"The use of bisphosphonates to treat skeletal complications in solid tumours"

The skeleton is the most common site of secondary disease in breast cancer and prostate cancer, with up to 80% of patients with advanced disease developing bone metastases (BM). The proportion is also substantial in advanced lung cancer (20%-40%). Because of the high prevalence of cancers of the breast, prostate and lung, these cancers account for more than 80% of cases of metastatic bone disease occurring in solid tumours. Metastatic bone disease is associated with greatly increased bone resorption by osteoclasts, leading to moderate to severe pain and other skeletal complications, with major impact on quality of life (QoL). Skeletal Related Events (SREs) have been defined as: pathological long bone or vertebral fractures; spinal cord compression; need for radiation for pain relief or to prevent fracture/spinal cord compression, need for surgery to bone and hypercalcaemia. More recently, Symptomatic Skeletal Events (SSEs) have been defined to monitor QoL. Although there are currently no curative treatments for metastatic bone disease, patients with breast or prostate cancer and BM are now surviving for several years and sometimes longer, and prevention of SREs is the key aim to optimization of QoL. Since their discovery 50 years ago and their introduction more than 30 years ago into the field of metastatic bone disease, a range of oral and intravenous bisphosphonate drugs have made a major contribution to prevention of SREs. Large trials have clearly demonstrated the clinical value of different bisphosphonate-based drugs (including the oral drugs ibandronate and clodronate and intravenous agents such as zoledronate and pamidronate), in treatment of hypercalcaemia of malignancy and the reduction of SREs and SSEs in a range of cancers. Despite the success of denosumab in reducing osteolysis, bisphosphonates also remain mainstay drugs for treatment of metastatic bone disease. Recognizing the 50th Anniversary of the discovery of bisphosphonates, this review focuses on their continuing value in BM treatment and their future potential, for example in providing a bone-targeting vehicle for cytotoxic drugs.

Detection and Characterization of Musculoskeletal Cancer Using Whole-Body Magnetic Resonance Imaging

Whole-body magnetic resonance imaging (WB-MRI) is gradually being integrated into clinical pathways for the detection, characterization, and staging of malignant tumors including those arising in the musculoskeletal (MSK) system. Although further developments and research are needed, it is now recognized that WB-MRI enables reliable, sensitive, and specific detection and quantification of disease burden, with clinical applications for a variety of disease types and a particular application for skeletal involvement. Advances in imaging techniques now allow the reliable incorporation of WB-MRI into clinical pathways, and guidelines recommending its use are emerging. This review assesses the benefits, clinical applications, limitations, and future capabilities of WB-MRI in the context of other next-generation imaging modalities, as a qualitative and quantitative tool for the detection and characterization of skeletal and soft tissue MSK malignancies.

Effects of abiraterone acetate plus prednisone on bone turnover markers in chemotherapy-naïve mCRPC patients after ADT failure: A prospective analysis of the italian real-world study ABITUDE

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Bone remodeling is disrupted in metastatic disease, affecting > 70% of mCRPC men.

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In metastatic disease, abnormal levels of specific BTMs are released.

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We prospectively measured four BTMs markers in chemotherapy-naïve mCRPC men on AAP therapy.

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AAP seems to act on the microenvironment of metastatic but not of normal bone.

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This action likely contributes to the antitumoral activity of AAP.

Background

Bone remodeling is disrupted in metastatic disease, which affects > 70% of metastatic castration-resistant prostate cancer (mCRPC) patients. As a result, abnormal levels of specific bone turnover biomarkers (BTMs) are released. In this prospective ancillary analysis of the Italian real-world study ABITUDE, four markers were measured during abiraterone acetate plus prednisone (AAP) treatment in chemotherapy-naïve mCRPC men failing androgen-deprivation therapy.

Methods

Patients were enrolled if a blood sample was obtained before the first administration of abiraterone (baseline); ad-hoc blood samples were withdrawn during routine tests after 3, 6, and 12 months. A centralized lab measured bone alkaline phosphatase (BALP, osteoblast activity marker), type-I collagen-C-telopeptide (CTX-1, bone resorption marker), parathyroid hormone (PTH) and vitamin D (vitD). At each time point, intra-patient variations vs baseline were compared by the signed-rank test (statistical significance: P-value < 0.05).

Results

Of 481 patients enrolled in ABITUDE, 186 (median age: 76 [range: 53–93] years) met the substudy criteria: 74.7% had bone metastases, 11.8% were on bone-targeted therapies (BTT) and 14.0% on vitD supplementation. BALP decreased significantly at month 6 (P = 0.0010) and 12 (P < 0.0001) and CTX-1 at month 6 (P = 0.0028); PTH increased at month 3 (P < 0.0001); no significant difference in vitD levels was observed. Similar findings were observed in BTT-untreated patients. The reduction in BALP and CTX-1 levels was more pronounced in patients with than without bone metastases; in the latter group, no significant variation in BALP and CTX-1 levels was observed.

Conclusions

AAP seems to exert an effect on the microenvironment of metastatic but not of normal bone, which likely contributes to its antitumoral activity.

Diet and Lifestyle in Prostate Cancer

A variety of diet and lifestyle factors have been studied with respect to prostate cancer risk in large, prospective cohort studies. In spite of this work, and in contrast to other common cancers, few modifiable risk factors have been firmly established as playing a role in prostate cancer. There are several possible explanations for the lack of well-established risk factors. First, prostate cancer has among the highest heritability of all common cancers; second, early life exposures may play an important role in risk, rather than mid- and later-life exposures assessed in most epidemiological studies. Finally, prostate-specific antigen (PSA) screening plays a critical role in prostate cancer detection and incidence rates, which has important implications for epidemiological studies.Among modifiable risk factors, smoking and obesity are consistently associated with higher risk specifically of advanced prostate cancer. There is also considerable evidence for a positive association between dairy intake and overall prostate cancer risk, and an inverse association between cooked tomato/lycopene intake and risk of advanced disease. Several other dietary factors consistently associated with risk in observational studies, including selenium and vitamin E, have been cast into doubt by results from clinical trials. Results for other well-studied dietary factors, including fat intake, red meat, fish, vitamin D, soy and phytoestrogens are mixed.In practical terms, men concerned with prostate cancer risk should be encouraged to stop smoking, be as physically active as possible, and achieve or maintain a healthy weight. These recommendations also have the advantage of having a positive impact on risk of type 2 diabetes, cardiovascular disease, and other chronic diseases. Reducing dairy intake while increasing consumption of fish and tomato products is also reasonable advice.

[Predictive factors for skeletal-related events in lung cancer]

INTRODUCTION

Skeletal-related events (SRE) are common in patients with bone metastatic lung cancer and have a negative impact on quality of life and survival. The objective of this study is to identify predictive factors for SRE occurrence among this population.

METHODS

We conducted a 3-year retrospective study including 100 lung cancer patients with bone metastasis.

RESULTS

Eighty-two patients presented at least one SRE (69.5% at baseline). The median occurrence for SRE was 4.5 months and severe bone pain was the most common SRE (56%). The alkaline phosphatase serum level>120IU/L (hazard ratio [sHR]=2.8; 95% confidence interval (CI) [1.5-5.4]; P=0.002) and calcemia>2.6mmol/L ([sHR]=9.7; 95% CI [5.1-18.4]; P<0.001) were identified as risk factors for SRE occurrence while the presence of an initial SRE was associated with a decrease of this risk ([sHR]=0.2; 95% CI [0.1-0.4]; P<0.001).

CONCLUSION

The elevated alkaline phosphatase serum level and hypercalcemia are risk factors for SRE occurrence in bone metastatic lung cancer patients and should be used as biomarkers to adapt current medical practice for these patients.

Relationship between melatonin and bone resorption rhythms in premenopausal women

Although evidence exists for a daily rhythm in bone metabolism, the contribution of factors such as melatonin levels, the light-dark cycle, and the sleep-wake cycle is difficult to differentiate given their highly correlated time courses. To examine these influences on bone resorption, we collected 48-h sequential urine samples under both ambulatory (8-h sleep:16-h wake) and constant routine (CR) (constant wake, posture, nutrition and dim light) conditions from 20 healthy premenopausal women. Urinary 6-sulphatoxymelatonin (aMT6s; ng/h) and the bone resorption marker amino-terminal cross-linked collagen I telopeptide (NTx; bone collagen equivalents nM/h) were assayed and fit by cosinor models to determine significant 24-h rhythms and acrophase. Most participants had significant 24-h aMT6s rhythms during both ambulatory and CR conditions (95 and 85%, respectively), but fewer had significant 24-h NTx rhythms (70 and 70%, respectively). Among individuals with significant rhythms, mean (± SD) aMT6s acrophase times were 3:57 ± 1:50 and 3:43 ± 1:25 h under ambulatory and CR conditions, respectively, and 23:44 ± 5:55 and 3:06 ± 5:15 h, respectively, for NTx. Mean 24-h levels of both aMT6s and NTx were significantly higher during CR compared with ambulatory conditions (p < 0.0001 and p = 0.03, respectively). Menstrual phase (follicular versus luteal) had no impact on aMT6s or NTx timing or 24-h levels. This study confirms an endogenous circadian rhythm in NTx with a night-time peak when measured under CR conditions, but also confirms that environmental factors such as the sleep-wake or light-dark cycles, posture or meal timing affects overall concentrations and peak timing under ambulatory conditions, the significance of which remains unclear.

Metabolic Effects of Single-Dose Pamidronate Administration in Prostate Cancer Patients with Bone Metastases

Background

Increased osteolysis usually accompanies sclerotic bone metastases from prostate cancer. This provides a rationale for the use of bisphosphonates to treat bone pain and prevent skeletal complications.

Methods

The fasting urinary levels of calcium, hydroxyproline (OHPRO), pyridinolines (PYD), deoxypyridinolines (DPYD), collagen cross-linked N-telopeptide (NTX) and the serum values of calcium, total alkaline phosphatase and relevant bone isoenzyme, bone gla protein (BGP), carboxy-telopeptide of type I collagen (ICTP) and parathyroid hormone (PTH) were determined at baseline and on the 15th, 30th, 60th and 90th days after single-dose (90 mg) pamidronate administration in 35 consecutive prostate cancer patients with bone metastases. These biochemical indices and serum interleukin 6 (IL-6) were also measured after four days in the last consecutive 17 cases.

Results

PYD, DPYD and NTX showed a significant decrease lasting four weeks (p<0.01, <0.01 and <0.001, respectively). OHPRO and ICTP did not change significantly. The NTX decline was greater than that of PYD and DPYD (maximum percent decrease: −71.3, −23.1 and −28.2, respectively). Bone formation markers and serum calcium did not change significantly. Serum PTH showed a rapid initial increase followed by a slow decrease (p<0.001). DPYD and NTX patterns did not correlate with changes in bone pain. As observed in the last 17 cases, the maximum osteolysis inhibition after pamidronate occurred on the fourth day after drug infusion. Serum IL-6 levels showed a short-lived decrease preceded by a transient rise on the fourth day.

Conclusions

Pamidronate is able to induce a decrease in bone resorption without significantly influencing bone formation. The maximum decrease in bone resorption occurs very early. NTX is the most sensitive bone resorption marker in bisphosphonate therapy monitoring. Changes in IL-6 but not bone resorption markers may be useful in the prediction of symptomatic response.

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.

Endothelin signaling regulates mineralization and posttranscriptionally regulates SOST in TMOb cells via miR 126-3p

Previously, our laboratory identified ECE‐1, encoding endothelin‐converting enzyme‐1 (ECE‐1), as a positional candidate for a pleiotropic quantitative trait locus affecting femoral size, shape, and biomechanical performance. We hypothesized that endothelin‐1 (ET‐1) signaling promotes osteogenesis. Exposure of immortalized mouse osteoblast (TMOb) cells to big ET‐1 increased mineralization. Following big ET‐1 treatment, we measured the secretion of insulin‐like‐growth factor‐1 (IGF1), dickkopf‐homolog‐1 protein 1 (DKK1), and sclerostin (SOST). In each case, big ET‐1 signaling changed secretion in a manner that favored increased osteogenic activity. Treatment with ECE‐1, endothelin receptor A (EDNRA), or WNT receptor antagonists inhibited the big ET‐1‐mediated increase in mineralization. In the presence of big ET‐1, message levels of Runx2, Igf1, Dkk1, and Sost are uncoupled from protein production, suggesting posttranscriptional regulation. To evaluate the role of big ET‐1 in normal bone physiology, we inhibited EDNRA signaling during mineralization in the absence of exogenous ET‐1. EDNRA blockade reduced mineralization, decreased IGF1, and increased DKK1 and SOST secretion, responses opposite to those induced by exogenous big ET‐1. Pharmacological and siRNA knockdown to inhibit ECE‐1 reduced mineralization and IGF1 secretion with decreasing DKK1 and decreasing or stable SOST secretion, suggesting a further, unknown role of ECE‐1 in osteoblast maturation. Previously we identified miR 126‐3p as a potential ET‐1‐responsive regulator of SOST in murine cells. Overexpression of miR126‐3p increased mineralization in TMOb cells and decreased SOST secretion. Osteoblasts express the ET‐1 signaling pathway and ET‐1 signaling is necessary for normal osteoblast differentiation and mineralization, acting through regulation of miRs that target osteogenic molecules.

Bone metabolism markers: Indicators of loading dose intravenous ibandronate treatment for bone metastases from breast cancer

To investigate the changes in bone metabolism markers after second-line treatment with loading dose intravenous (i.v.) ibandronate in patients with bone metastases (BM) from breast cancer, 80 patients were enrolled in this study during January 2010 to April 2014. All the patients were treated with a second-line loading dose ibandronate for advanced breast cancer with BM and moderate-to-severe bone pain. Ibandronate (6 mg) was intravenously administered on three consecutive days followed by maintenance treatment every 3-4 weeks. Clinical data, including pain score, Karnofsky performance status (KPS) score, and changes in bone metabolism markers, were analyzed. Sixty-two patients were included in the final analysis. Compared with their pre-treatment scores, patients exhibited significantly increased KPS scores (P < .01) and a reduced dose of analgesic medication (oxycodone) (P < .01) after 3 and 6 weeks' post-treatment. The levels of serum bone alkaline phosphatase (BAP), tartrate-resistant acid phosphatase (TRACP-5b), and cross-linked carboxy-terminal telopeptide of type I collagen (ICTP) were significantly reduced after 3 and 6 weeks' post-treatment (P < .001). Aside from a few adverse events, no liver or renal toxicity was observed. Bone metabolism markers decreased by varying degrees after treatment with a loading dose of ibandronate in patients with BM from breast cancer. It might be convenient using bone metabolism markers to potentially evaluate the efficacy of bisphosphonates treatment for bone metastasis.

Endothelin Signaling in Bone

The endothelin (ET) system includes 3 small peptide hormones and a pair of G-protein-coupled receptors. This review first outlines the ET signaling pathway and ET metabolism. Next, it summarizes the role of ET1 signaling in craniofacial development. Then, it discusses observations relating ET signaling to osteoblastic and other osteosclerotic processes in cancer. Finally, it describes recent work in our laboratory that points to endothelin signaling as an upstream mediator of WNT signaling, promoting bone matrix synthesis and mineralization. It concludes with a statement of some remaining gaps in knowledge and proposals for future research.

Refractory hypocalcaemia complicating metastatic prostatic carcinoma

A 72-year-old man with a background of ischaemic heart disease was referred to the accident and emergency department with a 1-week history of worsening dyspnoea and lethargy. A chest X-ray revealed a right-sided lobar pneumonia and a prolonged corrected QT interval was noted on his ECG at presentation. Laboratory investigations confirmed severe hypocalcaemia, significant vitamin D deficiency and relative hypoparathyroidism. A markedly elevated prostate-specific antigen was also identified. Bone scintigraphy demonstrated widespread osteoblastic bone metastases. Severe hypocalcaemia persisted despite treatment and he succumbed after 60 days of hospitalisation.

Discovery and horizontal follow-up of an autoantibody signature in human prostate cancer

In response to an urgent need for improved diagnostic and predictive serum biomarkers for management of metastatic prostate cancer, we used phage display fingerprinting to analyze sequentially acquired serum samples from a patient with advancing prostate cancer. We identified a peptide ligand, CTFAGSSC, demonstrating an increased recovery frequency over time. Serum antibody reactivity to this peptide epitope increased in the index patient, in parallel with development of deteriorating symptoms. The antigen mimicking the peptide epitope was identified as alpha-2-Heremans-Schmid glycoprotein, also known as fetuin-A. Metastatic prostate cancer cell lines and bone metastasis samples displayed robust fetuin-A expression, and we demonstrated serum immune reactivity to fetuin-A with concomitant development of metastatic castrate-resistant disease in a large cohort of prostate cancer patients. Whereas fetuin-A is an established tumor antigen in several types of cancer, including breast cancer, glioblastoma, and pancreas cancer, this report is to our knowledge the first study implicating fetuin-A in prostate cancer and indicating that autoantibodies specific for fetuin-A show utility as a prognostic indicator for prostate cancer patients prone to progress to metastatic disease.

Calcium and phosphorus intake and prostate cancer risk: a 24-y follow-up study

BACKGROUND

High calcium intake has been associated with an increased risk of advanced-stage and high-grade prostate cancer. Several studies have found a positive association between phosphorus intake and prostate cancer risk.

OBJECTIVE

We investigated the joint association between calcium and phosphorus and risk of prostate cancer in the Health Professionals Follow-Up Study, with a focus on lethal and high-grade disease.

DESIGN

In total, 47,885 men in the cohort reported diet data in 1986 and every 4 y thereafter. From 1986 to 2010, 5861 cases of prostate cancer were identified, including 789 lethal cancers (fatal or metastatic). We used Cox proportional hazards models to assess the association between calcium and phosphorus intake and prostate cancer, with adjustment for potential confounding.

RESULTS

Calcium intakes >2000 mg/d were associated with greater risk of total prostate cancer and lethal and high-grade cancers. These associations were attenuated and no longer statistically significant when phosphorus intake was adjusted for. Phosphorus intake was associated with greater risk of total, lethal, and high-grade cancers, independent of calcium and intakes of red meat, white meat, dairy, and fish. In latency analysis, calcium and phosphorus had independent effects for different time periods between exposure and diagnosis. Calcium intake was associated with an increased risk of advanced-stage and high-grade disease 12-16 y after exposure, whereas high phosphorus was associated with increased risk of advanced-stage and high-grade disease 0-8 y after exposure.

CONCLUSIONS

Phosphorus is independently associated with risk of lethal and high-grade prostate cancer. Calcium may not have a strong independent effect on prostate cancer risk except with long latency periods.

Significance of baseline bone markers on disease progression and survival in hormone-sensitive prostate cancer with bone metastasis

PURPOSE

This study evaluated the baseline patient characteristics associated with the time to biochemical progression and overall survival in patients who participated in a phase II trial on zoledronic acid combined with the initial androgen-deprivation therapy for treatment-naïve bone-metastatic prostate cancer.

METHODS

Patients received zoledronic acid 4 mg intravenously every 4 weeks for up to 24 months, concomitantly started with bicalutamide 80 mg orally every day and goserelin acetate 10.8 mg subcutaneously every 12 weeks.

RESULTS

A total of 53 Japanese patients were enrolled between July 2008 and April 2010, and 52 patients were evaluable. Median follow-up period was 41.6 months. Updated median time to biochemical progression was 25.9 months (95 % confidence interval 14.5-49.9). Higher serum bone-specific alkaline phosphatase was an independent risk factor for time to biochemical progression based on multivariate analysis (hazard ratio 6.51; 95 % confidence interval 2.71-15.62; P < 0.001). Median time to biochemical progression for patients with serum bone-specific alkaline phosphatase level higher than 26 μg/L was 12.7 months. Multivariate analysis indicated that higher serum C-terminal telopeptide of type I collagen independently increased the risk of death (hazard ratio 9.62; 95 % confidence interval 2.11-43.89; P = 0.003). Median overall survival for patients with serum C-terminal telopeptide of type I collagen level higher than 8.0 ng/ml was 31.1 months.

CONCLUSIONS

Baseline bone markers can be useful as predictors for disease progression and survival time in patients with bone metastasis from treatment-naïve prostate cancer treated with upfront zoledronic acid concomitantly started with androgen-deprivation therapy.

Bone resorption facilitates osteoblastic bone metastatic colonization by cooperation of insulin-like growth factor and hypoxia

Bone metastasis is a multistep process that includes cancer cell dissemination, colonization, and metastatic growth. Furthermore, this process involves complex, reciprocal interactions between cancer cells and the bone microenvironment. Bone resorption is known to be involved in both osteolytic and osteoblastic bone metastasis. However, the precise roles of the bone resorption in the multistep process of osteoblastic bone metastasis remain unidentified. In this study, we show that bone resorption plays important roles in cancer cell colonization during the initial stage of osteoblastic bone metastasis. We applied bioluminescence/X-ray computed tomography multimodal imaging that allows us to spatiotemporally analyze metastasized cancer cells and bone status in osteoblastic bone metastasis models. We found that treatment with receptor activator of factor-κB ligand (RANKL) increased osteoblastic bone metastasis when given at the same time as intracardiac injection of cancer cells, but failed to increase metastasis when given 4 days after cancer cell injection, suggesting that RANKL-induced bone resorption facilitates growth of cancer cells colonized in the bone. We show that insulin-like growth factor-1 released from the bone during bone resorption and hypoxia-inducible factor activity in cancer cells cooperatively promoted survival and proliferation of cancer cells in bone marrow. These results suggest a mechanism that bone resorption and hypoxic stress in the bone microenvironment cooperatively play an important role in establishing osteoblastic metastasis.

Prospective study on the incidence of bone metastasis (BM) and skeletal-related events (SREs) in patients (pts) with stage IIIB and IV lung cancer-CSP-HOR 13

BACKGROUND

Bone metastasis (BM) is a frequent complication in patients with advanced lung cancer and it causes skeletal-related events (SREs). Our study aim is to prospectively investigate the incidence of BM, incidence and types of SRE, and predictive factors of BM and SREs.

METHODS

Newly diagnosed, advanced non-small-cell lung cancer (NSCLC) or small-cell lung cancer (SCLC) patients were enrolled into the study. Patients were followed up every 4 weeks to monitor the development of SREs. Treatment for lung cancer was performed at the discretion of the investigator.

RESULTS

Two hundred seventy-four patients were enrolled in this study between April 2007 and December 2009 from 12 institutions. Patients included 77 cases of SCLC and 197 of NSCLC (stage IIIB/IV = 73/124). Median follow-up time was 13.8 months. The incidence of BM at initial diagnosis was 48% in stage IV NSCLC and 40% in extensive stage (ED)-SCLC. Forty-five percent of patients who developed BM had SREs consisting of pathologic fracture (4.7%), radiation to bone (15.3%), spinal cord compression (1.1%), and hypercalcemia (2.2%). Multivariate analysis revealed that factors predicting BM are stage IV, performance status 1 or greater and higher bone alkaline phosphatase in NSCLC patients, higher lactate dehydrogenase, and lower parathyroid hormone-related peptide in SCLC patients. Factors predicting SREs were stage IV, age 64 or younger, and lower albumin in NSCLC patients. Multivariate analysis of SRE was not performed for SCLC because of the small number of events.

CONCLUSION

Predictive factors should be taken into consideration in future randomized studies evaluating BM and SREs.

Clinical significance of serum BAP, TRACP 5b and ICTP as bone metabolic markers for bone metastasis screening in lung cancer patients

BACKGROUND

We investigated the clinical significance of serum bone-specific alkaline phosphatase (BAP), tartrate-resistant acid phosphatase isoform 5b (TRACP 5b) and type I collagen carboxyterminal telopeptide (ICTP) as bone metabolic markers for bone metastasis (BM) screening in lung cancer patients.

METHODS

Newly diagnosed advanced lung cancer patients with (N = 130) and without (N = 135) BM were enrolled in the study. Serum BAP, TRACP 5b and ICTP were measured before the treatment.

RESULTS

BAP, TRACP 5b and ICTP values were higher in patients with BM compared with patients without BM (all P < 0.0001). Area under ROC curve (AUC) of BAP, TRACP 5b and ICTP was 0.760, 0.753 and 0.835 (all P < 0.0001), respectively. The cut-off values for BAP, TRACP 5b and ICTP were 21.8 μg/l, 7.8 U/l and 8.8 μg/l, respectively. When TRACP 5b and ICTP were combined, AUC was elevated to 0.895 (P < 0.0001), and the cut-off values were TRACP 5b 7.6 U/l and ICTP 8.4 μg/l.

CONCLUSIONS

We conclude that serum BAP, TRACP 5b and ICTP may serve as useful tools for BM screening in lung cancer patients.

Pathobiology and management of prostate cancer-induced bone pain: recent insights and future treatments

Prostate cancer (PCa) has a high propensity for metastasis to bone. Despite the availability of multiple treatment options for relief of PCa-induced bone pain (PCIBP), satisfactory relief of intractable pain in patients with advanced bony metastases is challenging for the clinicians because currently available analgesic drugs are often limited by poor efficacy and/or dose-limiting side effects. Rodent models developed in the past decade show that the pathobiology of PCIBP comprises elements of inflammatory, neuropathic and ischemic pain arising from ectopic sprouting and sensitization of sensory nerve fibres within PCa-invaded bones. In addition, at the cellular level, PCIBP is underpinned by dynamic cross talk between metastatic PCa cells, cellular components of the bone matrix, factors associated with the bone microenvironment as well as peripheral components of the somatosensory system. These insights are aligned with the clinical management of PCIBP involving use of a multimodal treatment approach comprising analgesic agents (opioids, NSAIDs), radiotherapy, radioisotopes, cancer chemotherapy agents and bisphosphonates. However, a major drawback of most rodent models of PCIBP is their short-term applicability due to ethical concerns. Thus, it has been difficult to gain insight into the mal(adaptive) neuroplastic changes occurring at multiple levels of the somatosensory system that likely contribute to intractable pain at the advanced stages of metastatic disease. Specifically, the functional responsiveness of noxious circuitry as well as the neurochemical signature of a broad array of pro-hyperalgesic mediators in the dorsal root ganglia and spinal cord of rodent models of PCIBP is relatively poorly characterized. Hence, recent work from our laboratory to develop a protocol for an optimized rat model of PCIBP will enable these knowledge gaps to be addressed as well as identification of novel targets for drug discovery programs aimed at producing new analgesics for the improved relief of intractable PCIBP.

Serum levels of bone alkaline phosphatase in breast and prostate cancers with bone metastasis

BALP activity in the sera of metastatic patients of breast and prostate malignancy has increased significantly. Our studies with patients in India conform the earlier reports that BALP may have a useful complementary role in the early diagnosis of bone metastases.

Elevated pre-operative serum peptides for collagen I and III synthesis result in post-surgical atrial fibrillation

OBJECTIVES

This study sought to determine if serum markers for collagen I and III synthesis, the carboxyl terminal peptide from pro-collagen I (PICP) and the amino terminal peptide from pro-collagen III (PIIINP), correlate with left atrial (LA) fibrosis and post-operative atrial fibrillation (AF).

BACKGROUND

AF after cardiac surgery is associated with adverse outcomes. We recently demonstrated that LA fibrosis is associated with post-operative AF in patients with no previous history of AF.

METHODS

Fifty-four patients having cardiac surgery without a history of AF consented to left and right atrial biopsies and a pre-operative peripheral blood draw. Picrosirius red staining quantified the percentage of fibrosis, and reverse transcriptase polymerase chain reaction assessed atrial tissue messenger ribonucleic acid transcripts involved in the fibrosis pathway. PICP and PIIINP levels were measured using an enzyme immunosorbent assay.

RESULTS

Eighteen patients developed AF, whereas 36 remained in normal sinus rhythm. LA fibrosis was higher in patients who developed AF versus normal sinus rhythm (6.13 ± 2.9% vs. 2.03 ± 1.9%, p = 0.03). LA messenger ribonucleic acid transcripts for collagen I, III, transforming growth factor, and angiotensin were 1.5- to 2.0-fold higher in AF patients. Serum PICP and PIIINP levels were highest in AF versus normal sinus rhythm (PICP: 451.7 ± 200 ng/ml vs. 293.3 ± 114 ng/ml, p = 0.006; PIIINP: 379 ± 286 pg/ml vs. 191.6 ± 162 pg/ml, p = 0.01). Furthermore, there was a linear correlation between LA fibrosis and serum PICP levels (R(2) = 0.2; p = 0.01), and of the markers, only PICP was independently associated with AF.

CONCLUSIONS

This demonstrates that serum PICP and PIIINP levels correlate with the presence of LA fibrosis and may act as predictors for post-operative AF even in the absence of previous history of AF.

Chronic administration of the selective P2X3, P2X2/3 receptor antagonist, A-317491, transiently attenuates cancer-induced bone pain in mice

The purinergic P2X3 and P2X2/3 receptors are in the peripheral nervous system almost exclusively confined to afferent sensory neurons, where they are found both at peripheral and central synapses. The P2X3 receptor is implicated in both neuropathic and inflammatory pain. However, the role of the P2X3 receptor in chronic cancer-induced bone pain is less known. Here we investigated the effect of systemic acute and chronic administration of the selective P2X3, P2X2/3 receptor antagonist (5-[[[(3-Phenoxyphenyl)methyl][(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]amino]carbonyl]-1,2,4-benzenetricarboxylic acid sodium salt hydrate) (A-317491) in a murine model of cancer-induced bone pain. Chronic administration of A-317491 (30 μmol/kgs.c., b.i.d.) resulted in a transient attenuation of pain related behaviours in the early stage of the bone cancer model, but had no effect in the late and more progressed stage of bone cancer. Also, acute administration of A-317491 (100 μmol/kgs.c.) had no effect in the progressed stage of the bone cancer pain model. Thus, systemically administered A-317491 did not demonstrate a robust effect in the present mouse model of cancer-induced bone pain.

Increases in bone turnover marker levels at an early phase after starting zoledronic acid predicts skeletal-related events in patients with prostate cancer with bone metastasis

OBJECTIVE

To examine whether bone turnover markers could be predictive markers of the probability of newly arising skeletal-related events (SRE) after the start of zoledronic acid treatment in patients with prostate cancer with bone metastasis.

PATIENTS AND METHODS

In all, 30 patients with prostate cancer with bone metastasis were treated with zoledronic acid infusion every 4 weeks. Serum C-terminal crosslinking telopeptide of type 1 collagen (1CTP), bone alkaline phosphatase (BAP), and prostate-specific antigen (PSA) levels were measured at the start of zoledronic acid treatment to establish baseline values, and every 4 weeks thereafter. To judge in the early phase whether zoledronic acid is effective in these patients, we retrospectively compared 1CTP, BAP, and PSA levels at 1, 3, and 6 months after starting zoledronic acid treatment with those at baseline.

RESULTS

SRE-free survival of patients with increases of 1CTP levels at 1 and 3 months and BAP levels at 3 months were significantly poorer than those of patients with decreases in 1CTP or BAP levels (P = 0.001, P = 0.042, and P = 0.004, respectively). Overall survival of patients with increases of 1CTP levels at 1 and 3 months and of BAP levels at 6 months were significantly poorer than those of patients with decreases of 1CTP or BAP levels (P = 0.013, P = 0.027, and P = 0.035, respectively).

CONCLUSION

The measurement of 1CTP and BAP levels at an early phase after starting zoledronic acid treatment may be useful for physicians to inform patients of their prognosis and to determine the subsequent treatment plan.

Prognostic significance of bone markers in patients with lung cancer metastatic to the skeleton: a review of published data

The presence of bone metastases significantly affects clinical outcome and quality of life parameters in patients with lung cancer. In this review, we aimed to evaluate the predictive value of markers of bone turnover in skeletal morbidity and clinical parameters, including disease-free survival (DFS) and overall survival (OS), in patients with lung cancer metastatic to the skeleton who were receiving bisphosphonate treatment. A comprehensive overview of all articles published from 1995 to date in 3 medical databases (PubMed, Scopus, and Cochrane) was performed using the keywords bone markers and lung cancer. Most bone formation markers (including bone alkaline phosphatase [bALP], osteocalcin [OC], and osteoprotegerin [OPG]), most bone absorption markers (including urinary calcium, osteopontin [OPN], receptor activator of nuclear factor κ-B ligand [RANKL], tartrate-resistant acid phosphatase isoform-5b [TRACP 5b]), and the metabolites of type I collagen had elevated concentrations in patients with lung cancer and bone metastases compared with patients without skeletal involvement. Two large studies showed that urinary N-terminal telopeptide (NTX) levels are a valid diagnostic method for early detection of bone metastases and a more consistent prognosticator than bALP. Treatment with zoledronic acid reduces NTX, TRACP-5b, RANKL, and OPG levels. Furthermore posttherapeutic reduction of urinary NTX levels seems to correlate with lower risk of skeletal-related events (SREs). Levels of markers of bone remodeling reflect the presence of bone metastases and may contribute to early detection of occult skeletal disease or monitor the effect of bisphosphonate treatment. However their ability to predict SREs, as well as DFS and OS, remains debatable.

P2X7 receptor-deficient mice are susceptible to bone cancer pain

The purinergic P2X7 receptor is implicated in both neuropathic and inflammatory pain, and has been suggested as a possible target in pain treatment. However, the specific role of the P2X7 receptor in bone cancer pain is unknown. We demonstrated that BALB/cJ P2X7 receptor knockout (P2X7R KO) mice were susceptible to bone cancer pain and moreover had an earlier onset of pain-related behaviours compared with cancer-bearing, wild-type mice. Furthermore, acute treatment with the selective P2X7 receptor antagonist, A-438079, failed to alleviate pain-related behaviours in models of bone cancer pain with and without astrocyte activation (BALB/cJ or C3H mice inoculated with 4T1 mammary cancer cells or NCTC 2472 osteosarcoma cells, respectively), suggesting that astrocytic P2X7 receptors play a negligible role in bone cancer pain. The results support the hypothesis that bone cancer pain is a separate pain state compared with those of neuropathic and inflammatory pain. However, the recent discovery of a P2X7 receptor splice variant expressed in the knockout mice used for this study complicates the interpretation of the results. The P2X7 splice variant receptor was detected in the spinal cord but not in osteoclasts of the P2X7R KO mouse. Further experiments are needed to elucidate the exact role of the P2X7 receptors in bone cancer pain.

Consensus on the utility of bone markers in the malignant bone disease setting

Biochemical markers of bone turnover provide insight into ongoing rates of skeletal metabolism and tumor-bone interactions in patients with malignant bone disease. This article reviews the available recent evidence assessing the potential of bone markers for detecting and monitoring malignant bone lesions in patients with advanced cancers, and for assessing overall skeletal health and response to antiresorptive therapies in patients at all stages of cancer progression. Most data thus far are for urinary N-terminal cross-linked telopeptide of type I collagen (NTX) in predicting risks of skeletal morbidity and death and monitoring response to zoledronic acid in patients with bone metastases. Ongoing studies are evaluating such correlations for other markers and therapies. Emerging evidence suggests that bone markers may help identify patients at high risk for bone metastasis or bone lesion progression, thereby allowing improved follow-up. Results from ongoing clinical trials evaluating such potential applications of bone markers are awaited.

Serum N-Terminal Propeptide of Collagen Type I is Associated with the Number of Bone Metastases in Breast and Prostate Cancer and Correlates to Other Bone Related Markers

Background

A number of biomarkers have been proven potentially useful for their ability to indicate bone metastases (BM) in cancer patients. The aim of this study was to investigate the relative utility of a newly developed N-terminal propeptide of collagen type I (PINP) human serum assay for the detection of BM in cancer patients. This assay has a corresponding rat PINP assay which in the future might help in translational science between rodent and human trials.

Methods

Participants were 161 prostate, lung and breast cancer patients stratified by number of BM (Soloway score). PINP was assessed and correlated to number of BM. Additionally, the PINP marker was correlated to bone resorption of young (ALPHA CTX-I)- and aged bone (BETA CTX-I); number of osteoclasts (Tartrate-resistant acid phosphatase 5b, TRACP5B) and osteoclast activity (CTX-I/ TRACP5B).

Results

PINP was significantly elevated in breast- and prostate cancer patients +BM, compared to −BM (P < 0.001), however not in lung cancer patients. A strong linear association was seen between PINP and the number of BMs. Significant elevation of PINP was observed at Soloway scores 1–4 (<0 BM) compared with score 0 (0 BM) (P < 0.001). The correlation between bone resorption of young bone or aged bone and bone formation was highly significant in patients +BM and −BM (P < 0.0001).

Conclusions

Data suggest that the present PINP potentially could determine skeletal involvement in patients with breast or prostate cancer. Correlations suggested that coupling between bone resorption and bone formation was maintained in breast- and prostate cancer patients.

Biochemical markers of bone turnover and clinical outcomes in men with prostate cancer

OBJECTIVES

Disrupted skeletal homeostasis is common in patients with prostate cancer. Low bone density is common at diagnosis, and fracture risk is further elevated by the effects of androgen-deprivation therapy. Later in the disease course, bone metastases can result in skeletal morbidity. Although prostate-specific antigen (PSA) levels can provide important insights into overall disease progression, convenient, noninvasive tools for monitoring skeletal health are lacking. Biochemical markers released into serum and urine as a result of bone turnover might fulfill this unmet need. The objectives of this article are to assess current evidence examining the potential utility of bone turnover markers for monitoring skeletal health, bone disease progression, and response to antiresorptive therapies in the prostate cancer setting.

METHODS

Published articles and abstracts from major oncology or urology congresses pertaining to the use of bone turnover markers to monitor skeletal health and disease progression were identified and assessed for relevance and methodologic stringency.

RESULTS

Several randomized trials and correlative studies support the utility of bone marker level changes to assess disease progression in the metastatic setting, bone health during hormonal therapy, and response to bisphosphonate therapy. The available data support potential associations between levels of the collagen type I telopeptides (NTX and CTX) and the severity of metastatic bone disease as well as outcomes during antiresorptive therapy. Evidence linking bone marker level changes with early diagnosis of skeletal metastases is emerging. Although several markers have shown promising results in correlative studies, results from ongoing prospective trials are needed to establish the role of bone markers in this setting.

CONCLUSIONS

Bone marker levels reflect ongoing skeletal metabolism and can provide important insights into bone health and response to bisphosphonate therapy in patients with prostate cancer. The data supporting a role for bone markers to monitor skeletal disease progression and response to zoledronic acid therapy are especially strong. Bone marker assessments may complement established diagnostic and monitoring paradigms in prostate cancer.

Osteosclerotic prostate cancer metastasis to murine bone are enhanced with increased bone formation

Spontaneous development of osteoblastic lesions of prostate cancer (PCa) in mice is modeled by orthotopic (intraprostatic) deposition of neoplastic cells followed by an extremely long latency associated with low incidence of spontaneous bone metastasis. Intracardial injection results in overt bone metastases only with osteoclastic PCa cells (i.e., PC-3). Herein, we report that androgen independent osteoblastic PCa cells readily colonize bone when in a high remodeling state. SCID/Beige mice were subjected to periods of intermittent human parathyroid hormone 1-34 (hPTH) exposure, followed by an intracardiac infusion of osteoblastic C4-2 PCa cells. At the time of PCa infusion, analysis of bone turnover markers from mice treated with hPTH revealed significant increases in osteocalcin (55.06 +/- 7.5 vs. 74.01 +/- 18.5 ng/ml) and TRAcP-5b (3.3 +/- 0.6 vs. 4.81 +/- 0.8 U/l), but no change in type I collagen C-terminal teleopeptide levels relative to control mice. Analysis of femoral cancellous bone architecture revealed significant increases in bone mineral density, trabecular thickness (0.056 +/- 0.002 vs. 0.062 +/- 0.001 mm) and porosity, but significant decreases in connectivity density and trabecular number in hPTH treated mice relative to controls. By 8 weeks post-infusion, 70% of mice pre-treated with hPTH demonstrated detectable serum prostate specific antigen (PSAs) ranging between 2 and 18.8 ng/ml. Immuno-histochemical labeling of femurs for PSA and pan-Cytokeratin revealed the presence of significant tumor cell nests in marrow and trabecular spaces. These results suggest that: (1) local bone physiology is an important factor for developing osteoblastic/sclerotic PCa bone metastases in murine hosts; (2) the establishment of osteosclerotic PCa bone metastases in mice is enhanced by alterations that drive bone formation.

RANKL inhibition in the treatment of bone metastases

PURPOSE OF REVIEW

Bone metastases are common in patients with advanced malignancies and are associated with skeletal-related events, cancer progression, and death. Receptor activator of nuclear factor kappa beta ligand (RANKL) and its receptor, RANK, key mediators of osteoclast differentiation and function, play a pivotal role in bone destruction induced by metastatic bone tumors. The present review summarizes the contribution of RANKL to pathologic bone disease and presents early clinical data on RANKL inhibition in human metastatic cancer.

RECENT FINDINGS

RANKL/RANK interactions are essential for normal bone homeostasis. Binding of RANKL to RANK induces osteolytic bone resorption, a process that occurs in excess when tumor cells are present in bone. In cancer patients, increased tumor-induced osteolysis that is measurable using bone resorption markers can be used to monitor response to treatment or predict tumor progression. Denosumab, a novel, fully human monoclonal antibody specific to RANKL, suppresses bone resorption markers in patients with a variety of metastatic tumors and is being investigated in multiple clinical trials for the prevention and treatment of bone metastases.

SUMMARY

RANKL is an appropriate target to reduce the osteolytic bone damage caused by bone metastases. Clinical trials are ongoing to assess the safety and efficacy of denosumab for the treatment of bone resorption in patients with metastatic cancers.

Histopathological assessment of prostate cancer bone osteoblastic metastases

PURPOSE

Many patients with prostate cancer have bone metastases that appear osteoblastic on radiography, and yet these patients are at increased risk for fracture. The discrepancy between the radiological and clinical aspects of those events is not well understood. We better characterized the histopathology of bone processes in prostate cancer bone metastases.

MATERIALS AND METHODS

Histomorphometry was used to evaluate multisite bone biopsies in 12 patients who died with multiple bone metastases, of whom 7 had received bisphosphonate therapy.

RESULTS

Bone histomorphometry revealed a wide spectrum of cancer induced bone changes in different metastatic sites in individual patients, ranging from a pronounced osteodense to a pronounced osteopenic type. Each metastatic lesion was associated with various amounts of resorption. Decreased bone volume was seen in half of all biopsies. Osteodense lesions were largely composed of under mineralized woven bone, which increases the frailty of new bone. Interestingly woven bone was produced by alkaline phosphatase spindle-shaped cells arising from the connective stroma surrounding tumor cells. The bone response generally was similar in bisphosphonate treated patients and those who did not receive bisphosphonate.

CONCLUSIONS

Despite the osteoblastic nature of bone metastases in prostate cancer, the osteolytic-osteopenic bone lesions found in each clinically osteoblastic case may explain the frequent fractures observed in these cases. In addition, the finding that woven bone formed directly from the tumor stroma and not from the adjacent bone surface supports further research into the mechanisms of abnormal bone formation in prostate cancer bone metastases.

Does increased local bone resorption secondary to breast and prostate cancer result in increased cartilage degradation?

Background

Breast and prostate cancer patients often develop lesions of locally high bone turnover, when the primary tumor metastasizes to the bone causing an abnormal high bone resorption at this site. The objective of the present study was to determine whether local increased bone turnover in breast and prostate cancer patients is associated with an increase in cartilage degradation and to test in vitro whether osteoclasts or cathepsin K alone generate CTXII from human bone.

Methods

The study included 132 breast and prostate cancer patient, where presence of bone metastases was graded according to the Soloway score. Total bone resorption (CTXI_total) and cartilage degradation (CTXII) were determined.

Results

Breast and prostate cancer patients with bone metastases revealed significant increased levels of CTXI_total at Soloway scores 1 and higher compared to patients without bone metastases (p < 0.001). CTXII was statistically elevated at score 3 and 4 (p < 0.01). CTXII/CTXI_total significantly decreased at score 3 and 4 (p < 0.001). Levels of CTXI_total, CTXII and CTXII/CTXI_total changed +900%, +130%, and -90%, respectively at Soloway score 4 compared to score 0. The in vitro experiments revealed that osteoclasts released CTXI fragments but not CTXII from bone specimens. The same was observed for cathepsin K.

Conclusion

Data suggest that an uncoupling between bone resorption and cartilage degradation occurs in breast and lung cancer patient.

Prostate cancer, serum parathyroid hormone, and the progression of skeletal metastases

Bony metastases from prostate cancer are a significant cause of morbidity and mortality. These metastases are predominantly blastic (bone-forming) and commonly cause increased serum levels of parathyroid hormone (PTH) as calcium ions are transferred from serum into blastic bone. The epidemiologic and clinical significance of secondary hyperparathyroidism in advanced prostate cancer have not been widely appreciated. Prostate cancer bony metastases show increased expression of the PTH receptor (PTH-IR) and PTH promotes the growth and invasiveness of prostate cancer cells in bone. Thus, blastic metastases appear to induce a "vicious cycle" in which PTH resorbs normal bone to support the growth of blastic bone. Recognition of the potential role of PTH in the progression of skeletal metastases suggests novel opportunities for prostate cancer secondary prevention. In particular, we propose that suppressing serum PTH in advanced prostate cancer may reduce morbidity by decreasing fractures and pain caused by bone resorption and may reduce mortality by retarding the progression of metastatic disease.

The use of molecular markers of bone turnover in the management of patients with metastatic bone disease

Biochemical markers of bone turnover are widely used in clinical practice. These indices have been shown to be associated with the occurrence, prognosis and therapeutic response of malignant bone lesions. For example, markers of bone resorption are often elevated in patients with established bone metastases and while this may point to a role of these markers in the diagnostic workup of cancer patients, the available evidence does not permit any final conclusions as to the accuracy and validity of the presently used markers in the early diagnosis of bone metastases. Many bone turnover markers appear to respond to antiresorptive and antineoplastic therapies, and recent evidence from prospective trials suggests that the aim of bisphosphonate therapy should be to normalize rates of bone remodelling to optimize therapeutic and prognostic outcomes. However, it remains unknown whether the use of bone markers in the routine clinical setting has any defined beneficial effects on overall outcome in cancer patients. Clearly, bone turnover markers have insufficient diagnostic or prognostic value to be used in isolation; however, the combination of these markers with other diagnostic techniques may improve clinical assessment of patients with bone-seeking cancers. This article reviews the available evidence (as of August 2007) on the clinical use of bone turnover markers in the management of patients with metastatic bone disease.

Oral versus intravenous ibandronic acid: a comparison of treatment options for metastatic bone disease

PURPOSE

This trial is the first to compare directly the clinical response to and safety of oral and intravenous (IV) ibandronic acid for metastatic bone disease.

METHODS

Patients > or =18 years with breast, prostate, lung, urogenital or colon cancer received IV ibandronic acid 6 mg infused over 15 min every 28 days or oral ibandronic acid 50 mg/day. Clinical response was determined using bone scintigraphy, radiography and serum C-terminal telopeptide of type I collagen (S-CTX) at months 3-6. Adverse events and biochemical safety measures were recorded.

RESULTS

A total of 84.6 and 88.5% of patients had a complete/partial response to IV and oral ibandronic acid, respectively. Median percentage decreases in S-CTX were -39 and -35%, respectively. Bone pain scores decreased and analgesic use increased from month 0-3 and were stable from months 3-6. Both formulations improved physical and functioning scores.

CONCLUSION

Oral and IV ibandronic acid for bone metastases have similar efficacy and tolerability.

Changes of bone turnover markers and serum PTH after night or morning administration of zoledronic acid in breast cancer patients with bone metastases

Persistent circadian rhythm of bone turnover in bone metastatic breast cancer suggests greater skeletal retention of bisphosphonates if administered in the night. We assessed differential effects of night vs morning administration of zoledronic acid (ZA) on bone turnover. Forty-four breast cancer patients with bone metastases were randomised to receive intravenous ZA (4 mg) at 1100 or 2300 hours every 28 days for four times. Urinary concentration N-telopeptide of type-I collagen (NTX) and deoxypyridinolines, and serum C-telopeptide of type-I collagen (CTX), bone alkaline phosphatase (ALP), osteocalcin and Parathyroid hormone (PTH) was measured in the morning at baseline and after 4, 7, 14, 28, 56 and 84 days. Urinary ZA concentration was also measured. Zoledronic acid caused significant decreases of NTX and CTX (P<0.001), without any difference in percent changes between night and morning arms. Bone ALP and osteocalcin were also significantly affected by ZA (P=0.001), without any difference between arms. Parathyroid hormone significantly increased in both the arms; PTH increase was lower in the night arm (P=0.001). From the second administration onwards, urinary ZA level was significantly higher in the night arm (P<0.01). Administration of ZA at two opposite phases of the circadian cycle causes similar changes of bone-turnover marker levels, but has differential effects on the level of serum PTH.

Targeting the receptor activator of nuclear factor-kappaB (RANK) ligand in prostate cancer bone metastases

Newly formed bone in the typically osteoblastic bone metastases from prostate cancer shows characteristics of woven bone, e.g. marked defects in mineralization and microstructure. Adding to the reduced mechanical strength of prostate cancer bone metastasis is an increasingly recognized osteolytic component. The existence of osteoclasts in osteoblastic bone metastases and concomitant increases in urine or serum markers for bone resorption are reported in affected patients. Pathologically increased osteoclastic bone resorption is a key mediator of the clinical complications from bone metastases, among them fractures, spinal cord compression and bone pain. The receptor activator of nuclear factor (NF)-kappaB ligand (RANKL) pathway has been identified as the main driving force for osteoclastogenesis and resulting bone resorption. Emerging data indicate that bone marrow-derived RANKL might also constitute a chemoattractant factor for RANK-expressing tumour cells that is likely to contribute to the pathogenesis of bone metastases, including those arising from prostate cancer. Cumulative evidence supports RANKL inhibition as a therapeutic goal for the treatment and prevention of bone metastases from prostate cancer.

Predictive value of osteocalcin and β-CrossLaps in metastatic breast cancer

OBJECTIVES

Assessment of the diagnostic value of serum CEA, CA 15.3, osteocalcin (OC) and beta-CrossLaps (beta-CTX) in the detection of metastatic breast cancer.

DESIGN AND METHODS

This study included 47 patients with breast cancer (20 non-metastatic breast cancer, 11 bone metastasis, 11 soft tissue metastasis, 5 bone plus soft tissue metastasis), 10 patients with benign breast lesions and 13 healthy volunteers. CEA and CA 15.3 were determined using microparticle enzyme immunoassay; while OC and beta-CTX were measured by electrochemiluminescence immunoassay.

RESULTS

CEA, CA 15.3, OC and beta-CTX median levels were higher in breast cancer patients compared to controls (p=0.006, 0.001, 0.004 and 0.038, respectively). Increased levels of OC and beta-CTX were demonstrated in bone metastatic patients compared to non-metastatic or soft tissue metastatic patients (p=0.000).

CONCLUSIONS

Combined use of OC and beta-CTX could be useful in early detection of bone metastatic breast cancer which might improve the outcome of the disease.

Predictors of skeletal complications in men with hormone-refractory metastatic prostate cancer

OBJECTIVES

Skeletal complications are a major cause of morbidity in men with hormone-refractory metastatic prostate cancer. These analyses were designed to identify the variables associated with a greater risk of skeletal complications.

METHODS

The 643 subjects in this report were participants in a randomized placebo-controlled trial to evaluate the effects of zoledronic acid on the incidence of skeletal-related events. All subjects had bone metastases and disease progression despite medical or surgical castration. The relationships between the baseline covariates and the time to the first skeletal-related event were assessed by Cox proportional hazard analyses. The serum bone-specific alkaline phosphatase (BAP) and urinary N-telopeptide level was assessed as a representative specific marker of osteoblastic and osteoclastic activity, respectively. The other covariates included in the model were age, cancer duration, Eastern Cooperative Oncology Group performance status, analgesic use, and prostate-specific antigen, hemoglobin, and lactate dehydrogenase levels.

RESULTS

Elevated BAP levels were consistently associated with a greater risk of adverse skeletal outcomes. Elevated BAP was significantly associated with a shorter time to the first skeletal-related event on multivariate analyses of the entire study population (relative risk 1.84, 95% confidence interval 1.40 to 2.43; P <0.001) and in subset analyses of the placebo and zoledronic acid groups. Elevated BAP levels were also consistently associated with adverse skeletal outcomes on multivariate analyses of the time to radiotherapy and pathologic fracture, the most common types of skeletal-related events in the study population. No other baseline variable was consistently associated with the risk of adverse skeletal outcomes.

CONCLUSIONS

The results of our study have shown that elevated serum BAP levels are associated with a greater risk of adverse skeletal outcomes in men with hormone-refractory prostate cancer and bone metastases.

Oral ibandronate is as active as intravenous zoledronic acid for reducing bone turnover markers in women with breast cancer and bone metastases

BACKGROUND

Phase III study comparing the effect of oral ibandronate and intravenous zoledronic acid on bone markers.

PATIENTS AND METHODS

Breast cancer patients with bone metastases received ibandronate 50 mg/day (n = 137) or zoledronic acid 4 mg every 4 weeks (n = 138) for 12 weeks. The primary end point was mean percentage change in serum levels of cross-linked C-terminal telopeptide of type I collagen (S-CTX) at week 12. Urinary CTX (U-CTX), bone alkaline phosphatase (ALP), amino-terminal procollagen propeptide of type I collagen (PINP) and osteocalcin (OC) were also measured and bone pain and safety assessed.

RESULTS

Both bisphosphonates significantly reduced S-CTX (mean ibandronate 76% +/- 29 (SD) versus mean zoledronic acid 73% +/- 47; P < 0.001 for both versus baseline) and U-CTX (ibandronate 78% +/- 50 versus zoledronic acid 86% +/- 17; P < 0.001). The difference in S-CTX between treatments was 0.6% (confidence interval -1.7% to 3.0%), which was within the prespecified noninferiority margin. Bone ALP, PINP and OC decreased by 26%-47% compared with baseline with both bisphosphonates. Compared with zoledronic acid, ibandronate patients reported fewer adverse events overall (65.0% versus 75.9%), and on days 1-3 (8.0% versus 47.5%), including less pyrexia (overall incidence 0% versus 16.8%) and bone pain (5.8% versus 12.4%).

CONCLUSIONS

Oral ibandronate was well tolerated and statistically noninferior to zoledronic acid for percentage change in the bone resorption marker, S-CTX.

Prostate cancer and markers of bone metabolism: diagnostic, prognostic, and therapeutic implications

Knowledge of bone metastases complicating advanced prostate cancer (CaP) is increasingly relevant in patient selection for novel therapies. Current nuclear bone scintigraphy imaging has limited specificity for prostate metastases. As serum bone markers do correlate with bony lesions, they may play multiple roles in patients with advanced CaP. Currently, these markers play a role in prognostic nomograms for CaP. Recent studies suggest an expanding role for bone markers in the diagnosis and selection of patients for novel therapies. In the future, therapeutic roles for some of these marker pathways will emerge, eventually allowing greater individualization of patient care.

The central role of osteoblasts in the metastasis of prostate cancer

Prostate cancer (PCa) is the most common malignancy in men. Although mortality from PCa has been declining over the past decade, metastasis can substantially shorten survival time and remains a major challenge in maintaining quality of life for survivors. PCa cells preferentially metastasize to bone and typically result in osteoblastic lesions. In the late stages of disease, however, osteolytic lesions are observed. The mechanisms of PCa bone metastasis are still unclear, but relationships between the PCa cells and the bone tissue elements are suspected of being more complex than initially thought. Far from being an innocent bystander, the bone participates actively in the metastatic process and provides the cancer cells with growth factors and a fertile environment. Among the various cells in the bone environment, osteoblasts have a central role through their bidirectional interactions with the PCa cells. This review discusses the possible mechanisms of PCa bone metastasis and highlights the essential role of osteoblasts in the metastasis of PCa to bone.