PYRIDINOLINE CROSS-LINKED CARBOXYTERMINAL TELOPEPTIDE OF TYPE I COLLAGEN AS A USEFUL MARKER FOR MONITORING METASTATIC BONE ACTIVITY IN MEN WITH PROSTATE CANCER

Estimation of Levels of Salivary Pyridinoline Cross-Linked Carboxyterminal Telopeptide of Type I Collagen (ICTP) in Periodontally Healthy and Diseased Patients at Various Time Intervals Before and After Periodontal Therapy

INTRODUCTION

The bacterial plaque in the tooth-supporting tissues is the main cause of inflammatory conditions called periodontal diseases. Thus, the aim of this study is to determine the levels of intercellular matrix protein (ICTP) in patients with gingivitis and periodontitis and those who are periodontally healthy, both before and after treatment at different times.

MATERIALS AND METHODS

Thirty clinical parameters (bleeding on probing, probing pocket depth, and clinical attachment loss) were measured at baseline, one month, three months, and six months after the patients were divided into three groups of 60.

RESULTS

There was a significant difference between the two groups at all time intervals; the difference at one month was 34.77 (p=0.000). At three months, the difference became 31.25 (p=0.000) which increased to 36.62 (p=0.000) at six months.

CONCLUSION

When periodontal deterioration occurs, ICTP levels are higher, and when they are reduced, periodontal health is demonstrated.

Bone alkaline phosphatase as a surrogate marker of bone metastasis in gastric cancer patients

Background

Bone metastasis is relatively uncommon in gastric cancer patients, but its incidence has been rising. Early detection of bone metastasis is important in preventing complications related to bone metastasis such as pain, fracture and the compromise of chemotherapy. In this pilot study, we investigated the feasibility of bone turnover markers as surrogate markers of bone metastasis in gastric cancer patients.

Methods

Fifty-eight patients with gastric cancer were included in this study. Serum levels of bone alkaline phosphatase (ALP), parathyroid hormone (PTH), 25(OH) D, osteocalcin (OC) and C terminal telopeptide were measured and compared between patients with bone metastasis and those without. Student’s t-test and Mann-Whitney U test were used in comparing two groups, and Spearman’s rank order correlation coefficient was calculated to quantify the strength of the associations.

Results

Fifty eight age- and sex-matched patients were evaluated for bone turnover markers, among whom 29 patients had bone metastasis and 29 patients with no bone metastasis. The median age was 62 and there were 20 (68.9 %) males and 9 (31.1 %) females in each group. Bone ALP was significantly higher in the patient group (57.32 ± 46.83 vs. 34.57 ± 21.57, P = 0.037) than control group. Bone ALP was positively associated with ALP, osteocalcin, CA19-9, CA 72–4 and negatively associated with 25(OH) D. According to ROC-curve analysis, at the threshold value of 29.60 μg/L, the sensitivity of bone ALP was 76.7 % and the specificity was 59.4 %.

Conclusion

Bone ALP may be a surrogate marker of bone metastasis in gastric cancer patients. More prospective studies are warranted to determine the optimal bone turnover markers in the evaluation of bone metastasis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2415-x) contains supplementary material, which is available to authorized users.

Clinical usefulness of bone markers in prostate cancer with bone metastasis

Bone metastases occur in approximately 70% of patients with advanced prostate cancer. Skeletal-related events have been correlated with reduced survival and quality of life of patients with prostate cancer. Biochemical markers of bone metabolism (e.g. bone formation, bone resorption, osteoclastogenesis) might meet an unmet need for useful, non-invasive and sensitive surrogate information for following patients' skeletal health. Recently, zoledronic acid and denosumab have been proven to have the potential for preventing skeletal-related events among prostate cancer patients with bone metastasis. An improved understanding of the mechanisms underlying bone metastasis has also led to the recognition of multiple molecular targets and advances in therapy. However, estimating the efficacy of these agents is difficult. A clinical trial for castration-resistant prostate cancer is currently underway based on the definition of The Prostate Cancer Clinical Trials Working Group, and bone turnover markers are being used as conventional end-points for the clinical trial. Bone turnover markers are useful surrogate markers reflecting the effect of new therapeutic drugs and prognosis, as well as assessment of bone metastases. In particular, N-terminal cross-linked telopeptide of type 1 collagen and bone-specific alkaline phosphatase are widely used bone metabolism markers, and offer reliable surrogate markers to detect bone metastatic spread and to predict prognosis for prostate cancer patients with bone metastases.

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.

Implications of serum bone turnover markers in prostate cancer patients with bone metastasis

OBJECTIVES

To assess the diagnostic accuracy of serum bone turnover markers for detection of bone metastasis in patients with prostate cancer (PCa) and to assess the usefulness of these markers as predictors of mortality from PCa.

METHODS

Serum total alkaline phosphatase, bone-specific alkaline phosphatase, carboxy-terminal pyridinoline cross-linked telopeptide parts of type-I collagen (1CTP), tartrate-resistant acid phosphatase type 5 b, and prostate-specific antigen (PSA) levels were measured in 222 patients (58 with bone metastasis, 57 with T2M0 PCa, 55 with T3M0 PCa, and 52 without PCa). Multivariate stepwise logistic regression analysis was used to identify independent predictors of bone metastasis. Correlation of serum marker levels with bone metastasis was assessed using receiver operating characteristics analysis. Multivariate Cox proportional hazards analysis was used to predict cause-specific survival in PCa patients with bone metastasis.

RESULTS

Serum total alkaline phosphatase, bone-specific alkaline phosphatase, 1CTP, tartrate-resistant acid phosphatase type 5 b, and PSA levels were significantly elevated in patients with bone metastasis, and correlated significantly with the extent of disease on bone scintigraphy. Multivariate stepwise logistic regression analysis demonstrated that serum PSA and 1CTP were significant predictors of bone metastasis. Receiver operating characteristics analyses showed that serum 1CTP level was the most reliable predictor of bone metastasis (area under the curve = 0.85). Multivariate Cox proportional hazards analysis revealed that only serum 1CTP was an independent prognostic factor for PCa-related death.

CONCLUSIONS

Serum 1CTP level was a more reliable marker than the others to detect bone metastatic spread and to predict survival probability in PCa patients with bone metastasis.

GM-CSF Gene-Modifed Cancer Cell Immunotherapies: Of Mice and Men

GVAX cancer immunotherapies are composed of whole tumor cells genetically modified to secrete the immune stimulatory cytokine, granulocyte-macrophage colony-stimulating factor (GM-CSF), and then irradiated to prevent further cell division. Both autologous (patient specific) and allogeneic (non-patient specific) GVAX platforms have been evaluated either as single agents or in combination with other immunomodulatory strategies. Many early-phase clinical trials have now been completed. Results have consistently demonstrated a favorable safety profile manifested primarily by injection site reactions and flu-like symptoms. Consistent evidence of immune activation and clinical activity, including radiologic tumor regressions, has been seen across multiple cancer indications in both early- and late-stage disease. Phase 3 trials evaluating an allogeneic GVAX immunotherapy product in prostate cancer are under way.

The significance of carboxy-terminal telopeptide of type I collagen (ICTP) and osteocalcin (OC) in assessment of bone disease in patients with multiple myeloma

Bone disease occurring in multiple myeloma is usually evaluated using radiological methods. These methods, however, provide not much information about the dynamic process of bone resorption and formation. This study analysed levels of serum markers of bone turnover (ICTP and OC), reflecting function of osteoclasts and osteoblasts. It demonstrates increased level of ICTP in 75 patients with MM compared to control group (8 persons) and patients with Waldenström's macroglobulinemia (10 persons). The level of ICTP was also higher in patients with more advanced bone disease and probably in higher stage of disease according to Salmon and Durie classification. This tendency was not observed in relation to OC. Result of the research confirms that ICTP may incur sensitive and specific markers of bone lesions in multiple myeloma.

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

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

Granulocyte macrophage colony-stimulating factor--secreting allogeneic cellular immunotherapy for hormone-refractory prostate cancer

PURPOSE

This trial evaluated the safety, clinical activity, and immunogenicity of an allogeneic cellular immunotherapy in 55 chemotherapy-naïve patients with hormone-refractory prostate cancer (HRPC). The immunotherapy, based on the GVAX platform, is a combination of two prostate carcinoma cell lines modified with the granulocyte macrophage colony-stimulating factor (GM-CSF) gene.

EXPERIMENTAL DESIGN

HRPC patients with radiologic metastases (n = 34) or rising prostate-specific antigen (PSA) only (n = 21) received a prime dose of 500 million cells and 12 boost doses of either 100 million cells (low dose) or 300 million cells (high dose) biweekly for 6 months. End points were changes in PSA, time to progression, and survival.

RESULTS

Median survival was 26.2 months (95% confidence interval, 17, 36) in the radiologic group: 34.9 months (8, 57) after treatment with the high dose (n = 10) of immunotherapy and 24.0 months (11, 35) with the low dose (n = 24). The median time to bone scan progression in the radiologic group was 5.0 months (2.6, 11.6) with the high dose and 2.8 months (2.8, 5.7) with the low dose. In the rising-PSA group (n = 21) receiving the low dose, the median time to bone scan progression was 5.9 months (5.6, not reached), and median survival was 37.5 months (29, 56). No dose-limiting or autoimmune toxicities were seen; the most common adverse events were injection site reaction and fatigue.

CONCLUSIONS

These results suggest that this GM-CSF-secreting, allogeneic cellular immunotherapy is well tolerated and may have clinical activity in patients with metastatic HRPC. Phase 3 trials to confirm these results are under way.

Serum bone turnover markers (PINP and ICTP) for the early detection of bone metastases in patients with prostate cancer: a longitudinal approach

PURPOSE

An increase in bone turnover markers in patients with prostate cancer may predict bone metastases but it can also reflect the effects of androgen deprivation treatment. To assess the diagnostic efficacy of early detection of skeletal metastases we retrospectively performed serial measurements of a bone formation marker (PINP) and a bone resorption marker (ICTP) in serum of patients with prostate cancer.

MATERIALS AND METHODS

Residual serum samples from 64 patients with prostate cancer treated between 1999 and 2004 were selected from our prostate specific antigen serum archive, and divided into 3 groups of patients with no metastases (N0M0), with lymph node metastases only (N1M0) and with skeletal metastases (M1). In the M1 group the T(1) sample was collected near the first positive bone scintigraph.

RESULTS

The N1M0 and M1 groups showed increased PINP levels (ANOVA T(0) p = 0.035, T(1) p <0.001). The PINP levels in the M1 group increased further (paired t test p = 0.028), while no increase was found in the other groups. There was no significant difference between the number of patients receiving androgen deprivation therapy in the N1M0 and the M1 groups. Increased PINP levels in the M1 group were detectable 8 months before the first positive bone scintigraph. The increase in ICTP in the M1 group differed significantly from the other groups (the Student t test in 45 patients p = 0.029). The increases in PINP and ICTP differentiated between patients with or without skeletal metastases (AUC 0.71, p = 0.002 and AUC 0.64, p = 0.045, respectively).

CONCLUSIONS

Followup measurement of serum PINP and ICTP is useful in the early assessment of skeletal metastases in patients with prostate cancer regardless of the confounding role of androgen deprivation treatment. The bone formation marker is the most indicative.

Palliative Treatment of Bone Metastases in Hormone-Refractory Prostate Cancer: Effects of Pamidronate on the Carboxyterminal Telopeptide of Type-I Collagen Level in Patients with Increasing Prostate-Specific Antigen Levels

PURPOSE

Bisphosphonates have been reported to be effective in reducing bone pain and skeletal-related events associated with bone metastases in hormone-refractory prostate cancer (HRPC). However, whether bone resorption is reduced primarily by these particular drugs is difficult to evaluate because patients with HRPC are usually treated with secondary or tertiary hormonal manipulations including second-line antiandrogens, high-dose diethylstilbestrol, or low-dose dexamethasone therapies, some of which may also be effective. Thus, we assessed changes in the level of the carboxyterminal telopeptide of type-I collagen (ICTP), a bone resorption marker, before and after pamidronate administration in HRPC patients with increasing prostate-specific antigen (PSA) levels.

PATIENTS AND METHODS

Twenty-one HRPC patients with bone metastases and increasing PSA levels were intravenously treated with pamidronate at a dose of 30 mg either every 2 or every 4 weeks. Pamidronate administration was started immediately after confirmation of three consecutive increases in the PSA level.

RESULTS

In 14 patients (67%), the ICTP levels decreased after the administration of pamidronate, despite increasing PSA levels. In 7 of these cases, the ICTP levels were lower than those recorded for 6 months or longer before the start of pamidronate administration. The characteristics of the responders were compared with those of the non-responders.

CONCLUSION

In 67% of the HRPC patients with increasing PSA levels, pamidronate reduced the accelerated turnover of bone metabolism caused by metastases of prostate cancer.

Diagnosis of Bone Metastasis in Men with Prostate Cancer by Measurement of Serum ICTP in Combination with Alkali Phosphatase and Prostate-specific Antigen

AIMS

Carboxy-terminal telopeptide of type I collagen (ICTP) is a parameter of bone absorption, and has recently been introduced to monitor bone metastases. The aim of this retrospective study was to investigate the potential of ICTP as a candidate serum marker of bone metastasis in prostate cancer.

MATERIALS AND METHODS

Serum markers in 155 men pathologically diagnosed with prostate cancer were measured. The serum levels of ICTP, prostate-specific antigen (PSA), and alkali phosphatase (ALP) were compared to assess the extent of disease (EOD) scores from bone scans and then analysed statistically.

RESULTS

The serum ICTP levels were not well correlated with the EOD scores in the total group of men, men newly diagnosed with prostate cancer, or men previously diagnosed with prostate cancer who were followed up. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of ICTP (cut-off value, 5.0 ng/ ml) of the men newly diagnosed with prostate cancer were 78.6%, 88.0%, 78.6%, and 88.0%, respectively. In these men, the specificity and PPV of ALP (cut-off value, 335 IU/l) were 100%, whereas the sensitivity and NPV of PSA (cut-off value, 40 ng/ml) were 100% in this study. The serum levels of ICTP in the men with low ALP (< 335 IU/l) and high PSA (> or = 40 ng/ ml) clearly separated the men with or without bone metastasis, as judged by bone scans.

CONCLUSION

We found that the ICTP is not a superior serum marker for bone metastases compared with ALP or PSA. Our study suggests, however, that the ICTP measurement is useful in a certain subset of men with the combination of PSA and ALP in distinguishing men with bone metastasis from those without.

Natural history and treatment of bone complications in prostate cancer

Bone metastases are highly prevalent in patients with prostate cancer, and they commonly present a therapeutic challenge. The natural history of prostatic bone metastases is characterized by skeletal morbidity, often producing distressing symptoms for individual patients and reducing patient autonomy and mobility. These bone metastases are usually radiologically osteoblastic, but there is also a strong osteolytic component as evidenced by marked increases in bone resorption markers. Malignant bone lesions can reduce the structural integrity of the skeleton, resulting in skeletal complications such as pathologic fracture, spinal cord compression, and severe bone pain, which adversely affect quality of life. Preclinical and clinical studies have provided insight into the pathophysiology of malignant bone disease from prostate cancer and suggest that bone-directed therapies, including radionuclides, endothelin-1 antagonists, and bisphosphonates, may provide both palliative and therapeutic benefits. Clinical investigations with these agents are underway in patients with prostate cancer to gain insight into the pathophysiology of bone metastases and to evaluate the role of bone-specific therapies in treating and preventing bone metastases.

Prognostic value of serum markers for prostate cancer

The incidence of prostate cancer has increased dramatically during the last 10-15 years and it is now the commonest cancer in males in developed countries. The increase is mainly caused by the increasing use of opportunistic screening or case-finding based on the use of prostate-specific antigen (PSA) testing in serum. With this approach, prostate cancer is detected 5-10 years before giving rise to symptoms and on average 17 years before causing the death of the patient. While this has led to detection of prostate cancer at a potentially curable stage, it has also led to substantial overdiagnosis, i.e. detection of cancers that would not surface clinically in the absence of screening. A major challenge is thus to identify the cases that need to be treated while avoiding diagnosing patients who will not benefit from being diagnosed and who will only suffer from the stigma of being a cancer patient. It would be useful to have prognostic markers that could predict which patients need to be diagnosed and which do not. Ideally, it should be possible to measure these markers using non-invasive techniques, i.e. by means of serum or urine tests. As it is very useful for both early diagnosis and monitoring of prostate cancer, PSA is considered the most valuable marker available for any tumor. Although the prognostic value of PSA is limited, measurement of the proportion of free PSA has improved the identification of patients with aggressive disease. Furthermore, the rate of increase in serum PSA reflects tumor growth rate and prognosis but, due to substantial physiological variation in serum PSA, reliable estimation of the rate of PSA increase requires follow-up for at least 2 years. Algorithms based on the combined use of free and total PSA and prostate volume in logistic regression and neural networks can improve the diagnostic accuracy for prostate cancer, and assays for minor subfractions of PSA and other new markers may provide additional prognostic information. Markers of neuroendocrine differentiation are useful for the monitoring of androgen-independent disease and various bone markers are useful in patients with metastatic disease.

Clinical use of markers of bone turnover in metastatic bone disease

Bone metastases profoundly perturb normal bone remodeling. Biochemical markers of bone turnover have been shown to reflect these tumor-induced changes in bone remodeling and might therefore be useful in the diagnosis and follow-up of patients with malignant bone disease. Most markers of bone turnover, particularly those of bone resorption, are elevated in patients with established bone metastases. While this might indicate a role for bone markers as diagnostic tools in cancer patients, the available evidence does not provide any final conclusions as to the accuracy and validity of the markers presently used in the early diagnosis of bone metastases. Markers of bone resorption respond promptly and profoundly to bisphosphonate and antineoplastic therapy, and this response is associated with a favorable clinical outcome. Most markers, however, have been more useful in groups of patients monitored in clinical studies than in studies of individuals. While this makes them a good tool for drug development, it remains unknown whether the use of bone markers in a routine clinical setting has any defined beneficial effects on overall outcome in cancer patients. In particular, no study has addressed the question of whether patients with bone metastases should be treated according to their rate of bone turnover and what the treatment goals are in this respect. While it is unlikely that bone-turnover markers have sufficient diagnostic or prognostic value when used in isolation, the combination of these markers with other diagnostic techniques might be the way forward to improve the clinical assessment of patients with cancers of the bone.

Innovations in serum and urine markers in prostate cancer current European research in the P-Mark project

An overview is given of serum and urine prostate cancer markers that are currently under investigation and subsequently the P-Mark project is introduced. There are many markers showing promise to overcome the limitations of prostate specific antigen (PSA). Eventually, these markers should be able to increase the specificity in diagnosis, differentiate between harmless and aggressive disease and identify progression towards androgen independence at an early stage. In the P-Mark project, several recently developed, promising markers will be evaluated using clinically well-defined biorepositories. Following successful evaluation, these markers will be validated on a sample set derived from two large, European, prostate cancer studies and used for the identification of special risk groups in the general population. In addition, novel markers will be identified in the same biorepositories by different mass spectrometry techniques.

Immunological monitoring during combination of patient-oriented peptide vaccination and estramustine phosphate in patients with metastatic hormone refractory prostate cancer

BACKGROUND

Additive antitumor effects could be achieved by combination of immunotherapy and cytotoxic agents with no or minimum suppression.

METHODS

Thirteen patients positive for human leukocyte antigen (HLA)-A24 or -A2 with metastatic hormone refractory prostate cancer (HRPC) who had failed to respond to the prior-peptide vaccination were entered in the combined peptide vaccination and estramustine phosphate. Conducted immune monitoring on those 13 patients were mainly peptide-specific cytotoxic T lymphocyte (CTL) precursor analysis by IFN-gamma productions and peptide-reactive IgG by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Grade 3 arrhythmia or cerebral infarction was observed in two cases, and Grade 1 or 2 dermatologic reaction at the vaccination sites was observed in all 13 cases. Eleven patients who received more than one cycle of treatment were eligible for immunological and clinical evaluation. There was no significant immunosuppression in most cases when the peptide and a half dose (280 mg/day) of estramustine were administrated, whereas severe immunosuppression was observed in the first two patients who received both the peptide and a full dose (560 mg/day) estramustine. Augmentation of peptide-specific CTL precursors or peptide-specific IgG was observed in 6 of 11 or 10 of 11 cases, respectively. Ten of 11 patients showed serum prostate-specific antigen (PSA) level decrease from the baseline including 8 patients with a serum PSA level decrease of > or =50%.

CONCLUSIONS

These results encouraged the further evaluation of the combination of peptide vaccination and low-dose estramustine phosphate for metastatic HRPC patients.

Osteoporosis in men with prostate carcinoma receiving androgen-deprivation therapy: recommendations for diagnosis and therapies

BACKGROUND

Androgen-deprivation therapy (ADT) is prescribed with increasing frequency for men with prostate carcinoma. There is growing concern about the effects of such therapy on the skeleton. In the current review, the authors addressed the current research, diagnostic methods, and treatment recommendations for bone loss and osteoporosis in men with prostate carcinoma who received ADT.

METHODS

Data were obtained from electronic literature searches (for the years 1986 through 2002) and from abstracts and meeting proceedings. All randomized and nonrandomized clinical trials, retrospective studies, and cross-sectional studies of osteoporosis in men with prostate carcinoma who received ADT with or without other therapies were reviewed.

RESULTS

The findings confirmed that ADT resulted in significant bone loss in men with prostate carcinoma. Bone mineral density (BMD) of the hip, as measured by dual-energy X-ray absorptiometry (DXA), is considered the preferred site of assessment in older men. Spinal BMD is equally important, although careful interpretation of spinal DXA values is required, because of coexisting facet joint disease and extravertebral calcification. Osteoporosis is diagnosed when BMD is > 2.5 standard deviations below a reference mean. Men with prostate carcinoma who were treated with ADT had average BMD measurements below those of eugonadal men. Rates of bone loss ranged from 2% to 8% in the lumbar spine and from 1.8% to 6.5% in the femoral neck during the initial 12 months of continuous ADT. Retrospective data indicated an increased risk of fracture in men with prostate carcinoma who were treated with ADT.

CONCLUSIONS

For men with prostate carcinoma who are at high risk for osteoporosis and fractures, clinical management should be dictated by the results of radiographic and DXA skeletal assessment.

Clinical review 165: Markers of bone remodeling in metastatic bone disease

Many cancers have a strong propensity to spread to bone. The processes involved in cancer dissemination to bone are complex and variable, and the changes in bone metabolism, once bony metastases have occurred, are usually profound. This review surveys the usefulness of bone markers in the diagnosis and follow-up of patients with malignant bone disease. In patients with established bone metastases, most markers of bone remodeling are abnormal compared with healthy controls or cancer patients without bone lesions. Although bone markers may have a potential as diagnostic tools in cancer patients, the available data do not allow final conclusions regarding the accuracy and validity of any of the presently used markers in the diagnosis of bone metastases. As regards monitoring of anticancer therapy, most markers of bone remodeling respond to active treatments. These indices therefore may have the potential to be used in the monitoring of antitumor therapies. However, most if not all of the available evidence on the use of bone markers in monitoring anticancer therapy is observational, and it remains unclear whether they have any beneficial effects on overall outcome. The same is true for their prognostic value, although evidence suggests that suppressed levels of bone formation or high rates of bone resorption are independent predictors of poor survival.

Bone remodeling markers in the detection of bone metastases in prostate cancer

BACKGROUND

Early detection of bone metastases in prostatic carcinoma is very useful in treatment and prognosis of the disease. The aim of this work was to evaluate the sensitivity and specificity of a group of bone markers in order to discriminate between prostate carcinoma patients without (M(0)) and with (M(1)) bone metastases.

METHODS

Sixty-seven non-treated patients with: benign prostate hyperplasia (n=21), prostatic carcinoma in several stages without bone metastases (T(X)M(0)) (n=31) and with bone metastases (T(X)M(1)) (n=15) were studied. The following markers were studied: (A) bone formation: (1) serum bone alkaline phosphatase, IRMA (Tandem Ostase, Beckman); (2) serum procollagen I amino-terminal propeptide (PINP), RIA (Orion Diagnostica); (B) bone resorption: (1) urinary collagen I amino-terminal telopeptide (NTX), ELISA (Ostex); (2) collagen I carboxy terminal telopeptide (CTX): (2A) urinary alpha-CTX, RIA (Osteometer), (2B) serum beta-CTX, Elecsys (Roche); (3) collagen I cross-linked carboxy terminal telopeptide (ICTP), RIA (Orion Diagnostica).

RESULTS

Levels of all bone markers were significantly higher in group M(1) than in group M(0). A complete separation of groups M(0) and M(1) was achieved with PINP and beta-CTX (100% sensitivity and specificity).

CONCLUSIONS

These results support the use of PINP or beta-CTX as a tool to confirm the presence or absence of bone metastases in the first staging of prostatic carcinoma patients.

Serum levels of bone turnover markers parallel the results of bone scintigraphy in monitoring bone activity of prostate cancer

OBJECTIVES

To investigate the usefulness of bone turnover markers as a modality for monitoring bone metastasis in patients with prostate cancer with bone metastasis.

METHODS

Serial measurements of pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), carboxyterminal pro-peptide of type I procollagen (PICP), prostate-specific antigen (PSA), and the percentage of the positive area on the bone scan were prospectively performed before and after hormonal therapy in 84 patients with prostate cancer with bone metastasis for median follow-up of 29 months.

RESULTS

Serial ICTP and PICP levels in 48 patients without progression of bone metastasis demonstrated a downward trend during treatment and were almost within the normal range by the end of follow-up. The remaining 36 patients, who had PSA failure with progression of bone metastasis, showed an upward trend for serial ICTP and PICP levels before the progression of bone metastasis. The rates of detecting bone progression using bone turnover markers were higher than those using PSA levels on the basis of the percentage of clinical effectiveness and receiver operating characteristic curves.

CONCLUSIONS

Serial measurement of bone turnover markers is useful for monitoring the bone activity of prostate cancer and might detect early progression of bone metastasis in patients with PSA failure.

Cathepsin K mRNA and protein expression in prostate cancer progression

Prostate cancer (CaP) is the most commonly diagnosed malignancy in men and is often associated with bone metastases, which cause much of the morbidity associated with CaP. Lesions associated with CaP generally exhibit increased bone formation and resorption. Increased bone resorption may release factors from the extracellular matrix that contribute to tumor growth. Cathepsin K (cat K) is a cysteine protease that exhibits strong degradative activity against the extracellular matrix and is involved in osteoclast-mediated bone destruction. In this study, we analyzed the expression of cat K in CaP cell lines and patient samples. Cat K message was detected in CaP cell lines by reverse transcription-polymerase chain reaction (RT-PCR) and in primary CaP and metastases by in situ hybridization. Immunohistochemistry revealed variable expression of cat K in primary CaP samples, as well as nonosseous metastases, whereas expression in bone metastases was significantly higher than in primary CaP, and normal prostate tissues were negative. Cat K protein was detected in CaP cell lines by Western blotting after immunoprecipitation. Cat K enzymatic activity was also detected in CaP cell lines by a fluorogenic assay and by an assay for degradation of collagen type I. Increased levels of NTx, a marker of bone matrix degradation mediated primarily by cat K, were also detected in sera of patients with CaP bone metastases. We hypothesize that CaP-expressed cat K may contribute to the invasive potential of CaP, while increased expression in bone metastases is consistent with a role in matrix degradation.

Percentage of the positive area of bone metastasis is an independent predictor of disease death in advanced prostate cancer

We addressed in this study whether quantifying the extent of disease on bone scans can predict the disease death of patients with advanced prostate cancer using computer-assisted image analysis. Pretreatment radionuclide bone scans were reviewed in 56 patients with bone metastases from prostate cancer, and the percentage of the positive area on a bone scan (%PABS) was quantified automatically using a personal computer with the NIH Image program for estimation of the accurate extent of metastatic bone lesions on a bone scan. The significance of the %PABS as well as the other known prognostic factors was evaluated using univariate and multivariate Cox proportional hazards analysis. In univariate regression analysis, the %PABS (P=0.0155), serum alkaline phosphatase (P=0.0272), the tumour grade based on biopsy (P=0.044) and the number of bone lesions on bone scans (P=0.0388) were well associated with disease-specific survival. In multivariate analysis, the %PABS (P=0.0155, relative risk ratio 2.603), but not the other factors, was the independent predictor of the disease death. These results suggest that the %PABS is a novel parameter for predicting the prognosis of patients with advanced prostatic cancer.

Collagen turnover in bone diseases

PURPOSE OF REVIEW

The primary aim of this review is to highlight recent advances in techniques available for assessing collagen turnover, particularly in relation to the diagnosis and management of bone disorders. As collagen is the major protein constituent of bone, its metabolites form the basis of most of the biochemical markers, but their efficacy needs to be viewed in the context of other non-collagenous markers, for which methodology is also advancing rapidly.

RECENT FINDINGS

New markers of bone metabolism have been developed utilising the age-dependent isomerisation and racemisation of aspartyl residues at the C-terminal end of collagen. These methods allow measurement of the ratio between newly synthesised and mature collagen: this ratio appears to provide a novel indicator of the fracture risk for osteoporosis. Other studies have led to an improved understanding of biological variability, particularly in relation to the effects of feeding. Bone resorption assays have been applied to a wide range of diseases and have been especially useful in monitoring the efficacy of novel therapies.

SUMMARY

New assays have been developed to facilitate better monitoring of collagen metabolism in bone diseases. A more complete understanding of biological variability, particularly the effects of feeding, have led to improved clinical applicability of these assays in detecting disease and monitoring therapy. Part of the future challenge, however, is to ensure that commercial assay developments keep pace with clinical expectations.