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

Mass Spectrometry-Based Proteomics Identifies Serpin B9 as a Key Protein in Promoting Bone Metastases in Lung Cancer

Bone metastasis (BM) is one of the most common complications of advanced cancer. Immunotherapy for bone metastasis of lung cancer (LCBM) is not so promising and the immune mechanisms are still unknown. Here, we utilized a model of BM by injecting cancer cells through caudal artery (CA) to screen out a highly bone metastatic derivative (LLC1-BM3) from a murine lung cancer cell line LLC1. Mass spectrometry-based proteomics was performed in LLC1-parental and LLC1-BM3 cells. Combining with prognostic survival information from patients with lung cancer, we identified serpin B9 (SB9) as a key factor in BM. Molecular characterization showed that SB9 overexpression was associated with poor prognosis and high bone metastatic burden in lung cancer. Moreover, SB9 could increase the ability of lung cancer cells to metastasize to the bone. The mechanistic studies revealed that tumor-derived SB9 promoted BM through an immune cell-dependent way by inactivating granzyme B, manifesting with the decreased infiltration of cytotoxic T cells and increased expression level of exhausted markers. A specific SB9-targeting inhibitor [1,3-benzoxazole-6-carboxylic acid (BTCA)] significantly suppressed LCBM in the CA mouse model. This study reveals that SB9 may serve as a therapeutic target and potential prognostic marker for patients with LCBM.

IMPLICATIONS

SB9 as a therapeutic target for LCBM.

Predictive and Prognostic Biomarkers for Lung Cancer Bone Metastasis and Their Therapeutic Value

Lung cancer is the leading cause of cancer-related death worldwide. Bone metastasis, which usually accompanies severe skeletal-related events, is the most common site for tumor distant dissemination and detected in more than one-third of patients with advanced lung cancer. Biopsy and imaging play critical roles in the diagnosis of bone metastasis; however, these approaches are characterized by evident limitations. Recently, studies regarding potential biomarkers in the serum, urine, and tumor tissue, were performed to predict the bone metastases and prognosis in patients with lung cancer. In this review, we summarize the findings of recent clinical research studies on biomarkers detected in samples obtained from patients with lung cancer bone metastasis. These markers include the following: (1) bone resorption-associated markers, such as N-terminal telopeptide (NTx)/C-terminal telopeptide (CTx), C-terminal telopeptide of type I collagen (CTx-I), tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), pyridinoline (PYD), and parathyroid hormone related peptide (PTHrP); (2) bone formation-associated markers, including total serum alkaline phosphatase (ALP)/bone specific alkaline phosphatase(BAP), osteopontin (OP), osteocalcin (OS), amino-terminal extension propeptide of type I procollagen/carboxy-terminal extension propeptide of type I procollagen (PICP/PINP); (3) signaling markers, including epidermal growth factor receptor/Kirsten rat sarcoma/anaplastic lymphoma kinase (EGFR/KRAS/ALK), receptor activator of nuclear factor κB ligand/receptor activator of nuclear factor κB/osteoprotegerin (RANKL/RANK/OPG), C-X-C motif chemokine ligand 12/C-X-C motif chemokine receptor 4 (CXCL12/CXCR4), complement component 5a receptor (C5AR); and (4) other potential markers, such as calcium sensing receptor (CASR), bone sialoprotein (BSP), bone morphogenetic protein 2 (BMP2), cytokeratin 19 fragment/carcinoembryonic antigen (CYFRA/CEA), tissue factor, cell-free DNA, long non-coding RNA, and microRNA. The prognostic value of these markers is also investigated. Furthermore, we listed some clinical trials targeting hotspot biomarkers in advanced lung cancer referring for their therapeutic effects.

Development of Machine Learning Algorithms for Prediction of 30-Day Mortality After Surgery for Spinal Metastasis

BACKGROUND

Preoperative prognostication of short-term postoperative mortality in patients with spinal metastatic disease can improve shared decision making around end-of-life care.

OBJECTIVE

To (1) develop machine learning algorithms for prediction of short-term mortality and (2) deploy these models in an open access web application.

METHODS

The American College of Surgeons, National Surgical Quality Improvement Program was used to identify patients that underwent operative intervention for metastatic disease. Four machine learning algorithms were developed, and the algorithm with the best performance across discrimination, calibration, and overall performance was integrated into an open access web application.

RESULTS

The 30-d mortality for the 1790 patients undergoing surgery for spinal metastatic disease was 8.49%. Preoperative factors used for prognostication were albumin, functional status, white blood cell count, hematocrit, alkaline phosphatase, spinal location (cervical, thoracic, lumbosacral), and severity of comorbid systemic disease (American Society of Anesthesiologist Class). In this population, machine learning algorithms developed to predict 30-d mortality performed well on discrimination (c-statistic), calibration (assessed by calibration slope and intercept), Brier score, and decision analysis. An open access web application was developed for the best performing model and this web application can be found here: https://sorg-apps.shinyapps.io/spinemets/.

CONCLUSION

Machine learning algorithms are promising for prediction of postoperative outcomes in spinal oncology and these algorithms can be integrated into clinically useful decision tools. As the volume of data in oncology continues to grow, creation of learning systems and deployment of these systems as accessible tools may significantly enhance prognostication and management.

Retrospective study on the efficacy of bisphosphonates in tyrosine kinase inhibitor-treated patients with non-small cell lung cancer exhibiting bone metastasis

Bisphosphonates (Bps) inhibit the maturation of osteoclasts and suppress the adhesion of cancer cells to the bone matrix. They are recommended as the standard treatment for tumors exhibiting bone metastasis (BM). However, whether Bps can improve the prognosis of patients with tyrosine kinase inhibitor (TKI)-treated non-small cell lung cancer (NSCLC) exhibiting BM remains unclear. A total of 129 patients with NSCLC initially diagnosed with BM at The First Affiliated Hospital of Sun Yat-Sen University (Guangzhou, China) between January 2005 and December 2017 were analyzed in the present retrospective study. Median progression free survival (mPFS) time, median bone metastasis overall survival (mBM-OS) time and bone-associated progression-free survival were analyzed. Among the 129 patients, patients treated with Bps experienced significantly prolonged PFS time [mPFS: 7.1 vs. 5.1 months; hazard ratio (HR), 0.51; confidence interval (CI), 0.30-0.87; P=0.0114] in comparison with patients not treated with Bps. Of the 49 patients treated with frontline TKIs (EGFR TKIs or ALK TKI), 32 received Bps at the same time, while 17 patients received TKIs alone. The results revealed that mPFS time was significantly greater in the TKIs plus Bps group than in the TKIs alone group (mPFS: 11.2 vs. 6.9 months; HR, 0.13; CI, 0.05-0.35; P<0.0001). Significantly prolonged BM-OS time was also observed in the combination group in comparison with the TKIs alone group (mBM-OS: 31 vs. 22 months; HR, 0.31; CI, 0.10-0.96; P=0.0413). The present study demonstrated that among the patients who received TKIs (EGFR TKIs or ALK TKIs), those who also received Bps experienced significantly longer PFS time and tended to exhibit significantly improved BM-OS time, which indicated that Bps should be added to the treatment regimen of patients with NSCLC exhibiting genetic mutations and bone metastasis who have been prescribed TKIs (EGFR TKIs or ALK TKIs).

Bone turnover markers and novel biomarkers in lung cancer bone metastases

CONTEXT

Lung cancer still remains the leading cause of cancer-related mortality worldwide. Bone is one of preferred metastatic sites for lung cancer cells. So far, both accurate diagnosis and effective treatment of lung cancer bone metastases are difficult.

OBJECTIVE

This review aimed to evaluate roles of bone turnover markers (BTMs), microRNAs (miRNAs), dickkopf1 (DKK1) and insulin like growth factor binding protein 3 (IGFBP-3) in lung cancer bone metastases.

METHODS

We searched articles about these four biomarkers in lung cancer bone metastases mainly in PubMed.

RESULT

The levels of bone specific alkaline phosphatase (BALP), cross-linked carboxy-terminal telopeptide of type-I collagen (ICTP) and N-terminal telopeptides of type-I collagen (NTX) were reported to be significantly increased in lung cancer patients with bone metastases. ALP, NTX and bone sialoprotein were thought to be associated with prognosis of lung cancer patients with bone metastases. MiRNA-335, miRNA-33a, miRNA-21, DKK1 and IGFBP-3 were revealed to be novel biomarkers in lung cancer bone metastases.

DISCUSSION AND CONCLUSION

Current researches have revealed that BTMs, miRNAs, DKK1 and IGFBP-3 may be useful in diagnosis, prognosis evaluation or treatment of lung cancer bone metastases. More studies about these biomarkers in lung cancer bone metastases are needed.

A meta-analysis survey of appropriate bone turnover markers in the detection of bone metastasis in lung cancer

BACKGROUND

A number of studies have investigated the clinical significance of bone turnover markers (BTMs) for the diagnosis of bone metastasis (BM) in lung cancer; however, they led to contradictory results. The aim of this meta-analysis was to investigate whether BTMs differ between lung cancer patients with and without BM.

METHODS

Articles were identified by searching Medline, Embase, Web of Science and Scopus. The studies that were identified were pooled and the weighted mean difference (WMD) and its corresponding 95% confidence interval (CI) were calculated. Subgroup analyses and publication bias detection were also conducted.

RESULTS

A final analysis of 1720 subjects (707 patients with BM and 1013 patients without BM) was performed from 16 cohort studies. From the pooled data in the meta-analysis, the total alkaline phosphatase (TALP) (104.35 U/l [95% CI 33.36-175.34]), bone-specific ALP (BALP) (13.24 μg/l [95% CI 8.50-17.98] or 6.84 U/l [95% CI 2.98-10.70]), C-terminal cross-linked telopeptide of type I collagen (ICTP) (5.07 μg/l [95% CI 3.58-6.56]) and N-terminal cross-linked telopeptide of type I collagen (NTX) (5.08 nM bone collagen equivalent/l [95% CI 2.82-7.33]) were significantly lower among BM patients than non-BM patients. Subgroup analyses detected that the serum level of tartrate-resistant acid phosphatase isoform 5b was significantly reduced in Caucasian patients with BM (-0.64 U/l [95% CI -1.02 to -0.25]), while increased in Asian patients with BM (2.69 U/l [95% CI 0.08-5.31]), compared to patients without BM.

CONCLUSIONS

The present meta-analysis suggested that serum measurement of TALP, BALP, ICTP and NTX might be helpful in detecting BM in lung cancer.

Radiological features of experimental staphylococcal septic arthritis by micro computed tomography scan

BACKGROUND

Permanent joint dysfunction due to bone destruction occurs in up to 50% of patients with septic arthritis. Recently, imaging technologies such as micro computed tomography (μCT) scan have been widely used for preclinical models of autoimmune joint disorders. However, the radiological features of septic arthritis in mice are still largely unknown.

METHODS

NMRI mice were intravenously or intra-articularly inoculated with S. aureus Newman or LS-1 strain. The radiological and clinical signs of septic arthritis were followed for 10 days using μCT. We assessed the correlations between joint radiological changes and clinical signs, histological changes, and serum levels of cytokines.

RESULTS

On days 5-7 after intravenous infection, bone destruction verified by μCT became evident in most of the infected joints. Radiological signs of bone destruction were dependent on the bacterial dose. The site most commonly affected by septic arthritis was the distal femur in knees. The bone destruction detected by μCT was positively correlated with histological changes in both local and hematogenous septic arthritis. The serum levels of IL-6 were significantly correlated with the severity of joint destruction.

CONCLUSION

μCT is a sensitive method for monitoring disease progression and determining the severity of bone destruction in a mouse model of septic arthritis. IL-6 may be used as a biomarker for bone destruction in septic arthritis.

Bone metastases in lung cancer. Potential novel approaches to therapy

The skeleton is a common site of metastases in lung cancer, an event associated with significant morbidities and poor outcomes. Current antiresorptive therapies provide limited benefit, and novel strategies of prevention and treatment are urgently needed. This review summarizes the latest advances and new perspectives on emerging experimental and clinical approaches to block this deleterious process. Progress propelled by preclinical models has led to a deeper understanding on the complex interplay of tumor cells in the osseous milieu, unveiling potential new targets for drug development. Improvements in early diagnosis through the use of sophisticated imaging techniques with bone serum biomarkers are also discussed in the context of identifying patients at risk and monitoring disease progression during the course of treatment.

Diagnostic value of bone-specific alkaline phosphatase in lung carcinoma patients with bone metastases: a meta-analysis

Aim and Backgrounds: The accurate diagnosis of lung carcinoma patients with bone metastases is crucial for therapy and the prevention of complications. We performed a systematic review and meta-analysis to evaluate the diagnostic value of serum bone-specific alkaline phosphatase (BALP) in lung carcinoma patients with bone metastases.

METHODS

Such databases as PubMed, Embase, Cochrane Library, Web of Science, Ovid, BioMed Central, Biosis previews and four Chinese databases (Chinese Biomedical Literature Database-disc (CBM), Chinese National Knowledge Infrastructure (CNKI), Technology of Chongqing (VIP) and Wan Fang DATA) were retrieved on computer, and the relevant journals were also manually searched to collect the trials on BALP in diagnosis of lung carcinoma patients with bone metastases. The meta-analysis was conducted by using Meta-Disc 1.4 software.

RESULTS

A total of 8 studies were included, and there were 848 lung carcinoma patients diagnosed by gold standard, patients were divided into two groups: 419 cases with bone metastases and 429 cases without bone metastases. The meta-analysis showed that, the pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) was 0.48 [95% CI (0.43 to 0.53)], 0.86 [95% CI (0.82 to 0.89)], 3.14 [95% CI (2.47 to 3.99)], 0.62 [95% CI (0.56 to 0.68)], 6.66 [95% CI (4.62 to 9.60)] respectively. And the AUC of SROC was 0.78, (Q*=0.72).

CONCLUSION

BALP has greater diagnostic value in detecting lung carcinoma patients with bone metastases. However, further large scale studies are required to confirm the predictive value.

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 turnover markers in serum and urine as diagnostic, prognostic and monitoring biomarkers of bone metastasis

Bone metastases are characterized by increased osteoblastic and/or osteolytic processes depending on the tumor type. The altogether destructive effect of metastasis formation promoted by increased metabolic activity raises the release of components from the osseous metabolism into the blood stream. These components are either enzymes directly involved in the alteration processes, metabolites/proteins that develop during this or bone matrix proteins released during this. These biomarkers are categorized in relation to their involvement in the bone formation or resorption as bone formation and resorption markers. Based on a PubMed literature search, a critical appraisal of the various biomarkers for diagnostic, prognostic, and monitoring purposes is given for patients with skeletal metastases caused by breast, prostate, lung, or renal cell carcinomas.

Osteopontin genetic variants are associated with overall survival in advanced non-small-cell lung cancer patients and bone metastasis

PURPOSE

Osteopontin (OPN) plays important roles in the modulation of apoptosis, angiogenesis, immune response, and tumor invasion. Elevated osteopontin expression has been reported in the lung cancer tissues compared to counterpart normal tissues. This study examined whether genetic variations in the osteopontin gene are associated with survival of lung cancer patients and occurrence rate of bone metastasis.

EXPERIMENTAL DESIGN

Three hundred and sixty patients with stages I to IV between 2003 and 2007 were recruited in this study and same number of healthy persons were used as control. Three promoter osteopontin polymorphisms, OPN-66 T/G, -156G/GG, and -443C/T variants were genotyped using DNA from blood lymphocytes. Chi-square test and a Fisher's exact test were used to analyze the genotype distribution among TNM stages and incidence of bone metastasis and lymph mode metastasis. Kaplan-Meier method and log-rank test were used to compare survival by different genotypes.

RESULTS

For the variant at nt -443 (CC), there was a significant difference between the number of patients with stage IV and those with all other stages of lung cancer (p < 0.01). Patients with -443 (CC) variant had significant higher incidence of bone metastasis development compared to other genotypes. For the variant at nt -443 (CT), there was a significant difference between the number of lung cancer patients with stage III + IV and those with stage I + II (P < 0.01). The survival rates for patients with the C/C genotype were significantly lower than for patients with the other two genotypes (C/T, T/T).

CONCLUSION

OSTEOPONTIN -443C/T polymorphism is a potential predictive marker of survival in lung cancer patients, it is correlated with bone metastasis significantly.

Diagnostic and prognostic use of bone turnover markers

The use of bone turnover markers in oncology includes monitoring of anticancer treatment in patients with malignant disease metastatic to the bones (therapeutic monitoring), predicting the risk of bone relapse in patients with a first diagnosis of potentially curative, early-stage malignant tumors (prognostic use), and making an early diagnosis of (microscopic) malignant bone disease in patients with a known malignant tumor to start early bone-targeted treatment and avoid skeletal-related events (diagnostic use). Concerning prognostic use, there is limited evidence for bone turnover markers to predict the occurrence of metachronous bone metastases in patients with early-stage malignant tumors, with serum PINP (N-terminal propeptide of procollagen type 1), ICTP (Carboxyterminal cross-linked telopeptide of type I collagen), bone sialoprotein (BSP), and tumor immunoexpression of BSP being the most promising candidates. Concerning diagnostic use, serum bone-specific alkaline phosphatise (BSAP), PINP and osteoprotegerin (OPG) were repeatedly shown to be associated with synchronous bone metastases in patients with breast or lung cancer, but sensitivity of these markers was too low to suggest that they might be preferred over conventional bone scans for the diagnosis of bone metastases. A somewhat higher sensitivity for the diagnosis of bone metastases was found for urinary NTx (N-terminal cross-linked telopeptide of type I collagen) and serum ICTP in solid tumor patients, serum TRAcP-5b (Tartrate-resistant acid phosphatase type 5b) in patients with breast cancer and serum BSAP, PINP and OPG in prostate cancer patients. Both prognostic and diagnostic use of bone turnover markers are reviewed in this chapter.

Type I and III collagen degradation products in serum predict patient survival in head and neck squamous cell carcinoma

Cancer invasion induces extracellular matrix remodeling and collagen degradation. The aim of this study was to assess whether serum levels of type I and III collagen degradation products were associated with patient survival in head and neck squamous cell carcinoma (HNSCC). A novel enzyme immunoassay was developed for measuring type III collagen N-terminal telopeptide (IIINTP) in human serum samples. In addition, type I collagen C-terminal telopeptide (ICTP), matrix metalloprotease-8 (MMP-8) and tissue inhibitor of metalloproteases-1 (TIMP-1) were assessed in 205 blood samples from HNSCC patients. High levels of serum ICTP and IIINTP and plasma TIMP-1 were associated with poor survival. The concentration of ICTP was associated with levels of IIINTP and TIMP-1. The plasma concentration of MMP-8 was associated with tumor stage, but not with survival or levels of ICTP, IIINTP or TIMP-1 suggesting that other collagenases/proteases are responsible for the cleavage of type I and type III collagens. The rate of type I and type III collagen degradation is associated with patient survival and can be used as a prognostic marker in HNSCC.

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.

The role of whole-body FDG PET/CT, Tc 99m MDP bone scintigraphy, and serum alkaline phosphatase in detecting bone metastasis in patients with newly diagnosed lung cancer

Bone scan (BS) and serum alkaline phosphatase (ALP) concentration are used to detect bone metastasis in malignancy, although whole-body fluoro-D-glucose positron emission tomography computed tomography (FDG PET/CT) is being used increasingly. But BS is still used for the detection of metastatic bone lesion. So we compared the usefulness of PET/CT, BS, and serum ALP in detecting bone metastases in patients with newly diagnosed lung cancer. The medical record database was queried to identify all patients with a new diagnosis of lung cancer between January 2004 and December 2005, who had a PET/CT, BS, and serum ALP before treatment. We retrospectively reviewed all patients' records and radiological reports. One hundred eighty-two patients met the inclusion criteria. Bone metastases were confirmed in 30 patients. The sensitivity values were 93.3% for PET/CT, 93.3% for BS, 26.7% for serum ALP concentration, and 26.7% for BS complemented with serum ALP concentration. The respective specificity values were 94.1%, 44.1%, 94.1%, and 97.3%. The kappa statistic suggested a poor agreement among the three modalities. FDG PET/CT and BS had similar sensitivity, but PET/CT had better specificity and accuracy than BS. PET/CT is more useful than BS for evaluating bone metastasis. However, in the advanced stage, because of its high specificity, BS complemented with serum ALP is a cost-effective modality to avoid having to use PET/CT.

β-CTX and ICTP Act as Indicators of Skeletal Metastasis Status in Male Patients with Non-Small Cell Lung Cancer

Bone metastasis is common in lung cancer patients and associated with reduced quality of life and reduced overall and median survival, so the early detection of bone metastasis and monitoring of its status is very important for clinicians. Serum bone-specific alkaline phosphatase (BAP), osteocalcin (OC), β isomer of C-terminal telopeptide of type I collagen (β-CTX) and cross-linked C-terminal telopeptide of type I collagen (ICTP) were compared with regard to their usefulness as indicators of bone metastasis in lung cancer. The serum concentrations of the 4 markers were measured by commercially available tests in 96 male patients with non-small cell lung cancer and 30 male patients with other pulmonary diseases. The levels of both β-CTX and ICTP were significantly higher in 61 lung cancer patients with bone metastases than in 35 lung cancer patients without bone metastases (both p<0.001), and significantly correlated with the extent of bone disease. Although ICTP had a better sensitivity and accuracy than β-CTX (75.4% vs 65.6% and 72.9% vs 68.8%, respectively), they had a similar area under the receiver operating characteristic curve (0.85 vs 0.83). These results support the use of β-CTX and ICTP as an adjunct tool for the diagnosis and screening of bone metastasis in lung cancer.

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.

Bone markers and current laboratory assays

Metastasis of cancer to bone leads to significant alterations in normal bone remodelling that are reflected in changes in bone turnover markers. These markers are classically defined as markers of bone resorption or formation; markers of bone resorption are measures of osteoclastic activity, whereas markers of bone formation are measures of osteoblastic activity. Recently, there has been growing interest in the use of these markers in metastatic bone disease (MBD), and an increasing number of studies have investigated the potential use of these markers in diagnosis, monitoring of disease progression and treatment, and prediction of outcome. In this review, we briefly discuss the biology of bone metastases as well as describe the bone turnover markers and their possible role in aiding clinicians in the treatment of patients with MBD.

Human mesenchymal stem cell derived osteoblasts degrade organic bone matrix in vitro by matrix metalloproteinases

Some recent studies have suggested that cells of mesenchymal origin might participate in the organic bone matrix dissolution. In the present study, collagen synthesis and degradation by human mesenchymal stem cell (MSC) derived cells were studied at early stage of osteoblast differentiation using a special two-stage in vitro culture model. In this model, cells were cultured on bovine bone slices, which were first resorbed by osteoclasts. Synthesis of type I collagen was markedly enhanced when mesenchymal cells were cultured on bone matrix. After thorough osteoclast removal, MSC derived cells were capable of degrading the organic bone matrix, and caused a release of type I collagen degradation product (ICTP) into the culture medium. This was inhibited by matrix metalloproteinase (MMP) inhibitor, while cysteine proteinase inhibitor or estrogen had no inhibitory effect. Western blot analysis or gelatin zymography confirmed the presence of MMP-2, -8, -13 and -14, but not MMP-1 or -9, in the differentiated cells. 17beta-Estradiol was found to increase the expression of MMP-2 and -14 by these cells. Finally, scanning electron microscopy showed that the differentiating human MSCs were capable of degrading organic bone matrix remnants from the bottom of the resorption lacunae. These data support the hypothesis that collagen cleavage by the same cells that are subsequently responsible for bone formation is MMP mediated process and is an important step coupling bone formation into bone resorption.

Usefulness of bone metabolic markers in the diagnosis of bone metastasis from lung cancer

Bone metastasis is common in lung cancer patient and the diagnosis of bone metastasis is usually made by using imaging techniques, especially bone scintigraphy. However, the diagnostic yield from bone scintigraphy is limited. The aim of this study is to assess the clinical usefulness of urinary pyridinoline cross-linked N-telopeptides of Type I collagen (NTx), urinary deoxypyridinoline (DPD), and serum alkaline phosphatase (ALP) in the assessment of bone metastasis in patients with lung cancer. Urinary NTx, DPD, and serum ALP were measured in 151 lung cancer patients (33 with and 118 without bone metastasis). Lung cancer patients with bone metastasis had a higher urinary excretion of NTx and DPD, and a higher serum ALP than those without bone metastasis. NTx had a better receiver operating characteristic (ROC) curve than DPD and ALP, since the areas under the ROC curve were 0.82, 0.79, and 0.71, respectively. Although correlation coefficients among NTx, DPD and ALP were significantly positive (p < 0.005), the strongest relationship was appeared between NTx and DPD (R = 0.616). In conclusion, our results showed the utility of the new bone markers in detecting bone metastasis and suggested that measurement of urinary NTx was valid diagnostic method of bone metastasis from lung cancer.

The type I collagen fragments ICTP and CTX reveal distinct enzymatic pathways of bone collagen degradation

Bone resorption may generate collagen fragments such as ICTP and CTX, which can be quantified in serum and/or urine by using specific immunoassays, and which are used as clinical markers. However, the relative abundance of ICTP and CTX varies according to the type of bone pathology, suggesting that these two fragments are generated through distinct collagenolytic pathways. In this study, we analyzed the release of ICTP and CTX from bone collagen by the proteinases reported to play a role in the solubilization of bone matrix. Cathepsin K released large amounts of CTX, but did not allow a detectable release of ICTP. Conversely, the matrix metalloproteinases (MMPs) MMP-2, -9, -13, or -14 released ICTP, but did not allow a detectable release of CTX. Next we analyzed the release of ICTP and CTX from bone explants cultured in the presence of well-established inhibitors of these proteinases and of matrix solubilization. An inhibitor of cysteine proteinases including cathepsin K, inhibited the release of CTX, but not the release of ICTP. MMP inhibitors inhibited the release of ICTP, but also that of CTX, in agreement with the putative role of MMPs in the initiation of bone resorption in addition to matrix solubilization. Similarly the treatment of mice bearing bone metastasis with an MMP inhibitor led to a significant reduction of serum ICTP and CTX, and osteolytic lesions. We conclude that the generation of ICTP and CTX depends on different collagenolytic pathways. This finding may explain why these two markers may discriminate between different bone pathologies.

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.

Procollagen-derived biomarkers in malignant ascites of ovarian cancer. Independent prognosticators for progression-free interval and survival

OBJECTIVE

Matrix formation is a hallmark of solid tumor biology. Circulating antigens of structural matrix proteins should reflect this fact, yet are subject to systemic variables. We propose that if measured regionally, in a cancer-induced extravascular fluid pool such as malignant ascites of ovarian cancer, the same antigens retain their conceptual advantage as surrogate markers for tumor biology.

METHODS

In malignant ascites obtained at staging laparatomy of 35 women with ovarian cancer, the protein-normalized levels of the C-terminal propeptide of procollagen type I (pnPICP) and the N-terminal propeptide of procollagen type III (pnPIIINP) were determined. Using univariate and multivariate analysis, we examined these parameters, their (pnPIIINP/pnPICP) quotient, and clinical criteria (FIGO stage, age, residual tumor, histology, and tumor grade) for impact on progression-free interval and survival.

RESULTS

The absolute level of pnPIIINP was the single most powerful independent factor impacting on survival, its P value being distinctly below (P = 0.0005 vs 0.003) and its risk ratio distinctly above (15 vs 2.5) residual tumor after debulking surgery. The relative level of pnPIIINP, i.e. (pnPIIINP / pnPICP), impacted on the likelihood of recurrence even more than residual tumor. By Kaplan-Meier analysis, cutoff values for the absolute or relative pnPIIINP level significantly discriminated patients with shortened survival or progression-free interval, respectively.

CONCLUSIONS

Since malignant ovarian epithelium itself forms collagen type III, and since collagen type III is a solid-phase regulator of angiogenesis, we propose that ascitic pnPIIINP is a fluid-phase indicator for angiogenic activity in ovarian cancer and thus represents a tumor virulence index.

The bone scan flare phenomenon in non-small-cell lung cancer

PURPOSE

The bone scan flare phenomenon, defined as an increase in the number or intensity of bone lesions with subsequent improvement while the patient is receiving chemotherapy, has been described in solid tumors including breast cancers and small-cell lung cancers. The purpose of this study was to verify the existence of the bone scintigraphic flare phenomenon in patients with non-small-cell lung cancer (NSCLC) during chemotherapy and thus determine the utility of bone scintigraphy in the follow-up of these patients.

MATERIALS AND METHODS

Thirty-three patients with NSCLC with bone metastases and who had been treated with chemotherapy were included in the study. The outcome of bone scintigraphy was compared with that in other neoplastic sites.

RESULTS

The flare phenomenon was considered likely in 8 of the 33 patients. It was confirmed in two patients, invalidated in four, and remained doubtful in two.

CONCLUSIONS

The bone flare phenomenon occurs in NSCLC. It renders bone scintigraphy less useful in the evaluation of tumoral response in the patients in whom it is considered likely.

Usefulness of bone markers for detection of bone metastases in lung cancer patients

OBJECTIVES

Lung cancer commonly causes destructive bone metastases. The aim of this study was to compare efficiency of biochemical bone markers in the detection of bone metastases in lung cancer patients.

DESIGN AND METHODS

We measured serum calcium (Ca), alkaline phosphatase (ALP), bone isoenzyme of alkaline phosphatase (BALP), osteocalcin (OC) and urine deoxypyridinoline crosslinks (DPD) levels in 52 lung cancer patients; 27 patients with the evidence of bone metastases, 25 without metastases in bone when they were first diagnosed. BALP, OC and DPD were measured by specific immunoassays. ALP, Ca and urine creatinine levels were determined by colorimetric methods.

RESULTS

Ca, ALP, BALP, OC and DPD levels were significantly higher in the patients with bone metastases than those without bone metastases (p < 0.01 for BALP and OC, p < 0.001 for Ca, ALP and DPD). The sensitivity and specificities of all markers as follows: 89%-44% for BALP, 52%-88% for OC, 81%-76% for DPD, respectively. ROC curves were generated separately for BALP, OC and DPD to assess the diagnostic efficiency of markers in a different manner. DPD showed the best curve characteristics among the studied bone markers, followed by the BALP curve. OC curve showed poor characteristics.

CONCLUSIONS

Our results suggest that the measurement of DPD and BALP may be useful in detecting bone metastases in lung cancer patients. Also it could help in the follow-up of bone metastases from lung cancer since they can be repeated more often than roentgenography and bone scintigraphy, at less cost and with less discomfort to the patients.

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.

Estrogen reduces the depth of resorption pits by disturbing the organic bone matrix degradation activity of mature osteoclasts

Decreased E2 levels after menopause cause bone loss through increased penetrative resorption. The reversal effect of E2 substitution therapy is well documented in vivo, although the detailed mechanism of action is not fully understood. To study the effects of E2 on bone resorption, we developed a novel in vitro bone resorption assay in which degradation of inorganic and organic matrix could be measured separately. E2 treatment significantly decreased the depth of resorption pits, although the area resorbed was not changed. Electron microscopy further revealed that the resorption pits were filled with nondegraded collagen, suggesting that E2 disturbed the organic matrix degradation. Two major groups of proteinases, matrix metalloproteinases (MMPs) and cysteine proteinases, have been suggested to participate in organic matrix degradation by osteoclasts. We show here that MMP-9 released a cross-linked carboxyl-terminal telopeptide of type I collagen from bone collagen, and cathepsin K released another C-terminal fragment, the C-terminal cross-linked peptide of type I collagen. E2 significantly inhibited the release of the C-terminal cross-linked peptide of type I collagen into the culture medium without affecting the release of cross-linked carboxyl-terminal telopeptide of type I collagen in osteoclast cultures. These results suggest that organic matrix degradation is initiated by MMPs and continued by cysteine proteases; the latter event is regulated by E2.

Increased incidence of bone metastases in hepatocellular carcinoma

OBJECTIVES

Recently, we often encounter hepatocellular carcinoma patients with bone metastases. We therefore examined the changes in the incidence of bone metastases in hepatocellular carcinoma from 1978 to 1997 and tried to identify the characteristic clinical features. We also discuss the reasons for the increased incidence of bone metastasis in hepatocellular carcinoma.

METHODS

A total of 673 patients with hepatocellular carcinoma during the period 1978-1997 were studied. Bone metastasis was screened by bone scintigraphy, and bone lesions were confirmed by plain radiography, computed tomography and/or magnetic resonance imaging. The serum levels of the C-terminal telopeptide of type 1 collagen, which represent osteoclastic bone resorption, were also measured.

RESULTS

The incidence of bone metastasis during the decade 1988-1997 was significantly higher than that during the period 1978-1987. The median survival time of patients with hepatocellular carcinoma during 1988-1997 was also significantly longer than that during 1978-1987. Portal thrombus was found in about half of the patients with bone metastases. The most common site of bone metastases was the vertebra followed by the pelvis, rib and skull in that order. All bone lesions depicted by plain radiograph, computed tomography and/or magnetic resonance imaging were of the osteolytic type, and the serum levels of C-terminal telopeptide of type 1 collagen were significantly elevated in the patients with bone metastases.

CONCLUSIONS

The increased incidence of bone metastasis in hepatocellular carcinoma in the decade 1988-1997 is first attributed to the prolonged survival rate of hepatocellular carcinoma patients due to recent progress in both the diagnosis and treatment of the disease. Dissemination of hepatocellular carcinoma cells to the vertebra through the portal vein-vertebral vein plexuses due to the presence of portal thrombus and/or portal hypertension may be related to a higher incidence of bone metastasis in hepatocellular carcinoma. Both an early diagnosis and timely treatment of bone metastases are thus called for in the follow-up of hepatocellular carcinoma patients.

Serum level of the periostin, a homologue of an insect cell adhesion molecule, as a prognostic marker in nonsmall cell lung carcinomas

BACKGROUND

Periostin protein shares structural and sequence homology with fasciclin I, which is an insect adhesion molecule. Periostin has a typical signal peptide at the N-terminal end, which suggests that it is a secreted protein. Recently, the authors developed a novel sandwich chemiluminescence assay to determine serum concentrations of periostin.

METHODS

The authors investigated the serum periostin level in lung carcinoma patients and attempted to determine the influence of serum periostin level on clinical outcome for patients with nonsmall cell lung carcinoma (NSCLC) who had undergone surgery between January 1994 and July 1996. Expression of periostin messenger RNA was also examined by in situ RNA hybridization for lung carcinomas.

RESULTS

The periostin gene was shown to be highly expressed at the tumor periphery of lung carcinoma tissue but not within the tumor by in situ RNA hybridization. Serum periostin levels were not significantly different between the NSCLC patients (1142.1 +/- 89.2 ng/mL) and the normal control (962.0 +/- 118.6 ng/mL) (P = 0.2985). There was no relation between serum periostin level and gender, stage, bone metastasis, N status, or T status. However, the serum periostin levels of NSCLC patients had decreased significantly by 4 weeks after the resection of the tumor. The NSCLC patients with high periostin level (> 962 ng/mL) had significantly poorer survival than the patients with normal periostin level (P = 0.0406). Using the Cox proportional hazards regression model, the authors found that stage (P < 0.0001) and serum periostin level (P = 0.0226) were independent prognostic factors.

CONCLUSIONS

The in situ RNA hybridization data from the current study suggested that expression of periostin may be involved in tumor invasionand that the serum periostin level may serve as a prognostic marker for NSCLC.

Diagnostic value of bone-turnover metabolites in the diagnosis of bone metastases in patients with lung carcinoma

BACKGROUND

Several biochemical markers of bone formation and bone resorption have been developed recently. The authors evaluated the usefulness of new biomarkers, such as urinary deoxypyridinoline (D-PYD), serum pyridinoline cross-linked C-telopeptides of Type I collagen (1CTP), and urinary pyridinoline cross-linked N-telopeptides of Type I collagen (NTx), in the assessment of bone metastases in patients with lung carcinoma.

METHODS

The serum concentrations of 1CTP and the urinary concentrations of D-PYD and NTx were measured in 100 lung carcinoma patients, of whom 20 patients had bone metastases and 80 patients did not. Receiver operating characteristic (ROC) curves were drawn for these markers to compare their usefulness in detecting bone metastases originating in lung carcinoma.

RESULTS

Urinary concentrations of NTx in patients with bone metastases were significantly greater than in patients without bone metastases (147.1 +/- 129.3 pmol bone collagen equivalents [BCE]/micromol Cr vs. 47.2 +/- 29.9 pmol BCE/micromol Cr; P < 0.0001). Urinary concentrations of D-PYD in patients with bone metastases also were significantly greater than in patients without bone metastases (10.0 +/- 3.6 BCE/micromol Cr vs. 6.6 +/- 2.2 pmol BCE/micromol Cr; P = 0.0001). No significant difference was observed in serum concentrations of 1CTP between patients with and without bone metastases. A moderate but significant correlation was seen between NTx and D-PYD (correlation coefficient [R] = 0.435; P < 0.0001) and between D-PYD and 1CTP (R = 0.525; P < 0.0001). NTx had a better ROC curve than D-PYD and 1CTP (the areas under the ROC curve were 0.84, 0.79, and 0.62, respectively). Using the threshold of 62.5 pmol BCE/micromol Cr for NTx, sensitivity, specificity, and accuracy were 0.800, 0.737, and 0.750, respectively.

CONCLUSIONS

In the current study, the measurement of NTx appeared to be most useful as a marker of bone metastases in patients with lung carcinoma.

Prediction of disease progression in early rheumatoid arthritis by ICTP, RF and CRP. A comparative 3-year follow-up study

OBJECTIVE

To test the predictive value of the cross-linked carboxyterminal telopeptide of type I collagen (ICTP; a marker of type I collagen degradation), rheumatoid factor (RF) and C-reactive protein (CRP) for disease progression in patients with early rheumatoid arthritis (RA) METHOD: We tested the value of baseline values of RF, CRP and ICTP for the prediction of radiological joint progression over 3 yr in 63 consecutive patients with early RA who were treated with the 'saw-tooth strategy'.

RESULTS

Age- and sex-adjusted risks as odds ratios (95% confidence intervals) of elevated serum ICTP, RF positivity and increased CRP for progressive joint disease (defined as an increase of > 20 in Larsen's index on radiographs of the hands and feet) were 3.9 (1.3, 11.9), 3.9 (1.0, 15.5) and 2.6 (0.9, 7.5), respectively. Better prediction was achieved when the tests were used in combination, and where there was both elevated ICTP and positive RF the odds ratio was 9.1 (2.5, 32.9). This test combination showed good sensitivity and specificity (71 and 77%, respectively), with a positive predictive value of 65% and a likelihood ratio of 3.1.

CONCLUSION

This kind of risk profile, in which the tests used reflect different aspects of the disease process, may be useful in early disease assessment to find patients who will need the most active drug therapy.

Immunochemical characterization of assay for carboxyterminal telopeptide of human type I collagen: loss of antigenicity by treatment with cathepsin K

The assay for the cross-linked carboxyterminal telopeptide of type I collagen (ICTP) has been shown to reflect increased type I collagen degradation in such pathological conditions as bone metastases and rheumatoid arthritis, but to be rather insensitive to the changes in physiological bone collagen turnover (e.g., induced by estrogen or bisphosphonate treatment). To determine the reasons for this discrepancy we localized the antigenic determinant recognized by the ICTP assay and studied the effects of two major osteoclastic proteinases, cathepsin K (EC 3.4.22.38) and matrix metalloproteinase-9 (MMP-9; gelatinase B; EC 3.4.24.35), on immunoreactivity. The antigenic determinant was shown to reside within the hydrophobic phenylalanine-rich regions of the carboxyterminal telopeptides of the two alpha1 chains of human type I collagen, situated between the triple helical domain and the lysine-derived trivalent cross-link. This conclusion was based on differences between the amino acid sequences and cross reactivities of the corresponding human and bovine antigens before and after proteolytic treatments with chymotrypsin. A trivalent cross-link is necessary for providing such a structure, because the divalently cross-linked and monomeric natural and synthetic peptides from the same region, but containing only one phenylalanine-rich sequence, showed poor immunoreaction. Recombinant human cathepsin K cleaved the trivalently cross-linked ICTP structure at two sites between the phenylalanine-rich region and the cross-link, destroying the reactivity with ICTP antibodies. On the contrary, the treatment of isolated ICTP by the matrix metalloproteinases MMP-9 (gelatinase B), MMP-1 (collagenase 1), or MMP-13 (collagenase 3) had no effect on the immunoreaction. Our results indicate that the increased circulating concentrations of ICTP found in several clinical situations are most likely produced by matrix metalloproteinases, whereas cathepsin K-mediated, osteoclastic bone resorption destroys ICTP antigenicity.

Bone metastasis after a resection of stage I and II primary lung cancer

In the present study, we reviewed the patients who developed bone metastases after a surgical resection of primary lung cancer and evaluated their clinicopathological features. From 1992 to 1995, 177 patients with stage I and II primary lung cancer underwent a surgical resection at the Kitakyushu Municipal Medical Center. Bone metastases were detected in 14 patients (7.9%) by follow-up examinations including bone scintigraphy (scan). Bone metastasis was one of the most frequent extra-thoracic recurrent forms. Patients with adenocarcinoma tended to develop bone metastases more frequently than those with squamous cell carcinoma. In the preoperative bone scans, an abnormal uptake was observed in 76 patients (42.9%), and 10 (13.1%) of them were found to develop bone metastases in the follow-up studies. A microscopic examination of the primary tumor demonstrated close correlation between intratumoral and peritumoral lymphatic vessel invasion and postoperative development of bone metastases. A bone scan is a very useful and indispensable procedure for diagnosing bone metastases. However, this scan may also show false positive finding in a number of benign conditions. Therefore, a surgical resection should be considered as the first-line treatment for patients with positive findings in the bone scan when the diagnosis of bone metastasis can not be confirmed based on both their symptoms and other clinical examinations.