Coagulation Activation In Cancer Patients Research Articles

Endothelial Microparticles and Blood Coagulation Activation in Head and Neck Cancer Patients Undergoing Radiotherapy or Radiochemotherapy.

Endothelial microparticles (EMP) are small vesicles which are released from the endothelium and contribute to blood coagulation activation in various clinical settings. The aim of this study was to examine whether EMP influence blood coagulation activation in cancer patients during radiotherapy/radiochemotherapy (RT/RCT). Sixteen head and neck cancer (HNC) patients undergoing RT/RCT and 10 controls were examined. EMP and thrombin-antithrombin complex (TAT) were measured by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively. Tissue factor-positive EMP (TF+EMP) were defined as CD31+/CD142+/CD42b- Results: TF+EMP were significantly elevated in HNC patients before RT/RCT (T0) (1299±1154/μl), one day after RT/RCT (T1d) (1257±603/μl) and 3 months after RT/RCT (T3m) (1289±372/μl) compared to controls (688±647/μl). TF+EMP levels at T0/T1d and T0, as well as at T1d and T3m were not significantly different. TAT levels at T0 and T1d did not differ significantly but at T3m were significantly lower compared to T0 and T1d TF+EMP and TAT concentrations were not significantly correlated at T0 (r=0.058; p=0.828), T1d (r=0.373, p=0.154) and T3m (r=-0.302, p=0.204). TF+EMP may not contribute to hemostatic abnormalities in HNC patients.

Mechanisms of thrombosis in cancer

Patients with cancer are at high risk of developing thrombosis. The pathogenesis of blood coagulation activation in cancer patients is complex involves both clinical and biological factors. The thrombotic risk varies according to the type of malignancy and its disease stage, and is increased by concomitant patient-related thrombotic risk factors (i.e. advanced age, infection, heart disease). In addition, the tumor cell-specific prothrombotic properties and the host cell inflammatory response dramatically contribute to the risk of thrombosis in these patients. The current development of risk assessment models to predict thrombosis in cancer is important for identifying high-risk patients and predispose the adequate preventive measures. In this review we provide an overview of the principal mechanisms of thrombosis in cancer, including clinical and biological risk factors, and a summary of risk assessment tools to predict thrombosis in the single patient.

Coagulation activation and microparticle-associated coagulant activity in cancer patients

Cancer increases the risk of venous thromboembolism (VTE). Here, we investigated the contribution of microparticle (MP)-dependent procoagulant activity to the prothrombotic state in these patients. In 43 cancer patients without VTE at study entry and 22 healthy volunteers, markers of in vivo and MP-dependent coagulation were measured and patients were prospectively followed for six months for the development of VTE. Procoagulant activity of MPs was measured in vitro using a tissue factor (TF)-independent phospholipid dependent test, a factor Xa-generation assay with and without anti-TF, and a fibrin generation test (FGT) with and without anti-factor VII(a). Markers of in vivo coagulation activation and total number of MPs at baseline were significantly elevated in cancer patients compared to controls (F1+2 246 vs. 156 pM, thrombin-antithrombin complexes 4.1 vs. 3.0 mg/l, D-dimer 0.76 vs. 0.22 mg/l and 5.53 x 10⁶ vs. 3.37 x 10⁶ MPs/ml). Five patients (11.6%) developed VTE. Patients with VTE had comparable levels of coagulation activation markers and phospholipid-dependent MP procoagulant activity. However, median TF-mediated Xa-generation (0.82 vs. 0.21 pg/ml, p=0.016) and median VIIa-dependent FGT (13% vs. 0%, p=0.036) were higher in the VTE group compared with the non-VTE group. In this exploratory study the overall hypercoagulable state in cancer patients was not associated directly with the MP phospholipid-dependent procoagulant activity. However, in the patients who developed VTE within six months when compared to those who did not, an increased MP procoagulant activity was present already at baseline, suggesting this activity can be used to predict VTE.

Protein Z/protein Z-dependent protease inhibitor system in human non-small-cell lung cancer tissue

IntroductionNSCLC progression is often associated with VTE. Activation of factor X is an important step in blood coagulation activation in cancer patients. PZ)/ZPI contribute to direct factor Xa inhibition, and ZPI - attenuates factors IXa and XIa activity. The role of the PZ/ZPI in NSCLC is obscure. The aim of the study was to localize ZPI and PZ in NSCLC tissue in relation to factors X, IX and XI, as well as indicators of blood coagulation activation: prothrombin fragment F1+2 (F1+2) and fibrin. Material & MethodsImmunohistochemical studies were performed on surgical NSCLC specimens employing antibodies against ZPI, PZ, coagulation factors X, IX, XI, as well as fibrinogen, F1+2 and fibrin. A semiquantitative analysis (acc. to immunoreactive score-IRS) was conducted. ResultsMedium expression of ZPI(IRS=6.5), together with weak expression of PZ(IRS=4), was observed in cancer cells. Strong or medium staining for factors IX, X, and XI(IRS=8–9) was revealed in cancer cells. Fibrinogen(IRS=10) and fibrin(IRS=8) were demonstrated in tumor stroma and cancer cells. F1+2(IRS=10) was localized in NSCLC cells. Endothelial cells (ECs) and tumor infiltrating macrophages (TAMs) were characterized by a positive staining for ZPI and PZ. ConclusionsZPI and PZ expression in NSCLC cells, ECs and TAMs may suggest a role for PZ/ZPI in the anticoagulant mechanisms at the tumor site. The presence of F1+2 and fibrin, along with a disproportional expression of ZPI and PZ, might point to impaired function of the coagulation inhibitory system in NSCLC tissue.

Expression of tissue factor pathway inhibitor (TFPI) in human breast and colon cancer tissue

Activation of blood coagulation, a phenomenon frequently observed in breast and colon cancer patients, contributes to tumour progression. The principal initiator of blood coagulation activation in cancer patients is tissue factor (TF), while tissue factor pathway inhibitor (TFPI) is the main inhibitor of the TF-dependent pathway of blood coagulation. Previous immunohistochemical studies revealed no expression of TFPI in human cancer cells. The aim of the study was to evaluate the expression of TFPI protein and mRNA in breast and colon cancer tissues. A total of 108 cancer tissues (from primary tumours and metastatic lymph nodes) were obtained from 87 patients during surgical treatment. Immunohistochemical studies using a polyclonal anti-TFPI antibody were performed including a semiquantitative analysis. The in situ hybridisation method employed single-stranded DNA oligonucleotide (probe sequence: 5'Biotin-CCACCATACTTGAAACGTTCACACT-Biotin3') directed against TFPI mRNA. Strong or medium expression of TFPI protein was observed in cancer cell bodies in all breast cancers and in most (39/66 cases) colon cancers examined. Weaker expression of TFPI was detected in cancer cells localised in lymph node metastatic foci of breast cancer. Endothelial cells were also TFPI-positive. TFPI mRNA was demonstrated in all cases of breast and in approximately 80% cases of colon cancer cells. TFPI mRNA and protein are present in association with colon and breast cancer cells, suggesting that the protein may play a role in cancer biology. The presence of TFPI in association with breast cancer cells localised in regional lymph nodes may indicate its role in lymphatic spread.

TFPI (Tissue Factor Pathway Inhibitor) Is Present in Breast Cancer Tumor Cells.

Abnormalities in hemostatic system are common in breast cancer patients. The principal initiator of blood coagulation activation in cancer patients is tissue factor (TF). Tissue factor plays an important role in the processes of angiogenesis, invasion and metastatic dissemination. Tissue factor pathway inhibitor (TFPI) is the main inhibitor of TF-dependent pathway of blood coagulation. The catalytic activity of the TF/VIIa complex triggers activation of factor X, consequently thrombin generation and finally fibrin formation. Thrombin and fibrin facilitate cancer progression. Previous immunohistochemical studies revealed no expression of TFPI in cancer cells of different malignant tumor types (Werling et al, Thromb Haemost 1993; 69: 366–369) The aim of the study was to evaluate the expression of TFPI protein and mRNA in tumor cells of breast cancer.Breast cancer tissues were obtained during surgical treatment of 35 women. The patients undergoing surgery had not received any previous anticancer therapy. Tumor fragments were preserved in 4% paraformaldehyde/phosphate buffered saline and than embedded in paraffin. Immunohistochemical studies (avidin-biotin complex-ABC - technique) were performed using polyclonal antibodies against TFPI. In situ hybridization method employed single-stranded DNA oligonucleotide (probe sequence: 5′Biotin-CATCGCCCAGTGCAGCCTCCGTCAG-Biotin3′) directed against locus NM 006287 of TFPI mRNA.Strong expression of TFPI protein was observed in cancer cell bodies in examined specimens. Weak expression of the above protein was observed in tumor infiltrating macrophages. Normal cells revealed much weaker staining for TFPI than cancer cells. Similarly, mRNA for TFPI was observed in cancer cells of all breast cancer tissues.The above data indicate that TFPI is present in neoplastic cells of breast cancer and may play a role in neutralizing TF procoagulant and signaling functions.

Antimetastatic effect of tinzaparin, a low-molecular-weight heparin

The importance of coagulation activation in cancer patients is suggested by the clinical finding of hypercoagulability, experimental enhancement of metastasis and angiogenesis by coagulation factors such as tissue factor (TF) and thrombin and the possible antitumor effects of anticoagulant agents. Tinzaparin is a low-molecular-weight heparin (LMWH) with a relatively high molecular weight distribution and high sulfate to carboxylate ratio. In addition to its ability to inhibit thrombin and factor Xa, tinzaparin is particularly effective at releasing endothelial tissue factor pathway inhibitor (TFPI), the natural inhibitor of both procoagulant and non-coagulant effects of TF. The present study was undertaken to investigate the effect of tinzaparin on lung metastasis using a B16 melanoma model in experimental mice. Tinzaparin's anticoagulant effect in mice and its ability to release TFPI from human endothelial cells at various time points were demonstrated. Subcutaneous (s.c.) injection of tinzaparin (10 mg kg-1) 4 h before intravenous administration of melanoma cells (2.0 x 105) markedly (89%) reduced lung tumor formation (3 +/- 2) compared with controls (31 +/- 23; P < 0.001). In a second group of animals, tinzaparin (10 mg kg-1, s.c.) administered daily for 14 days following the initial (pretumor cell) dose, before assessment of lung seeding, reduced tumor formation by 96% (P < 0.001). No bleeding problems were observed in any of the tinzaparin-treated animals, despite a 4-fold prolongation of the whole blood clotting time after a single s.c. dose of tinzaparin (10 mg kg-1). Administration of tumor cells (2 x 106) caused a rapid and significant fall in platelet count 15 min after injection (a sensitive marker of intravascular coagulation) in controls (939 +/- 37 vs. 498 +/- 94 x 106 mL-1, P < 0.01), but this was prevented by tinzaparin treatment (921 +/- 104 x 106 mL-1). These data provide further experimental evidence to support the potential for LMWH as antimetastatic agents.

Abnormal coagulation and deep venous thrombosis in patients with advanced cancer.

Many studies have demonstrated increased coagulation activation in cancer patients and have shown evidence of chronic, low-grade disseminated intravascular coagulation, although most patients remained asymptomatic. In general, patients have not been screened for deep venous thrombosis (DVT). We screened 98 patients with advanced malignancy for DVT using light reflection rheography. Coagulation profiles of DVT and non-DVT groups were studied. We found a high prevalence of DVT (50%) on screening. Overall, the patients had raised levels of fibrinogen (66% patients), factor VIII:C (43%), fragment 1 + 2 (71%) and TAT levels (89%). Patients with DVT had a significantly lower level of fibrinogen than those without (4.0 g/dl, SD 1.4, compared with 4.7 g/dl SD 1.6, P = 0.04). There was no significant difference in other coagulation or liver function tests between the DVT and non-DVT groups. The wide variation of results makes their interpretation difficult and unlikely to be of predictive value in estimating individual thrombotic risk.