 0.05). These results confirm the interest of HR-pQCT measurements for the evaluation of fracture risk, also in women matched for their baseline FRAX score. They also highlight that UDR aBMD contains pertinent information.

Bone health in childhood cancer: review of the literature and recommendations for the management of bone health in childhood cancer survivors

In the past decades, new cancer treatment approaches for children and adolescents have led to a decrease in recurrence rates and an increase in long-term survival. Recent studies have focused on the evaluation of the late effects on bone of pediatric cancer-related treatments, such as chemotherapy, radiation and surgery. Treatment of childhood cancer can impair the attainment of peak bone mass, predisposing to premature onset of low bone mineral density, or causing other bone side-effects, such as bone quality impairment or avascular necrosis of bone. Lower bone mineral density and microarchitectural deterioration can persist during adulthood, thereby increasing fracture risk. Overall, long-term follow-up of childhood cancer survivors is essential to define specific groups at higher risk of long-term bone complications, identify unrecognized long-term adverse effects, and improve patient care. Children and adolescents with a cancer history should be carefully monitored, and patients should be informed of possible late complications of their previous medical treatment. The International Osteoporosis Foundation convened a working group to review the bone complications of pediatric cancer survivors, outlining recommendations for the management of bone health, in order to prevent and treat these complications.

Farnesoid X receptor as marker of osteotropism of breast cancers through its role in the osteomimetism of tumor cells

Background

The skeleton is the first and most common distant metastatic site for breast cancer. Such metastases complicate cancer management, inducing considerable morbidities and decreasing patient survival. Osteomimetism is part of the complex process of osteotropism of breast cancer cells. Recent data indicate that Farnesoid X Receptor (FXR) is involved in the transformation and progression of breast cancer.

Methods

The expression of FXR, Runt-related transcription factor 2 (RUNX2) and bone proteins were evaluated on two tumor cell lines (MCF-7 and MDA-MB-231) by immunohistochemistry, immunofluorescence and western blotting and quantified.

Results

In a series of 81 breast cancer patients who developed distant metastases, we found a strong correlation between FXR expression in primary breast tumors and the development of bone metastases, especially in patients with histological grade 3 tumors. In in vitro studies, FXR activation by Chenodeoxycholic acid (CDCA) increased the expression of numerous bone proteins. FXR inhibition by lithocholic acid and z-guggulsterone decreased bone protein expression. Short Hairpin RNA (ShRNA) against FXR validated the involvement of FXR in the osteomimetism of breast cancer cells.

Conclusion

Our experimental results point to a relationship between the expression of FXR in breast cancer cells and the propensity of these tumor cells to develop bone metastases. FXR induces the expression of RUNX2 which itself causes the synthesis of bone proteins by tumor cells.

Osteoporosis treatment gap in a prospective cohort of volunteer women

Despite the availability of efficient drugs to prevent osteoporotic fractures, only a minority of women receives osteoporosis therapy after a fracture. The high treatment gap in our cohort consisted of unselected volunteer patients highlights the urgent need of additional education, especially for the medical profession, regarding the risk-benefit balance of treatment.

INTRODUCTION

Despite the availability of efficient drugs to prevent osteoporotic fractures, only a minority of women receives osteoporosis therapy after a fracture, with a treatment gap around 80%. This can have dramatic consequences for patients and the healthcare systems.

METHODS

In this study based on longitudinal data from the FRISBEE (Fracture RIsk Brussels Epidemiological Enquiry) cohort of 3560 volunteer women aged 60 to 85 years, we evaluated the 1-year treatment gap after a first major incident fragility fracture.

RESULTS

There were 386 first validated fragility fractures, 285 major osteoporotic fractures (MOF) and 101 "other major" fractures. The rate of untreated patients was 85.0% (82.8% for MOF versus 91.0 % for "other major" fracture sites) (p = 0.04), with a lower rate for spine (70.5%) and hip (72.5%) versus shoulder (91.6%) and wrist (94.1%) (p < 0.0001). More specifically, the treatment gap for patients with osteoporosis, defined by a T-score < - 2.5 SD was 74.6% versus 76.5% for patients with osteoporosis defined by the presence of hip, shoulder, or spine fractures, independently of DXA results. When considering age groups, the rate of untreated women was 87.9% for women 60-70 years old, 88.2% between 70 and 80 years and 77.8% above 80 years (p = 0.03), with a greater difference between women who were younger or older than 80 years at inclusion: 88.1% versus 77.8% (p = 0.009). A diagnosis of osteoporosis (p = 0.01) and age (p = 0.03) were the only clinical risk factors (CRFs) significantly associated with treatment initiation.

CONCLUSIONS

This study highlights the urgent need of additional education, especially for the medical profession, regarding the risk-benefit balance of treatment.

How to manage osteoporosis before the age of 50

This narrative review discusses several aspects of the management of osteoporosis in patients under 50 years of age. Peak bone mass is genetically determined but can also be affected by lifestyle factors. Puberty constitutes a vulnerable period. Idiopathic osteoporosis is a rare, heterogeneous condition in young adults due in part to decreased osteoblast function and deficient bone acquisition. There are no evidence-based treatment recommendations. Drugs use can be proposed to elderly patients at very high risk. Diagnosis and management of osteoporosis in the young can be challenging, in particular in the absence of a manifest secondary cause. Young adults with low bone mineral density (BMD) do not necessarily have osteoporosis and it is important to avoid unnecessary treatment. A determination of BMD is recommended for premenopausal women who have had a fragility fracture or who have secondary causes of osteoporosis: secondary causes of excessive bone loss need to be excluded and treatment should be targeted. Adequate calcium, vitamin D, and a healthy lifestyle should be recommended. In the absence of fractures, conservative management is generally sufficient, but in rare cases, such as chemotherapy-induced osteoporosis, antiresorptive medication can be used. Osteoporosis in young men is most often of secondary origin and hypogonadism is a major cause; testosterone replacement therapy will improve BMD in these patients. Diabetes is characterized by major alterations in bone quality, implying that medical therapy should be started sooner than for other causes of osteoporosis. Primary hyperparathyroidism, hyperthyroidism, Cushing's syndrome and growth hormone deficiency or excess affect cortical bone more often than trabecular bone.

The Belgian Bone Club 2020 guidelines for the management of osteoporosis in postmenopausal women

PURPOSE

To provide updated evidence-based guidelines for the management of osteoporosis in postmenopausal women in Belgium.

METHODS

The Belgian Bone Club (BBC) gathered a guideline developer group. Nine "Population, Intervention, Comparator, Outcome" (PICO) questions covering screening, diagnosis, non-pharmacological and pharmacological treatments, and monitoring were formulated. A systematic search of MEDLINE, the Cochrane Database of Systematic Reviews, and Scopus was performed to find network meta-analyses, meta-analyses, systematic reviews, guidelines, and recommendations from scientific societies published in the last 10 years. Manual searches were also performed. Summaries of evidence were provided, and recommendations were further validated by the BBC board members and other national scientific societies' experts.

RESULTS

Of the 3840 references in the search, 333 full texts were assessed for eligibility, and 129 met the inclusion criteria. Osteoporosis screening using clinical risk factors should be considered. Patients with a recent (<2 years) major osteoporotic fracture were considered at very high and imminent risk of future fracture. The combination of bone mineral density measured by dual-energy X-ray absorptiometry and 10-year fracture risk was used to categorize patients as low or high risk. Patient education, the combination of weight-bearing and resistance training, and optimal calcium intake and vitamin D status were recommended. Antiresorptive and anabolic osteoporosis treatment should be considered for patients at high and very high fracture risk, respectively. Follow-up should focus on compliance, and patient-tailored monitoring should be considered.

CONCLUSION

BBC guidelines and 25 guideline recommendations bridge the gap between research and clinical practice for the screening, diagnosis, and management of osteoporosis.

What is the validity of self-reported fractures?

We assessed the validity of self-reported fractures, over a median follow-up period of 6.2 years, in a well characterized population-based cohort of 3560 postmenopausal women, aged 60-85 years, from the Fracture Risk Brussels Epidemiological Enquiry (FRISBEE) study. Incident low-traumatic (falls from a standing height or less) or non-traumatic fractures, including peripheral fractures, were registered during each annual follow-up telephone interview. A self-reported fracture was considered as a true positive if it was validated by written reliable medical reports (radiographs, CT scans or surgical report). False positives fractures were considered to be those for which the radiology report indicated that there was no fracture at the reported site. Among self-reported fractures, false positive rates were 14.4% for all fractures. The rate of false positives of 11.2% (n = 48/429) was not negligible for the four classical major osteoporotic fractures (MOFs: hip, clinical spine, forearm or shoulder fractures). In terms of fracture site, we found the lowest false positive rate (4.4%) at the hip, and the highest (16.8%) at the spine, with the proximal humerus and the wrist in between, at about 10% each. The global rates of false positives were 12.5% (n = 22/176) for other major fractures and 22.3% (n = 49/220) for minor fractures. Younger subjects, individuals with fractures at sites other than the hip, with a lower education level, or with a higher BMI were more likely to report false positive fractures. Our data indicate that the inaccuracy of self-reported fractures is clinically relevant for several major fractures, which could influence any fracture risk prediction model.

Does the Prediction Accuracy of Osteoporotic Fractures by BMD and Clinical Risk Factors Vary With Fracture Site?

Several clinical risk factors (CRFs) have been shown to predict the risk of fragility fractures independently of BMD, but their accuracy in the prediction of a particular fracture site has not been extensively studied. In this study based on longitudinal data from the FRISBEE cohort (Fracture Risk Brussels Epidemiological Enquiry), we evaluated if CRFs are specific for sites of incident osteoporotic fractures during follow‐up. We recruited 3560 postmenopausal women, aged 60 to 85 years, from 2007 to 2013, and surveyed yearly for the occurrence of fragility fractures during 6.2 years (median). We analyzed the association between CRFs included in the FRAX (fracture risk assessment tool) model or additional CRFs (falls, sedentary lifestyle, early untreated menopause, diabetes, use of selective serotonin reuptake inhibitors or proton pump inhibitors) and the first incident validated major osteoporotic fracture (MOF; n = 362; vertebra, hip, shoulder, and wrist) or other major fractures (n = 74; ankle, pelvis/sacrum, elbow, knee, long bones). Uni‐ and multivariate analyses using the Cox proportional hazards model were used. For MOFs considered together, the risk of fracture was highly associated in uni‐ and multivariate analyses (p<0.01) with osteoporosis (T‐score < −2.5), prior fracture, age, BMD (assessed by DXA), and fall history (HR 2.34, 1.82,1.71, 1.38, and 1.32, respectively). For each site analyzed separately, prior OF, age, smoking, and total hip BMD remained independent predictors for hip fractures (HR 5.72, 3.98, 3.10, 2.32, and 1.92, respectively); osteoporosis, age, prior OF, glucocorticoids, and spine BMD for vertebral fracture (HR 2.08, 1.87, 1.78, 1.76, and 1.45, respectively); osteoporosis, prior OF, and femoral neck BMD (HR 1.83, 1.60, and 1.56, respectively) for wrist fracture; osteoporosis, prior OF, and spine BMD (HR 2.48, 1.78, and 1.31, respectively) for shoulder fracture; prior OF and diabetes (HR 2.62 and 2.03) for other major fractures. Thus, a prior fracture and BMD were the best predictors of fracture risk at any site. Other CRFs have a weaker predictive value, which is a function of the site of a future fracture. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Bone management in hematologic stem cell transplant recipients

Autologous and allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for patients with some malignant and non-malignant hematological diseases. Advances in transplantation techniques and supportive care measures have substantially increased the number of long-term HSCT survivors. This has led to an increasing patient population suffering from the late effects of HSCT, of which, bone loss and its consequent fragility fractures lead to substantial morbidity. Altered bone health, with consequent fragility fractures, and chronic graft-versus-host disease (GVHD) are factors affecting long-term quality of life after HSCT. Hypogonadism, HSCT preparative regimens, nutritional factors, and glucocorticoids all contribute to accelerated bone loss and increased fracture risk. Management strategies should include bone mineral density examination, evaluation of clinical risk factors, and general dietary and physical activity measures. Evidence has accumulated permitting recommendations for more attentiveness to evaluation and monitoring of bone health, with appropriate application of osteoporosis pharmacotherapies to patients at increased risk of bone loss and fracture.

Usefulness of Bone Formation Markers in Breast Cancer

The skeleton is the main site affected by metastases and breast cancer is the most frequent tumor to invade bone. The assessment of bone metastases is difficult and biochemical markers of bone formation (BFMs) could be a promising alternative. Although the essential role of osteoblasts in the metastatic process of bone destruction is now well established, little attention has been paid to BFMs. We conducted a Medline search for studies about BFMs in breast cancer. Our review allows us to conclude that BFMs have high specificity but low sensitivity for the diagnosis of bone metastases. The available biochemical markers cannot replace imaging techniques for the diagnosis of bone metastases. Several studies indicate that BFM serum levels reflect total tumor burden in the skeleton. BFM levels are higher in patients with blastic lesions compared to those with lytic lesions. Serial measurements of BFMs could be useful for the clinical assessment of response to antineoplastic treatment or to bisphosphonate therapy. Besides markers of bone resorption, biochemical markers of bone formation are a promising alternative for the assessment of metastatic bone disease, but large prospective studies are needed to address this important issue.

Gorham-Stout disease of the proximal fibula treated with radiotherapy and zoledronic acid

Gorham-Stout disease is a rare disease characterized by anarchic lymphovascular proliferation causing resorption of bone sometimes leading to disastrous complications. Bone tissue is progressively replaced by angiomatic and lymphangiomatic tissue and finally by fibrous tissue. This disease is known to be ubiquitous and of complex etiology. We present a case of Gorham-Stout disease of the proximal fibula invading the proximal tibia and soft tissues of the popliteal space that was successfully treated with radiotherapy and zoledronic acid.

The PRIMARA study: a prospective, descriptive, observational study to review cinacalcet use in patients with primary hyperparathyroidism in clinical practice

OBJECTIVE

Medical management of primary hyperparathyroidism (PHPT) is important in patients for whom surgery is inappropriate. We aimed to describe clinical profiles of adults with PHPT receiving cinacalcet.

DESIGN

A descriptive, prospective, observational study in hospital and specialist care centres.

METHODS

For patients with PHPT, aged 23-92 years, starting cinacalcet treatment for the first time, information was collected on dosing pattern, biochemistry and adverse drug reactions (ADRs). Initial cinacalcet dosage and subsequent dose changes were at the investigator's discretion.

RESULTS

Of 303 evaluable patients with PHPT, 134 (44%) had symptoms at diagnosis (mostly bone pain (58) or renal stones (50)). Mean albumin-corrected serum calcium (ACSC) at baseline was 11.4 mg/dl (2.9 mmol/l). The reasons for prescribing cinacalcet included: surgery deemed inappropriate (35%), patient declined surgery (28%) and surgery failed or contraindicated (22%). Mean cinacalcet dose was 43.9 mg/day (s.d., 15.8) at treatment start and 51.3 mg/day (31.8) at month 12; 219 (72%) patients completed 12 months treatment. The main reason for cinacalcet discontinuation was parathyroidectomy (40; 13%). At 3, 6 and 12 months from the start of treatment, 63, 69 and 71% of patients, respectively, had an ACSC of ≤10.3 mg/dl vs 9.9% at baseline. Reductions from baseline in ACSC of ≥1 mg/dl were seen in 56, 63 and 60% of patients respectively. ADRs were reported in 81 patients (27%), most commonly nausea. A total of 7.6% of patients discontinued cinacalcet due to ADRs.

CONCLUSIONS

Reductions in calcium levels of ≥1 mg/dl was observed in 60% of patients 12 months after initiation of cinacalcet, without notable safety concerns.

Bone health in cancer patients: ESMO Clinical Practice Guidelines

There are three distinct areas of cancer management that make bone health in cancer patients of increasing clinical importance. First, bone metastases are common in many solid tumours, notably those arising from the breast, prostate and lung, as well as multiple myeloma, and may cause major morbidity including fractures, severe pain, nerve compression and hypercalcaemia. Through optimum multidisciplinary management of patients with bone metastases, including the use of bone-targeted treatments such as potent bisphosphonates or denosumab, it has been possible to transform the course of advanced cancer for many patients resulting in a major reduction in skeletal complications, reduced bone pain and improved quality of life. Secondly, many of the treatments we use to treat cancer patients have effects on reproductive hormones, which are critical for the maintenance of normal bone remodelling. This endocrine disturbance results in accelerated bone loss and an increased risk of osteoporosis and fractures that can have a significant negative impact on the lives of the rapidly expanding number of long-term cancer survivors. Finally, the bone marrow micro-environment is also intimately involved in the metastatic processes required for cancer dissemination, and there are emerging data showing that, at least in some clinical situations, the use of bone-targeted treatments can reduce metastasis to bone and has potential impact on patient survival.

Non-malignant causes of hypercalcemia in cancer patients: a frequent and neglected occurrence

PURPOSE

Hypercalcemia is a frequent finding in cancer patients and can be observed in any type of cancer. The physician in charge of cancer patients often ignores non-malignant causes of hypercalcemia. Our objective was to review the causes of hypercalcemia in a large series of cancer patients.

METHODS

We have retrospectively studied in a Cancer Centre all consecutive hypercalcemic (Ca> 10.5 mg/dl) patients over an 8-year period. Of 699 evaluated patients, 642 were analyzed after exclusion of patients whose hypercalcemia resolved after rehydration or who had a normal Ca level after correction for protein concentrations. Clinical information was gathered on the type of cancer, its histology, whether the disease was active or in complete remission, and on the presence of bone metastases. Biochemical data included serum Ca, P(i), proteins in all patients, PTH in most patients, and PTHrP, 25OH-Vitamin D, 1,25(OH)(2)-Vitamin D, TSH, and T4 in selected cases.

RESULTS

By order of decreasing frequency, the main causes of hypercalcemia were cancer (69.0 %), primary hyperparathyroidism (24.6 %), hyperthyroidism (2.2 %), milk alkali syndrome (0.9 %), and sarcoidosis (0.45 %). In cancer-related causes, bone metastases accounted for 53.0 % of the cases, humoral hypercalcemia of malignancy (HHM) for 35.3 % while there were 11.7 % of cases apparently due to both HHM and bone metastases. Hypercalcemia was not due to cancer in 97 % (84/87) of the patients who were in complete remission. Even in patients with active neoplastic disease, the number of patients whose hypercalcemia was not due to cancer remained clinically relevant (115/555 = 20.5 %). In the 158 patients with primary hyperparathyroidism, 92 patients were in complete remission and 66 patients had active neoplastic disease.

CONCLUSIONS

In this large series of hypercalcemia in cancer patients, the cause was not due to cancer in almost one third of the cases. Most patients considered to be in complete remission had hypercalcemia due to a benign condition. In that perspective, serum PTH determination is essential in the approach of hypercalcemic cancer patients since primary hyperparathyroidism is by far the first non-malignant cause of hypercalcemia.

Skeletal-related events and clinical outcomes in patients with bone metastases and normal levels of osteolysis: exploratory analyses

AIMS

High levels of bone resorption markers (e.g. N-telopeptide of type I collagen; NTX) have been correlated with increased risks of skeletal-related events and death in patients with bone metastases from solid tumours. However, the disease course has not been well characterised in patients with bone metastases but normal NTX levels. Therefore, the aim of this study was to evaluate the patterns of skeletal morbidity in patients with normal NTX levels.

MATERIALS AND METHODS

Exploratory analyses were carried out on patients with bone metastases from breast cancer, castration-resistant prostate cancer, non-small cell lung cancer or other solid tumours treated with zoledronic acid (ZOL) in phase III trials. The effects of covariates on the relative risk of death were estimated using the Cox proportional hazard model. The prognostic values of covariates were compared between patients with normal (<64 nmol/mmol creatinine) versus elevated (≥64 nmol/mmol creatinine) NTX levels.

RESULTS

Among patients with normal baseline NTX (n = 501), less than 10% developed elevated NTX levels before a skeletal-related event or death during ZOL treatment over 12 months. The prognostic factors identified in these analyses were mostly similar across NTX groups. However, some indicators of aggressive disease (e.g. visceral/cerebral metastases from breast cancer) were associated with poor clinical outcomes only in the normal NTX group.

CONCLUSIONS

Skeletal-related events were generally not preceded or followed by transition to elevated NTX in patients treated with ZOL. Elevated baseline NTX and aggressive extraskeletal disease were independently associated with reduced survival.

Guidance for the prevention of bone loss and fractures in postmenopausal women treated with aromatase inhibitors for breast cancer: an ESCEO position paper

Aromatase inhibitors (AIs) are widely used in women with breast cancer, but they are known to increase bone loss and risk of fractures. Based on available evidence and recommendations, an ESCEO working group proposes specific guidance for the prevention of AIs-induced bone loss and fragility fractures.

INTRODUCTION

Aromatase inhibitors (AIs) are now the standard treatment for hormone receptor-positive breast cancer. However, deleterious effects of AIs on bone health have been reported. An ESCEO working group proposes guidance for the prevention of bone loss and fragility fractures in post-menopausal women with breast cancer receiving AIs.

METHODS

A panel of experts addressed the issue of skeletal effects of AIs and effectiveness of antifracture therapies for the prevention of AI-induced bone loss and fractures. Recommendations by national and international organizations, and experts' opinions on this topic were evaluated.

RESULTS

All aromatase inhibitors are associated with negative effects on the skeleton, resulting in bone loss and increased risk of fragility fractures. Current guidelines suggest approaches that differ both in terms of drugs proposed for fracture prevention and duration of treatment.

CONCLUSION

The ESCEO working group recommends that all AI-treated women should be evaluated for fracture risk. Besides general recommendations, zoledronic acid 4 mg i.v. every 6 months, denosumab s.c., or possibly oral bisphosphonates should be administered for the entire period of AI treatment to all osteoporotic women (T-score hip/spine <-2.5 or ≥ 1 prevalent fragility fracture), to women aged ≥ 75 irrespective of BMD, and to patients with T-score <-1.5 + ≥ 1 clinical risk factor or T-score <-1.0 + ≥ 2 clinical risk factors. Alternatively, therapy could be considered in patients with a FRAX-determined 10-year hip fracture probability ≥ 3%.

[Primary hyperparathyroidism: diagnosis and management]

The prevalence of primary hyperparathyroidism (HPT) varies between 1 and 4/1.000 in the general population. HPT is nowadays most often asymptomatic. The classical bone disease has been replaced by osteopenia or osteoporosis with a preferential bone loss in cortical sites. The incidence of nephrolithiasis has been considerably lowered, but renal lithiasis is still the most frequent complication of HPT. The diagnosis is most often made by chance or during the workup of an abnormal bone mass. Hypercalcemia and an elevated PTH concentration, or at least a PTH level in the upper part of the normal range, generally point to a diagnosis of HPT. Additional tests include an evaluation of renal function, vitamin D measurement, determination of 24-hour urinary calcium and bone densitometry. Besides symptomatic HPT, classical recommendations for surgery include age less than 50, serum Ca at least 1 mg/dl above the upper limit of normal, creatinine clearance < 60 ml/min and osteoporosis. Surgical referral will, however, take into account patient age and comorbidities, as well as patient preferences. In the hands of an experienced surgeon, the success rate of parathyroidectomy is 95-98% and the rate of permanent complications is 1-3%. Parathyroid scintigraphy is the best preoperative localization technique of the adenoma. When surgery is contraindicated or refused by the patient, bisphosphonates or cinacalcet can be indicated in cases of osteoporosis or clinically significant hypercalcemia, respectively.

How to manage postmenopausal osteoporosis?

Osteoporosis is characterized by reduced bone mass and disruption of bone architecture, resulting in increased fracture risk. Several therapeutic agents are now available to treat postmenopausal osteoporosis and prevent fractures. Combined calcium and vitamin D supplementation reduce the relative risk of non-vertebral fractures by about 18%. Hormone replacement therapy (HRT) should not be prescribed for osteoporosis in women who do not experience menopausal symptoms. The marked benefits of raloxifene on the reduction in invasive breast cancer and vertebral fracture risk are partially counterbalanced by a lack of effect on non-vertebral fracture risk, and an increased risk of venous thromboembolism and stroke. All four bisphosphonates available in Belgium, except ibandronate, have been shown to reduce the risk of vertebral, non-vertebral and hip fractures in prospective, placebo-controlled trials. Globally, the incidence of vertebral fractures is reduced by 41%-70%, and the incidence of non-vertebral fractures by 25%-39%. The anti-fracture efficacy of weekly or monthly doses of oral bisphosphonates has not been directly shown but is assumed from bridging studies based on BMD changes. To date, the various bisphosphonates have not been studied in head-to-head comparative trials with fracture endpoints. There are potential concerns that long-term suppression of bone turnover associated with bisphosphonate treatment may eventually lead to adverse effects, especially atypical femoral fractures and osteonecrosis of the jaw, but these cases are extremely rare. Teri-paratide (recombinant human 1-34 PTH) administered by daily subcutaneous injections decreases by 65% the relative risk of new vertebral fractures in patients with severe osteoporosis. Pivotal trials with strontium ranelate have shown a 41% reduction in new vertebral fractures and a 16% reduction in non-vertebral fractures over 3 years. Denosumab is a fully human monoclonal antibody to RANK Ligand that is administered as a 60-mg subcutaneous injection every 6 months. In the pivotal phase III trial, there was a 68% reduction in the incidence of new vertebral fractures, whereas the incidence of non-vertebral fractures was reduced by 20%. Several new approaches are being explored, including antibodies to sclerostin, cathepsin K inhibitors, src kinase inhibitors, and drugs that act on calcium sensing receptors.

Loading and skeletal development and maintenance

Mechanical loading is a major regulator of bone mass and geometry. The osteocytes network is considered the main sensor of loads, through the shear stress generated by strain induced fluid flow in the lacuno-canalicular system. Intracellular transduction implies several kinases and phosphorylation of the estrogen receptor. Several extra-cellular mediators, among which NO and prostaglandins are transducing the signal to the effector cells. Disuse results in osteocytes apoptosis and rapid imbalanced bone resorption, leading to severe osteoporosis. Exercising during growth increases peak bone mass, and could be beneficial with regards to osteoporosis later in life, but the gain could be lost if training is abandoned. Exercise programs in adults and seniors have barely significant effects on bone mass and geometry at least at short term. There are few data on a possible additive effect of exercise and drugs in osteoporosis treatment, but disuse could decrease drugs action. Exercise programs proposed for bone health are tedious and compliance is usually low. The most practical advice for patients is to walk a minimum of 30 to 60 minutes per day. Other exercises like swimming or cycling have less effect on bone, but could reduce fracture risk indirectly by maintaining muscle mass and force.

Renal tolerability of intermittent intravenous ibandronate treatment for patients with postmenopausal osteoporosis: a review

While intravenous (IV) bisphosphonates are well established in managing metastatic bone disease and hypercalcemia of malignancy, oral bisphosphonates are the primary treatment for postmenopausal osteoporosis. The availability of a well-tolerated, effective, IV bisphosphonate regimen for postmenopausal osteoporosis would increase physicians' options, allowing treatment of patients who cannot tolerate oral therapy, for whom oral bisphosphonates should be avoided or patients who are unable to comply with the oral dosing recommendations. Ibandronate is a potent, nitrogen-containing bisphosphonate, with proven efficacy and good tolerability when administered intermittently either orally or intravenously. Preclinical experience in animal models with IV ibandronate indicated that it had good renal tolerability. These data are supported by clinical pharmacology studies. Prolonged follow-up of patients receiving intermittent IV 15-30 second injections of 0.5-3 mg IV ibandronate has demonstrated no clinical evidence of renal toxicity in patients with postmenopausal osteoporosis. What is seen in controlled studies is not always the case in uncontrolled studies, however, no reports of renal failure have been received in post-marketing surveillance of >500,000 patients receiving IV ibandronate infusions in various indications including metastatic breast and prostate cancer. The good renal tolerability of IV ibandronate in patients with osteoporosis with glomerular filtration rates >30 mL/minute and without renal co-morbid conditions is reassuring.

[Absolute risk fracture prediction by risk factors validation and survey of osteoporosis in a Brussels cohort followed during 10 years (FRISBEE study)]

Osteoporosis is a major public health problem. For the time being, the diagnosis of osteoporosis relies on densitometry (T-score < -2.5 by DXA), although the risk of fracture depends also on other factors than the bone mass. Osteoporosis diagnosis (DXA) must be distinguished from the individual risk assessment of fracture. Different risk factors complementary to bone mass have been already validated in different populations. These include an old age, a history of fracture after the age of 50, a familial history of hip fracture (father or mother), a low BMI (< 20), corticoid treatment (> 3 months), tabagism and excessive alcohol consumption. A WHO taskforce has combined these different factors in order to integrate them in a 10-years predictive risk model of fracture (FRAX**). This model should still be validated in different populations, especially in populations not included in its development, which is the case for Belgium. We are evaluating these different risk factors for fracture in a Brussels population of 5000 women (60-80 years) who will be followed each year during 10 years. We also assess the predictive value of other risk factors for fracture not included in the WHO model (tendency to fall, use of sleeping pills, early non substituted menopause, sedentarity, ...). In an interim analysis of the first 452 women included and with data yet available at the time of this writing, we could find a significant (P < 0.05) relationship between diagnosis of osteoporosis at DXA and the number of risk factors, age > 70 years, a personal history of fracture after 50 years and a BMI < 20.

[Update on treatment of postmenopausal osteoporosis]

The most frequent sites of osteoporotic fractures are the vertebrae, the hip, the forearm and the proximal humerus. Drugs that inhibit bone resorption constitute the mainstay for the treatment of postmenopausal osteoporosis. A recent meta-analysis indicates that vitamin D can reduce the risk of hip fractures only if calcium supplements are also administered. The effect of hormone replacement therapy on the risk of non vertebral fractures is less clear than on vertebral fractures. Raloxifene (a SERM) reduces the rate of vertebral fractures and of breast cancer, but it does not protect against hip fracture. Bisphosphonates are the most commonly used compounds to treat postmenopausal osteoporosis. The level of evidence for currently used bisphosphonates (alendronate, ibandronate, risedronate, zoledronate) to reduce vertebral fracture rate is maximal. Results of controlled clinical trials indicate a reduction in the risk of vertebral fractures of 40-50% and of 20-40% for non vertebral fractures, including hip fractures. However, their relative efficacy on hip fractures has been less well studied and remains more controversial. Long-term compliance of bisphosphonate therapy is improved by intermittent schemes. The most recent developpements concern the intravenous administration of ibandronate and even more of zoledronate (yearly infusions). The reduction in the rate of vertebral and hip fractures has been demonstrated in the main zoledronate trial and a prolongation of survival has been shown in the study including patients with a recent hip fracture. Whereas hyperparathyroidism is a cause of bone loss, the intermittent administration of parathyroid hormone or of its 1-34 fragment (teriparatide) exerts anabolic effects on the skeleton. The treatment is demanding and costly (daily sc injections during 18 months), requires some monitoring (serum and urinary calcium) but the results, at least for vertebral fractures, are quite favorable. Strontium ranelate is a less powerful stimulator of bone formation but it also reduces bone resorption. Its daily administration for 3 years reduces the risk of vertebral fractures and, to a lesser extent, of non vertebral fractures. Lastly, denosumab is a high affinity antibody against RANK Ligand that specifically blocks the formation and the activity of osteoclasts. The efficacy of this promising compound will soon be known.

Guidance on the use of bisphosphonates in solid tumours: recommendations of an international expert panel

Bisphosphonates (BP) prevent, reduce, and delay cancer-related skeletal complications in patients, and have substantially decreased the prevalence of such events since their introduction. Today, a broad range of BP with differences in potency, efficacy, dosing, and administration as well as approved indications is available. In addition, results of clinical trials investigating the efficacy of BP in cancer treatment-induced bone loss (CTIBL) have been recently published. The purpose of this paper is to review the current evidence on the use of BP in solid tumours and provide clinical recommendations. An interdisciplinary expert panel of clinical oncologists and of specialists in metabolic bone diseases assessed the widespread evidence and information on the efficacy of BP in the metastatic and nonmetastatic setting, as well as ongoing research on the adjuvant use of BP. Based on available evidence, the panel recommends amino-bisphosphonates for patients with metastatic bone disease from breast cancer and zoledronic acid for patients with other solid tumours as primary disease. Dosing of BP should follow approved indications with adjustments if necessary. While i.v. administration is most often preferable, oral administration (clodronate, IBA) may be considered for breast cancer patients who cannot or do not need to attend regular hospital care. Early-stage cancer patients at risk of developing CTIBL should be considered for preventative BP treatment. The strongest evidence in this setting is now available for ZOL. Overall, BP are well-tolerated, and most common adverse events are influenza-like syndrome, arthralgia, and when used orally, gastrointestinal symptoms. The dose of BP may need to be adapted to renal function and initial creatinine clearance calculation is mandatory according to the panel for use of any BP. Subsequent monitoring is recommended for ZOL and PAM, as described by the regulatory authority guidelines. Patients scheduled to receive BP (mainly every 3-4 weeks i.v.) should have a dental examination and be advised on appropriate measures for reducing the risk of jaw osteonecrosis. BP are well established as supportive therapy to reduce the frequency and severity of skeletal complications in patients with bone metastases from different cancers.

The use of bone markers in a 6-week study to assess the efficacy of oral clodronate in patients with metastatic bone disease

Biochemical markers of bone metabolism are strongly associated with skeletal complications in metastatic bone disease. The bisphosphonate clodronate reduces skeletal morbidity by inhibiting bone resorption. This study investigated the use of bone markers to assess the efficacy of oral clodronate across a range of clinically relevant doses. There were 125 patients with metastatic bone disease randomized to daily oral clodronate (800, 1,600, 2,400 and 3,200 mg) or placebo in a double-blind, multicenter study. Urinary N-terminal telopeptide of type I collagen (U-NTX), serum C-terminal telopeptide of type I collagen (S-CTX), urinary calcium (U-Ca), and bone alkaline phosphatase were measured weekly for a 6-week treatment period. Doses of >or=1,600 mg clodronate produced mean reductions of >40% in U-NTX, S-CTX and U-Ca, all significantly different from placebo (P=0.0015, 0.001, 0.0036, respectively), after 6 weeks. Evaluation of least significant changes in markers suggested that the commonly used 1,600 mg dose was most appropriate for breast cancer patients. However, this dose was suboptimal for other (mainly prostate cancer) patients, who showed better response to 2,400 mg. The number of adverse events in the treatment arms was not significantly different from that in placebo, but a higher number of patients had diarrhea in the 3,200 mg arm and withdrew from the study. This trial is the first to explore the dose-response relationship of clodronate in oncology using specific markers of bone turnover. It has confirmed that the 1,600 mg dose is safe and effective for breast cancer patients but may be suboptimal for the other tumors studied.

Management of cancer treatment-induced bone loss in early breast and prostate cancer -- a consensus paper of the Belgian Bone Club

Cancer treatment-induced bone loss (CTIBL) is one of the most important side effects of adjuvant antineoplastic treatment in hormone-dependent neoplasms. Chemotherapy, GnRH analogs and tamoxifen can induce marked bone loss in premenopausal women with early breast cancer. Aromatase inhibitors (AIs) are replacing tamoxifen as the preferred treatment for postmenopausal women. As a class effect, steroidal (exemestane) and non-steroidal (anastrozole and letrozole) AIs increase bone turnover and cause bone loss (4%-5% over 2 years). When compared to tamoxifen, the risk of getting a clinical fracture under AI treatment is increased by 35%-50%. In patients with prostate cancer, androgen deprivation therapy (ADT) increases bone turnover, reduces bone mass (4%-5% per year) and increases the fracture rate depending on the duration of therapy. Zoledronic acid can prevent accelerated bone loss induced by goserelin in premenopausal women, by letrozole in postmenopausal women and by ADT in men. More limited data indicate that weekly alendronate or risedronate could also be effective for preventing CTIBL. Initiation of therapy early, prior to the occurrence of severe osteoporosis, rather than after, may be more effective. Bisphosphonate treatment should be considered in osteoporotic but also in osteopenic patients if other risk factor(s) for fractures are present.

Increased Dickkopf-1 expression in breast cancer bone metastases

The aim of this study was to determine whether Dickkopf-1 (Dkk-1) expression in breast cancer was associated with bone metastases. We first analysed Dkk-1 expression by human breast cancer cell lines that induce osteolytic or osteoblastic lesions in animals. Dickkopf-1 levels were then measured in the bone marrow aspirates of hind limbs from eight NMRI mice inoculated with breast cancer cells that induced bone metastases and 11 age-matched non-inoculated control animals. Finally, Dkk-1 was measured in the serum of 17 women with breast cancer in complete remission, 19 women with breast cancer and bone metastases, 16 women with breast cancer and metastases at non-bone sites and 16 healthy women. Only breast cancer cells that induce osteolytic lesions in animals produced Dkk-1. There was a six-fold increase in Dkk-1 levels in the bone marrow from animals inoculated with MDA-B02 cells when compared with that of control non-inoculated animals (P=0.003). Median Dkk-1 levels in the serum of patients with breast cancer and bone metastases were significantly higher than levels of patients in complete remission (P=0.016), patients with breast cancer having metastases at non-bone sites (P<0.0001) and healthy women (P=0.047), although there was a large overlap in individual levels between the different groups. In conclusion, Dkk-1 is secreted by osteolytic human breast cancer cells lines and increased circulating levels are associated with the presence of bone metastases in patients with breast cancer. Measurements of circulating Dkk-1 levels may be useful for the clinical investigation of patients with breast cancer and bone metastases.

Zoledronic acid efficacy and safety over five years in postmenopausal osteoporosis

In a 5-year study involving 119 postmenopausal women, zoledronic acid 4 mg given once-yearly for 2, 3 or 5 years was well tolerated with no evidence of excessive bone turnover reduction or any safety signals. BMD increased significantly. Bone turnover markers decreased from baseline and were maintained within premenopausal reference ranges.

INTRODUCTION

After completion of the core study, two consecutive, 2-year, open-label extensions investigated the efficacy and safety of zoledronic acid 4 mg over 5 years in postmenopausal osteoporosis.

METHODS

In the core study, patients received 1 to 4 mg zoledronic acid or placebo. In the first extension, most patients received 4 mg per year and then patients entered the second extension and received 4 mg per year or calcium only. Patients were divided into three subgroups according to years of active treatment received (2, 3 or 5 years). Changes in BMD and bone turnover markers (bone ALP and CTX-I) were assessed.

RESULTS

All subgroups showed substantial increases in BMD and decreases in bone markers. By the end of the core study, 37.5% of patients revealed a suboptimal reduction (< 30%) of bone ALP levels. After subsequent study drug administration during the extensions, there was no evidence of progressive reduction of bone turnover markers. Furthermore, increased marker levels after treatment discontinuation demonstrates preservation of bone remodelling capacity.

CONCLUSIONS

This study showed that zoledronic acid 4 mg once-yearly was well tolerated and effective in reducing biomarkers over 5 years. Detailed analysis of bone marker changes, however, suggests that this drug regimen causes insufficient reduction of remodelling activity in one third of patients.

Intravenous ibandronate does not affect time to renal function deterioration in patients with skeletal metastases from breast cancer: phase III trial results

As patients with metastatic bone disease typically receive long-term treatment with bisphosphonates, and often antineoplastic compounds, drug-related safety is of considerable importance. Clinical trial data for intravenous (i.v.) ibandronate suggest that its nephrotoxic potential is comparable with placebo. We conducted a post hoc Kaplan-Meier analysis of time to serum creatinine increase with i.v. ibandronate throughout 2 years of treatment. After 96 weeks, 12% of patients in the placebo group and 6% in the ibandronate 6 mg group (ns, P = 0.22) had defined serum creatinine increases. After 12 treatment months (48 weeks), 4% of patients receiving placebo and 2% of patients receiving ibandronate 6 mg showed increased serum creatinine. These results suggest that there is no clinically relevant change in serum creatinine levels with i.v. ibandronate 6 mg infused every 3-4 weeks for 2 years. Comparative trials to examine the renal safety of ibandronate and other i.v. bisphosphonates are warranted.

[Treatment of Paget's disease of bone with zoledronic acid]

Bone pain and bone deformities are the most common manifestations of Paget's disease of bone, even if the diagnosis is nowadays most often made by chance following a routine measurement of serum alkaline phosphatase. Woven bone is formed following a marked increase in bone resorption due to a stimulation of osteoclast activity. Biphosphonates constitute the modern treatment of Paget's disease of bone. Tiludronate (Skelid), or better risedronate (Actonel), are administered orally every day during at least 2 months. Zoledronic acid (Aclasta), as a single 15-min 5 mg infusion, has been recently compared to risedronate, 30 mg/d orally for 2 months, in two randomized studies including 357 patients. Zoledronic acid had a superior therapeutic efficacy, as judged by its rapidity of action, the duration of the biochemical response and the percentage of responders. Thus, at 6 months, alkaline phosphatase levels were normalized in 89% of the patients in the zoledronic acid group as compared to 58% in the risedronate group. The most frequent side effect was a flu-like syndrome, observed in 10% of the patients. An adequate intake of calcium and vitamin D is recommended to avoid posttreatment hypocalcemia. The introduction of Aclasta should simplify and improve the therapeutic management of Paget's disease of bone.

Cost-effectiveness of oral ibandronate versus IV zoledronic acid or IV pamidronate for bone metastases in patients receiving oral hormonal therapy for breast cancer in the United Kingdom

BACKGROUND

Oral ibandronate is a single-nitrogen bisphosphonate whose efficacy is similar to that of IV ibandronate for the treatment of bone metastases.

OBJECTIVE

The aim of this study was to compare the cost-effectiveness of oral ibandronate with zoledronic acid and generic pamidronate (both administered by IV) for the treatment of bone metastases in patients with breast cancer receiving oral hormonal therapy in the United Kingdom.

METHODS

A global economic model was adapted to the UK National Health Service. Patients were assumed to receive oral hormonal therapy for 50% of their projected 14.3-month survival. The primary outcome was incremental cost per quality-adjusted life-year (QALY). Bisphosphonate efficacy data for relative risk reduction of skeletal-related events (SREs) were obtained from clinical trials. Resource use data and costs associated with IV bisphosphonate infusions were derived from published studies and a unit cost database; monthly drug acquisition costs were obtained from the British National Formulary. Utility scores were applied to time with or without an SRE to adjust survival for quality of life. Therefore, differences in QALYs were driven by utility weights rather than survival time. Model design and inputs were validated through expert UK clinician review. The absence of comparative efficacy and safety data from clinical trials for the different bisphosphonates was a model limitation that we addressed by supporting our assumptions with UK expert clinician opinion and with expert clinician opinion outside of the United Kingdom, and by conducting sensitivity analyses.

RESULTS

The projected total cost per patient was pound307 less with oral ibandronate compared with zoledronic acid, and pound158 less compared with the use of generic pamidronate (due to a reduction in staff time for infusions, avoidance of renal safety monitoring visits, and, in the case of IV generic pamidronate, a reduction in the number of SREs). Oral ibandronate was estimated to lead to a gain of 0.02 QALY, making it the economically dominant treatment option.

CONCLUSIONS

In this study, we found that oral ibandronate was cost-effective for the management of bone metastases from breast cancer among patients receiving oral hormonal therapy in the United Kingdom. Oral ibandronate provided effective SRE and bone-pain management while avoiding resource use and costs associated with regular IV bisphosphonate infusions. Due to uncertainty surrounding the model assumptions, it would be valuable to repeat the analyses using data from comparative bisphosphonate trials, once they become available.

Cost-effectiveness of oral ibandronate compared with intravenous (i.v.) zoledronic acid or i.v. generic pamidronate in breast cancer patients with metastatic bone disease undergoing i.v. chemotherapy

BACKGROUND

Ibandronate is the first third-generation bisphosphonate to have both oral and intravenous (i.v.) efficacy. An incremental cost-effectiveness model compared oral ibandronate with i.v. zoledronic acid and i.v. generic pamidronate in female breast cancer patients with metastatic bone disease, undergoing i.v. chemotherapy.

METHODS

A global economic model was adapted to the UK National Health Service (NHS), with primary outcomes of direct healthcare costs and quality-adjusted life years (QALYs). Efficacy, measured as relative risk reduction of skeletal-related events (SREs), was obtained from clinical trials. Resource use data for i.v. bisphosphonates and the cost of managing SREs were obtained from published studies. Hospital management and SRE treatment costs were taken from unit cost databases. Monthly drug acquisition costs were obtained from the British National Formulary. Utility scores were applied to time with/without an SRE to adjust survival for quality of life. Model design and inputs were validated through expert UK clinician review.

RESULTS

Total cost, including drug acquisition, was pound 386 less per patient with oral ibandronate vs. i.v. zoledronic acid and pound 224 less vs. i.v. generic pamidronate. Oral ibandronate gained 0.019 and 0.02 QALYs vs. i.v. zoledronic acid and i.v. pamidronate, respectively, making it the economically dominant option. At a threshold of pound 30,000 per QALY, oral ibandronate was cost-effective vs. zoledronic acid in 85% of simulations and vs. pamidronate in 79%.

CONCLUSIONS

Oral ibandronate is a cost-effective treatment for metastatic bone disease from breast cancer due to reduced SREs, bone pain, and cost savings from avoidance of resource use commonly associated with bisphosphonate infusions.

[Gabapentin (Neurontin) and cancer pain: a pilot study]

Gabapentin (GBP) is a new antiepileptic agent with an original spectrum of activity. Its mechanism of action has not yet been fully elucidated but appears not to involve binding to GABA receptors despite being a structural analogue of GABA and is distinct from tricyclic antidepressants (TCAs). It has been shown to modulate high threshold calcium currents in brain neurons. As some other anticonvulsants, GBP has been recently proposed for the treatment of noncancer neuropathic pain like diabetic neuropathy and post herpetic neuralgia (double blind studies with placebo). We prospectively followed 20 cancer patients with advanced disease suffering from neuropathic pain. All were already treated for their pain syndrome. We started with 300 mg of GBP given orally in order to reach a dose of 900 mg on D3. All coanalgesics were stopped before entering the study. The only relevant side effect due to GBP was somnolence, otherwise time limited. GBP treatment was associated with a decrease of opioids doses in 9 patients and a decrease of VAS for pain intensity in all cases. Furthermore, the need of rescue doses decreased in all cases but 2. GBP appears to be one of the most effective drugs for the treatment of neuropathic pain. It is well tolerated and its effectiveness appears shortly after its administration. A synergistic action with opioids is suggested. Despite the small number of patients, our study suggests that GBP could be a treatment of neuropathic pain in cancer. Comparative trials should be performed with other neuropathic pain drugs including TCAs and antiepileptic drugs, especially carbamazepine.

Hypovitaminosis D in a normal, apparently healthy urban European population

Serum 25 OH Vitamin D (25 OH D) concentrations generally vary with latitude, season, and the composition of the population studied. There is a growing recognition that rather than a seasonal specific decline in serum 25 OH Vitamin D, a significant proportion of the population may exhibit asymtomatic subclinical Vitamin D insufficiency. Vitamin D insufficiency has been described in populations at risk, such as nursing home residents and the homebound elderly. We assessed a population of normal, apparently healthy volunteers at a single European urban center for 25 OH Vitamin D sufficiency. Serum 25 OH D concentrations were determined using an automated LIAISON((R)) 25 OH Vitamin D assay. For the purposes of this study, Vitamin D insufficiency was defined as a serum 25 OH Vitamin D concentration of <15 ng/mL. Of the total population (n = 126) 34% exhibited 25 OH Vitamin D concentrations of <15 ng/ml. The mean +/- S.D. serum 25 OH Vitamin D concentration among the total, sufficient, and insufficient populations was 19.4 +/- 7.7, 23.6 +/- 6.4, and 12.1 +/- 2.3 ng/mL. From these data, we conclude that 25 OH Vitamin D insufficiency is more common than previously thought, and is not restricted to high-risk groups.

Oral ibandronate reduces the risk of skeletal complications in breast cancer patients with metastatic bone disease: results from two randomised, placebo-controlled phase III studies

Although intravenous (i.v.) bisphosphonates are the standard of care for metastatic bone disease, they are less than ideal for many patients due to infusion-related adverse events (AEs), an increased risk of renal toxicity and the inconvenience of regular hospital visits. The use of oral bisphosphonate therapy is limited by concerns over efficacy and gastrointestinal (GI) side effects. There remains a clinical need for an oral bisphosphonate that offers equivalent efficacy to i.v. bisphosphonates, good tolerability and dosing convenience. Oral ibandronate, a highly potent, third-generation aminobisphosphonate, has been evaluated in phase III clinical trials of patients with bone metastases from breast cancer. In two pooled phase III studies, patients with breast cancer and bone metastases were randomised to receive oral ibandronate 50 mg (n=287) or placebo (n=277) once daily for up to 96 weeks. The primary end point was the skeletal morbidity period rate (SMPR), defined as the number of 12-week periods with new skeletal complications. Multivariate Poisson's regression analysis was used to assess the relative risk of skeletal-related events in each treatment group during the study period. Oral ibandronate 50 mg significantly reduced the mean SMPR compared with placebo (0.95 vs 1.18, P=0.004). There was a significant reduction in the mean number of events requiring radiotherapy (0.73 vs 0.98, P<0.001) and events requiring surgery (0.47 vs 0.53, P=0.037). Poisson's regression analysis confirmed that oral ibandronate significantly reduced the risk of a skeletal event compared with placebo (hazard ratio 0.62, 95% CI=0.48, 0.79; P=0.0001). The incidence of mild treatment-related upper GI AEs was slightly higher in the oral ibandronate 50 mg group compared with placebo, but very few serious drug-related AEs were reported. Oral ibandronate 50 mg is an effective, well-tolerated and convenient treatment for the prevention of skeletal complications of metastatic bone disease.

Management of primary osteoporosis

Although there is a great need for better therapeutic approaches to the patient who presents with a fracture, osteoporotic fractures will remain a condition that is more amenable to prevention than treatment. Hormone replacement therapy (HRT) is still considered by many the mainstay for the prevention and the treatment of posrmenopausal osteoporosis. However, there are several controversies regarding HRT, especially the duration of treatment and the risks/benefits ratio. Recent studies have challenged the assumption that HRT conveys real long-term beneficial effects. Raloxifene or other "selective estrogen receptor modulators" (SERMs) should progressively replace HRT in elderly women. Bisphosphonates have demonstrated a clearcut efficacy in the treatment of osteoporosis. Alendronate and risedronate have been the most extensively studied bisphosphonates under randomized controlled trials conditions. Both agents can reduce the risk of vertebral and hip fractures by one-fourth to one-half. However, oral bisphosphonates are not without gastro-intestinal toxicity and strict adherence to constraining therapeutic schemes is mandatory. Intermittent treatments are already in use. Weekly alendronate is as efficient as daily therapy and improves treatment compliance. Newer more potent bisphosphonates, such as oral ibandronate or intravenous zoledronic acid, will allow much less frequent administration. The anti-fracture efficacy of yearly zoledronic acid infusions is thus currently tested. On the other hand, bone-forming agents, such as daily subcutaneous injections of teriparatide (rhPTH 1-34) offer exciting perspectives for the treatment of severe osteoporosis despite the complexity of such therapy.

Bisphosphonates for cancer patients: why, how, and when?

Bisphosphonates (BPs) are potent inhibitors of osteoclast-mediated bone resorption, and it is well accepted that tumor cells in bone, especially breast cancer and myeloma cells, can stimulate osteoclast formation and activity leading to the release of growth factors or cytokines, which will further stimulate cancer cells' growth and their secretion of osteolytic factors. BPs are now the standard treatment for cancer hypercalcemia, for which a dose of 90 mg of pamidronate or 1500 mg of clodronate is recommended; the former compound is more potent and has a longer lasting effect. Repeated pamidronate infusions exert clinically relevant analgesic effects in more than half of patients with metastatic bone pain. Recent data suggest that non-responding patients should perhaps be treated with higher doses. The optimal dose actually remains to be defined, especially as it is thought that it is probably a function of the disease stage. Regular pamidronate infusions can also achieve a partial objective response according to conventional UICC criteria and they can almost double the objective response rate to chemotherapy. Lifelong administration of oral clodronate to patients with breast cancer metastatic to bone reduces the frequency of morbid skeletal events by more than one-fourth. Two double-blind randomized placebo-controlled trials comparing monthly 90 mg pamidronate infusions to placebo infusions for 1-2 years in addition to hormone or chemotherapy in patients with at least one lytic bone metastasis have shown that the mean skeletal morbidity rate could be reduced by 30-40%. The results obtained with intravenous BPs are generally viewed as better than those obtained with oral clodronate. However, preference can be given to the oral route when BPs are started early in the process of metastatic bone disease in a patient receiving hormone therapy. According to the recently published ASCO guidelines, pamidronate 90 mg i.v. delivered over 2 h every 3-4 weeks can be recommended in patients with metastatic breast cancer who have imaging evidence of lytic destruction of bone and who are concurrently receiving systemic therapy with hormonal therapy or chemotherapy. Furthermore, the ASCO Panel considered it "reasonable" to start i.v. BPs in women with localized pain whose bone scans were abnormal and plain radiographs normal, but not when an abnormal bone scan is asymptomatic. The pertinence of these criteria is discussed below. Because BPs are providing supportive care, reducing the rate of skeletal morbidity but evidently not abolishing it, the criteria for stopping their administration have to be different from those used for classic antineoplastic drugs, and they should not be stopped when metastatic bone disease is progressing. However, criteria to determine whether and for how long an individual patient benefits from their administration are lacking. New biochemical markers of bone resorption might help identify those patients continuing to benefit from therapy. Even better results have been achieved in patients with multiple myeloma, and the general consensus is that BPs should be started as soon as the diagnosis of lytic disease is made in myeloma patients. On the other hand, data are scanty in prostate cancer, but large-scale trials with potent BPs are ongoing or planned in such patients. Similar results to those achieved with pamidronate have been obtained with monthly 6-mg infusions of the newer BP ibandronate in patients with breast cancer metastatic to bone. The tolerance of ibandronate could be better, and the drug has the potential to be administered as a 15- to 30-min infusion. Zoledronate can also be administered safely as a 15-min 4-mg infusion, and large scale phase III trials have just been completed. These newer BPs will simplify the current therapeutic schemes and improve the cost-effectiveness ratio; they also have the potential to improve the therapeutic efficacy, at least in patients with an aggressive osteolytic disease or when given as adjuvant therapy. For that matter, initial data with clodronate indicate that they have the potential to prevent the development of bone metastases, but the use of BPs in the adjuvant setting must still be viewed as experimental.

Bisphosphonates influence the proliferation and the maturation of normal human osteoblasts

The key pharmacological action for the clinical use of bisphosphonates lies in the inhibition of osteoclast-mediated bone resorption. Osteoblasts could be other target cells for bisphosphonates. We studied the effects of bisphosphonates on the proliferation and the differentiation of normal human bone trabecular osteoblastic cells (hOB). We tested 4 different compounds: clodronate, pamidronate and 2 newer compounds: ibandronate, a nitrogen-containing bisphosphonate and zoledronate, which is a heterocyclic imidazole compound. Ibandronate and zoledronate stimulated hOB cell proliferation by up to 30% (p<0.05) after 72 h for concentrations ranging from 10(-8) M to 10(-5) M. Clodronate transiently enhanced hOB cell survival after only 24 h (+60%, p<0.001) whereas pamidronate had no effect. Longer time course studies, in presence of fetal calf serum, revealed that cell growth was finally reduced by all 4 bisphosphonates (40% after 7 days). Type I collagen synthesis was transiently increased by all 4 bisphosphonates after only 48 h incubation (+17% to +67%, p<0.05). Clodronate increased ALP activity by up to 1.7-fold after 4 days of culture (p<0.05) whereas ibandronate or zoledronate exhibited lesser stimulatory effects (+17 to +30%), and pamidronate had no significant effect. In conclusion, we found that different bisphosphonates, currently used or tested in various clinical conditions, transiently stimulated the growth of preosteoblastic cells and thereafter increased their differentiation according to sequential events (type I collagen synthesis first, then ALP activity to a lesser extent). Our data suggest that the beneficial effects of bisphosphonate treatment on bone mass and integrity could be partly mediated through a direct action on osteoblasts.

Supportive and palliative care: experience at the Institut Jules Bordet

The Supportive and Palliative Care Unit of the Institut Jules Bordet officially started its activities in February 1999. Our Unit comprises eight beds (four rooms with one bed each and two rooms with two beds each). We admit advanced cancer patients presenting with severe symptoms whose control is going to require all the expertise of a multidisciplinary team. Whilst these eight beds are identified geographically in the hospital, the team's mobility assures continuity of care for patients who wish to stay in another department. The infrastructure of the Unit and its rooms allow close family members who wish to sleep close to the patients to do so. Otherwise, visits are allowed round the clock, though always with due consideration for patients' comfort. Patients are referred either by a physician working in our Institution (medical oncologist, surgeon, or radiotherapist) or by their family physicians. Less frequently, patients themselves specifically ask to be admitted to our Unit. The activity of the Unit itself during its first year of functioning can be summarized as follows. We admitted 155 advanced cancer patients, for a total number of 210 hospitalizations. Patients were admitted a median of 35 months after their diagnosis and a median of 20 days before death. Stays were generally short (median 11 days). We systematically used quantitative assessment tools (MMSQ, MDAS,EFAT and various VAS) to detect and monitor their symptoms and any complications. The main symptoms on admission were pain, anorexia, asthenia, dyspnea and anxiety/depression. Pain, nausea/vomiting, constipation and cough were controlled in almost all patients, whereas control of asthenia and anorexia was most often insufficient. In 51% of our cases the patients could be discharged home; 40% died in the unit; 4% were transferred to long-term palliative care units and 1% to other units within our Institution (4% were still hospitalized at the time of this analysis).

Hypercalcaemia of melanoma: incidence, pathogenesis and therapy with bisphosphonates

Tumour-induced hypercalcaemia (TIH) is a frequent complication of advanced cancer but has been rarely reported in patients with malignant melanoma, and its pathogenesis remains unexplored. We studied eight patients with TIH and melanoma. We determined the incidence and pathogenesis of this complication and the effects of bisphosphonate therapy. The incidence of TIH in 751 patients with melanoma was 1.1%. All patients had liver and bone metastases at the time of hypercalcaemia. All patients had osteolytic lesions, most often multiple. The median survival was 30 days (range 4-136 days). After rehydration, the mean (+/- SEM) corrected calcium was 3.42 +/- 0.17 mmol/l. Parathyroid hormone levels were adequately suppressed and vitamin D concentrations were normal. Serum osteocalcin, a marker of bone formation, was low, except in the two patients with renal insufficiency, whereas fasting urinary calcium and hydroxyproline were increased, indicating inhibition of bone formation and stimulation of bone resorption. Increased parathyroid hormone-related protein secretion was noted in only one patient. Three of four patients became normocalcaemic after bisphosphonate therapy for a median duration of 2 weeks. In conclusion, hypercalcaemia is a rare complication of melanoma. It occurs in the context of far advanced disease and is essentially due to aggressive lytic bone metastases with an uncoupling in bone turnover. Bisphosphonates can offer short-term palliation.

Bisphosphonates in the treatment of metastatic breast cancer

The skeleton is the most common site of metastatic disease in breast cancer and the most common site of first distant relapse. Bone metastases in breast cancer are the source of considerable morbidity, including severe pain, pathological fractures, need for radiotherapy or surgery, and hypercalcemia. Bisphosphonates are potent inhibitors of osteoclast-mediated bone resorption, and it is well known that breast cancer cells in bone can stimulate osteoclast formation and activity leading to the release of growth factors and cytokines, which will further stimulate cancer cell growth and their secretion of osteolytic factors. We are thus typically dealing with a vicious cycle, as the bone resorption-induced release of growth factors from the bone matrix will stimulate breast cancer cell growth (probably mainly by IGFs) and the production of the osteolytic factor PTHrP (probably mainly by TGF-beta but also by extracellular calcium). Clodronate, but not the aminobisphosphonates, can be metabolized to an ATP analog that is toxic for osteoclasts. Nitrogen-containing bisphosphonates, such as pamidronate, ibandronate, and zoledronate, interfere with the mevalonate pathway that is crucial to maintain cell membrane integrity. The net result, regardless of the mechanism, is osteoclast apoptosis, notably through the induction of caspase-3. Bisphosphonates are now the standard treatment for cancer hypercalcemia. Repeated bisphosphonate infusions also exert clinically relevant analgesic effects in at least one half of the patients with metastatic bone pain. Most importantly, prolonged administration of bisphosphonates (for at least 1 year) reduces the frequency of morbid skeletal events by 30-40% in breast cancer metastatic to bone and in up to 50% in patients with multiple myeloma. Newer bisphosphonates, such as ibandronate and zoledronate, will simplify the current therapeutic schemes and improve the cost-effectiveness ratio, and they have the potential to improve the therapeutic efficacy, at least in patients with aggressive osteolytic disease or in the adjuvant setting.

Breast cancer cells release factors that induced apoptosis in human bone marrow stromal cells

Breast cancer is associated frequently with skeletal metastases, which cause significant morbidity. The main mechanism is an increase in osteoclast-mediated bone resorption. We postulated that osteoblasts could be other essential target cells and previously showed that conditioned medium (CM) of breast cancer cells (BCCs) inhibits the proliferation of osteoblast-like cells. In this study, we investigated the effects of BCC-secreted products on osteoprogenitor cells using a clonal fetal human bone marrow stromal preosteoblastic cell line (FHSO-6) that expresses alkaline phosphatase (ALP) activity, type I collagen (COLI), and increased osteocalcin (OC) and osteopontin under treatment with dexamethasone (Dex), 1,25-dihydroxyvitamin D [1,25(OH)2D], or recombinant human bone morphogenetic protein 2 (rhBMP-2). Treatment with MCF-7 CM inhibited FHSO-6 cell survival in a dose-dependent and irreversible manner. Morphological investigation indicated that MCF-7 CM increased both apoptotic and necrotic cell number. MCF-7 CM increased caspases activity and a broad inhibitor of caspase activity (benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethyl ketone [z-VAD-fmk]) partly reversed the CM-induced inhibition of FHSO-6 cell survival. Western blot analyses revealed an increased bax/bcl-2 ratio in MCF-7 CM-treated FHSO-6 cells. MCF-7 cells exhibit FasLigand as membrane-bound protein and as a soluble cytokine in the CM. Deprivation of MCF-7 CM from active FasLigand by saturation with a soluble Fas molecule suppressed the induction of FHSO-6 apoptosis, whereas fibroblast CM, which did not contain FasLigand, only weakly modified FHSO-6 cell survival because of increased cell necrosis. These data indicate that FasLigand secreted by BCCs induces apoptosis and necrosis of human preosteoblastic stromal cells through caspase cascade modulated by the bax and bcl-2 protein level. The induction of apoptosis in human bone marrow stromal cells by BCCs may contribute to the inappropriately low osteoblast reaction and bone formation during tumor-induced osteolysis in bone metastases.

Interleukins-6 and -11 expression in primary breast cancer and subsequent development of bone metastases

Breast cancers frequently metastasize to bone where they often cause extensive tumor-induced osteoclast-mediated osteolysis. Interleukin-6 (IL-6) and IL-11 are two cytokines exhibiting osteolytic properties through their potent stimulation of osteoclast formation. We investigated the expression of IL-6 and IL-11 in 99 invasive primary breast tumors by immunohistochemistry and in situ hybridization, respectively. We examined their potential as predictive factors for further development of bone metastases. 52/90 (57%) of tumor samples showed IL-6 cytoplasmic immunostaining. There was no significant association between IL-6 status and any of the classical prognostic factors. 15/89 (17%) of the tumor samples expressed IL-11 mRNA. A positive IL-11 mRNA status was associated with a low tumor grade (P=0.05). Tumors expressing IL-11 mRNA had a statistically significant (P=0.002) higher rate of bone metastases occurrence (12/15, 80%) than IL-11 negative tumors (27/74, 37%). Such association was not found for IL-6. Our findings demonstrate for the first time IL-11 gene expression in some primary invasive breast tumors and suggest the potential of this cytokine as possible biological predictive factor for the development of bone metastases.

Dosing regimens and main adverse events of bisphosphonates

The bisphosphonates pamidronate and clodronate are most often used in oncology. Newer, more potent compounds under study are ibandronate and zoledronate. The main route of administration is by intravenous infusion (1-2 hours for pamidronate) but oral formulations are or soon will be available for some bisphosphonates (clodronate, ibandronate) and shorter infusion times are being studied (zoledronate, ibandronate). After oral administration of aminobisphosphonates, the main adverse event can be epigastric pain and esophagitis for which the current recommendations include swallowing 180 to 240 mL of water and remaining upright for 30 minutes after tablet ingestion. After intravenous administration, the main adverse events are injection site reaction and flu-like syndrome. Injection site reactions are seen in up to 6% of patients given pamidronate, and this figure is likely to be lower with ibandronate and zoledronate. Flu-like syndrome is seen in up to one third of patients given pamidronate, less with ibandronate, and no figure is yet available for zoledronate. Adverse effects on kidney function were only seen when using a high dose of zoledronate (8 mg over 5-15 minutes) and the current recommended dose is 4 mg given as a 15-minute infusion. Disadvantages of the oral route are poor absorption (<5%) and occasional digestive side effects. With protracted use the size and number of tablets required can reduce compliance. The advantage of oral administration is use on an outpatient basis and it may thus be the preferred route for patients on hormonal therapy and in the adjuvant setting. The main route of administration, however, is currently a 1- to 2-hour intravenous pamidronate infusion, often preferred for patients receiving chemotherapy. The disadvantage of the latter is the need for an appropriate hospital environment. Shorter infusion times are being studied with newer compounds. Intravenous administration is the preferred route for patients receiving chemotherapy. Equivalent intravenous doses to achieve similar success rates in normalizing serum calcium levels are approximately 90 mg, 4 mg, and 2 mg for pamidronate, ibandronate, and zoledronate, respectively. The expectation from the new, more potent compounds is for more convenient therapeutic schemes leading to increased patient compliance and improvements in the reduction of the skeletal morbidity rate and hopefully increase in survival rate.