Bone metabolic markers in bone metastases

Practical update for the use of bone-targeted agents in patients with bone metastases from metastatic breast cancer or castration-resistant prostate cancer

Bone metastases are a significant source of morbidity and mortality for patients with breast and prostate cancer. In this review, we discuss key practical themes regarding the use of bone-targeted agents (btas) such as bisphosphonates and denosumab for managing bony metastatic disease. The btas both delay the onset and reduce the incidence of skeletal-related events (sres), defined as any or all of a need for radiation therapy or surgery to bone, pathologic fracture, spinal cord compression, or hypercalcemia of malignancy. They have more modest benefits for pain and other quality-of-life measures. Regardless of the benefits of btas, it should always be remembered that the palliative management of metastatic bone disease is multimodal and multidisciplinary. The collaboration of all disciplines is essential for optimal patient care. Special consideration is given to these key questions: ■ What are btas, and what is their efficacy?■ What are their common toxicities?■ When should they be initiated?■ How do we choose the appropriate bta?■ What is the appropriate dose, schedule, and duration of btas?

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.

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.

The relationship between skeletal-related events and bone scan index for the treatment of bone metastasis with breast cancer patients

The aim of the present study was to investigate the relationships between the automated bone scan index (aBSI) and skeletal-related events (SRE) in breast cancer patients with bone metastasis. A computer-aided software (BONENAVI™) that was developed using an Artificial Neural Network (Artificial Neural Network) was used for the present analysis. Forty-five patients diagnosed with bone metastasis due to breast cancer from April 2005 through March 2013 were retrospectively analyzed. Before and after the time of initial treatment, aBSI, Artificial Neural Network score, and hotspot number were calculated, and the relationships between these scores and SRE were analyzed. Twenty cases showed decreased (improved) aBSI values after initial treatment (Group A), and 25 cases showed unchanged/increased (worsened) aBSI values (Group B). Chi-square analysis revealed a significant difference in incident numbers of SRE between the two groups--one case in Group A and 12 in Group B (P<0.001). Event-free survival was significantly shorter in Group B (hazard ratio: 8.31, 95% CI: 1.33-12.14, log-rank test; P<0.05). The groups were also divided by the results of 2 radiologists' visual scan interpretations, and no significant differences were shown in the number of SRE (P=0.82, P=0.10). When correlation analyses were performed between aBSI and bone metabolic or tumor markers, alkaline phosphatase was significantly correlated with aBSI at the time of initial treatment (R=0.69, P<0.05). In conclusion, aBSI is proposed as a useful and objective imaging biomarker in the detection of breast-cancer patients with bone metastasis at high risk of SRE.

Analysis of clinicopathological factors associated with bone metastasis in breast cancer

Breast cancer is the second leading cause of cancer death in women today. Once breast cancer metastasizes to bone, mortality increases. Thus, there is an urgent need to identify patients with high risk of bone metastasis, and to find predictive factors for the occurrence of bone metastasis at an earlier stage of breast cancer. Three hundred and sixty patients with pathologically proved breast cancer visiting the Department of Nuclear Medicine for whole body bone scan from January 2006 and January 2009 were investigated in this study. Clinicopathological information was obtained, which consisted of age, menopausal status, clinical staging, lymph node stage, histological grade, the expression of estrogen receptor (ER), progesterone receptor (PR) and epidermal growth factor receptor 2 (HER2). Correlation between bone metastasis and the associated factors was tested by using the Chi-square test. A Cox multivariate analysis was used to assess the factors which independently contributed to survival after bone metastasis in breast cancer patients. Survival curves were drawn for metastasis-free interval and the independent factors which contributed to survival, using the Kaplan-Meier method. Twenty-four patients were excluded from subsequent analysis. Three hundred and thirty-six enrolled patients ranged in age from 22 to 77 years (mean, 47.8 years). ER/PR status [ER(+) vs. ER(-), χ (2)=4.328, P=0.037; ER(+)PR(+) vs. ER(+)PR(-), χ (2)=4.425, P=0.035] and histological grade (χ (2)=7.131, P=0.028) were significantly associated with bone metastasis. ER status (x (2)=8.315, P=0.004) and metastasis-free interval (χ (2)=6.863, P=0.009) were independent prognostic factors for survival in breast cancer patients with bone metastasis. Our study suggested that ER/PR status and histological grade are risk factors for the development of bone metastasis in breast cancer patients. However, ER status and metastasis-free interval are independent prognostic factors for survival in breast cancer patients with bone metastasis. Breast cancer bone metastasis has its unique characteristics, which is helpful to choose the appropriate treatment for breast cancer patients with bone metastasis.

Topical treatment with Tong-Luo-San-Jie gel alleviates bone cancer pain in rats

ETHNOPHARMACOLOGICAL RELEVANCE

The herbal analgesic gel Tong-Luo-San-Jie (TLSJ) and its modifications are used in traditional Chinese medicine to manage cancer pain. However, its mechanisms are still unknown.

AIM OF THE STUDY

To investigate the effects and mechanisms of TLSJ gel on bone cancer pain in a rat model.

MATERIALS AND METHODS

A bone cancer pain rat model was established by inoculating Walker 256 rat carcinoma cells directly into the right tibial medullary cavity of Sprague-Dawley rats (150-170 g); Phosphate buffered saline (PBS) tibial inoculation was used as control. Cancer-bearing rats were treated twice a day with external TLSJ gel (0.5 g/cm(2)/day) or inert gel control for 21 day (n=10/group). Behavioral tests such as mechanical threshold and paw withdrawal latency (PWL) were carried out. Osteoclastic activities were determined and carboxyterminal pyridinoline cross-linked type I collagen telopeptides (ICTP) and bone-specific alkaline phosphatase (BAP) concentrations were detected with ELISA after treatment. Adverse effects were monitored, and biochemical and histological tests were performed in naïve rats treated with local TLSJ gel for six weeks.

RESULTS

TLSJ treatment significantly restored bone cancer-induced decrease of PWL and mechanical threshold compared to inert gel. It also decreased the level of blood serum ICTP and BAP and inhibited osteoclast activities. No adverse effects or abnormal biochemical and histological changes were detected after TLSJ treatment.

CONCLUSION

The present study shows that TLSJ significantly inhibits bone cancer-induced thermal and mechanical sensitization. It suggests that the gel may be useful in managing cancer pain and that it may act by inhibiting osteoclastic activity.

Skeletal morbidity in lung cancer patients with bone metastases: demonstrating the need for early diagnosis and treatment with bisphosphonates

BACKGROUND

The skeleton is one of the most frequent sites for metastases from non-small cell lung cancer (NSCLC), and skeletal-related events (SREs) can decrease quality of life (QOL). However, limited guidance exists regarding the diagnosis and treatment of bone metastases in patients with NSCLC.

METHODS

Data on the burden of skeletal morbidity and the diagnosis and treatment of bone metastases in patients with NSCLC were obtained from reviewing the published literature (PubMed) and presentations and abstracts from recent oncology congresses.

RESULTS

Bone metastases are common but underdiagnosed in patients with NSCLC. Most NSCLC patients with bone metastases develop > or =1 SRE during their lifetimes. As survival improves with new treatment modalities, the prevalence of SREs is likely to increase. Direct costs of SREs and their subsequent supportive care are approximately $28,000 per patient. Although bone metastases often are not diagnosed until after the onset of symptoms, early treatment can delay the onset of potentially debilitating SREs. In patients with NSCLC and other solid tumors (n=773), zoledronic acid (ZOL; 4 mg via 15-min infusion every 3 weeks) delayed the median time to first on-study SRE by >80 days compared with placebo (p=0.009). Moreover, ZOL significantly reduced the ongoing risk of SREs by 32% versus placebo (p=0.016).

CONCLUSIONS

Skeletal morbidity is an important concern in patients with NSCLC. The incidence of SREs is expected to increase as survival improves in this setting. Prevention of SREs with therapies such as ZOL may preserve patients' QOL and possibly reduce healthcare costs.

A novel organotypic model mimics the tumor microenvironment

Carcinoma cell invasion is traditionally studied in three-dimensional organotypic models composed of type I collagen and fibroblasts. However, carcinoma cell behavior is affected by the various cell types and the extracellular matrix (ECM) in the tumor microenvironment. In this study, a novel organotypic model based on human uterine leiomyoma tissue was established and characterized to create a more authentic environment for carcinoma cells. Human tongue squamous cell carcinoma cells (HSC-3) were cultured on top of either collagen or myoma. Organotypic sections were examined by immunohistochemistry and in situ hybridization. The maximal invasion depth of HSC-3 cells was markedly increased in myomas compared with collagen. In myomas, various cell types and ECM components were present, and the HSC-3 cells only expressed ECM molecules in the myoma model. Organotypic media were analyzed by radioimmunoassay, zymography, or Western blotting. During carcinoma cell invasion, matrix metalloprotease-9 production and collagen degradation were enhanced particularly in the myoma model. To evaluate the general applicability of the myoma model, several oral carcinoma, breast carcinoma, and melanoma cell lines were cultured on myomas and found to invade in highly distinct patterns. We conclude that myoma tissue mimics the native tumor microenvironment better than previous organotypic models and possibly enhances epithelial-to-mesenchymal transition. Thus, the myoma model provides a promising tool for analyzing the behavior of carcinoma cells.

Host-derived RANKL is responsible for osteolysis in a C4-2 human prostate cancer xenograft model of experimental bone metastases

BACKGROUND

C4-2 prostate cancer (CaP) cells grown in mouse tibiae cause a mixed osteoblastic/osteolytic response with increases in osteoclast numbers and bone resorption. Administration of osteoprotegerin (OPG) blocks these increases, indicating the critical role of RANKL in osteolysis in this model. The objective of our study was to investigate whether RANKL expressed by tumor cells (human origin) directly stimulates osteolysis associated with the growth of these cells in bone or whether the increased osteolysis is caused by RANKL expressed by the host environment cells (murine origin). The relative contribution of tumor-vs. host-derived RANKL has been difficult to establish, even with human xenografts, because murine and human RANKL are both capable of stimulating osteolysis in mice, and the RANKL inhibitors used to date (OPG and RANK-Fc) inhibit human and murine RANKL.

METHODS

To address this question we used a neutralizing, antibody (huRANKL MAb), which specifically neutralizes the biological activities of human RANKL and thereby the contribution of C4-2 derived RANKL in this tibial injection model of experimental bone metastases.

RESULTS

Administration of huRANKL MAb did not inhibit the osteolytic response of the bone to these cells, or affect the establishment and growth of the C4-2 tumors in this environment.

CONCLUSION

In conclusion, our results suggest that in this model, murine RANKL and not the tumor-derived human RANKL is the mediator of the osteolytic reaction associated with C4-2 growth in bone. We hypothesize that C4-2 cells express other factor/s inducing host production of RANKL, thereby driving tumor-associated osteolysis.

Change of cross-linked telopeptide of type I collagen (ICTP) and other bone resorption markers in patients with bone fragility fractures

BACKGROUND

The serum concentration of cross-linked telopeptide of type I collagen (ICTP) has been reported to be a useful marker and for both diagnosis and monitoring of bone metastasis. This study was performed to clarify the changes in various bone turnover markers, including ICTP, after bone fragility fracture.

METHODS

Seventy-six bone fragility fracture patients (14 men and 62 postmenopausal women; mean age, 77.0 years) were evaluated for bone resorption markers, including serum ICTP. We measured urinary N-terminal telopeptides of type I collagen (NTX) several times after fracture. Furthermore, serum ICTP, serum NTX, urinary deoxypyridinoline (DPD), and urinary C-telopeptide-cross-linked type I collagen (CTX) were measured at the times of both minimum and maximum urinary NTX.

RESULTS

Urinary NTX was increased significantly from 86.4 +/- 57.9 to 214.3 +/- 137.2 nmol BCE/mmol Cr following fracture. Serum ICTP showed a similar significant increase from 7.6 +/- 4.7 to 10.4 +/- 5.5 ng/ml in bone fragility fracture patients. Furthermore, other markers also showed similar increases. The level of increase in urinary NTX (148.0%) was especially high compared with other bone resorption markers. On the other hand, the level of increase in serum ICTP (36.8%) was similar to that in serum NTX (39.8%). Serum ICTP levels were significantly correlated with other bone resorption markers, with an especially strong correlation between serum ICTP and serum NTX (r = 0.647, P < 0.001). The percentage of cases in which ICTP exceeded the cutoff value for suspected bone metastasis in postmenopausal women was 73.6%.

CONCLUSIONS

The value of ICTP increases with bone fragility fracture and is correlated with other bone resorption markers, and ICTP obviously exceeded the reference value as compared with other bone resorption markers.

Biochemical approach to the detection and monitoring of metastatic bone disease: What do we know and what questions need answers?

Metastatic spread to bones frequently occurs in several types of cancer diseases, in particular breast, prostate, and lung cancer. Infiltration of bone by tumour cells is a source of several complications including severe bone pain, spinal cord compression, hypercalcemia, pathologic fractures, all reducing quality of life and worsening prognosis. Therefore, early recognition of bone metastases is among the highest priorities in the clinical management of cancer disease. Currently, detection and staging relies on radiological imaging techniques (scintigraphy, radiography, computer tomography, etc.). Due to their limited sensitivity and/or inconveniences, irradiation, and considerable costs related to serial use, they are not suited for close monitoring of cancer patients to capture skeletal spread in an early stage or to follow-up on therapeutical responses. Interaction of tumour cells with surrounding bone cells leads to enhanced bone resorption and/or bone formation. These cellular processes result in the release of numerous epitopes that, if detected by immunoassays, can reflect the changes of the rate of bone turnover and the occurrence of metastatic spread to bone. Numerous studies reported elevated levels of bone turnover markers in patients with bone metastases proportionally to the extent of skeletal involvement. Furthermore, preliminary data suggest that biomarkers can predict skeletal-related events (SREs), disease progression, and even cancer-related death. The present review intends to summarize the list of emerged biomarkers, major studies assessing their relative utility for detection of bone metastases in different types of cancer disease, and discuss their potentials for becoming part of screening protocols for improving our success rate in the early detection of metastatic bone disease.

Three-dimensional trabecular bone architecture of the lumbar spine in bone metastasis from prostate cancer: comparison with degenerative sclerosis

OBJECTIVE

Prostate cancer frequently metastasizes to bone, inducing osteosclerotic lesions. The objective of this study was to clarify the three-dimensional (3D) trabecular bone microstructure in bone metastasis from prostate cancer by comparison with normal and degenerative sclerotic bone lesions, using microcomputed tomography (micro-CT).

DESIGN AND MATERIALS

A total of 32 cancellous bone samples were excised from the lumbar spine of six autopsy patients: 15 metastatic samples (one patient), eight degenerative sclerotic samples (four patients) and the rest from normal sites (three patients). The samples were serially scanned cross-sectionally by micro-CT with a pixel size of 23.20 microm, slice thickness of 18.56 microm, and image matrix of 512 x 512. Each image data set consisted of 250 consecutive slices. The volumes of interest (96 x 96 x 120 voxels) were defined in the original image sets and 3D indices of the trabecular microstructure were determined.

RESULTS

The trabecular thickness (Tb.Th) in degenerative sclerotic lesions was significantly higher than that in normal sites, whereas no significant difference was observed in trabecular number (Tb.N). By contrast, in metastatic lesions, the Tb.N was significantly higher with increased bone volume fraction (BV/TV) than in normal sites, and no significant difference was found in Tb.Th. The characteristics of the trabecular surface in the metastatic samples showed concave structural elements with an increase in BV/TV, indicating osteolysis of the trabecular bone. In 3D reconstructed images, increased trabecular bone with an irregular surface was observed in samples from metastatic sites, which were uniformly sclerotic on soft X-ray radiographs.

CONCLUSION

These results support, through 3D morphological features, the strong bone resorption effect in bone metastasis from prostate cancer.

Evaluation of the clinical value of bone metabolic parameters for the screening of osseous metastases compared to bone scintigraphy

Background

Bone metastases are common in many types of cancer. As screening methods different imaging modalities are available. A new approach for the screening of osseous metastases represents the measurement of bone metabolic markers. Therefore aim of this study was to evaluate the usefulness of the determination of bone metabolic markers aminoterminal propeptide of type I procollagen (PINP, osteoblastic activity) and the carboxyterminal pyridinoline cross-linked telopeptide of type I collagen (ICTP, osteoclastic activity) for the detection of bone metastases associated with other malignancies.

Methods

88 patients aged 21 – 82 years with malignant tumors were prospectively studied. The serum concentrations of PINP and ICTP were measured and compared to the results of bone scintigraphy, radiological bone series, CT, MRI and clinical follow-up.

Results

Osseous metastases were found in 21 patients. 19 of them were correctly identified by bone scintigraphy (sensitivity: 90%). For bone metabolic markers results were as follows: ICTP sensitivity: 71%, specificity: 42%; PINP sensitivity: 24%, specificity: 96%.

Conclusions

As markers of bone metabolism PINP and ICTP showed low sensitivity and/or specificity for the detection of osseous metastases. The presented markers did not seem to be sufficient enough to identify patients with bone metastases or to replace established screening methods.

Growth Inhibition of Human Prostate Cancer Cells in Human Adult Bone Implanted into Nonobese Diabetic/Severe Combined Immunodeficient Mice by a Ligand-Specific Antibody to Human Insulin-Like Growth Factors

Advanced prostate cancer frequently involves the bone that has the largest content of insulin-like growth factors (IGFs). However, the role of bone-derived IGFs in bone metastasis of prostate cancer has not been studied extensively because of the lack of a reliable animal model. Therefore, we investigated whether a novel antibody directed against human IGF-I and IGF-II (KM1468) could inhibit the development of new bone tumors and the progression of established bone tumors in nonobese diabetic/severe combined immunodeficient mice implanted with human adult bone. We first confirmed that KM1468 bound specifically to human IGF-I, human IGF-II, and mouse IGF-II but not to insulin. It also blocked autophosphorylation of the type I IGF receptor induced by the binding of IGFs in human-type I IGF receptor-overexpressing BALB/c 3T3 cells, and it inhibited the IGF-stimulated growth of MDA PCa 2b cells in vitro. Then mice were injected intraperitoneally with KM1468 once weekly for 4 weeks either immediately or 4 weeks after inoculation of MDA PCa 2b cells. KM1468 markedly and dose-dependently suppressed the development of new bone tumors and the progression of established tumor foci, as determined by histomorphometry, and it also decreased serum prostate-specific antigen levels, compared with the control. This is the first report of an IGF ligand-specific inhibitory antibody that suppresses the growth of human prostate cancer cells in human adult bone. These results indicate that the IGF signaling axis is a potential target for prevention and treatment of bone metastases arising from prostate cancer.

Relationship between bone scintigraphy and tumor markers in patients with breast cancer

PURPOSE

The aim of this study is to specify the precise role of bone scintigraphy and serum CEA and CA 15-3 assays in the monitoring of breast cancers in order to optimize their use and to determine whether it is possible to guide the prescription of bone scan by the use of CEA and CA 15-3 assays in the monitoring of breast cancer.

METHODS

For this purpose, from November 1997 to May 2002, 98 consecutive female breast cancer patients (median age, 52 years; range 35-77 years) underwent bone scintigraphy during follow-up. In these patients values of tumor markers were compared with the results of bone scintigraphy. Some of the patients with bone metastasis were checked repeatedly at intervals of 6 to 12 months, resulting in 49 patients with bone metastasis and 74 patients without bone metastasis being included in the study.

RESULTS

In patients with bone metastasis, serum CEA levels were abnormal in 23/49 cases and CA 15-3 serum concentrations were elevated above the cut-off in 33/49 cases. Among patients without bone metastasis, CEA and CA 15-3 serum concentrations were normal in 50/74 and 55/74 cases respectively. The combination of the two markers improved the diagnostic sensitivity.

CONCLUSION

Although serial tumor marker measurements are an efficient and cost effective method of monitoring disease progression, it does not allow prediction of the bone scan results; so it is not justifiable to reject a bone scintigraphy on the basis of these markers.

Bone metabolic markers in bisphosphonate therapy for skeletal metastases in patients with breast cancer

The use of bisphosphonates for skeletal metastasis of breast cancer is now well established. Although clinical judgement for treating skeletal metastasis is based on symptoms and imaging studies, accurate or quantitative means are few. Various bone metabolic markers have been developed and these were evaluated in patients with metastasis to bone. Bone metabolic markers, especially resorption markers, have been shown to be a good tool for the monitoring the response to therapy for skeletal metastasis. This is also true for bisphosphonate treatment for skeletal metastasis. Bone metabolic markers are produced by different mechanisms. There are some different classes of resorption markers; tartrate-resistant acid phosphatase (TRAP) is secreted by osteoclast, N- and C-terminal cross-linking telopeptide of type I collagen (NTx and CTx) are the degradation the products of type I collagen, mainly produced by cathepsin K, and pyridinoline cross-linked carboxyl-terminal telopeptides of type I collagen (I CTP) is also a degradation product of type I collagen, by matrix metalloproteases. Even though bone resorption markers are a good tool to monitor response to bisphosphonate therapy, there remains the question of which class of bone resorption markers is best suited to the task.

Serum prolidase I activity and some bone metabolic markers in patients with breast cancer: in relation to menopausal status

OBJECTIVES

The purpose of this study was to investigate the diagnostic value of some osteoblastic/osteoclastic biochemical markers and serum prolidase I activity in breast cancer (BC).

DESIGN AND METHODS

Serum bone gla protein (BGP), prolidase I activity, urinary deoxypyridinoline (Dpy) and calcium excretions were measured, in metastatic and nonmetastatic BC patients, and in 52 healthy women.

RESULTS

In patients with metastases, bone turnover markers were found to be significantly higher than those in the control group and in patients without metastases. Serum prolidase activity in patients with and without metastases was also significantly higher than those in the control group, but there was no difference between the two patient groups.

CONCLUSIONS

Bone turnover has been suggested to be accelerated in BC patients with the more pronounced osteolytic activation, especially in metastatic state. Serum prolidase in premenopausal period appears to be valuable in discriminating cancer patients from controls. BGP and to a lesser degree of Dpy, may be useful markers for predicting the metastatic bone involvement, as well as for the more cost effective management of BC patients and monitoring the effects of antiresorptive therapy of malignant osteolysis before any metastasis could be detected by other invasive techniques.

Elevated serum periostin levels in patients with bone metastases from breast but not lung cancer

Periostin is a recently identified gene that is preferentially expressed in periosteum, indicating a potential role in bone formation and maintenance of structure. We independently identified and isolated periostin from cancer tissue, using the palindromic PCR-driven cDNA Differential Display technique. For the present work, we developed a novel sandwich chemiluminescence assay to detect serum periostin level using newly developed monoclonal and polyclonal antibodies. We investigated serum periostin levels in breast cancer and small cell lung cancer patients, especially in patients with bone metastasis. The study included 58 breast cancer and 44 small cell lung cancer patients. Serum periostin levels were elevated in breast cancer patients presenting with bone metastases (92.0 +/- 28.6 ng/ml) compared to similar breast cancer patients without evidence of bone metastasis (55.0 +/- 16.6 ng/ml, p = 0.04). No correlation was found between the serum periostin level and any other prognostic factors, such as clinical stage and lymph node metastasis in breast cancer. Serum periostin levels thus appear to serve as a marker of bone metastasis from breast cancer. In contrast, serum periostin levels were similar in samples from patients with small cell lung cancer who did or did not have bone metastasis. However, increasing T-stage and N-stage of patients with small cell lung cancer were correlated with higher periostin levels (T4, 126.5 +/- 29.7 ng/ml v.s. T2, 64.9 +/- 16.1 ng/ml, p = 0.03; and T4 v.s. T1, 36.3+/- 7.5 ng/ml, p = 0.01; N3, 108.7 +/- 17.3 ng/ml v.s. N2, 49.7+/- 10.9 ng/ml, p = 0.01). Periostin has a substantial homology with the insect cell adhesion molecule, fasciclin I. Thus, expression of periostin may facilitate tumor cell adhesion to the bone surface. In fact, we found by in situ RNA hybridization, that the periostin gene was highly expressed in the stromal cells immediately surrounding the tumor, but not within the breast cancer cells themselves.

Bone metabolic markers as gauges of metastasis to bone: a review

Currently, imaging techniques are the leading methods used to diagnose of metastasis to bone. However, these techniques are expensive, expose patients to toxic and radioactive compounds, and monitor response to treatment poorly; these drawbacks have prompted the search for alternative screening methods. Therefore, bone metabolic markers have been evaluated as possible methods to diagnose and monitor the development and progression of metastatic bone disease. Although bone metabolic markers are often grouped as either resorption or formation markers, studies have revealed that each marker has its own biologic meaning and clinical relevance. Recent milestones in the use of bone metabolic markers as screening methods for metastatic bone disease and as evaluation methods for treatment response are shown in the following lists. 1. Bone metabolic marker measurements provide insight into mechanisms of metastasis to bone. 2. Although promising data have been reported, bone metabolic markers are not yet considered to be reliable screening methods for metastasis to bone. 3. Bone metabolic markers are reliable indicators of response to both conventional and bisphosphonate therapies. 4. Preliminary results indicate bone metabolic markers might be an independent prognostic factor in patients whose tumors metastasize to bone. 5. New or refined assays for bone metabolic markers are expected to improve the sensitivity and specificity of bone metabolic marker use in diagnosing and monitoring metastasis to bone.

The serum level of the amino-terminal propeptide of type I procollagen is a sensitive marker for prostate cancer metastasis to bone

OBJECTIVE

To assess the level of a bone-formation marker, the amino-terminal propeptide of type I procollagen (PINP), for its utility in indicating bone metastasis in patients with prostate cancer.

PATIENTS AND METHODS

Several bone formation markers, i.e. PINP, the carboxy-terminal propeptide of type I procollagen (PICP), bone-specific alkaline phosphatase (BALP), and bone Gla protein (BGP), a bone resorption marker (pyridinoline cross-linked carboxy-terminal telopeptide, ICTP), and prostate specific antigen (PSA) were measured in 40 patients without and 25 patients with bone metastasis. No patient had undergone previous treatment, except for six who developed bone metastasis while undergoing hormone therapy.

RESULTS

All markers except BGP were significantly higher in patients with bone metastasis than in those without. The levels of PINP correlated best with the extent of disease, although the levels of PSA, BALP and ICTP also correlated well. While PINP had the largest area under the receiver-operator characteristic curve, PSA, BALP and ICTP also produced useful curves.

CONCLUSION

The bone formation marker PINP seems to be useful for discriminating patients with and without bone metastasis. PINP may help in the early and accurate diagnosis of bone metastasis in such patients.

Markers of bone turnover in bone metastases

BACKGROUND

Bone metastases are a frequent complication of cancer disease. The evaluation of metastatic bone disease is crucial for the primary cancer staging because it will influence the therapeutic decision. The diagnosis of bone metastases usually relies on skeletal X-ray and bone scintigraphy. This latter technique is a sensitive diagnostic tool but lacks specificity. Moreover, the assessment of efficacy in the treatment of bone metastasis is difficult because the increased radionucleotide uptake does not always reflect an active metastatic area but may correspond to a bone reconstruction in patients responding to treatment. Markers of bone remodeling could help the clinician in the diagnosis and follow-up of bone metastases.

METHODS

A common feature of both types of bone metastases (lytic or sclerotic) is an alteration of bone remodeling activity. The rate of formation or degradation of the bone matrix can be assessed either by measuring a prominent enzymatic activity of the bone forming or resorbing cells or by measuring bone matrix components released into the circulation during formation or resorption. They have been separated into markers of formation and resorption, but when both events are coupled and in balance, either of these markers will reflect the overall rate of bone turnover. These markers are of unequal specificity and sensitivity, and some of them have not been fully investigated yet in bone metastases. None of these markers is disease specific.

RESULTS

Several studies of breast carcinoma showed increased levels of pyridinium cross-links in patients with bone metastases. However, in most studies, breast carcinoma patients without evidence of metastatic bone disease excreted pyridinium cross-links at a much higher rate than healthy controls. Similar findings have been observed with other types of primary cancer including lung, prostate, kidney, throat, and digestive carcinoma. Markers of bone formation had a low sensitivity in the diagnosis of bone metastasis, but they could be useful for prostate carcinoma, in which studies have shown that all patients without bone metastasis had normal value of bone alkaline phosphatase. Bone markers can be used for the follow-up of treatment, especially bisphosphonates therapy. Bisphosphonate infusion induces a large decrease of pyridinium cross-link level. Some studies suggest that a high level of resorption markers after treatment could reflect a resistance to the treatment. Moreover, some studies have shown that level of pyridinium cross-links before treatment could be a predictive factor of the response in multiple myeloma and prostate carcinoma.

CONCLUSIONS

Bone markers have improved greatly in terms of sensitivity and specificity and could be useful for an early diagnosis of bone metastases. However, the clinical value of the use of bone markers in the diagnosis of bone metastasis has not been clearly shown yet with the possible exception of BPAL in prostate carcinoma. When bone is the only site of metastases, bone markers may be useful for monitoring patients with bone metastases. Markers of bone resorption are sensitive to changes in bone turnover induced by treatment. Bone resorption markers may be particularly useful for the follow-up of bisphosphonate treatment, which is increasingly used in the management of bone metastases.

Use of bone turnover marker, pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), in the assessment and monitoring of bone metastasis in prostate cancer

BACKGROUND

We investigated whether a new marker of bone turnover, pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), could be useful in the assessment of bone metastasis and in monitoring of the response to treatment in patients with prostate cancer with bone metastasis.

METHODS

In all, 58 patients with prostate cancer (25 with bone metastasis and 33 without bone metastasis) and 52 patients with benign prostate hypertrophy who were treated between June 1994-August 1997 were included in this study. All patients were newly diagnosed.

RESULTS

Serum ICTP levels in patients with prostate cancer with bone metastasis were significantly higher than those in patients with prostate cancer without bone metastasis (P<0.0001) or with benign prostate hypertrophy (P<0.0001). No significant differences were observed in serum ICTP levels between patients with prostate cancer without bone metastasis and those with benign prostate hypertrophy. Serum ICTP levels correlated significantly with Soloway's grading system for bone scans. Serum ICTP levels in patients with bone metastasis showed a significant downward trend in response to hormonal treatment.

CONCLUSIONS

The determination of serum ICTP levels is useful in the assessment of bone metastasis and in monitoring the response of bone metastasis to treatment to prostate cancer.

Bone metabolic markers in the evaluation of bone scan flare phenomenon in bone metastases of breast cancer

Bone scan flare seriously complicates evaluations of the therapeutic response of bone metastases. The value of bone metabolic markers in monitoring the therapeutic response for bone metastases in breast cancer was assessed. Twenty-three breast cancer patients with bone metastases treated by combined chemotherapy of cyclophosphamide, doxorubicin, and 5-fluorouracil (CAF) were monitored using bone scans; a bone resorption marker, pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP); a bone formation marker, bone-specific alkaline phosphatase (BAI-p); and a tumor-specific marker (CA15-3). Bone scans were performed before and 3 or 4 months after therapy. After CAF therapy, markers were measured monthly. As a control, the markers of nine patients without bone metastases who received adjuvant CAF therapy were also measured monthly. The therapeutic effect on bone metastases was assessed after the study. Five patients had progression of disease (PD), three had no change (NC), and 15 patients had partial responses (PR). Bone scan flare-up was seen in five PR patients. In patients who received adjuvant therapy, ICTP, BAI-p, and CA15-3 did not change. ICTP increased significantly in PD patients. ICTP did not increase in either NC or PR, including bone scan flare patients. BAI-p and CA15-3 did not show any discernible pattern among PD, PR, flare, and NC patients. Thus measuring ICTP could distinguish PD from NC or PR patients' responses to CAF therapy. This was true also for patients who showed bone scan flare-up. Measuring a bone resorption marker, ICTP, allows clinicians to monitor patients' responses to CAF therapy and may prevent prolonged ineffective therapy or unnecessary changes in therapy as a result of the flare phenomenon.

Diagnostic value of some biochemical bone markers for the detection of bone metastases in prostate cancer

Bone metastases in cancer of the prostate are diagnosed routinely by isotope bone scintigraphy and the measurement of alkaline phosphatase in serum and the calcium excretion in urine. The specificity of these examinations is in general not satisfactory. We therefore investigated the diagnostic value of five new markers of bone formation and bone resorption for the detection of the metastatic process. In a group of 43 patients with carcinoma of the prostate the carboxyterminal propeptide, the carboxyterminal cross-linked telopeptide, the aminoterminal cross-linked telopeptide, and the deoxypyridinoline cross-links of type 1 collagen were measured as well as the specific bone alkaline phosphatase isoenzyme. A group of 34 patients with benign prostatic hyperplasia served as a control. A receiver-operating characteristic analysis was performed. It appeared that the sensitivity of carboxyterminal cross-linked telopeptide of type I collagen was the greatest (89%), while the best specificity was obtained for the deoxypyridinoline cross-links assay (92%). The diagnostic values of the new markers were generally comparable with those of alkaline phosphatase although carboxyterminal cross-linked telopeptide of type I collagen yielded better results, but those with carboxyterminal propeptide of type I procollagen were less satisfactory. Calcium excretion in urine had no added value at all.

Dissociation of bone formation markers in bone metastasis of prostate cancer

To clarify the meaning and clinical value of bone formation markers in bone metastasis from prostate cancer, we investigated the bone formation markers carboxy-terminal propeptide of type I procollagen (PICP), bone-specific alkaline phosphatase (BA1-p) and osteocalcin, so-called bone gla protein (BGP) in 43 prostate cancer patients with and 46 patients without overt bone metastasis. Patients with bone metastasis were evaluated repeatedly by bone scan at intervals of 3-6 months. The expression patterns of bone formation markers in patients with progression of bone metastasis became dissociated; BA1-p and PICP were elevated in patients with progression of bone metastasis but BGP was not. Instead, BGP showed slight elevation in patients with improvement and complete remission of bone metastasis. PICP, BA1-p and BGP are all bone formation markers, but each marker appears in a different phase of bone formation: PICP appears in proliferation phase, BA1-p appears in matrix maturation phase and BGP appears in late bone formation phase. Our findings that BGP was not elevated in progression of bone metastasis and that it increased slightly with improvement and complete remission of bone metastasis may imply that the bone formation that occurs in blastic bone metastasis is different from normal bone formation.

Usefulness of bone metabolic markers in the diagnosis and follow-up of bone metastasis from lung cancer

Ninety-one lung cancer patients were evaluated to determine the usefulness of bone metabolic markers in the diagnosis and follow-up of bone metastases and also to investigate their clinical usefulness as an adjunct to bone scintigraphy. Both bone resorption markers, ICTP and fDPD, and bone formation markers, Al-p, BAL, PICP and BGP, were evaluated in 47 patients with and 44 without bone metastasis. The patients with bone metastasis were classified according to the bone metastatic burden, and they were also separately classified into groups according to the course of the bone metastasis. ICTP, fDPD, Al-p and BAL were significantly elevated (P < 0.001) in patients with bone metastasis, but PICP and BGP were not. Receiver-operating characteristic (ROC) curves of these markers revealed that ICTP was most highly correlated with the diagnosis of bone metastasis. The sensitivity of ICTP (71.4%) and fDPD (61.0%) were good with high specificity. T scores of ICTP, fDPD and BAL tended to be higher at higher grades of bone metastasis. T-scores of ICTP, fDPD and BAL were elevated in the newly diagnosed cases and progressed cases, but the T-scores of ICTP and fDPD in those cases were higher than that of BAL. In the follow-up study, ICTP was well correlated with uncontrolled or controlled bone metastasis. Thus, bone resorption markers, especially ICTP, could be a good indicator of the progression and multiplicity of disease, and it could help in the follow-up and in the monitoring of therapy for bone metastasis from lung cancer.