PO-26 - Whole blood rotational thromboelastometry (ROTEM) to detect hypercoagulability in patients with myeloproliferative neoplasms (MPN)

Abstracts / Thrombosis Research 140S1 (2016) S168–S200

technique cannot be used because the site of degradation of fondaparinux by heparanase is masked by AT present in plasma. Conclusions: Heparanase was found in in many cancer cell lines and its level depends on origin of tumor cells and on its aggressivity. Taking into account the pro-metastatic functions, proangiogenic and procoagulant activity of HPA and its overexpression in gastric signet ring cell carcinoma of poor prognosis and its cell line, HPA can be considered as a biomarker of malignancy and as a therapeutic target in GSRC patients.

PO-24 Determinants of thrombin generation in gynaecological malignancies L.A. Norris1, F.A. Martin1, S.A. O’Toole1,2, F. Abu Saadeh3, N. Gleeson3 Coagulation Research Laboratory, Dept of Obstetrics and Gynaecology, Trinity Centre for Health Sciences, 2Trinity College Dept of Histopathology, 3Dept of Gynae-oncology, St. James’s Hospital; Dublin, Ireland

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Introduction: Increased thrombin production is associated with malignancy and is a marker for venous thromboembolism (VTE). Our group has shown that thrombin generation is increased in gynaecological malignancies. Although tumour derived Tissue Factor (TF) has been implicated, the precise mechanism by which thrombin production is increased is not fully understood. Our group has shown that gynaecological cancers can alter tumour expression of cogulation proteases. These changes may be implicated in the increased thrombin generation observed. Previous studies in normal control patients by other groups have shown that multiple coagulation factors are implicated in thrombin generation and that the effects depend on assay conditions however free Tissue Factor Pathway Inhibitor (TFPI), Factors V, VIIIc and protein S, were significant determinants of thrombin generation. Aim: The aim of this study was to determine the effect of factor V factor, VIIIc, TFPI and free protein S on the thrombin generation in patients with endometrial and ovarian cancer compared with benign controls. Materials and Methods: Patients with a gynaecological malignancy (n=43) (ovarian or endometrial) were matched with patients with a benign tumour (n=43) gave full and informed consent. Venous blood samples were obtained prior to surgery and chemotherapy. Thrombin generation was was measured using a fluorogenic assay. Lag time,peak thrombin and area under the thrombin generation curve (ETP) was determined and reported for each sample. Free protein S, free TFPI and factor V were determined using ELISA. Factor VIIIc was determined using a hromogenic assay. Results: Factor V and factor VIIIc were significantly increased in the malignant group compared with the benign group (P<0.03; P<0.006). Increased free TFPI levels were also observed in the malignant group but this did not reach significance (P<0.06). There was no difference in free Protein S levels between the groups. Highest levels of peak thrombin generation were observed in the high grade serous and clear cell ovarian cancer patients. Changes were less marked in the endometrial patients. Free TFPI, factor V and factor VIIIc were important determinants of thrombin generation in the malignant group. Conclusions: Coagulation factors V and VIIIc and free TFPI are altered in patients with gynaecological malignancies and contribute to the increased thrombin generation found in these cancer patients. We have previously found increased expression of factor V in tumours from patients with ovarian cancer in addition to increased TF expression. These changes may explain the high rate of venous thromboembolism found in these patients.

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PO-25 FATCAT: an observational cohort study investigating fractal dimension (df) as a biomarker of thrombogenicity in cancer associated thrombosis during chemotherapy for lung cancer N.A. Davies1,2, S. Noble3, N.K. Harrison4, R.H.K. Morris5, P.A. Evans1,2 1 College of Medicine, Swansea University, 2Haemostasis Biomedical Research Unit, 3School of Medicine, Cardiff University, 4Respiratory Unit, Morriston Hospital, ABMU Health Board, Swansea, 5School of Applied Science, Cardiff Metropolitan University; United Kingdom Introduction: Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE) are common complications in patients with cancer, affecting up to 18% of patients. VTE risk is increased by surgery and disease progression, whilst chemotherapy further increases risk up to 7-fold compared to patients without cancer. VTE contributes significantly to morbidity and mortality in patients with cancer, and is the second most common cause of death. Lung cancer is well established to be high risk for VTE, with up to a 22-fold increase in VTE risk associated with this malignancy, and 12% incidence in a recent study of patients with lung cancer undergoing chemotherapy. Furthermore, platinum based chemotherapy agents used in treatment of lung cancer are further associated with increased VTE risk. Aim: Current risk assessment tools have little value in predicting VTE risk, but prophylactic anticoagulation of patients with cancer increases bleeding incidence and no overall survival benefit. There is therefore a need for a pragmatic test with which assesses coagulation in patients with cancer, and potentially predict VTE risk, leading to personalised management and targeted treatment. We have previously demonstrated that fractal dimension (df) is sensitive to changes in clot microstructure in patients with lung cancer, assessing global coagulation in these patients. Furthermore, df is significantly different in patients with extensive disease (stages 3&4), which conventional laboratory markers failed to identify. Given the increased risk of VTE associated with chemotherapy, FATCAT will aim to assess changes in df in a larger cohort of patients with lung cancer undergoing chemotherapy, quantifying changes in df and relating these to clinical outcome. Materials and Methods: This is a prospective observational cohort study investigating changes in df in patients with lung cancer undergoing chemotherapy. Patients will have a new diagnosis of cytologically or histologically confirmed lung cancer planned for chemotherapy and no history of previous cancer treatment, any thromboembolic / haemostatic disorders or be on anticoagulation. Results: Following a power calculation, 300 patients will be recruited and followed up for 1 year. df, Doppler ultrasonography and standard coagulation markers will be performed on recruitment, at the mid point, and on completion of chemotherapy in line with standard diagnostic procedures i.e. CT scanning. Conclusions: The primary endpoint of the study will be VTE diagnosis, whilst secondary outcomes will determine the change in df during and after treatment with chemotherapy.

PO-26 Whole blood rotational thromboelastometry (ROTEM) to detect hypercoagulability in patients with myeloproliferative neoplasms (MPN) C. Giaccherini1, C. Verzeroli1, M. Marchetti1, S. Gamba1, F. Piras1, L. Russo1, S. Tessarolo1, A. Vignoli1, G. Finazzi2, A. Rambaldi2, A. Falanga1 1 Division of Immunohematology and Transfusion Medicine, 2Division of Hematology; Hospital Papa Giovanni XXIII, Bergamo, Italy Introduction: Essential Thrombocythemia (ET) and Polycythemia Vera (PV) are two MPNs characterized by a “clonal” overproduction of one or more blood cell lines, hypercoagulability, and an increased incidence of thrombosis. ROTEM is a point of care global coagulation assay performed in whole blood, able to evaluate platelets and fibrinogen contributions to the clotting process. Until now few studies evaluated the thromboelastometry profile of MPN patients.

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Abstracts / Thrombosis Research 140S1 (2016) S168–S200

Aim: This study assess the feasibility of using ROTEM to characterize the prothrombotic state of MPN patients and to evaluate whether the thromboelastometry profile varies according to mutational status and/or treatment, and is influenced by hemocromocytometric parameters. Materials and Methods: Venous blood samples were collected from 39 ET and 23 PV patients upon informed consent. Analysis was performed using INTEM and EXTEM reagents, to evaluate the intrinsic and extrinsic pathway, respectively. Maximum clot firmness (MCF, [mm]), which reflects the maximum tensile strength of the thrombus, clotting formation time (CFT [sec]), namely the time that clot takes to increase from 2 to 20 mm above baseline, and clotting time (CT [sec]), the time to clot initiation, were recorded. Nineteen healthy subjects acted as a control group. Results: ROTEM analysis showed a hypercoagulable profile in MPN patients, who had shorter CFT and higher MCF compared to controls, both with EXTEM and INTEM reagents; no differences were observed in CT parameters. Platelet count was significantly higher in patients compared to controls (p<0.01). In patients, a strong statistically significant (p<0.01) correlation was found between platelet count, and MCF [r=0.650 (ET), r=0.601 (PV)] or CFT [r=-0.641 (ET), r=-0.558 (PV)]. Multivariate analysis, according to blood cell counts, showed that only platelet count was independently associated to ROTEM results. To correct for platelet differences, a ratio between MCF and the respective platelet value (rMCF) was created. Interestingly, rMCF was significantly lower in patients compared to controls (p<0.01), suggesting a weaker clot formation potential of patients’ samples. Furthermore, rMCF was lower in ET compared to PV (p<0.05), and in calreticulin-positive subjects (p<0.05), while was higher in patients under cytoreductive therapy (Hydroxyurea) (p=ns). Conclusions: This study confirms, by the ROTEM evaluation, the occurrence of a hypercoagulable state in ET and PV patients. In addition, the ROTEM parameters are significantly influenced by the platelet count. Finally, MCF values corrected for platelet count reveal a lower platelet reactivity in MPN patients, confirming the hypothesis that platelet function is exhausted upon clotting activation. Acknowledgement: Project funded by “AIRC-IG2013” grant Nr. 14505 from the “Italian Association for Cancer Research” (A.I.R.C.).

PO-27 Thrombin generation in pancreatic cancer and multiple myeloma with use of calibrated automated thrombography M.A. Adesanya1, A. Maraveyas1, L.A. Madden2 Hull York Medical School, Universities of Hull and York, USA, 2School of Biological, Biomedical and Environmental Sciences, University of Hull, UK 1

Introduction: The calibrated automated thrombography (CAT) assay is emerging as a reliable tool for real time estimation of thrombin generation (TG) potential. As a time-dependent colorimetric assessment of thrombin quantity generated per sample, it measures the amount of thrombincleaved fluorogenic substrate produced, and so is regarded as a better overall indicator of the clotting efficiency and function of the haemostatic process than one stage clotting-time based assays. Aim: We already recognise that the pathways underlying the thrombotic phenotype for different malignancies may be driven by different factors of the coagulation cascade with TG has a common denominator. Two such malignancies with high venous thromboembolism (VTE) incidence are Multiple myeloma (MM) and Pancreatic cancer (PC). Understanding the underlying variations in these two distinct cancer models using patient samples and cell lines might potentially allow individual approaches to identifying thrombotic risk and relevant prevention strategies. Materials and Methods: Citrated blood samples were taken from healthy controls, pre-surgical pancreatic cancer and pre-chemotherapy multiple myeloma patients enrolled into ongoing clinical trials. The clotting ability was tested using platelet free plasma (PPP) on a one-step clotting timebased (CT) assay and the TG profiles were evaluated on a Thrombinoscope™ software (Thrombinoscope BV, Maastricht, Netherlands). Solid tumour cells of pancreatic cancer and malignant haematological cell lines were used at various cell concentrations for the CAT assay, which was performed with

the addition of platelet-free control plasma or control plasma deficient in coagulation factors VII and XII. Results: At TF concentration conditions of 1 pmol/L, the peak height of thrombin generated on thrombogram curves strongly correlated with CT of patient samples. Compared to healthy controls, pancreatic cancer had higher thrombin peaks (P), shorter lag times (LG), and an overall stronger TG profile than MM. Pancreatic cancer cell lines exhibited higher concentrationdependent TG profiles in control plasma than haematological cell lines, with higher peaks, endogenous thrombin potential (ETP), shorter lag times (LG) and faster times-to-peak (ttPeak). Conclusions: This study demonstrates that the CAT assay is a useful predictor of the thrombotic phenotype in cancer patients as it gives a more comprehensive overall coagulation profile than one stage CT-based assays. It shows that for patient samples and cell lines, the similarities and differences that exists in the TG potential, significantly depends on specific coagulation factors present in the intrinsic or extrinsic arms of the clotting cascade.

PO-28 Protein C levels are associated with mortality in patients with advanced cancer I.T. Wilts1, B.A. Hutten2, J.C. Meijers3,4, C.A. Spek5, H.R. Büller3, P.W. Kamphuisen1 1 Dept. of Vascular Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands, 2Dept. of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam Medical Center, 3Dept. of Vascular Medicine, Amsterdam Medical Center, 4Dept. of Plasma Proteins, Sanquin Blood Supply, 5Center for Experimental and Molecular Medicine, Amsterdam Medical Center, Amsterdam, The Netherlands Introduction: In cancer, tumor progression and metastasis are promoted by prohemostatic activity. Protein C (PC) is involved in hemostasis, inflammation and signal transduction, and has a protective effect on the endothelial barrier. In mice, administration of activated PC reduced experimental metastasis. It is unclear whether PC level is associated with mortality in patients with cancer. Aim: To assess the relation between PC level and survival in patients with advanced cancer. Materials and Methods: A multicenter, randomized, open-label study was performed in 11 countries between May 2006 and August 2008 (INPACT study, van Doormaal et al, JCO 2011). Patients (n=503) with hormonerefractory prostate cancer, non-small cell lung cancer stage IIIB and locally advanced pancreatic cancer were randomized to receive nadroparin or placebo for 6 to 46 weeks following a specific schedule. Patients were followed till death or the end of the study in May 2009. PC activity levels were measured at baseline and categorized in tertiles. The association between PC level and mortality was evaluated with Cox proportional hazard models, adjustments were made by multivariate Cox proportional hazard models. Results: PC activity could be measured in 479 (95%) patients (tertiles: <97, 97-120 and >120%). Two patients with missing information on type of cancer were excluded. Mean age was 65±10 years; 87 (18%) were female; and 161 patients had lung cancer, 125 pancreatic cancer and 191 prostate cancer. During median follow-up of 10.5 months, 291 (61%) patients died. Median PC activity was 107% (IQR 92-129). There was a clear inverse relation between PC activity and mortality (p for trend=0.036). In the lowest tertile, mortality was 66%, in the middle and high tertile 61% and 56%, respectively. Compared to the highest tertile, the lowest tertile was associated with a HR on mortality of 1.36 (95% CI 1.02-1.80). Adjustment for age, gender and nadroparin use did not affect this association. The association appeared to be strongest in the patients with lung cancer, HR 0.818 (p=0.11) as compared to the patients with prostate cancer, HR 0.972 (p=0.83) and pancreatic cancer, HR 0.950 (p=0.68). Conclusions: Lower PC activity is associated with increased mortality in patients with advanced cancer. However, validation of our findings in a larger cohort is necessary. When the association of PC and mortality has