Bone metastases and breast cancer

Remineralization of lytic spinal metastases after radiotherapy

BACKGROUND CONTEXT

Palliative radiotherapy (RT) can lead to remineralization of osteolytic lesions thereby potentially restoring some of the weight-bearing capacity and preventing vertebral collapse. It is not clear, however, under which circumstances remineralization of osteolytic lesions occurs.

PURPOSE

The aim of this study was to investigate the change in bone mineral density in spinal metastases after RT compared to a reference region, and find associated factors.

STUDY DESIGN

Retrospective analysis within prospective observational cohort OUTCOME MEASURES: change in bone mineral density measured in Hounsfield Units (HU).

PATIENT SAMPLE

patients treated with RT for (painful) bone metastases.

METHODS

Patients with spinal metastases were included if computed tomography scans both pre- and post-RT were available. Bone density was measured in HU. A region of interest (ROI) was drawn manually in the metastatic lesion. As a reference, a measurement of bone density in adjacent, unaffected, and non-irradiated vertebrae was used. Factors tested for association were origin of the primary tumor, RT dose and fractionation scheme, and concomitant use of bisphosphonates.

RESULTS

A total of 31 patients with 49 spinal metastases, originating from various primary tumors, were included. The median age on baseline was 58 years (IQR: 53-63) and median time between baseline and follow-up scan was 8.2 months (IQR: 3.0-18.4). Difference in HU in the lesion before and after treatment was 146.9 HU (95% CI 68.4-225.4; p<.01). Difference in HU in the reference vertebra between baseline and first follow-up was 19.1 HU (95% CI -47.9 to 86.0; p=.58). Difference between reference vertebrae and metastatic lesions on baseline was -194.1 HU (95% CI -276.2 to -112.0; p<.01). After RT, this difference was reduced to -50.3 HU (95% CI -199.6 to 99.0; p=.52). Patients using bisphosphonates showed a greater increase in HU, 194.1 HU versus 60.6 HU, p=.01.

CONCLUSIONS

Palliative radiation of osteolytic lytic spinal metastases is positively associated with an increased bone mineral density at follow-up. The use of bisphosphonates was linked to an increased bone mineral density when used during or after RT.

Practical consensus recommendaton for adjuvant bone-modifying agents in breast cancer

Bone-modifying therapy is a primary research interest in breast cancer. Several features contribute to the importance of the bone environment in the management of breast cancer. Firstly, bone metastases represent the most common site of breast cancer metastases and secondly, the emergence of cancer treatment-induced bone loss (CTIBL) among breast cancer survivors and patients is of increasing concern. In the adjuvant setting, bisphosphonates can be given to prevent and treat tumor therapy-induced bone loss in premenopausal and postmenopausal women and, owing to their beneficial effect on bone turnover, have also been evaluated for prevention of bone metastases occurrence. Expert oncologists discusses on the update on the approaches of Bone-modifying Agents and its treatment options. This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at this practical consensus recommendations for the benefit of community oncologists.

Comparison between CEA, TPA, CA 15/3 and Hydroxyproline, Alkaline Phosphatase, Whole Body Retention of 99mTc MDP in the follow-up of Bone Metastases in Breast Cancer

The development of bone metastases in cancer can be monitored easily using three markers: 24 h urinary hydroxyproline excretion (HOP) (an index of osteoclastic activity), serum alkaline phosphatase (Alk.Ph.) (an index of osteoblastic activity) and 24 h whole body retention of 99mTc-methylene diphosphonate (WBR%) (an index of bone turnover). To evaluate the effectiveness of this group of bone tumor markers in breast cancer we compared it with the following group of three markers which are commonly used in the monitoring of breast cancer and in the follow-up of advanced disease with or without bone metastases: carcinoembryonic antigen (CEA), tissue polypeptide antigen (TPA) and breast carcinoma antigen (CA 15/3).

In 48 patients with bone metastases CEA, TPA and CA 15/3 were shown to be sensitive (79%, 85%, 90% respectively), while HOP, Alk.Ph. and WBR%, which are commonly accepted as reliable markers of bone activity, showed a lower sensitivity (67%, 46%, 75% respectively).

These results may be explained by the lack of osteoclastic or osteoblastic (or both) activity at the time of diagnosis. This explanation is supported by the fact that the bone markers HOP, Alk.Ph. and WBR% were found to be more sensitive than the others in the subsequent follow-up study.

We conclude that in our study, CEA, TPA and CA 15/3 are at first more sensitive than Alk. Ph., HOP and WBR% but during the follow-up Alk.Ph., HOP and WBR% are possibly both more specific and more sensitive

Bisphosphonates and other bone agents for breast cancer

BACKGROUND

Bone is the most common site of metastatic disease associated with breast cancer (BC). Bisphosphonates inhibit osteoclast-mediated bone resorption, and novel targeted therapies such as denosumab inhibit other key bone metabolism pathways. We have studied these agents in both early breast cancer and advanced breast cancer settings. This is an update of the review originally published in 2002 and subsequently updated in 2005 and 2012.

OBJECTIVES

To assess the effects of bisphosphonates and other bone agents in addition to anti-cancer treatment: (i) in women with early breast cancer (EBC); (ii) in women with advanced breast cancer without bone metastases (ABC); and (iii) in women with metastatic breast cancer and bone metastases (BCBM).

SEARCH METHODS

In this review update, we searched Cochrane Breast Cancer's Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov on 19 September 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing: (a) one treatment with a bisphosphonate/bone-acting agent with the same treatment without a bisphosphonate/bone-acting agent; (b) treatment with one bisphosphonate versus treatment with a different bisphosphonate; (c) treatment with a bisphosphonate versus another bone-acting agent of a different mechanism of action (e.g. denosumab); and (d) immediate treatment with a bisphosphonate/bone-acting agent versus delayed treatment of the same bisphosphonate/bone-acting agent.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data, and assessed risk of bias and quality of the evidence. The primary outcome measure was bone metastases for EBC and ABC, and a skeletal-related event (SRE) for BCBM. We derived risk ratios (RRs) for dichotomous outcomes and the meta-analyses used random-effects models. Secondary outcomes included overall survival and disease-free survival for EBC; we derived hazard ratios (HRs) for these time-to-event outcomes where possible. We collected toxicity and quality-of-life information. GRADE was used to assess the quality of evidence for the most important outcomes in each treatment setting.

MAIN RESULTS

We included 44 RCTs involving 37,302 women.In women with EBC, bisphosphonates were associated with a reduced risk of bone metastases compared to placebo/no bisphosphonate (RR 0.86, 95% confidence interval (CI) 0.75 to 0.99; P = 0.03, 11 studies; 15,005 women; moderate-quality evidence with no significant heterogeneity). Bisphosphonates provided an overall survival benefit with time-to-event data (HR 0.91, 95% CI 0.83 to 0.99; P = 0.04; 9 studies; 13,949 women; high-quality evidence with evidence of heterogeneity). Subgroup analysis by menopausal status showed a survival benefit from bisphosphonates in postmenopausal women (HR 0.77, 95% CI 0.66 to 0.90; P = 0.001; 4 studies; 6048 women; high-quality evidence with no evidence of heterogeneity) but no survival benefit for premenopausal women (HR 1.03, 95% CI 0.86 to 1.22; P = 0.78; 2 studies; 3501 women; high-quality evidence with no heterogeneity). There was evidence of no effect of bisphosphonates on disease-free survival (HR 0.94, 95% 0.87 to 1.02; P = 0.13; 7 studies; 12,578 women; high-quality evidence with significant heterogeneity present) however subgroup analyses showed a disease-free survival benefit from bisphosphonates in postmenopausal women only (HR 0.82, 95% CI 0.74 to 0.91; P < 0.001; 7 studies; 8314 women; high-quality evidence with no heterogeneity). Bisphosphonates did not significantly reduce the incidence of fractures when compared to placebo/no bisphosphonates (RR 0.77, 95% CI 0.54 to 1.08, P = 0.13, 6 studies, 7602 women; moderate-quality evidence due to wide confidence intervals). We await mature overall survival and disease-free survival results for denosumab trials.In women with ABC without clinically evident bone metastases, there was no evidence of an effect of bisphosphonates on bone metastases (RR 0.96, 95% CI 0.65 to 1.43; P = 0.86; 3 studies; 330 women; moderate-quality evidence with no heterogeneity) or overall survival (RR 0.89, 95% CI 0.73 to 1.09; P = 0.28; 3 studies; 330 women; high-quality evidence with no heterogeneity) compared to placebo/no bisphosphonates however the confidence intervals were wide. One study reported a trend towards an extended period of time without a SRE with bisphosphonate compared to placebo (low-quality evidence). One study reported quality of life and there was no apparent difference in scores between bisphosphonate and placebo (moderate-quality evidence).In women with BCBM, bisphosphonates reduced the SRE risk by 14% (RR 0.86, 95% CI 0.78 to 0.95; P = 0.003; 9 studies; 2810 women; high-quality evidence with evidence of heterogeneity) compared with placebo/no bisphosphonates. This benefit persisted when administering either intravenous or oral bisphosphonates versus placebo. Bisphosphonates delayed the median time to a SRE with a median ratio of 1.43 (95% CI 1.29 to 1.58; P < 0.00001; 9 studies; 2891 women; high-quality evidence with no heterogeneity) and reduced bone pain (in 6 out of 11 studies; moderate-quality evidence) compared to placebo/no bisphosphonate. Treatment with bisphosphonates did not appear to affect overall survival (RR 1.01, 95% CI 0.91 to 1.11; P = 0.85; 7 studies; 1935 women; moderate-quality evidence with significant heterogeneity). Quality-of-life scores were slightly better with bisphosphonates than placebo at comparable time points (in three out of five studies; moderate-quality evidence) however scores decreased during the course of the studies. Denosumab reduced the risk of developing a SRE compared with bisphosphonates by 22% (RR 0.78, 0.72 to 0.85; P < 0.001; 3 studies, 2345 women). One study reported data on overall survival and observed no difference in survival between denosumab and bisphosphonate.Reported toxicities across all settings were generally mild. Osteonecrosis of the jaw was rare, occurring less than 0.5% in the adjuvant setting (high-quality evidence).

AUTHORS' CONCLUSIONS

For women with EBC, bisphosphonates reduce the risk of bone metastases and provide an overall survival benefit compared to placebo or no bisphosphonates. There is preliminary evidence suggestive that bisphosphonates provide an overall survival and disease-free survival benefit in postmenopausal women only when compared to placebo or no bisphosphonate. This was not a planned subgroup for these early trials, and we await the completion of new large clinical trials assessing benefit for postmenopausal women. For women with BCBM, bisphosphonates reduce the risk of developing SREs, delay the median time to an SRE, and appear to reduce bone pain compared to placebo or no bisphosphonate.

Bone-targeted therapy use in patients with bone metastases from lung cancer: A systematic review of randomized controlled trials

BACKGROUND

Patients with advanced lung cancer commonly have bone metastases. Compared with other malignancies, the use of bone-targeted agents (e.g. bisphosphonates and denosumab) is less common in lung cancer patients. This may be due to the perception that bone-targeted agents are less effective in this population.

OBJECTIVE

To perform a systematic review to evaluate data from randomized trials of bone-targeted agents in lung cancer patients with bone metastases.

METHODS

A systematic search of Medline, Embase and the Cochrane Register of Controlled Trials through May 2015 was performed. Randomized trials of bone-targeted therapies in lung cancer patients with bone metastases were sought. Outcomes studied included skeletal related events (SREs), pain, quality of life, progression-free survival and overall survival. Random effects meta-analyses were planned if studies were judged homogeneous.

RESULTS

Of 632 abstracts, 17 publications describing 13 studies were included. Sample sizes ranged between 50 and 1776. Of 3379 patients, 1903 had lung cancer, with subgroup data available for 8 of 13 studies. Patient demographics were comparable, but enrollment criteria and endpoints were heterogeneous across studies, precluding meta-analysis. Study-specific results suggested that bone-modifying agents reduce the incidence of SREs and bone pain in lung cancer patients. Three studies suggested a survival benefit.

CONCLUSION

Data from included trials suggests benefit of bone-targeted agents in lung cancer for the prevention of SREs and bone pain. There is a trend toward improvement in overall survival and progression-free survival, although further research is needed. Impact on quality of life and key subgroups for benefit both require future research.

Bisphosphonates and other bone agents for breast cancer

BACKGROUND

Bone is the most common site of metastatic disease associated with breast cancer (BC). Bisphosphonates inhibit osteoclast-mediated bone resorption, and novel targeted therapies such as denosumab, inhibit key pathways in the vicious cycle of bone metastases.

OBJECTIVES

To assess the effect of bisphosphonates on skeletal-related events (SREs), bone pain, quality of life (QoL), recurrence and survival in women with breast cancer with bone metastases (BCBM), advanced breast cancer (ABC) without clinical evidence of bone metastases and early breast cancer (EBC).To assess the effect of denosumab on SREs, bone pain and (QoL) in women with (BCBM).

SEARCH METHODS

We searched the Specialised Register maintained by the Cochrane Breast Cancer Group (CBCGSR), MEDLINE, EMBASE and the WHO International Cancer Trials Registry Platform (WHO ICTRP) on 30 April 2011. We conducted additional handsearching of journals and proceedings of key meetings.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing: (a) bisphosphonates and control, or different bisphosphonates in women with BCBM; (b) denosumab and bisphosphonates in women with BCBM; (c) bisphosphonates and control in women with ABC; (d) bisphosphonates and control in women with EBC; and (e) early versus delayed bisphosphonate treatment in women with EBC.

DATA COLLECTION AND ANALYSIS

Two review authors (MW and NP) independently assessed the trials and extracted the data. We collected toxicity information from the trials.

MAIN RESULTS

We included thirty-four RCTs. In nine studies (2806 patients with BCBM), comparing bisphosphonates with placebo or no bisphosphonates, bisphosphonates reduced the SRE risk by 15% (risk ratio (RR) 0.85; 95% confidence interval (CI) 0.77 to 0.94; P = 0.001). This benefit was most certain with intravenous (i.v.) zoledronic acid (4 mg) (RR 0.59; 95% CI 0.42 to 0.82); i.v. pamidronate (90 mg) (RR 0.77; 95% CI 0.69 to 0.87); and i.v. ibandronate (RR 0.80; 95% CI 0.67 to 0.96). A direct comparison of i.v. zoledronic acid and i.v. pamidronate confirmed at least equivalent efficacy in a single large study. In three studies (3405 patients with BCBM), compared with bisphosphonates, subcutaneous (s.c.) denosumab was more effective in reducing the risk of SREs (RR 0.78; 95% CI 0.72 to 0.85; P < 0.00001).Bisphosphonates reduced the SRE rate in 12 studies (median reduction 28%, range 14% to 48%), with statistically significant reductions reported in 10 studies. Women with BCBM treated with bisphosphonates showed significant delays in the median time to SREs. Compared with placebo or no bisphosphonates, treatment with bisphosphonates significantly improved bone pain in six out of eleven studies. Improvements in global QoL with bisphosphonates compared to placebo were reported in two out of five studies (both ibandronate studies). Treatment with bisphosphonates did not appear to affect survival in women with BCBM. Compared to i.v. zoledronic acid, denosumab also significantly reduced the SRE rate, delayed the time to SREs and prolonged the time in developing pain for patients with no or mild pain at baseline; but there was no difference in survival between patients treated with denosumab and zoledronic acid.Bisphosphonates in women with ABC without clinically evident bone metastases did not reduce the incidence of bone metastases, or improve survival in three studies (320 patients).In seven studies (7847 patients with EBC), currently there is no evidence supporting bisphosphonates in reducing the incidence of bone metastases compared to no bisphosphonates (RR 0.94; 95% CI 0.82 to 1.07; P = 0.36). In three studies (2190 patients with EBC), early bisphosphonate treatment also did not significantly reduce the incidence of bone metastases compared to delayed bisphosphonate treatment (RR 0.73; 95% CI 0.40 to 1.33; P = 0.31). Currently, there is insufficient evidence to make a conclusion about the role of adjuvant bisphosphonates in reducing visceral metastases, locoregional recurrence and total recurrence, or improving survival. There was strong heterogeneity in EBC studies examining the outcomes of total recurrence and survival.Reported toxicity was generally mild. Renal toxicity and osteonecrosis of the jaw (ONJ) have been identified as potential problems with bisphosphonate use. ONJ was reported at similar rates for patients on denosumab compared to zoledronic acid. This highlighted a need for maintaining good oral care, prior to and during treatment, for patients who received long-term bone agents.

AUTHORS' CONCLUSIONS

In women with clinically evident BCBM, bisphosphonates (oral and i.v.) and denosumab (s.c.) reduced the risk of developing SREs, as well as delaying the time to SREs. Some bisphosphonates may also reduce bone pain and may improve QoL. The optimal timing and duration of treatment for patients with BCBM remains uncertain. There is currently insufficient evidence to support the routine use of bisphosphonates as adjuvant treatment for patients with EBC. However, a number of large clinical trials investigating bisphosphonates in EBC have completed accrual and are awaiting results.

Pharmacological treatment of neuropathic cancer pain: a comprehensive review of the current literature

Neuropathic cancer pain (NCP), commonly encountered in clinical practice, may be cancer-related, namely resulting from nervous system tumor invasion, surgical nerve damage during tumor removal, radiation-induced nerve damage and chemotherapy-related neuropathy, or may be of benign origin, unrelated to cancer. A neuropathic component is evident in about 1/3 of cancer pain cases. Although from a pathophysiological perspective NCP may differ from chronic neuropathic pain (NP), such as noncancer-related pain, clinical practice, and limited publications have shown that these two pain entities may share some treatment modalities. For example, co-analgesics have been well integrated into cancer pain-management strategies and are often used as First-Line options for the treatment of NCP. These drugs, including antidepressants and anticonvulsants, are recommended by evidence-based guidelines, whereas, others such as lidocaine patch 5%, are supported by randomized, controlled, clinical data and are included in guidelines for restricted conditions treatment. The vast majority of these drugs have already been proven useful in the management of benign NP syndromes. Treatment decisions for patients with NP can be difficult. The intrinsic difficulties in performing randomized controlled trials in cancer pain have traditionally justified the acceptance of drugs already known to be effective in benign NP for the management of malignant NP, despite the lack of relevant high quality data. Interest in NCP mechanisms and pharmacotherapy has increased, resulting in significant mechanism-based treatment advances for the future. In this comprehensive review, we present the latest knowledge regarding NCP pharmacological management.

Bone-targeted agents in the treatment of bone metastases: RANK outsider or new kid on the block?

Stopeck AT, Lipton A, Body JJ et al.: Denosumab compared with zoledronic acid for the treatment of bone metastases in patients with advanced breast cancer: a randomized, double-blind study. Clin. Oncol. 28(35), 5132–5139 (2010). Bone is the most common site of recurrence in patients with advanced breast cancer. Bisphosphonates have revolutionized the care for patients with bone metastases by delaying and reducing skeletal complications. The RANK ligand inhibitor denosumab has been developed as a result of our enhanced understanding of bone physiology. In a recent randomized, double-blind trial, denosumab has been shown to be superior to zoledronic acid in delaying the onset of skeletal complications in advanced breast cancer patients. While these results are exciting, the absence of any survival benefit and the considerable cost of this agent mean that further quality-of-life data are needed before it becomes widely used as a new standard of care.

Behavioral, medical imaging and histopathological features of a new rat model of bone cancer pain

Pre-clinical bone cancer pain models mimicking the human condition are required to respond to clinical realities. Breast or prostate cancer patients coping with bone metastases experience intractable pain, which affects their quality of life. Advanced monitoring is thus required to clarify bone cancer pain mechanisms and refine treatments. In our model of rat femoral mammary carcinoma MRMT-1 cell implantation, pain onset and tumor growth were monitored for 21 days. The surgical procedure performed without arthrotomy allowed recording of incidental pain in free-moving rats. Along with the gradual development of mechanical allodynia and hyperalgesia, behavioral signs of ambulatory pain were detected at day 14 by using a dynamic weight-bearing apparatus. Osteopenia was revealed from day 14 concomitantly with disorganization of the trabecular architecture (µCT). Bone metastases were visualized as early as day 8 by MRI (T₁-Gd-DTPA) before pain detection. PET (Na¹⁸F) co-registration revealed intra-osseous activity, as determined by anatomical superimposition over MRI in accordance with osteoclastic hyperactivity (TRAP staining). Pain and bone destruction were aggravated with time. Bone remodeling was accompanied by c-Fos (spinal) and ATF3 (DRG) neuronal activation, sustained by astrocyte (GFAP) and microglia (Iba1) reactivity in lumbar spinal cord. Our animal model demonstrates the importance of simultaneously recording pain and tumor progression and will allow us to better characterize therapeutic strategies in the future.

Use of intravenous bisphosphonates in older women with breast cancer

INTRODUCTION

i.v. bisphosphonates reduce skeletal events in women with bone metastases from breast cancer, but little is known about the prevalence and duration of bisphosphonate use.

METHODS

Patients were identified from the Surveillance, Epidemiology, and End Results-Medicare database who were aged > or =65 years and were diagnosed with invasive breast cancer in 1995-2002. Healthcare Common Procedure Coding System codes were used to identify patients treated with pamidronate and zoledronic acid. Descriptive statistics were used to describe patterns of use. Multivariate analyses were performed to determine the predictors of bisphosphonate use.

RESULTS

In total, 55,864 women with breast cancer were included, with 307,467 person-years of follow-up. Overall, 1.26% of women with all stages of breast cancer received i.v. bisphosphonates. In 2004, 2% of all breast cancer patients and 32% of patients with distant stage disease received bisphosphonates. Approximately two thirds of patients treated with bisphosphonates received zoledronic acid and one third received pamidronate in 2004. Multivariate analyses showed that patients who were > or =75 years old were less likely to receive bisphosphonates (75-79 years versus 65-69 years: odds ratio [OR], 0.81; 95% confidence interval [CI], 0.70-0.93; 80+ years versus 65-69 years: OR, 0.49; 95% CI, 0.42-0.57). The use of bisphosphonates dramatically increased over time. The majority of living patients were continued on i.v. bisphosphonates once started (83% at 1 year, 64% at 3 years, 50% at 5 years), but the median survival time after initiation of i.v. bisphosphonates was only 21 months.

CONCLUSIONS

i.v. bisphosphonates appear to be underused in patients with metastatic breast cancer, particularly among those patients >75 years of age.

Translational medicine: cancer pain mechanisms and management

Cancer-induced bone pain (CIBP) is a major clinical problem with up to 85% of patients with bony metastases having pain, often associated with anxiety and depression, reduced performance status, and a poor quality of life. Malignant bone disease creates a chronic pain state through sensitization and synaptic plasticity within the spinal cord that amplifies nociceptive signals and their transmission to the brain. Fifty per cent of patients are expected to gain adequate analgesia from palliative radiotherapy within 4-6 weeks of treatment. Opioid analgesia does make a useful contribution to the management of CIBP, especially in terms of suppressing tonic background pain. However, CIBP remains a clinical challenge because the spontaneous and movement-related components are more difficult to treat with opioids and commonly used analgesic drugs, without unacceptable side-effects. Recently developed laboratory models of CIBP, which show congruency with the clinical syndrome, are contributing to an improved understanding of the neurobiology of CIBP. This chronic pain syndrome appears to be unique and distinct from other chronic pain states, such as inflammatory or neuropathic pain. This has clear implications for treatment and development of future therapies. A translational medicine approach, using a highly iterative process between the clinic and the laboratory, may allow improved understanding of the underlying mechanisms of CIBP to be rapidly translated into real clinical benefits in terms of improved pain management.

Economic burden of metastatic bone disease in the U.S

BACKGROUND

Previous research has documented the prevalence of primary bone cancer; however, there are few data available regarding the impact of metastatic bone disease (MBD) on national expenditure. In this study, the authors quantified the prevalence and direct medical care costs of patients with MBD and the resulting cost impact on U.S. oncology expenditure.

METHODS

Anonymous, patient-level data on health care utilization and cost were obtained from the Thomson Medstat MarketScan research databases. In total, 396,200 patients who were diagnosed with cancer between 2000 and 2004 were selected for the study. Patients with MBD were matched subsequently to non-MBD controls. A 2-part linear regression model was used to compare cases with controls to quantify the incremental cost associated with the disease.

RESULTS

Cancer prevalence in the U.S. during the study period was estimated at 4,861,987 cases annually, and 5.3% (n=256,137) of those patients had MBD. Rates of MBD were highest in patients with multiple myeloma (28.8%) and lung cancer (15.6%). The mean direct medical cost for all cancers combined was $75,329 for patients with MBD and $31,382 for controls. Regression-adjusted, incremental costs were $44,442 (P<.001) across all cancer types. The incremental cost was highest for patients with multiple myeloma ($63,455) and lowest for patients with lung cancer ($24,946).

CONCLUSIONS

The national cost burden for patients with MBD was estimated at $12.6 billion, which is 17% of the $74 billion in total direct medical cost estimated by the National Institutes of Health, suggesting that MBD is a significant driver of overall oncology cost.

Lytic Metastases in Thoracolumbar Spine: Computer-aided Detection at CT—Preliminary Study

PURPOSE

To evaluate the sensitivity of a computer-aided detection (CAD) system for detection of lytic thoracolumbar spinal lesions at body CT, with results of manual lesion segmentation as the reference standard.

MATERIALS AND METHODS

The study was HIPAA compliant and institutional review board approved; the institutional review board waived the need for informed consent. The CAD system segments the spine on CT images and searches for detections that match size, shape, location, and attenuation criteria. To reduce false-positive findings, 16 features for each detection were computed and fed to a classifier trained with manually segmented lesions. The data set consisted of CT studies of 50 patients (30 men, 20 women; range, 18-82 years; mean, 54.8 years) with 28 lesions. Studies were assigned to either a training (29 studies) or testing (21 studies) set. Sensitivities and false-positive rates (FPRs) for training and testing sets were calculated for these lesions, which were probable lytic metastases with areas 0.8 cm(2) or greater.

RESULTS

Training set sensitivity was 0.83 (10 of 12; 95% confidence interval: 0.51, 0.97), with an FPR of 7.4 per patient. Test set sensitivity was 0.94 (15 of 16; 95% confidence interval: 0.68, 1.00), with an FPR of 4.5 per patient. There was no significant difference between the CAD sensitivities of the training and test sets (P = .56). Of three false-negative findings, two were due to incomplete segmentation of the vertebral pedicle, and the third was rejected by the classifier. False-positive detections were most often attributable to veins that connect the basivertebral vein with the anterior venous plexus (106 [34%] of 310) and to low-attenuating disks (83 [27%] of 310).

CONCLUSION

This CAD system successfully identified probable lytic metastases in the thoracolumbar spine and generalized well to an independent testing set.

Bisphosphonates for breast cancer

BACKGROUND

Bone is the most common site of metastatic disease associated with breast cancer affecting more than half of women during the course of their disease. Bone metastases are a significant cause of morbidity due to pain, pathological fractures, hypercalcaemia and spinal cord compression, and contribute to mortality. Bisphosphonates, which inhibit osteoclast-mediated bone resorption, are standard care for tumour-associated hypercalcaemia, and have been shown to reduce bone pain, improve quality of life, and to delay skeletal events and reduce their number in patients with multiple myeloma. Several randomized controlled trials have evaluated the role of bisphosphonates in breast cancer.

OBJECTIVES

To assess the effect of bisphosphonates on skeletal events, bone pain, quality of life and survival in women with early and advanced breast cancer.

SEARCH STRATEGY

Randomized controlled trials were identified using the specialized register maintained by the Cochrane Breast Cancer Group (the search was applied to the databases Medline, Central/CCTR, Embase, CancerLit, and included handsearches from a number of other relevant sources). See: Cochrane Collaboration Collaborative Review Group in Breast Cancer search strategy.

SELECTION CRITERIA

Randomized controlled trials evaluating skeletal events in women with metastatic breast cancer and early breast cancer comparing: 1. treatment with a bisphosphonate with the same treatment without a bisphosphonate 2. treatment with one bisphosphonate with treatment with a different bisphosphonate.

DATA COLLECTION AND ANALYSIS

Studies were selected by two independent reviewers. Studies fulfilling the eligibility criteria were evaluated for quality, particularly concealment of allocation to randomized groups. Data were extracted from the published papers or abstracts independently by the two primary reviewers for each of the specified endpoints (skeletal events, bone pain, quality of life and survival). Data on skeletal events and survival were presented as numbers of events, risk ratios and ratios of event rates. Meta-analyses were based on the fixed-effects model (Mantel-Haenszel). Subjective qualitative ratings were used to summarize the quality of life and pain data.

MAIN RESULTS

Twenty one randomized studies were included. All studies in advanced breast cancer included women with clinically evident bone metastases (osteolytic and/or mixed osteolytic/osteoblastic) by plain xray and/or radionucleotide bone scans. In nine studies that included 2189 women with advanced breast cancer and existing bone metastases, bisphosphonates reduced the risk of developing a skeletal event by 17% (RR 0.83; 95% confidence interval (CI) 0.78-0.89; P < 0.00001). This effect was more modest, but still highly significant if episodes of hypercalcaemia were excluded (10 studies, 2656 women, RR 0.85; 95% CI 0.79-0.91 P = 0.0001). Overall, intravenous bisphosphonates reduce the risk of developing a skeletal event by 17 % (95% CI 0.78-0.89) compared with oral bisphosphonates, which reduce the risk of developing a skeletal event by 16 % (95% CI 0.76-0.93). Of the currently available bisphosphonates, 4 mg IV zolendronate reduces the risk of developing a skeletal event by 41% (RR 0.59, 95% CI 0.42-0.82), compared with 33 % by 90 mg IV pamdronate (RR 0.77, 95% CI 0.69-0.87), 18 % by 6 mg IV ibandronate (RR 0.82, 95% CI 0.67-1.00), 14 % by 50mg oral ibandronate (RR 0.86, 95% CI 0.73-1.02) and 16 % by 1600 mg oral clodronate (RR 0.84, 95% CI 0.72-0.98). Compared with placebo or no bisphosphonate, with bisphosphonates the skeletal event rate was lower in all of 12 studies in women with clinically evident bone metastases (median reduction of 29%, range 14-48%); statistically significant reductions were reported in 10 trials (four intravenous pamidronate, two oral clodronate, one intravenous ibandronate and two oral ibandronate, a single intravenous zolendronate study). Studies of intravenous zolendronate, pamidronate and oral clodronate in women with advanced breast cancer and clinically evident bone metastases showed significant delays in the median time to a skeletal event. Event-free survival was also reported to be longer in women receiving 6 mg of ibandronate compared with controls. Compared with placebo or no bisphosphonate, with bisphosphonates significant improvements in bone pain were reported in seven studies (90 mg iv pamidronate, 4 mg iv zolendronate, 6 mg iv ibandronate, 1600 mg oral clodronate and 50 mg oral ibandronate). Eight studies tested the effect of bisphosphonates compared with placebo on patient-rated quality of life using a referenced scale. Improvements in global quality of life were reported in only the three studies of iv and oral ibandronate. Treatment with bisphosphonates does not appear to affect survival in women with advanced breast cancer. Intravenous zolendronate (4 mg) appeared to be as effective as pamidronate (90mg) when directly compared in a single randomized double-blind study, based on the risk of developing a skeletal related event, the median time to first skeletal event and skeletal morbidity rate (events per year). Updated re-evaluation of the primary data in the overall population, by multiple event analysis using the method of Anderson-Gill, showed a reduction in the risk of developing any skeletal complication (including hypercalcamia) of 20 % (zolendronate 4 mg compared with pamidronate 90 mg, RR = 0.80, 95% CI 0.66 - 0.97, p = 0.025), suggesting a possible advantage of zolendronate 4 mg compared with pamidronate 90 mg. In the three studies of bisphosphonates in 320 women with advanced breast cancer without clinically evident bone metastases, there was no significant reduction in the incidence of skeletal events (RR 0.99; 95% CI 0.67-1.47; P = 0.97). In the three studies of oral clodronate that included 1653 women with early breast cancer, there was no statistically significant evidence of reduction in the risk of developing skeletal metastases (RR 0.82; 95% CI 0.66-1.01; P = 0.07), or of visceral metastases (RR 0.95; 95% CI 0.80-1.12, p = 0.53). However there was evidence of improved survival (RR 0.82; 95% CI 0.69-0.97, p = 0.02). However there was statistically significant heterogeneity among these studies and a random effects meta-analysis emphasizes the uncertainty of this finding (RR 0.75; 95% CI 0.45 - 1.25; p = 0.19). Toxicity or adverse events were described in 18 of the 21 studies. In general, few serious adverse events were reported. Toxicity associated with bisphosphonates is generally mild and infrequent. Renal toxicity is the main issue with intravenous zolendronate and is dose (8 mg) and infusion time related (< 15 minutes). With daily oral calcium (500 mg) and vitamin D (300-400IU) no significant renal impairment or hypocalcamia was observed with a 15 minute infusion of 4 mg IV zolendronate compared with 90 mg pamidronate. Monitoring of renal function with every cycle of zolendronate was undertaken in all studies and is recommended in practice. No significant renal toxicity was observed with intravenous pamidronate or ibandronate. Mild gastrointestinal toxicity is the main toxicity with oral clodronate and oral ibandronate.

AUTHORS' CONCLUSIONS

In women with advanced breast cancer and clinically evident bone metastases, the use of bisphosphonates (oral or intravenous) in addition to hormone therapy or chemotherapy, when compared with placebo or no bisphosphonates, reduces the risk of developing a skeletal event and the skeletal event rate, as well as increasing the time to skeletal event. Some bisphosphonates may also reduce bone pain in women with advanced breast cancer and clinically evident bone metastases and may improve global quality of life. The optimal timing of initiation of bisphosphonate therapy and duration of treatment is uncertain. In women with early breast cancer the effectiveness of bisphosphonates remains an open question for research.

Bone imaging in metastatic breast cancer

Bone is the most common site to which breast cancer metastasizes. Imaging-by skeletal scintigraphy, plain radiography, computed tomography, or magnetic resonance imaging-is an essential part, and positron emission tomography or single-photon emission computed tomography have a potential of evaluating bone metastases, but no consensus exists as to the best modality for diagnosing the lesion and for assessing its response to treatment. Imaging bone metastases is problematic because the lesions can be osteolytic, osteoblastic, or mixed, and imaging modalities are based on either direct anatomic visualization of the bone or tumor or indirect measurements of bone or tumor metabolism. Although bone metastases can be treated, their response to treatment is considered "unmeasurable" according to existing response criteria. Therefore, the process by which oncologists and radiologists diagnose and monitor the response of bone metastases needs revision, and the current inability to assess the response of bone metastases excludes patients with breast cancer and bone disease from participating in clinical trials of new treatments for breast cancer. In this review of the MEDLINE literature, we discuss the pros and cons of each modality for diagnosing bone metastases and for assessing their response to treatment and we present a practical approach for diagnosis and assessment of bone metastasis.

Duration of bisphosphonate treatment: results of a non-randomised study in patients previously treated with local irradiation for bone metastases from breast cancer

PURPOSE

To assess whether disodium pamidronate (DP) once started should be given life-long in women with lytic bone metastases.

PATIENTS AND METHODS

One hundred and three women with breast cancer who had at least one osteolytic lesion received 180 mg of DP as a 2-h intravenous infusion given every 4 weeks for a life-time, following local radiotherapy. After six cycles, 26 out of 103 patients (25%) refused to continue their bisphosphonate-treatment. Thus two groups were constituted: non-stop (group A) and premature discontinued (group B). The new skeletal complication free survival (NSCFS) was the primary endpoint verified during extramural review. Performance status, pain-score and biochemical markers were secondary endpoints.

RESULTS

Generally DP was well tolerated. At 36 months, the proportion of patients having had any skeletal complication was 54.5 and 84.6% in group A and B, respectively. The median time of NSCFS was apparently longer for group A. In group A, the pain score and the ECOG status were significantly lower, while the overall survival appeared to be longer. Multivariate analysis revealed age, nodal status and interruption of treatment as prognostic factors to NSCFS, with relative risk 1.05, 2.3 and 1.5 respectively.

CONCLUSION

Data concerning the suspension of new skeletal complications, as well as the apparent improvement of overall survival, pain score and ECOG status, suggest that the pamidronate-treatment should not be stopped once started. These results should be confirmed in a randomised trial.

Animal and cellular models of chronic pain

Chronic pain, especially neuropathic pain and cancer pain, is often not adequately treated by currently available analgesics. Animal models provide pivotal systems for preclinical study of pain. This article reviews some of the most widely used or promising new models for chronic pain. Partial spinal ligation, chronic constriction injury, and L5/L6 spinal nerve ligation represent three of the best characterized rodent models of peripheral neuropathy. Recently, several mouse and rat bone cancer pain models have been reported. Primary or permanent cultures of sensory neurons have been established to study the molecular mechanism of pain, especially for neurotransmitter release and signal transduction. The emerging gene microarray, genomics and proteomics methods may be applied to throughly characterize these cells. Each model is uniquely created with distinct mechanisms, it is therefore essential to report and interpret results in the context of a specific model.

Efficacy of zoledronic acid and pamidronate in breast cancer patients: a comparative analysis of randomized phase III trials

Results of a large, randomized, comparative phase III trial involving 1,130 breast cancer patients demonstrated that 4 mg zoledronic acid and 90 mg pamidronate were equally effective at reducing the occurrence and delaying the onset of skeletal-related events in patients with bone metastases secondary to breast cancer. However, zoledronic acid has demonstrated a treatment advantage over pamidronate with respect to the proportion of patients receiving radiation therapy to bone. Moreover, among patients with at least one osteolytic lesion (N = 352), zoledronic acid achieved a 17% reduction in the proportion of patients with a skeletal-related event compared with pamidronate and significantly prolonged the time to first event. In general, zoledronic acid and pamidronate had comparable effects on time to progression of bone metastases, overall disease progression, pain and analgesia scores, and overall survival. Both zoledronic acid and pamidronate effectively suppressed markers of bone resorption. However, zoledronic acid demonstrated a greater and more sustained suppressive effect. Zoledronic acid (4 mg via 15-minute infusion) also demonstrated a safety profile similar to that of pamidronate (90 mg via 2-hour infusion). In summary, the increased efficacy of zoledronic acid in specific patient subsets and the convenience of a 15-minute infusion suggest that 4 mg zoledronic acid has advantages over 90 mg pamidronate for treatment of bone metastases in patients with breast cancer.

Comparative diagnostic value and therapeutic relevance of magnetic resonance imaging and bone marrow scintigraphy in patients with metastatic solid tumors of the axial skeleton

PURPOSE

To evaluate the comparative impact of magnetic resonance imaging (MRI) and bone marrow scintigraphy (BMS) in bone marrow metastases of solid tumors.

METHODS

In 20 patients with solid tumors MRI of the axial skeleton and whole-body BMS were retrospectively reviewed. Detectability of metastases, extent of disease and therapeutic implications were assessed.

RESULTS

In 15/20 (75%) patients MRI and BMS concordantly revealed bone marrow metastases of the axial skeleton. In nine of these 15 patients (60%) MRI showed more metastases. Local radiotherapy or surgery was performed in seven of these cases (78%). BMS detected additional metastases of the appendicular skeleton in 8/15 (53%) patients. In 4/20 cases (20%) the imaging findings were discordant. In three patients with degenerative changes (n=2) or lipoma (n=1) BMS was false positive. In another patient BMS failed to detect metastases proven by MRI and clinical follow-up resulting in subsequent radiation therapy. One patient had normal bone marrow.

CONCLUSION

MRI appears to be more sensitive and specific in the detection of bone marrow metastases in the axial skeleton and is of clinical importance for subsequent local therapy.

Bisphosphonates for breast cancer

BACKGROUND

Bone is the most common site of metastatic disease associated with breast cancer, and affects more than half of women during the course of their disease. Bone metastases are a significant cause of morbidity due to pain, pathological fractures, hypercalcaemia and spinal cord compression, and contribute to mortality. Bisphosphonates, which inhibit osteoclast-mediated bone resorption, are standard care for tumour-associated hypercalcaemia, and have been shown to reduce bone pain, improve quality of life, and to delay skeletal events and reduce their number in patients with multiple myeloma. Several randomized controlled trials have evaluated the role of bisphosphonates in breast cancer.

OBJECTIVES

The aim of this systematic review was to identify, describe and summarize high-quality evidence regarding the effect of bisphosphonates on skeletal events, bone pain, quality of life and survival in women with early and advanced breast cancer.

SEARCH STRATEGY

Randomized controlled trials were identified in the specialized register maintained by the secretariat of the Cochrane Breast Cancer Group (the search was applied to the databases Medline, Central/CCTR, Embase, CancerLit, and included handsearches from a number of other relevant sources). See: Cochrane Collaboration Collaborative Review Group in Breast Cancer search strategy.

SELECTION CRITERIA

Randomized controlled trials evaluating skeletal events in women with metastatic breast cancer and in women with early breast cancer comparing: 1. treatment with a bisphosphonate with the same treatment without a bisphosphonate 2. treatment with one bisphosphonate with treatment with a different bisphosphonate.

DATA COLLECTION AND ANALYSIS

Studies were selected by two independent reviewers. Studies fulfilling the eligibility criteria were evaluated for quality, particularly concealment of allocation to randomized groups. Data were extracted from the published papers or abstracts independently by the two primary reviewers for each of the specified endpoints (skeletal events, bone pain, quality of life and survival). Data on skeletal events and survival were presented as numbers of events, risk ratios and ratios of event rates. Meta-analyses were based on the fixed-effects model (Mantel-Haenszel). Subjective qualitative ratings were used to summarize the quality of life and pain data.

MAIN RESULTS

From 37 reports considered in detail after screening of the 117 reports identified by our search, 19 randomized studies were included. In eight studies that included 1962 women with advanced breast cancer and existing bone metastases, bisphosphonates reduced the risk of developing a skeletal event by 14% (RR 0.86; 95% confidence interval (CI) 0.80-0.91; P < 0.00001). This effect was more modest, but still highly significant if episodes of hypercalcaemia were excluded (6 studies, 1553 women, RR 0.88; 95% CI 0.81-0.96; P = 0.004). For intravenous pamidronate the reduction in the risk of skeletal event was greatest with a dosage of 90 mg (RR 0.77; 95% CI 0.69-0.87). Oral bisphosphonates reduced the risk of a skeletal event by 17% (pooled RR 0.83; 95% CI 0.73-0.94, P = 0.004). Oral clodronate reduced the risk of a skeletal event by 16% in women with advanced breast cancer and clinically evident bone metastases (pooled RR 0.84; 95% CI 0.72-0.98; P = 0.03). Compared with placebo or no bisphosphonate, with bisphosphonates the skeletal event rate was lower in all of eight studies (median reduction of 30%, range 20-48%); statistically significant reductions were reported in six trials (three intravenous pamidronate, two oral clodronate and one intravenous ibandronate). All studies of intravenous pamidronate and oral clodronate in women with advanced breast cancer and clinically evident bone metastases showed significant delays in the median time to a skeletal event. Event-free survival was reported to be longer in women receiving 6 mg of ibandronate compared with control women. Compared with placebo or no bisphosphonate, with bisphosphonates significant improvements in pain were reported in four studies, and improvements in quality of life were reported in two studies. Treatment with bisphosphonates does not appear to affect survival in women with advanced breast cancer. Intravenous zolendronate (4 mg) appeared to have equivalent efficacy when compared with intravenous pamidronate in a single randomized double-blind study. In the three studies of bisphosphonates in 320 women with advanced breast cancer without clinically evident bone metastases, there was no significant reduction in the incidence of skeletal events (RR 0.99; 95% CI 0.67-1.47; P > 0.9). In three studies of oral clodronate that included 1680 women with early breast cancer, there was borderline evidence of a reduction in the risk of developing skeletal metastases (RR 0.73; 95% CI 0.55-0.98; P = 0.04), but there was significant heterogeneity among these studies (P = 0.035). Toxicity or adverse events were described in 14 of the 19 studies. In general, few adverse events were reported.

REVIEWER'S CONCLUSIONS

In women with advanced breast cancer and clinically evident bone metastases, the use of bisphosphonates (oral or intravenous) in addition to hormone therapy or chemotherapy, when compared with placebo or no bisphosphonates, reduces the risk of developing a skeletal event and the skeletal event rate, as well as increasing the time toskeletal event. Bisphosphonates may also reduce bone pain in women with advanced breast cancer and clinically evident bone metastases. In women with early breast cancer the effectiveness of oral clodronate in reducing the incidence of bone metastases remains an open question for research.

Prognostic factors for skeletal relapse in breast cancer

Bone metastases and the strong interaction between osseous and metastatic cell populations require interdisciplinary thought and actions. If it were possible to interrupt the malignant dialogue between tumour and bone at an early stage, this might not only reduce the amount of bone destruction, but could also reduce the incidence of osseous metastases and remove the source of secondary metastases to other organs. Studies into the preventive effects of bisphosphonates are currently running or are planned. Most of these studies are in breast cancer patients with involvement of the axillary lymph nodes. The prognostic factors of lymph node status, tumour size and grading are better than none, but do not select patients at a high risk of skeletal metastasis. This would be much better done by using immunohistochemical methods to investigate the primary tumour for bone sialoprotein and parathyroid hormone-related protein (PTHrP). However, these methods are complicated, have not been validated in large numbers of patients and are not standardized. Serum tests for bone sialoprotein, PTHrP and collagen fragments are currently still under development and cannot be recommended generally. The clinical importance of tumour cells in the bone marrow has been demonstrated but is still only used at a few centres.

Pamidronate improves the quality of life and induces clinical remission of bone metastases in patients with thyroid cancer

Skeletal metastases from thyroid cancer are poorly responsive to medical or radioiodine treatment. Bone destruction in skeletal metastases results from osteoclast-induced bone resorption. Therefore, a new approach in the therapy of bone metastases consists in using aminobisphosphonates, such as pamidronate, which are potent inhibitors of osteoclastic activity. In the present study, 10 thyroid cancer patients with painful osteolytic bone metastases were administered pamidronate (90 mg, as a 2 hour intravenous infusion) monthly for 12 consecutive cycles. Bone pain, quality of life, performance status, analgesic consumption and disease staging were evaluated before and during the trial. The patients who had been administered pamidronate showed a significant decrease in bone pain (P = 0.0052). Performance status improved nearly significantly (P = 0.051), while the quality of life showed a remarkable amelioration. However, no significant decrease in analgesic consumption was recorded. Partial radiographic response of bone lesions was observed in 2/10 patients. The side effects of pamidronate were mild and transient. In conclusion, monthly infusion of pamidronate is a well-tolerated treatment that induces significant relief from bone pain and improves the quality of life of thyroid cancer patients with symptomatic and osteolytic bone metastases.

Prognostic significance of the number of bone scan abnormalities at the time of initial bone metastatic recurrence in breast carcinoma

BACKGROUND

To gain insight into the factors that contribute to the more favorable prognosis associated with recurrence limited to bone in patients with breast carcinoma, the authors analyzed the number of sites of initial involvement identified on radionuclide bone scans in relation to long term outcome.

METHODS

Records of 641 patients with clinical Stage I-III breast carcinoma that originally was diagnosed in 1974-1985 were reviewed. During follow-up, 295 patients (46%) experienced distant recurrence, including 116 with bone as the sole initial site of metastatic disease. Radionuclide bone scans identified the initial site(s) of recurrence in 113 of these latter 116 patients, and these studies were categorized by the number of skeletal lesions subsequently confirmed as metastases (1, 2, or > or = 3). Survival from time of recurrence and time of original diagnosis was analyzed using Kaplan-Meier methods, and factors associated with recurrence and mortality were examined using logistic and Cox regression.

RESULTS

Median survival from time of recurrence was 35 months in the patients with bone-only metastases, compared with 11-26 months for all other sites of visceral recurrence exclusive of bone. Number of positive lymph nodes and estrogen receptor status were the only predictive variables for recurrence. Median survival from time of recurrence and time of original diagnosis for the 3 bone scan categories was: 1 lesion (n = 47), 53 and 86 months; 2 lesions (n = 22), 38 and 68 months; and > or = 3 lesions (n = 44), 22 and 58 months (P < 0.0001 and P < 0.005 for 1 and 2 lesions vs. > or = 3). In the "bone-only" group, the number of scan lesions was the strongest predictor of length of survival.

CONCLUSIONS

Patients with breast carcinoma who experience a recurrence in bone at only one or two sites initially have a survival advantage over those with more extensive (> or = 3 sites) skeletal metastases and those with metastatic disease involving other visceral organs.

Extracellular calcium-sensing receptor expression and its potential role in regulating parathyroid hormone-related peptide secretion in human breast cancer cell lines

Metastasis of breast cancer to bone occurs with advanced disease and produces substantial morbidity. Secretion of PTH-related peptide (PTHrP) from breast cancer cells is thought to play a key role in osteolytic metastases and is increased by transforming growth factor-beta (TGFbeta), which is released from resorbed bone. Elevated extracellular calcium (Ca2+(o)) also stimulates PTHrP secretion from various normal and malignant cells, an action that could potentially be mediated by the Ca2+(o)-sensing receptor (CaR) originally cloned from the parathyroid gland. Indeed, we previously showed that both normal breast ductal epithelial cells and primary breast cancers express the CaR. In this study we investigated whether the MCF-7 and MDA-MB-231 human breast cancer cell lines express the CaR and whether CaR agonists modulate PTHrP secretion. Northern blot analysis and RT-PCR revealed bona fide CaR transcripts, and immunocytochemistry and Western analysis with a specific anti-CaR antiserum demonstrated CaR protein expression in both breast cancer cell lines. Furthermore, elevated Ca2+(o) and the polycationic CaR agonists, neomycin and spermine, stimulated PTHrP secretion dose dependently, with maximal, 2.1- to 2.3-fold stimulation. In addition, pretreatment of MDA-MB-231 cells overnight with TGFbeta1 (0.2, 1, or 5 ng/ml) augmented both basal and high Ca2+-stimulated PTHrP secretion. Thus, in PTHrP-secreting breast cancers metastatic to bone, the CaR could potentially participate in a vicious cycle in which PTHrP-induced bone resorption raises the levels of Ca2+(o) and TGFbeta within the bony microenvironment, which then act in concert to evoke further PTHrP release and worsening osteolysis.

Bisphosphonates in the adjuvant treatment of cancer: experimental evidence and first clinical results. International Bone and Cancer Study Group (IBCG)

Several animal models, as well as a number of cell culture experiments, indicate a prophylactic effect of bisphosphonates in respect of subsequent bone metastasis. Moreover, in preliminary clinical trials involving patients with advanced breast cancer and local or remote metastases, biophosphonates produced a reduction in new skeletal metastases. This overview summarizes and discusses the results of the latest investigations. It opens with a section on the pathophysiology of bone metastasis, which is followed by a report on animal models and first studies of bisphosphonate treatment as a new approach in systemic adjuvant therapy.

Antitumour effects of bisphosphonates: first evidence and possible mechanisms

Bisphosphonates have been used successfully for many years in the treatment of hypercalcaemia and to reduce skeletal complications of metastases. In the first years of bisphosphonate use the efficacy of these substances was thought to lie purely in the inhibition of osteoclasts. However, there is recent evidence to suggest that an antitumour effect may also play a role. As well as having an apoptotic and antiproliferative effect on osteoclasts, bisphosphonates may exert a similar influence on macrophages and tumour cells. Whether this effect (at low doses) also plays a role in vivo remains unclear and requires further investigation. Improvements in the survival time of certain subpopulations have been found in many phase III studies with bisphosphonates to date, both in the setting of metastatic breast cancer and in multiple myeloma. However, because survival time in subgroups of patients was neither a primary nor a secondary objective in these studies, these advantages could only be seen as important pointers for future studies. Some preclinical studies have shown that down-regulation of bone metabolism by bisphosphonates is associated with a lower incidence of bone metastases and destruction in animals, whereas activation is correlated with a higher number of metastases. However, varying results were found in animal experiments with regard to the effect of bisphosphonates on the incidence and growth pattern of non-osseous metastases. The results of 3 randomised studies in patients with primary breast cancer who received clodronate 1600 mg/day orally have now been evaluated and presented. All 3 studies arrived at different results. In the Heidelberg study there was a reduction in both osseous and non-osseous metastases, whereas in a much larger study performed in Great Britain, Canada and Scandinavia there was a reduction only in the incidence of skeletal metastases. A third study from Finland found no effect on bone metastases, but an increase in the number of visceral metastases and a deterioration in overall survival. Because the dosage was identical in all 3 studies, the differing results can only be either random or methodological (for example inclusion criteria or sample size). Overall, the results are very promising, but there is a need for further studies.

Neurochemical and cellular reorganization of the spinal cord in a murine model of bone cancer pain

The cancer-related event that is most disruptive to the cancer patient's quality of life is pain. To begin to define the mechanisms that give rise to cancer pain, we examined the neurochemical changes that occur in the spinal cord and associated dorsal root ganglia in a murine model of bone cancer. Twenty-one days after intramedullary injection of osteolytic sarcoma cells into the femur, there was extensive bone destruction and invasion of the tumor into the periosteum, similar to that found in patients with osteolytic bone cancer. In the spinal cord, ipsilateral to the cancerous bone, there was a massive astrocyte hypertrophy without neuronal loss, an expression of dynorphin and c-Fos protein in neurons in the deep laminae of the dorsal horn. Additionally, normally non-noxious palpation of the bone with cancer induced behaviors indicative of pain, the internalization of the substance P receptor, and c-Fos expression in lamina I neurons. The alterations in the neurochemistry of the spinal cord and the sensitization of primary afferents were positively correlated with the extent of bone destruction and the growth of the tumor. This "neurochemical signature" of bone cancer pain appears unique when compared to changes that occur in persistent inflammatory or neuropathic pain states. Understanding the mechanisms by which the cancer cells induce this neurochemical reorganization may provide insight into peripheral factors that drive spinal cord plasticity and in the development of more effective treatments for cancer pain.

Monitoring therapeutic response in skeletal metastases using dual-energy x-ray absorptiometry: a prospective feasibility study in breast cancer patients

Response to systemic therapy in breast cancer patients with lytic skeletal metastases manifests as a shift from increased bone resorption to new bone formation. We hypothesized that dual-energy x-ray absorptiometry (DXA) could be used to prospectively quantitate changes in bone mineral density (BMD) in metastatic skeletal lesions in breast cancer patients receiving systemic therapy. Nine metastatic breast cancer patients with one or more assessable lytic skeletal metastases receiving systemic therapy were prospectively evaluated with DXA, skeletal radiographs, computed tomography (CT), and radionuclide bone scans at baseline (t = 0 months, 2 months, and 6 months). The median (range) percentage change in BMD in skeletal lesions among patients responding to systemic therapy was 10.7% (0.1-21.85), 5.0% (-1.3-23.8), and 16.7% (-2.0-50.8) at 0-2, 2-6, and 0-6 months, respectively. Changes in BMD between 0-2, and 0-6 months were significant (Wilcoxin signed rank test; p = 0.013 and p = 0.017, respectively). The percentage change in BMD skeletal lesions between 0-2 and 2-6 months correlated with the changes imaged on skeletal x-rays (Spearman rank order correlation coefficient [Rs] = 0.511, p = 0.011) and CTs (Rs = 0.416, p = 0.046) but less so with bone scans (Rs = 0.293, p = 0.189). It is technically feasible to use DXA to prospectively monitor changes in lytic skeletal metastases in breast cancer patients receiving systemic therapy. The BMD of skeletal metastases increases in patients responding to treatment and was significantly correlated with the changes imaged on skeletal x-rays and CTs. Additional studies of DXA to evaluate response in skeletal metastasis are warranted.

Clodronate: a review of its use in breast cancer

Like other members of its class, the bisphosphonate clodronate (clodronic acid) inhibits bone resorption. The efficacy of oral clodronate 1600 mg/day in reducing the incidence of skeletal complications and metastasis development has been assessed in several clinical trials in patients with breast cancer. Long term use of oral clodronate significantly reduced the total cumulative incidence of skeletal events (including fractures, hypercalcaemia, and the need for radiotherapy for bone pain) compared with that in placebo recipients in 2 randomised double-blind placebo-controlled studies, each involving >100 patients. Significant differences in favour of clodronate were also seen in the frequency of some individual skeletal events in 1 trial. A nonblind trial in 302 patients considered to be at high risk of developing metastases found that, at a 3-year follow-up, significantly fewer patients who received clodronate for 2 years developed skeletal metastases than those in a control group. Clodronate recipients were also significantly less likely than controls to develop visceral metastases, and had significantly higher survival rates. A smaller double-blind placebo-controlled study in women with recurrent breast cancer found that clodronate significantly decreased the total number of new skeletal metastases, but not the number of patients who developed them. In a nonblind trial in 299 patients with node-positive breast cancer, however, the incidence of skeletal metastases did not differ significantly between patients who received clodronate for 3 years and those in a control group. In addition, clodronate recipients had a significantly greater incidence of nonskeletal metastases (local and visceral), and significantly lower survival rates. Intravenous or oral clodronate has been well tolerated in clinical trials. The most common adverse effects reported were mild gastrointestinal disturbances such as nausea, vomiting and diarrhoea. All these events were transient, and usually resolved without stopping treatment.

CONCLUSIONS

Clodronate is a well tolerated bisphosphonate, available in both oral and intravenous forms, that significantly reduces the incidence of skeletal complications associated with breast cancer. Further research is needed to establish more clearly its efficacy in reducing metastasis development, to assess its efficacy compared with other bisphosphonates, and to determine which patients will benefit most from treatment. Currently, clodronate is probably most effective in the treatment and prevention of general skeletal complications in patients with breast cancer.

Assessment of bone response to systemic therapy in an EORTC trial: preliminary experience with the use of collagen cross-link excretion. European Organization for Research and Treatment of Cancer

This study was designed to evaluate new bone resorption and tumour markers as possible alternatives to serial plain radiographs for the assessment of response to treatment. Thirty-seven patients with newly diagnosed bone metastases from breast cancer, randomized to receive oral pamidronate or placebo tablets in addition to anticancer treatment within the context of a multicentre EORTC trial, who were both assessable for radiographic response in bone and had serum and urine samples collected for more than 1 month were studied. The markers of bone metabolism measured included urinary calcium (uCa), hydroxyproline (hyp), the N-telopeptide cross-links of type I collagen (NTx) and total alkaline phosphatase. The tumour markers measured were CA15-3 and cancer-associated serum antigen (CASA). Before treatment, levels of Ntx, uCa and Hyp were elevated in 41%, 24% and 28% respectively, and CA15-3 and CASA increased in 69% and 50%. For assessment of response and identification of progression, Ntx was the most useful bone marker. All markers behaved similarly in no change (NC) and partial response (PR) patients. There was a significant difference (P < or = 0.05) in Ntx levels (compared to baseline) at 1 and 4 months and in CA15-3/CASA at 4 months between patients with PR or NC and those with progressive disease (PD), and at 4 months between those with time to progression (TP) > 7 and those with TP < or = 7 months. The diagnostic efficiency (DE) for prediction of PD following a > 50% increase in Ntx or CA15-3 was 78% and 62% respectively. An algorithm to predict response to therapy has been developed for future prospective evaluation.

Pamidronate reduces skeletal morbidity in women with advanced breast cancer and lytic bone lesions: a randomized, placebo-controlled trial. Protocol 18 Aredia Breast Cancer Study Group

PURPOSE

To assess whether pamidronate can reduce the frequency of skeletal morbidity in women with lytic bone metastases from breast cancer treated with hormone therapy.

PATIENTS AND METHODS

Three hundred seventy-two women with breast cancer who had at least one lytic bone lesion and who were receiving hormonal therapy were randomized to receive 90 mg of pamidronate or placebo as a 2-hour intravenous infusion given in double-blind fashion every 4 weeks for 24 cycles. Patients were evaluated for skeletal complications: pathologic fractures, spinal cord compression, irradiation of or surgery on bone, or hypercalcemia. The skeletal morbidity rate (the ratio of the number of skeletal complications to the time on trial) was the primary efficacy variable. Bone pain, use of analgesics, quality of life, performance status, bone tumor response, and biochemical parameters were also evaluated.

RESULTS

One hundred eighty-two patients who received pamidronate and 189 who received placebo were assessable. The skeletal morbidity rate was significantly reduced at 12, 18, and 24 cycles in patients treated with 90 mg of pamidronate (P = .028, .023, and .008, respectively). At 24 cycles, the proportion of patients having had any skeletal complication was 56% in the pamidronate group and 67% in the placebo group (P = .027). The time to the first skeletal complication was longer for patients receiving pamidronate than for those given placebo (P = .049). There was no statistical difference in survival or in objective bone response rate. Pamidronate was well tolerated.

CONCLUSION

Treatment with 90 mg of pamidronate as a 2-hour intravenous infusion every 4 weeks in addition to hormonal therapy significantly reduces skeletal morbidity from osteolytic metastases.

Skeletal metastases from breast cancer: imaging with nuclear medicine

Breast cancer is a disease that commonly metastasizes to bone, increasing morbidity, mortality, and health service costs. The 99m technetium (99mTc) diphosphonate bone scan historically has played a significant part in the evaluation of skeletal disease and continues to be one of the most clinically utilized investigations in the staging and follow up of breast cancer patients. More tumor-specific radiopharmaceuticals are now being evaluated and, in particular, 18-fluoro-2-deoxyglucose positron emission tomography (18FDG PET) may have a greater role in this disease in the future.

Reduction in new metastases in breast cancer with adjuvant clodronate treatment

BACKGROUND

Bisphosphonates are effective against the increased bone resorption caused by certain diseases because they inhibit the activity of osteoclasts. In patients who have breast cancer and metastatic bone disease, the bisphosphonate clodronate (clodronic acid) reduces the frequency of skeletal complications. Experiments in animals and preliminary clinical observations indicate that early clodronate therapy reduces the incidence of new bony metastases in breast cancer. We investigated the effects of clodronate on the incidence and extent of new metastases in patients with breast cancer.

METHODS

Between 1990 and 1995, 302 patients with primary breast cancer and tumor cells in the bone marrow (the presence of which is a risk factor for the development of distant metastases) were randomly assigned to receive clodronate at a dose of 1600 mg per day orally for two years (157 patients) or standard follow-up (145 patients). The median length of observation was 36 months. All patients in both groups received standard surgical treatment and customary hormonal therapy or chemotherapy.

RESULTS

Distant metastases were detected in 21 patients in the clodronate group and in 42 patients in the control group (P<0.001). The incidence of both osseous and visceral metastases was significantly lower in the clodronate group than in the control group (P=0.003 for both osseous and visceral metastases). Six patients in the clodronate group died, as did 22 in the control group (P=0.001). The mean number of bony metastases per patient in the clodronate group was roughly half that in the control group (3.1 vs. 6.3).

CONCLUSIONS

Clodronate can reduce the incidence and number of new bony and visceral metastases in women with breast cancer who are at high risk for distant metastases.

The salubrious effect of tamoxifen [correction of Tamaxifen] on serum marker enzymes, glycoproteins, and lysosomal enzymes level in breast cancer woman

Tumour markers correlate strongly with prognosis based on tumour burden and surgical resectability. If chemotherapy is extremely effective in certain stage of the disease, the sensitive marker may be of great use in monitoring disease response and drug treatment. Hence, this study was launched to evaluate the changes in tumour marker enzymes like lactate dehydrogenase (LDH), glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), alkaline phosphatase, and acid phosphatase in before and after 3 and 6 months tamoxifen treated breast cancer patients. In addition, the changes in serum glycoproteins viz., hexose, hexosamine, and sialic acid and lysosomal enzymes such as N-acetyl-beta-D-glucosaminidase, beta-D-galactosidase, and beta-D-glucuronidase were analysed in these patients. These values were compared with their age matched healthy control subjects. At 6 months evaluation, the tamoxifen treated postmenopausal breast cancer women showed a statistically significant decreased (p < 0.001, 0.05 respectively) levels of LDH, SGOT, SGPT, alkaline and acid phosphatases than their baseline values. Similarly, the levels of hexose, hexosamine, and sialic acid and N-acetyl-beta-D-glucosaminidase, beta-D-galactosidase, and beta-D-glucuronidase were decreased significantly (p < 0.001) in tamoxifen received postmenopausal women. The result of this study suggested that tamoxifen potentially retard the metastasis of breast cancer as well as the bone demineralisation in postmenopausal breast cancer women. Thus, tamoxifen may also have its antitumour activity through its beneficial effects on tumour marker enzymes and serum proteins in breast cancer women.

Efficacy of pamidronate in reducing skeletal complications in patients with breast cancer and lytic bone metastases. Protocol 19 Aredia Breast Cancer Study Group

BACKGROUND

Bisphosphonates such as pamidronate disodium inhibit osteoclast-induced bone resorption associated with cancer that has metastasized to bone.

METHODS

Women with stage IV breast cancer who were receiving cytotoxic chemotherapy and had at least one lytic bone lesion were given either placebo or pamidronate (90 mg) as a two-hour intravenous infusion monthly for 12 cycles. Skeletal complications, including pathologic fractures, the need for radiation to bone or bone surgery, spinal cord compression, and hypercalcemia (a serum calcium concentration above 12 mg per deciliter [3.0 mmol per liter] or elevated to any degree and requiring treatment), were assessed monthly. Bone pain, use of analgesic drugs, performance status, and quality of life were assessed throughout the trial.

RESULTS

The efficacy of treatment was evaluated in 380 of 382 randomized patients, 185 receiving pamidronate and 195 receiving placebo. The median time to the occurrence of the first skeletal complication was greater in the pamidronate group than in the placebo group (13.1 vs. 7.0 months, P=0.005), and the proportion of patients in whom any skeletal complication occurred was lower (43 percent vs. 56 percent, P = 0.008). There was significantly less increase in bone pain (P=0.046) and deterioration of performance status (P=0.027) in the pamidronate group than in the placebo group. Pamidronate was well tolerated.

CONCLUSIONS

Monthly infusions of pamidronate as a supplement to chemotherapy can protect against skeletal complications in women with stage IV breast cancer who have osteolytic bone metastases.

The role of bisphosphonates in the treatment of bone metastases--the U.S. experience

Frequent complications of bone metastases include pain, pathologic fracture, hypercalcemia and spinal cord compression. Lytic bone metastases result from excessive activation of osteoclasts by tumor-produced cytokines. Aredia (pamidronate) is a potent bisphosphonate that inhibits osteoclast activation. In two dose-seeking phase I trials in patients with breast cancer and prostate cancer, repeated intravenous infusion of Aredia was shown to be safe and effective in reducing bone resorption and pain. In a randomized phase III trial of 377 patients with multiple myeloma, Aredia was administered in a dosage of 90 mg i.v. every 4 weeks. Compared with placebo, treatment with Aredia was associated with a significant decrease in bone pain and in the incidence and time to development of all skeleton-related events. Data from two phase III breast cancer trials each involving 300 patients are now being analyzed. The newer bisphosphonates can safely be used together with standard anticancer therapy to provide effective palliation of symptoms caused by lytic bone metastases.

Pamidronate infusions as single-agent therapy for bone metastases: a phase II trial in patients with breast cancer

Pamidronate is a potent biphosphonate which modulates tumour-induced osteolysis (TIO) by inhibiting osteoclast-mediated bone resorption. In a phase II trial, 69 breast cancer patients with symptomatic progressive bone metastases were given infusions of pamidronate 60 mg over 1 or 4 h every 2 weeks for a maximum of 13 infusions or until progressive disease (PD) at any site. No other systemic anticancer therapy was allowed. Pain was measured using a visual analogue scale, mobility using a detailed eight-point questionnaire and analgesic intake using a six-point scale. Improvements in pain, mobility and analgesic scores occurred in 61, 50 and 30% of patients, respectively, with 33, 21 and 16% achieving a 40% improvement for > or = 8 weeks. At trial discontinuation, baseline levels of pain and mobility had improved by 27% (P = 0.001) and 20% (P = 0.004), respectively, despite a one category reduction in analgesic intake in 27% of patients. Using this relatively high dose of pamidronate, symptomatic response was independent of the number of bone metastases and also of infusion rate. The infusions were well tolerated with no major toxicities reported. Pamidronate infusions provide useful palliation for breast cancer patients with symptomatic bone metastases.

Parathyroid hormone-related protein: primary osteolytic factor produced by breast tumor cells in vitro?

Tumor cells in bone metastases are thought to induce bone resorption primarily by releasing paracrine factors. Parathyroid hormone related protein (PTHrp) has been proposed to mediate osteolytic activity of many tumors. PTHrp is produced by 40% to 60% of breast tumors and is elevated in the serum of up to 50% of patients with breast cancer metastases to bone. Most biologic processes in humans are heterogeneous in nature, so the purpose of this study was to investigate the hypothesis that paracrine factors other than PTHrp could mediate bone resorption by breast tumor cells. Serum-free conditioned medium (CM) was collected from five human breast tumor cell lines and tested for bone resorption-stimulating activity (BRSA) in mouse calvaria organ cultures. CM from all tumor cells studied produced significant bone resorption, comparable to that produced by 10 nM PTH. Small amounts of immunoreactive PTHrp (1.4-12.5 pM) were produced by all breast tumor cell lines. When tested in vitro, equivalent amounts of human PTHrp [1-36] did not produce significant bone resorption. Indomethacin (1 microM) significantly blocked BRSA by CM from all cell lines but did not decrease BRSA by PTHrp. In contrast PTHrp antibody (130 micrograms/ml) completely blocked BRSA by 1 nM PTHrp but did not modify BRSA by CM of breast tumor cells. The results of this study support the hypothesis that breast cancer cells release paracrine factors in vitro that stimulate bone resorption by a mechanism that is partially dependent on prostaglandin synthesis and at least in part different from that of PTHrp.(ABSTRACT TRUNCATED AT 250 WORDS)

Intravenous pamidronate disodium treatment of bone metastases in patients with breast cancer. A dose-seeking study

BACKGROUND

Treatment of the symptoms of bone metastases currently involves the use of narcotic medication, radiation therapy, or hormonal therapy. Pamidronate disodium, a bisphosphonate, may prove helpful in the palliative treatment of bone metastases in patients with breast cancer as demonstrated in this multicenter, dose-ranging trial.

METHODS

Ambulatory female patients age 18 years or older with breast cancer metastatic to bone and a life expectancy of at least 3 months were eligible for the study. Bone metastases were confirmed by bone scan or bone survey within 6 months of enrollment. Sixty-one patients were treated as outpatients and were randomized to receive one of four intravenous pamidronate regimens for 12 weeks: 30 mg administered every 2 weeks, 60 mg every 4 weeks, 60 mg every 2 weeks, or 90 mg every 4 weeks. The primary efficacy parameter for this study was pain score. The change from baseline in pain score was determined for each patient at each study visit and at endpoint, defined as the last postbaseline evaluation for each patient before or at week 12. Secondary efficacy variables included narcotic scores, urinary calcium/creatinine and hydroxyproline/creatinine ratios, serum osteocalcin and bone alkaline phosphatase concentrations, and bone lesion (radiologic) response.

RESULTS

At 3 months, the regimens of 60 mg every 4 weeks, 60 mg every 2 weeks, and 90 mg every 4 weeks resulted in significant reduction in bone pain beginning by week 6 of treatment. The regimen of 30 mg every 2 weeks was not effective. Narcotic use, as reflected by narcotic scores, did not parallel the pain scores, because there was little evidence of any effect for any of the treatment groups. Reduction in bone pain was accompanied by decreases in urinary calcium/creatinine and hydroxyproline/creatinine ratios, and bone alkaline phosphatase concentrations. Side effects of pamidronate were mild and transient. Radiographic changes consistent with healing of lytic lesions were observed in 15 patients (25%).

CONCLUSION

Intravenous pamidronate is a well tolerated treatment that produced significant relief of bone pain in the majority of patients with metastatic breast cancer at the three highest doses tested.

Hypercalcemia in patients with breast cancer: a survival study

In a retrospective study survival after hypercalcemia in breast cancer patients has been investigated. A group of 72 patients were treated with bisphosphonate APD [3-(amino-1,1-hydroxypropylidene)bisphosphonate] and third-generation amino-containing bisphosphonates between January 1980 and October 1992. A median survival of 4.5 months was found. In a multivariate analysis, four independent prognostic factors for survival have been found: the interval between first relapse and hypercalcemia, sites of metastases at the moment of hypercalcemia, primary treatment, and the level of serum alkaline phosphatase. Patients with a "flare" reaction on tamoxifen treatment and patients with a normal serum alkaline phosphatase level and bone metastases only had a prolonged survival. Hypercalcemia associated with visceral metastases carried a very poor prognosis. The level of serum calcium in this series of patients was no prognostic indicator for survival.