Association of 12 serum biochemical markers of angiogenesis, tumour invasion and bone turnover with bone metastases from breast cancer: a crossectional and longitudinal evaluation

Diagnostic value of alkaline phosphatase and bone-specific alkaline phosphatase for metastases in breast cancer: a systematic review and meta-analysis

PURPOSE

Numerous studies had reported the diagnostic value of alkaline phosphatase (ALP) and its bone-specific isoforms (BAP) in the metastases of breast cancer (BC). The purpose of this meta-analysis was to summarize the diagnostic value of serum ALP and BAP in metastatic BC, especially focused on bone metastases.

METHODS

We searched comprehensively in the PubMed, Cochrane Library, and EMBASE for studies to explore the diagnostic accuracy of serum ALP/BAP level for metastatic BC. Qualities of including studies were assessed and pooled sensitivity, specificity, and summary receiver operating characteristic curve were calculated. Publication bias was assessed and meta-regression was conducted.

RESULTS

We finally included 25 studies with a total of 12,155 BC patients (1681 metastatic cases and 10,474 controls). According to the QUADAS-2 tool to assessment the methodological quality, most of the included studies were judged as high risk of patient selection bias. High serum levels of ALP/BAP in bone metastatic BC patients could be found compared with non-metastatic BC patients. The pooled sensitivity and specificity of ALP for BC bone metastases were 0.62 and 0.86, and the area under the curve (AUC) was 0.80. The pooled sensitivity and specificity of ALP for all site metastases (mainly bone and liver) were 0.56 and 0.91, and the AUC was 0.90. The pooled sensitivity and specificity of BAP for BC bone metastases were 0.66 and 0.92, and the AUC was 0.89.

CONCLUSION

Although not promising, serum ALP and BAP could bring useful information for the early detection of BC metastases especially for the bone metastases.

Causal relationships between serum matrix metalloproteinases and estrogen receptor-negative breast cancer: a bidirectional mendelian randomization study

To better clarify the causal effects between matrix metalloproteinases (MMPs) and estrogen-receptor (ER)-negative breast cancer (BC), we investigated the bidirectional causal relationship between MMPs and ER-negative BC by mendelian randomization (MR) analysis. Summary statistic data of five MMPs were extracted from European participants in 13 cohorts. Data of ER-negative BC collected from one of genome-wide association studies of European ancestry was used as experimental datasets and another four ER-negative BC datasets were used as validation sets. Inverse variance weighted method was used for main MR analysis and sensitivity analysis was also conducted. Serum level of MMP-1 has negative effect on ER-negative BC (odds ratio = 0.92, P = 0.0008) but the latter one was not the cause of the former one, which was supported by validation sets. No bidirectional causal effect was detected between the other four types of MMPs and ER-negative BC (P > 0.05). Sensitivity analysis indicated robustness of the above results without remarkable bias. To conclude, serum MMP-1 may be a protective factor against ER-negative BC. No reciprocal causality was found between the other kinds of MMPs and ER-negative BC. MMP-1 was indicated as a biomarker for risk of ER-negative BC.

Prognostic value of alkaline phosphatase and bone-specific alkaline phosphatase in breast cancer: A systematic review and meta-analysis

Numerous studies have reported the clinical value of alkaline phosphatase (ALP) and its bone-specific isoforms (bone-specific alkaline phosphatase (BAP)) in breast cancer. The purpose of this meta-analysis was to summarize the prognostic value of serum ALP and BAP in breast cancer, especially focused on bone metastasis and survival. PRISMA guidelines were followed to conduct this review. Observational studies were searched in PubMed, Cochcrane Library and EMBASE to January 1, 2022. Data were extracted to explore the prognostic value of ALP and BAP. The quality of the included studies was assessed and the outcome effects were evaluated. Subgroup and sensitivity analyses were performed to explore the potential sources of heterogeneity. Publication bias was assessed. There was a total of 53 studies with 22,436 patients included. For the primary outcome of survival, high levels of both ALP and BAP were associated with short survival time. The hazard ratio of high ALP level on overall survival was 1.72 (95% CI 1.37, 2.16, P < 0.001). For the secondary outcomes, a high ALP level (not BAP) was detected in breast cancer compared with healthy controls, and high levels of both ALP and BAP were risk factors for bone metastasis, while ALP (not BAP) was a risk factor for non-bone metastasis. This study showed that high levels of both serum ALP and BAP were associated with metastasis (BAP was associated with bone metastasis) and survival in breast cancer. The biomarkers could provide useful information for the early diagnostic assessment and monitoring in the follow-up of breast cancer patients.

Landscape Analysis of Matrix Metalloproteinases Unveils Key Prognostic Markers for Patients With Breast Cancer

Breast cancer (BRCA) is the most common cancer in the world, of which incidence rate and mortality are the highest in women. Being responsible for the remodeling and degradation of extracellular matrix proteins, matrix metalloproteinases (MMPs) have been regarded as one of the most important protease family related to tumorigenesis. It has been demonstrated that MMPs play crucial roles in some tumor invasion and metastasis. However, the potential roles of MMPs in tumorigenesis and progression of BRCA and its subtype remain elusive. Herein, we conducted a systematic study on MMPs via a series of database-based retrospective analysis, including TCGA, R Studio, GEPIA, Kaplan-Meier Plotter, cBioPortal, STRING, GeneMANIA and TIMER. As a result, many MMP family members were differentially expressed in patients with BRCA, e.g., the expressions of MMP1, MMP9, MMP11 and MMP13 were up-regulated, whereas the expression levels of MMP19 and MMP28 were down-regulated. MMP9, MMP12, MMP15 and MMP27 were significantly correlated with the clinical stages of BRCA, implying their important roles in the occurrence and development of BRCA. In addition, the survival analysis indicated that different expression pattern of MMPs exhibited distinct outcomes in patient with BRCA, e.g., patients with high expression of MMP2, MMP8, MMP16, MMP17, MMP19, MMP20, MMP21, MMP24, MMP25, MMP26 and MMP27 had a prolonged survival time, while the others (MMP1, MMP7, MMP9, MMP12 and MMP15) exhibited poor prognosis. Subsequent functional and network analysis revealed MMPs were mainly correlated with parathyroid hormone synthesis and secretion pathway, collagen metabolism, and their effect on the activities of serine hydrolase, serine peptidase and aminopeptidase. Notably, our analysis showed that the expression of MMPs was significantly correlated with the infiltration of various immune cells in BRCA, including CD8+T cells, CD4+T cells, macrophages, neutrophils, B cells, and dendritic cells, suggesting the close correlations between MMPs and immune functions. In short, our study disclosed MMPs play multiple biological roles in the development of BRCA, MMP1 and MMP9 might be used as independent prognostic markers and potential therapeutic targets for diagnosis and treatment for patients with BRCA.

Dendrimer-based micelles with highly potent targeting to sites of active bone turnover for the treatment of bone metastasis

Bone-drug targeting therapies using nanoparticles based on targeting ligands remain challenging due to their uptake clearance at non-target sites such as the liver, kidney, and spleen. Furthermore, the distribution sites of nanoparticles in bones have not been fully investigated, thus halting the development of more effective bone metastasis treatment strategies. In this study, we developed nanoparticles self-assembled from cholesterol-terminated, polyethylene glycol-conjugated, aspartic acid (Asp)-modified polyamidoamine dendrimer (Asp-PAMAM-Micelles) with targeting to active bone turnover sites associated with bone metastasis pathogenesis. On analysis through whole-body single photon emission computed tomography/computed tomography (SPECT/CT) imaging, ¹¹¹In-Asp-PAMAM-Micelles showed high specificity to active bone turnover sites (especially the joints in the lower limbs, shoulder, and pelvis) after intravenous injection in mice. The lower limb bone uptake clearance for ¹¹¹In-Asp-PAMAM-Micelles encapsulating paclitaxel (PTX) was 3.5-fold higher than that for ¹¹¹In-unmodified PAMAM-Micelles (PTX). ³H-PTX encapsulated Asp-PAMAM-Micelles effectively accumulated in the lower limb bones in a similar manner as the ¹¹¹In-Asp-PAMAM-Micelles (PTX). In a bone metastatic tumor mouse model, the tumor growth in the lower limb bones was significantly inhibited by injection of Asp-PAMAM-Micelles (PTX) compared to unmodified PAMAM-Micelles (PTX). Our results demonstrate that Asp-PAMAM-Micelles are sophisticated drug delivery systems for highly potent targeting to active bone turnover sites.

Clinical value of serum bone resorption markers for predicting clinical outcomes after use of bone modifying agents in metastatic bone tumors: A prospective cohort study

Bone modifying agents (BMAs) have become a standard treatment to prevent skeletal-related events (SREs) in bone metastases (BMs). The aim of our study is to determine the clinical value of serum bone resorption markers for predicting clinical outcomes after using BMAs in patients with BM. Patients were enrolled between May 2013 and October 2017 at the Nagoya University Hospital, Japan. We prospectively observed changes in pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) and tartrate-resistant acid phosphatase 5b (TRACP-5b) during treatment with BMAs. The relationship between serum markers before and after treatment and clinical outcomes such as progression of bone disease (BD), SREs and overall survival (OS) were evaluated. Pearson chi-square test and Kaplan-Meier product limit methods were used for analysis. Sixty-seven patients were analyzed. The primary tumor sites were 21 lung, 16 breast and 30 others. Forty and 27 patients were treated with Denosumab and Zoledronic acid, respectively. Progression of BDs, SREs and death were observed in 10, 16 and 31 cases, respectively. The median follow-up period after using BMAs was 12.3 (range 0.3-66.3) months. ICTP at 3-4 weeks was significantly correlated with increasing BD progression, SREs and death after treatment in both the whole and lung cancer cohorts. Base line ICTP and TRACP-5b were also associated with increasing BD progression in the whole cohort. Our study showed that early posttreatment ICTP is useful for predicting BD progression, SREs and OS after use of BMAs in patients with BM and even in patients with lung cancer BM.

Use of CTX-I and PINP as bone turnover markers: National Bone Health Alliance recommendations to standardize sample handling and patient preparation to reduce pre-analytical variability

The National Bone Health Alliance (NBHA) recommends standardized sample handling and patient preparation for C-terminal telopeptide of type I collagen (CTX-I) and N-terminal propeptide of type I procollagen (PINP) measurements to reduce pre-analytical variability. Controllable and uncontrollable patient-related factors are reviewed to facilitate interpretation and minimize pre-analytical variability.

INTRODUCTION

The IOF and the International Federation of Clinical Chemistry (IFCC) Bone Marker Standards Working Group have identified PINP and CTX-I in blood to be the reference markers of bone turnover for the fracture risk prediction and monitoring of osteoporosis treatment. Although used in clinical research for many years, bone turnover markers (BTM) have not been widely adopted in clinical practice primarily due to their poor within-subject and between-lab reproducibility. The NBHA Bone Turnover Marker Project team aim to reduce pre-analytical variability of CTX-I and PINP measurements through standardized sample handling and patient preparation.

METHODS

Recommendations for sample handling and patient preparations were made based on review of available publications and pragmatic considerations to reduce pre-analytical variability. Controllable and un-controllable patient-related factors were reviewed to facilitate interpretation and sample collection.

RESULTS

Samples for CTX-I must be collected consistently in the morning hours in the fasted state. EDTA plasma is preferred for CTX-I for its greater sample stability. Sample collection conditions for PINP are less critical as PINP has minimal circadian variability and is not affected by food intake. Sample stability limits should be observed. The uncontrollable aspects (age, sex, pregnancy, immobility, recent fracture, co-morbidities, anti-osteoporotic drugs, other medications) should be considered in BTM interpretation.

CONCLUSION

Adopting standardized sample handling and patient preparation procedures will significantly reduce controllable pre-analytical variability. The successful adoption of such recommendations necessitates the close collaboration of various stakeholders at the global stage, including the laboratories, the medical community, the reagent manufacturers and the regulatory agencies.

抗酒石酸酸性磷酸酶在恶性肿瘤中的研究进展

抗酒石酸酸性磷酸酶(type 5 acid phosphatase/tartrate-resistant acid phosphatase, ACP5/TRACP/TRAP)是酸性磷酸酶家族中的金属蛋白酶, 是骨吸收和破骨细胞活性的良好标志物. 近来发现ACP5在多种肿瘤中的表达比配对正常组织中的表达显著上调, 该现象提示, ACP5可能肿瘤的发生发展中起到一定的作用.

Tricetin inhibits human osteosarcoma cells metastasis by transcriptionally repressing MMP-9 via p38 and Akt pathways

Tricetin, a dietary flavonoid, has cytostatic properties and anti-metastasis activities in various cancer cells. However, the detailed impacts and underlying mechanisms of tricetin on human osteosarcoma cell metastasis are still unclear. Here, the hypothesis that tricetin possesses the anti-metastatic effects on human osteosarcoma cells was tested. The effects of tricetin on cell viability, motility, migration, and invasion in human osteosarcoma U2OS and HOS cells were investigated. Gelatin zymography, western blotting, polymerase chain reaction (PCR), and the luciferase assay were used to further explore the underlying mechanisms involved in anti-metastatic effects in U2OS cells. Their results showed that Tricetin, up to 80 μM without cytotoxicity, attenuated U2OS and HOS cells motility, invasiveness, and migration by reducing matrix metalloproteinase (MMP)-9 enzyme activities. In U2OS cells, tricetin decreased MMP-9 protein and mRNA expressions, which was confirmed by real-time PCR. Next, tricetin reduced phosphorylation of p38 and Akt, but no effect on phosphorylation of ERK1/2 and JNK. In conclusion, tricetin possesses the anti-metastatic activity of osteosarcoma cells by transcriptionally repressing MMP-9 via p38 and Akt signaling pathways. This may be potentially useful as anti-metastatic agents for osteosarcoma chemotherapy.

Plasma Levels and Diagnostic Utility of Macrophage Colony-Stimulating Factor, Matrix Metalloproteinase-9, and Tissue Inhibitor of Metalloproteinases-1 as New Biomarkers of Breast Cancer

Background

Macrophage colony-stimulating factor (M-CSF), matrix metalloproteinase-9 (MMP-9), and its specific tissue inhibitor - tissue inhibitor of metalloproteinases-1 (TIMP-1) may play an important role in the pathogenesis and spread of cancer. We investigated the plasma levels of M-CSF, MMP-9, and TIMP-1 in comparison with a commonly accepted tumor marker CA 15-3 in breast cancer patients and in control groups.

Methods

The cohort included 110 breast cancer patients in groups at stages I-IV. The control group consisted of 50 healthy volunteers and 50 benign tumor patients. Plasma levels of M-CSF, MMP-9, and TIMP-1 were determined by using ELISA, while CA 15-3 concentrations were determined by using chemiluminescent microparticle immunoassay (CMIA).

Results

The results showed significant differences in concentrations of the analyzed parameters and in levels of CA 15-3 between the groups of breast cancer patients and the two control groups. Diagnosis using these markers was equal to that using CA 15-3 in terms of sensitivity, predictive values of positive and negativetest results (PPV, NPV) and area under the ROC curve (AUC) in the studied groups. The diagnostic specificities of MMP-9, TIMP-1, M-CSF, and CA 15-3 showed equally high values (95%). The combined use of all tested parameters with CA 15-3 resulted in increased sensitivity, NPV, and AUC, especially in the combination of M-CSF with tumor markers (76%, 64%, and 0.8653).

Conclusions

These findings suggest the tested parameters are useful in the diagnosis of breast cancer patients (except stage I), when combined with CA 15-3.

The effects of lung and prostate cancer bone metastasis on serum osteoprotegerin levels: a meta-analysis

Bone metastasis leads to skeletal-related events in final-stage cancer patients. The incidence of prostate and lung cancers increases yearly; these cancers readily invade the bone. Some recent studies have found that serum osteoprotegerin (OPG) levels may be altered in patients with bone metastasis, whereas other reports have produced inconsistent findings. Hence, we conducted a meta-analysis to examine the effects of lung and prostate cancer on serum OPG levels. A systematic literature search was conducted using PubMed, Medline, and CNKI to identify relevant studies. A total of 11 studies were included. The standardized mean difference (SMD) and 95% confidence interval (95% CI) of the bone metastasis (BM) group, the non-bone metastasis (BM-) group and healthy controls were calculated. In prostate cancer, serum OPG levels in the BM group were higher than in the BM- group and healthy controls. Additionally, no significant difference in serum OPG levels was found between the BM- group and healthy controls. In lung cancer, serum OPG levels in the BM and BM- groups were significantly increased compared with healthy controls. However, no significant difference in serum OPG levels was found between the BM and BM- groups. Studies with larger sample sizes are required to confirm these findings.

Positron emission tomography of tumour [(18)F]fluoroestradiol uptake in patients with acquired hormone-resistant metastatic breast cancer prior to oestradiol therapy

PURPOSE

Whereas anti-oestrogen therapy is widely applied to treat oestrogen receptor (ER) positive breast cancer, paradoxically, oestrogens can also induce tumour regression. Up-regulation of ER expression is a marker for oestrogen hypersensitivity. We, therefore, performed an exploratory study to evaluate positron emission tomography (PET) with the tracer 16α-[(18)F]fluoro-17β-oestradiol ((18)F-FES) as potential marker to select breast cancer patients for oestradiol therapy.

METHODS

Eligible patients had acquired endocrine-resistant metastatic breast cancer that progressed after ≥2 lines of endocrine therapy. All patients had prior ER-positive histology. Treatment consisted of oestradiol 2 mg, three times daily, orally. Patients underwent (18)F-FES-PET/CT imaging at baseline. Tumour (18)F-FES-uptake was quantified for a maximum of 20 lesions and expressed as maximum standardised uptake value (SUVmax). CT-scan was repeated every 3 months to evaluate treatment response. Clinical benefit was defined as time to radiologic or clinical progression ≥24 weeks.

RESULTS

(18)F-FES uptake, quantified for 255 lesions in 19 patients, varied greatly between lesions (median 2.8; range 0.6-24.3) and between patients (median 2.5; range 1.1-15.5). Seven (37%) patients experienced clinical benefit of oestrogen therapy, eight progressed (PD), and four were non-evaluable due to side effects. The positive and negative predictive value (PPV/NPV) of (18)F-FES-PET for response to treatment were 60% (95% CI: 31-83%) and 80% (95% CI: 38-96%), respectively, using SUVmax >1.5.

CONCLUSION

(18)F-FES-PET may aid identification of patients with acquired antihormone resistant breast cancer that are unlikely to benefit from oestradiol therapy.

Alterations in enhancer of zeste homolog 2, matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 expression are associated with ex vivo and in vitro bone metastasis in renal cell carcinoma

Renal cell carcinoma (RCC) has a high potential for bone metastasis; however, the molecular mechanisms underlying this metastasis have remained to be elucidated. The present study aimed to explore the expression levels of enhancer of zeste homolog 2 (EZH2), matrix metalloproteinase-2 (MMP2) and tissue inhibitor of metalloproteinase-2 (TIMP2) as determinants of RCC-associated bone metastasis. Their expression was evaluated in a newly generated RCC cell subline that has a high potential for bone metastasis, in tissue specimens from metastasized bone tissues from patients with RCC and in RCC tissues without metastasis. A total of 25 RCC tissue specimens without metastasis and 13 RCC tissue specimens with bone metastasis were acquired for immunohistochemical analysis of EZH2, MMP2 and TIMP2 protein expression. The expression levels of EZH2, MMP2 and TIMP2 mRNA and protein were analyzed in the ACHN and ACHN-BO5 cell lines using western blot and reverse transcription polymerase chain reaction (PCR) analyses. Methylation-specific PCR was also used to analyze TIMP2 promoter methylation. EZH2 and MMP2 proteins were found to be expressed at higher levels in tissues from patients where RCC had metastasized to the bone as compared with those in RCC patients without metastasis, whereas there was no significant difference in the expression of TIMP2 protein between the two tissues. Furthermore, the expression of EZH2 protein was correlated with MMP2 expression, but there was no significant correlation between the expression of EZH2 and TIMP2 proteins. The in vitro results using cell lines confirmed the ex vivo findings, indicating that the expression levels of EZH2 and MMP2 protein and mRNA were higher in ACHN-BO5 cells than those in ACHN cells. By contrast, TIMP2 protein and mRNA expression levels were lower in ACHN-BO5 cells than those in the parental ACHN cells. The TIMP2 promoter was highly methylated in ACHN-BO5 cells compared with that in ACHN cells. Upregulation of EZH2, MMP2 and TIMP2 expression was correlated with metastasis of RCC to bone tissues ex vivo and in vitro. Further studies are required in order to elucidate the mechanism underlying the altered expression of these genes.

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.

Heparinoids activate a protease, secreted by mucosa and tumors, via tethering supplemented by allostery

Activation by glycosaminoglycans (GAGs) is an emerging trend among extracellular proteases important in disease. ProMMP-7, the zymogen of a matrix metalloproteinase secreted by mucosal epithelial and tumor cells, is activated at their surfaces by sulfated GAGs, but how? ProMMP-7 is activated in trans by representative heparin oligosaccharides in a length-dependent manner, with a large jump in activation at lengths of 16 monosaccharides. Imaging by atomic force microscopy visualized small complexes of proMMP-7 molecules linked by 8-mer lengths of heparinoids and extended assembles formed with 16-mer lengths of heparin. Complexes of proMMP-7 with polydisperse heparin or heparan sulfate were more diverse. Heparinoids evidently accelerate activation by tethering multiple proMMP-7 molecules together for proteolytic attack among neighbors. Removal of either the prodomain or C-terminal peptide sequence of KRSNSRKK from MMP-7 prevents formation of the long arrays induced by heparin 16-mers or heparan sulfate. The role of the C-terminus in activation assays suggests it contributes to remote, allosteric binding of GAGs. Enhancement of proteolytic velocity of MMP-by GAGs indicates them to be effectors of V-type allostery. GAGs from proteoglycans appear to assemble proMMP-7 molecules for activation, an event preceding its tumorigenic or antibacterial proteolytic activities at cell surfaces.

Postoperative simple biochemical markers for prediction of bone metastases in Egyptian breast cancer patients

Objective:

The present study was undertaken to identify patient populations at high risk for bone metastases (BM) at any time after diagnosis of operable breast cancer.

Subjects and methods:

A total number of 59 cases with breast cancer after mastectomy was subdivided into two main groups that included 30 patients with radiologically confirmed BM and 29 patients with no bone metastasis (NBM). Patients with NBM were formerly observed for a one-year follow-up interval to monitor the development of bone metastasis (new BM). Parameters included a full blood picture, tumour markers (carcinoembryonic antigen and CA 15.3) and some biochemical markers (vascular endothelial growth factor and zinc levels, as well as tartrate-resistant acid phosphatase and alkaline phosphatase activities).

Results:

A significant elevation was recorded in carcinoembryonic antigen level and alkaline phosphatase activity, as well as inflammation and vascularisation markers at the time of primary diagnosis in patients with BM, compared with those without BM. CA 15.3 was significantly higher in the new BM group as compared with the other two groups (patients free of bone metastasis [free BM] and BM). According to the likelihood ratio, a panel of single, calculated as well as combined markers was proposed to predict BM within one year in breast cancer patients.

Conclusion:

Vascularisation and inflammation markers, as well as CA 15.3 are predictive of bone recurrence within one year in breast carcinoma patients. We suggest that in cancer validation studies it is imperative to search for markers that link to the premetastatic process and to determine what type of mechanism is active in each stage.

Increased prevalence of vitamin D insufficiency in patients with breast cancer after neoadjuvant chemotherapy

Patients with locally advanced breast cancer treated with neoadjuvant chemotherapy are at risk of cancer treatment-induced bone loss and consequently of increased skeletal morbidity. In addition, this situation could be worsened by the fact that only a minority of patients with breast cancer have sufficient vitamin D. A comprehensive evaluation of bone homeostasis is critical in this context. We retrospectively evaluated the serum levels of calcium, vitamin D, TRAIL, RANK ligand (RANKL), Osteoprotegerin (OPG), Bone TRAP, CrossLaps and DKK1 in 77 patients (median age: 50 years; range 25-74), with locally advanced breast cancer treated in our institute with anthracyclines-taxane neoadjuvant chemotherapy (7 cycles of 21 days/each) between March 2007 and August 2008. Serum samples were collected before the first (baseline) and the last treatment cycle. Variations and correlations between biomarker levels were evaluated. At baseline, 79.5 % of patients had vitamin D insufficiency (<30 ng/ml), increasing to 97.4 % at the end of the neoadjuvant chemotherapy (p < 0.0001). Calcium and RANKL serum concentrations were also significantly decreased, while OPG was significantly increased, resulting in lower RANKL/OPG ratio. Calcium and vitamin D, RANKL and vitamin D and RANKL and OPG levels were significantly correlated (Spearman's coefficient r = 0.2721, p = 0.0006; r = 0.1916, p = 0.002; and r = -0.179, p = 0.03, respectively). Nearly all included patients suffered from vitamin D insufficiency by the end of the neoadjuvant chemotherapy with changes in the calcium/RANKL/OPG axis that are evocative of deregulation of a functional regulatory mechanism. Further studies are needed to determine how drugs modulate this regulatory mechanism to preserve bone homeostasis in patients with breast cancer.

The role of bone turnover markers in monitoring treatment in postmenopausal osteoporosis

Bone metabolism is assessed using biochemical bone turnover markers (BTM). BTM reflect the metabolic effect of drugs on bone turnover, help to establish the lowest dose inducing the largest change in the BTM, predict treatment-related reduction in fracture risk, and are helpful in bridging studies. Changes in BTM during anti-osteoporotic therapy depend on the cellular mechanism of action of the drug, degree of change in bone turnover rate and route of administration. BTM help to establish the optimal dose of anti-osteoporotic drugs because treatment-related changes in BTM are more rapid compared with change in BMD. A greater decrease in BTM levels during the first year of tantiresorptive treatment is associated with greater antifracture efficacy over 3 years. According to preliminary data, measurement of BTM can improve persistence with anti-resorptive treatment. The use of BTM to monitor anti-osteoporotic therapy in "real life" is limited at this stage.

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.

2-methoxyestradiol analogue ENMD-1198 reduces breast cancer-induced osteolysis and tumor burden both in vitro and in vivo

It has been estimated that 70% of advanced breast cancer patients will face the complication of bone metastases. Three processes are pivotal during bone metastatic growth of breast cancer, namely, tumor cell proliferation, angiogenesis, and osteolysis. During tumor-induced osteolysis, a number of cytokines and growth factors are released from the degraded bone matrix. These factors stimulate further tumor growth, tumor angiogenesis, and tumor-induced osteolysis. New therapies should target all relevant processes to halt this powerful feedback loop. Here, we characterized the new 2-methoxyestradiol analogue ENMD-1198 and showed that it is cytotoxic to tumor cells. Moreover, ENMD-1198 showed both antiangiogenic and vascular disruptive properties and was capable of protecting the bone against tumor-induced osteolysis. We confirmed the in vitro data with a series of in vivo experiments showing the beneficial effects of ENMD-1198 and ENMD-1198-based combination treatments of metastatic breast cancer in bone both on tumor progression and on survival with long-term ENMD-1198 treatment. We confirmed the in vivo relevance of the ENMD-1198 protective effect on bone both with X-ray radiographs and microcomputed tomography. In addition, we combined ENMD-1198 treatment with low-dose metronomic cyclophosphamide and the bisphosphonate risedronic acid, leading to a mild increase in treatment efficacy.

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

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Optical advances in skeletal imaging applied to bone metastases

Optical Imaging has evolved into one of the standard molecular imaging modalities used in pre-clinical cancer research. Bone research however, strongly depends on other imaging modalities such as SPECT, PET, x-ray and μCT. Each imaging modality has its own specific strengths and weaknesses concerning spatial resolution, sensitivity and the possibility to quantify the signal. An increasing number of bone specific optical imaging models and probes have been developed over the past years. This review gives an overview of optical imaging modalities, models and probes that can be used to study skeletal complications of cancer in small laboratory animals.

Drug-induced vessel remodeling in bone metastases as assessed by dynamic contrast enhanced magnetic resonance imaging and vessel size imaging: a longitudinal in vivo study

PURPOSE

The aim of this study was to assess the antiangiogenic treatment effects of zoledronic acid (ZA) and sunitinib malate (SM) noninvasively in experimental breast cancer bone metastases by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and vessel size imaging.

EXPERIMENTAL DESIGN

Nude rats bearing bone metastases after inoculation of MDA-MB-231 breast cancer cells were treated with ZA (40 microg/kg weekly; n = 8 rats), SM (20 mg/kg daily; n = 8 rats), or their combination (ZA and SM; n = 8 rats) and compared with sham-treated controls (n = 10 rats). Vascular changes in bone metastases were longitudinally imaged in vivo using DCE-MRI [amplitude (A) and exchange rate coefficient (k(ep))] and vessel size imaging [blood volume (BV) and vessel size index (VI)]. In addition, antiresorptive and antitumor changes were assessed in these lesions by flat-panel volumetric computed tomography as well as morphologic MRI and diffusion-weighted imaging.

RESULTS

In bone metastases, significant changes in A, k(ep), BV, and VI in accordance with decreased blood volume and vessel permeability as well as with increased mean vessel diameters were observed after application of ZA and SM as compared with controls. In this longitudinal study, antiangiogenic changes preceded the inhibition of osteolysis and antitumor effects after treatment.

CONCLUSIONS

These results indicate vessel remodeling in breast cancer bone metastases on ZA and SM treatment and implicate substantial effects on imaging and treatment of malignant bone lesions.

Serum tartrate-resistant acid phosphatase 5b activity as a prognostic marker of survival in breast cancer with bone metastasis

Background

Serum tartrate-resistant acid phosphatase 5b (TRACP 5b) activity is a marker of osteoclast number and is elevated in breast cancer (BC) patients with extensive bone metastasis, which might in turn reflect the tumour burden. We tested the hypothesis that baseline serum TRACP 5b activity and its interval change are potential prognostic markers of survival in BC patients with bone metastasis.

Methods

We analyzed the data from previous prospective studies. A total of 100 patients with newly diagnosed bone metastasis were included. Cox proportional regression model was used to evaluate the correlation between the overall survival time (OS) and baseline serum TRACP 5b activity and its interval changes. The least significant change (LSC) of TRACP 5b was calculated from data obtained from 15 patients with early BC.

Results

Estrogen receptor status (Hazard Ratio (HR) = 0.397; p = 0.003) and visceral metastasis (HR = 0.492; p = 0.0045) were significantly correlated with OS. The OS was significantly shorter in those patients with higher baseline TRACP 5b activity based on a cut-off value to delineate the highest tertile (HR = 3.524; p < 0.0001). Further analysis demonstrated that among patients in the highest tertile, OS was significantly longer in those patients who had achieved a decrease of serum TRACP 5b activity greater than the LSC (38.59%) (p = 0.0015).

Conclusions

We found that TRACP 5b activity and its interval change after treatment bore a prognostic role in BC patients with bone metastasis and a high baseline serum TRACP 5b activity. Further prospective phase II study is necessary to confirm these results.

Biology and clinical significance of tartrate-resistant acid phosphatases: new perspectives on an old enzyme

Type 5 tartrate-resistant acid phosphatase (TRAP) has been a clinically relevant biomarker for about 50 years. It has always been a reliable and specific cytochemical marker for hairy cell leukemia and for differentiated cells of monocytic lineage. Only recently has the test for serum TRAP activity been accepted as sensitive and specific enough for clinical use as a marker of osteoclasts and bone resorption. This has come about through steady advances in knowledge about TRAP enzymology, structure, function, and molecular regulation and a consequent appreciation that TRAP isoforms 5a and 5b have very different clinical significance. As a measure of osteoclast number and bone resorption, TRAP 5b has diagnostic and prognostic applications in osteoporosis, cancers with bone metastasis, chronic renal failure, and perhaps other metabolic and pathologic bone diseases. Serum TRAP 5a, on the other hand, has no relationship to bone metabolism but seems instead to be a measure of activated macrophages and chronic inflammation. Exploration of the real clinical usefulness of serum TRAP 5a for diagnosis and disease management in a wide variety of chronic inflammatory diseases is only now beginning. This perspective traces the important basic scientific developments that have led up to the refinement of serum TRAP isoform immunoassays and their validation as biomarkers of disease. Many unanswered questions remain, providing a wealth of opportunity for continued research of this multifaceted enzyme.

Correlation of decreased survival and IL-18 in bone metastasis

OBJECTIVE

Previous studies have reported that serum IL-18 levels are increased in some cancers. We investigated whether IL-18 production is increased in sera and cancer cells of patients with non-small cell lung cancer (NSCLC).

PATIENTS OR MATERIALS

Serum levels of IFN-gamma and IL-18 and thioredoxin 1 (TRX1) were measured in 79 patients (51 males, 28 females, median age 67 years) with advanced NSCLC (57 adenocarcinoma, 22 squamous cell carcinoma; TNM stages IIIA [n=11], IIIB [n=24], and IV [n=44]) and 75 healthy age-matched controls (44 males, 31 females, median age 65 years) by enzyme-linked immunosorbent assay. We examined IL-18 production in the lungs and sites of bone metastasis of adenocarcinoma by immunohistochemistry.

RESULTS

Serum IL-18, IFN-gamma, and TRX1 levels in NSCLC patients were significantly (p<0.0001, p=0.0031, and p<0.0001, respectively) higher than in control subjects, while serum IFN-gamma levels in NSCLC were slightly increased. Serum IL-18, but not IFN-gamma or TRX1, levels were significantly (p=0.0102) and negatively associated with overall survival in NSCLC. The serum IL-18 level was identified as an independent prognostic factor for overall survival in multivariate survival analysis. Moreover, serum IL-18 levels were significantly (p=0.049) higher in NSCLC with bone metastasis than in NSCLC without bone metastasis. Based on immunohistochemistry, we observed that cancer cells in the lungs and bone metastases markedly produced IL-18.

CONCLUSION

Our results suggest that elevated serum IL-18 levels may be associated with IL-18 producing cancer cells in advanced NSCLC.

Genetic polymorphisms in the MMP-7 gene and breast cancer survival

Matrix metalloproteinase-7 (MMP-7) is a small secreted proteolytic enzyme with broad substrate specificity. Its expression has been shown to be associated with tumor invasion, metastasis and survival for a variety of cancers. We systematically evaluated single nucleotide polymorphisms (SNPs) in MMP-7 in relation to breast cancer survival in a large follow-up study. Included were 1,079 breast cancer cases that were recruited from 1996 to 1998 and followed for a median of 7.1 years as part of the Shanghai Breast Cancer Study (SBCS). Eleven SNPs, including 2 known functional promoter SNPs, were analyzed using the Affymetrix Targeted Genotyping System. Associations with survival were evaluated by Cox proportional hazards regression and Kaplan-Meier functions. Statistically significant associations with disease-free and/or overall survival (OS) were found for 5 polymorphisms; these associations were explained primarily by 2 SNPs (rs11568818 and rs11225297) that were in high linkage disequilibrium (LD) with the others. Patients homozygous for the rs11568818 rare allele (G) had a significantly worse prognosis (OS HR: 6.7, 95% CI: 2.4-18.6) than patients homozygous for the common allele (A). Significantly improved survival was seen for patients with the rs11225297 T allele, and this association occurred in a dose-response manner; patients with AT (OS HR: 0.7, 95% CI: 0.5-0.9) and TT (OS HR: 0.3, 95% CI: 0.1-0.8) fared better than patients with AA (p-value for trend: 0.001). Thus, common MMP-7 genetic polymorphisms were found to be significant determinants of survival among Chinese women with breast cancer.

Biochemical markers of bone turnover: potential use in the investigation and management of postmenopausal osteoporosis

INTRODUCTION

The aim was to analyse data on the use of biochemical bone turnover markers (BTM) in postmenopausal osteoporosis.

METHODS

We carried out a comparative analysis of the most important papers concerning BTM in postmenopausal osteoporosis that have been published recently.

RESULTS

The BTM levels are influenced by several factors. They are moderately correlated with BMD and subsequent bone loss. Increased levels of bone resorption markers are associated with a higher risk of fracture. Changes in the BTM during the anti-osteoporotic treatment (including combination therapy) reflect the mechanisms of action of the drugs and help to establish their effective doses. Changes in the BTM during the anti-resorptive treatment are correlated with their anti-fracture efficacy.

CONCLUSION

Biological samples should be obtained in a standardised way. BTM cannot be used for prediction of the accelerated bone loss at the level of the individual. BTM help to detect postmenopausal women who are at high risk of fracture; however, adequate practical guidelines are lacking. BTM measurements taken during the anti-resorptive therapy help to identify non-compliers. They may improve adherence to the anti-resorptive therapy and the fall in the BTM levels that exceeds the predefined threshold improves patients' persistence with the treatment. There are no guidelines concerning the use of BTM in monitoring anti-osteoporotic therapy in postmenopausal women.

Advancing treatment for metastatic bone cancer: consensus recommendations from the Second Cambridge Conference

PURPOSE

Summarize current knowledge, critical gaps in knowledge, and recommendations to advance the field of metastatic bone cancer.

EXPERIMENTAL DESIGN

A multidisciplinary consensus conference was convened to review recent progress in basic and clinical research, assess critical gaps in current knowledge, and prioritize recommendations to advance research in the next 5 years. The program addressed three principal topics: biology of metastasis, preserving normal bone health, and optimizing bone-targeted therapies.

RESULTS

A variety of specific recommendations were identified as important to advance research and clinical care over the next 5 years.

CONCLUSIONS

Priorities for research in bone biology include characterizing components of the stem cell niche in bone, developing oncogenic immunocompetent animal models of bone metastasis, and investigating the unique contribution of the bone microenvironment to tumor growth and dormancy. Priorities for research in preserving normal bone health include developing methods to measure and characterize disseminating tumor cells, assessing outcomes from the major prevention trials currently in progress, and improving methodologies to assess risks and benefits of treatment. Priorities for optimizing bone-targeted therapies include advancing studies of serum proteomics and genomics to reliably identify patients who will develop bone metastases, enhancing imaging for early detection of bone metastases and early response evaluation, and developing new tests to evaluate response to bone-directed treatments.

Bevacizumab inhibits breast cancer-induced osteolysis, surrounding soft tissue metastasis, and angiogenesis in rats as visualized by VCT and MRI

The aim of this study was to evaluate the effect of an antiangiogenic treatment with the vascular endothelial growth factor antibody bevacizumab in an experimental model of breast cancer bone metastasis and to monitor osteolysis, soft tissue tumor, and angiogenesis in bone metastasis noninvasively by volumetric computed tomography (VCT) and magnetic resonance imaging (MRI). After inoculation of MDA-MB-231 human breast cancer cells into nude rats, bone metastasis was monitored with contrast-enhanced VCT and MRI from day 30 to day 70 after tumor cell inoculation, respectively. Thereby, animals of the treatment group (10 mg/kg bevacizumab IV weekly, n = 15) were compared with sham-treated animals (n = 17). Treatment with bevacizumab resulted in a significant difference versus control in osteolytic as well as soft tissue lesion sizes (days 50 to 70 and 40 to 70 after tumor cell inoculation, respectively; P < .05). This observation was paralleled with significantly reduced vascularization in the treatment group as shown by reduced increase in relative signal intensity in dynamic contrast-enhanced MRI from days 40 to 70 (P < .05). Contrast-enhanced VCT and histology confirmed decreased angiogenesis as well as new bone formation after application of bevacizumab. In conclusion, bevacizumab significantly inhibited osteolysis, surrounding soft tissue tumor growth, and angiogenesis in an experimental model of breast cancer bone metastasis as visualized by VCT and MRI.

The amino- and carboxyterminal cross-linked telopeptides of collagen type I, NTX-I and CTX-I: a comparative review

Bone diseases such as osteoporosis or bone metastases are a continuously growing problem in the ageing populations across the world. In recent years, great efforts have been made to develop specific and sensitive biochemical markers of bone turnover that could help in the assessment and monitoring of bone turnover. The amino- and carboxyterminal cross-linked telopeptides of type I collagen (NTX-I and CTX-I, respectively) are two widely used bone resorption markers that attracted great attention due to their relatively high sensitivity and specificity for the degradation of type I collagen, and their rapid adaptation to automated analyzers. However, the clinical performance of both markers differs significantly depending on the clinical situation. These differences have caused considerable confusion and uncertainty. If used correctly, both markers have great potential to improve the management of many bone diseases. We here review the biochemistry, analytical background and clinical performance of NTX-I and CTX-I, as documented in the accessible literature until March 2008.

Prognostic significance of MMP-9 and TIMP-1 serum and tissue expression in breast cancer

Tumor progression and metastasis contribute to the great majority of breast cancer deaths. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are thought to be involved in tumor progression and metastasis. Thus, we determined whether the expression of MMP-9 and TIMP-1 is associated with prognosis in breast cancer patients. We measured serum MMP-9 and TIMP-1 by enzyme-linked immunosorbent assay in 60 breast cancer patients, 18 benign breast disease patients and 15 healthy controls. We also evaluated the expression of MMP-9 and TIMP-1 protein and mRNA in paraffin-embedded tumor tissues from the 60 breast cancer patients by immunohistochemistry and in situ hybridization. We then correlated serum and tissue levels of MMP-9 and TIMP-1 in breast cancer samples and their expression with patients' clinicopathologic characteristics. We found that serum levels of MMP-9 and TIMP-1 were significantly higher in breast cancer patients than in benign breast disease and in healthy controls. High serum levels of MMP-9 and TIMP-1 were associated with lymph node metastasis, higher tumor stage and lower relapse-free and overall survival (OS) rates. Compared to low expression, high tissue expression of MMP-9 protein was associated with lymph node metastasis and higher tumor stage; and high tissue expression of TIMP-1 was associated with a lower OS rate. Our findings suggest that MMP-9 and TIMP-1 may further be evaluated as biomarkers for predicting progression and prognosis of breast cancer.

In vitro method for diagnosing and monitoring renal cell carcinoma using matrix metalloprotease-7 as humoral biomarker

Matrix metalloprotease (MMP)-7 is associated with malignant aggressiveness and prognosis in various cancers. In renal cell carcinoma (RCC) tissues, it has been reported that MMP-7 is overexpressed in cancer cells and on newly formed vascular endothelial cells, and it is associated with cancer cell invasion and metastasis. From these facts, the possibility exists that measurement of blood MMP-7 levels is useful marker in diagnosis and monitoring or prediction of prognosis in patients with RCC. MMP-7 is secreted in its precursor form and it can be activated by endoproteases. Furthermore, MMP-7 is composed of various domains and fragments. Reliable method and objection is needed to investigate the usefulness of MMP-7 as a human biomarker of RCC.

Elevated plasma tissue inhibitor of metalloproteinase-1 level predicts decreased response and survival in metastatic breast cancer

BACKGROUND

Tissue inhibitors of metalloproteinase (TIMPs) have at least 2 different functions. They inhibit the catalytic activity of matrix metalloproteinases, and they act as growth factors.

METHODS

Pretreatment ethylenediamine tetracetic acid plasma TIMP-1 was assayed from 251 patients who were enrolled in a Phase III, second-line, hormone therapy trial, and from a control group of 50 healthy, postmenopausal women by using the TIMP-1 enzyme-linked immunosorbent assay.

RESULTS

The plasma TIMP-1 levels from the postmenopausal control group (n = 50 women) were 201 +/- 86 ng/mL mean +/- standard deviation (range, 49-455 ng/mL). The upper limit of normal was defined as the mean +/- 2 standard deviations of the control group (373 ng/mL). Patient pretreatment plasma TIMP-1 levels ranged from 70 ng/mL to 982 ng/mL. Plasma TIMP-1 was elevated above the mean + 2 standard deviations of the control group (373 ng/mL) in 19 patients (7.6%). In univariate analysis, patients who had elevated versus normal plasma TIMP-1 levels had a reduced clinical benefit rate (CBR) (16% vs 42%; P = .03). The time to progression (TTP) (84 days vs 174 days; P < .0001) and overall survival (141 days vs 860 days; P = .0001) also were significantly shorter in patients who had elevated TIMP-1 levels. TTP and overall survival also were significantly shorter in patients who had higher TIMP-1 plasma levels when it was analyzed as a continuous variable. In multivariate analysis, elevated plasma TIMP-1 level remained a prognostic factor for reduced overall survival (P < .0001) along with elevated serum HER-2/neu (P < .0001) and the presence of visceral metastases (P = .008).

CONCLUSIONS

Elevated pretreatment plasma levels of TIMP-1 predicted a decreased response to second-line hormone therapy and reduced survival in women with metastatic breast cancer.