Mechanisms of disease: the impact of antithrombotic therapy in cancer patients

Effect of Perioperative Antithrombotics on Postoperative Transfusion and Hematoma in Head and Neck Free Flaps

Objective

To explore if antiplatelet or anticoagulant therapy increases the risk of transfusion requirement or postoperative hematoma formation in patients undergoing microvascular reconstruction for head and neck defects.

Study Design

Retrospective cohort study.

Setting

Departments of Otolaryngology-Head and Neck Surgery at the University of Alabama at Birmingham, the University of Colorado, and the University of California Irvine.

Methods

A multi-institutional, retrospective review on microvascular reconstruction of the head and neck between August 2013 to July 2021. Perioperative antithrombotic data were collected to examine predictors of postoperative transfusion and hematoma.

Results

A total of 843 free flaps were performed. Preoperative hemoglobin, hematocrit, operative time, and flap type were positive predictors of postoperative transfusion in both bivariate (P < .0001) and multivariate analyses (P < .0001). However, neither anticoagulation nor antiplatelet therapy were predictive of postoperative transfusion rates and hematoma formation.

Conclusion

Antithrombotic regimens do not increase the risk of postoperative transfusion or hematoma in head and neck microvascular reconstruction. Based on this limited data, perioperative antithrombotic regimens can be considered in patients who may otherwise be at risk for these postoperative complications.

The Tissue Factor Pathway in Cancer: Overview and Role of Heparan Sulfate Proteoglycans

Historically, the only focus on tissue factor (TF) in clinical pathophysiology has been on its function as the initiation of the extrinsic coagulation cascade. This obsolete vessel-wall TF dogma is now being challenged by the findings that TF circulates throughout the body as a soluble form, a cell-associated protein, and a binding microparticle. Furthermore, it has been observed that TF is expressed by various cell types, including T-lymphocytes and platelets, and that certain pathological situations, such as chronic and acute inflammatory states, and cancer, may increase its expression and activity. Transmembrane G protein-coupled protease-activated receptors can be proteolytically cleaved by the TF:FVIIa complex that develops when TF binds to Factor VII (PARs). The TF:FVIIa complex can activate integrins, receptor tyrosine kinases (RTKs), and PARs in addition to PARs. Cancer cells use these signaling pathways to promote cell division, angiogenesis, metastasis, and the maintenance of cancer stem-like cells. Proteoglycans play a crucial role in the biochemical and mechanical properties of the cellular extracellular matrix, where they control cellular behavior via interacting with transmembrane receptors. For TFPI.fXa complexes, heparan sulfate proteoglycans (HSPGs) may serve as the primary receptor for uptake and degradation. The regulation of TF expression, TF signaling mechanisms, their pathogenic effects, and their therapeutic targeting in cancer are all covered in detail here.

Antioxidant and Anticoagulant Status Were Improved by Personalized Dietary Intervention Based on Biochemical and Clinical Parameters in Cancer Patients

We investigated whether personalized dietary intervention could improve clinical measurements such as immune cell-mediated cytotoxicity, serum albumin, derivatives of reactive oxygen metabolites (D-ROMS), D-dimer, and fibrinogen. Cancer patients received either a treatment support diet (TD, for those with chemotherapy), or a remission support diet (RD; for those in remission) for at least 3 wk (21-61 days). Both diets were low glycemic, low fat, and high plant protein diets; the diet for the TD group contained an additional 0.5 servings of protein. Based on clinical values, additional amounts of garlic, onion, tomato, shiitake, rice bran, kale, blueberry, pineapples, and/or turmeric powder were provided in regular meals. Estimated daily intake of protein, plant fat, garlic, onion, allicin, and quercetin was greater in the TD compared to the RD. An increased intake of vitamin A, vitamin C, vitamin E and selenium and a reduction in D-dimer were noted compared to baseline diets in both groups. A decrease in D-ROMS in the RD and an increase in albumin and an increased tendency in cytotoxicity in the TD were observed. In conclusion, personalized diets with supplemented functional ingredients improved antioxidant status and/or anticoagulant activity in cancer patients undergoing chemotherapy and in remission.

Pathologies at the nexus of blood coagulation and inflammation: thrombin in hemostasis, cancer, and beyond

Thrombin is the protease involved in blood coagulation. Its deregulation can lead to hemostatic abnormalities, which range from subtle subclinical to serious life-threatening coagulopathies, i.e., during septicemia. Additionally, thrombin plays important roles in many (patho)physiological conditions that reach far beyond its well-established role in stemming blood loss and thrombosis, including embryonic development and angiogenesis but also extending to inflammatory processes, complement activation, and even tumor biology. In this review, we will address thrombin's broad roles in diverse (patho)physiological processes in an integrative way. We will also discuss thrombin as an emerging major target for novel therapies.

Prognostic value of the D-dimer test in oesophageal cancer during the perioperative period

BACKGROUND

There has been little research on the perioperative D-dimer levels in oesophageal cancer patients. Plasma D-dimer levels can be used to predict the outcome in cancer patients.

METHODS

A cancer group of 66 oesophageal cancer patients and a control group of 12 patients with benign disease were enrolled in this cohort study. The plasma D-dimer levels during the pre-operation and 3rd and 9th day post-operation periods were prospectively examined and analysed between the two groups. Plasma D-dimer levels were also compared with the clinicopathological characteristics and 3-year survival of the oesophageal cancer patients.

RESULTS

Plasma D-dimer levels increased in both groups after surgery, but they were significantly higher in the cancer group. In oesophageal cancer patients, pre-operation plasma D-dimer levels were significantly higher in TNM stage IV patients. Perioperative plasma D-dimer levels significantly increased after surgery, and the survival was shortened in those patients whose D-dimer levels on the 3rd and 9th post-operative day above the median. In addition, increased plasma D-dimer levels at the 3rd and 9th days after surgery were influenced by the patient's age.

CONCLUSION

In oesophageal cancer patients, D-dimer levels increased after surgery, and the increases were associated with poor outcomes.

Genetic pathways linking hemostasis and cancer

Oncogenic events impact interactions of cancer cells with their surroundings. Amongst the most consequential, in this regard, is the influence on angiogenesis, inflammation and hemostasis. Indeed, mutant oncogenes (EGFR, HER2, RAS, MET, PML-RARα) are known to alter the expression of angiogenic and pro-inflammatory factors, as well as change the cancer cell coagulome, including the levels of tissue factor (TF) and other mediators (PAI-1, COX2). Accompanying losses of tumour suppressor genes (PTEN, p53), and changes in microRNA (miR-19b, miR-520) facilitate these effects. Transforming genes may also trigger ectopic production of coagulation factors (e.g. FVII) by cancer cells and their release and properties of procoagulant microparticles (MPs). By deregulating protease activated receptors (PAR1/2) oncogenes may also change tumour cell responses to coagulation factor signalling. These changes act in concert with microenvironmental factors (hypoxia), stress responses (therapy) and differentiation programs, including epithelial-to-mesechymal transitions (EMT) and through tumour initiating cell (TIC) compartment. In so doing, the coagulation system influences early (initiation, angiogenesis), intermediate (growth, invasion) and late stages (metastasis, relapse) of cancer progression. In fact, TF may act as a molecular switch that controls the transition between dormant, latent and progressive/metastatic disease. TIC-like cells may play a role in these effects, as they express TF and PAR-1/2, and respond to stimulation with their agonists. As major human malignancies (e.g. glioblastoma) are increasingly recognized to consist of a spectrum of molecularly distinct disease subtypes driven by specific genetic pathways, so too may their patterns of interaction differ with the coagulation system. A better understanding of these linkages may be a source of new diagnostic, prognostic and therapeutic opportunities.

p38 MAPK controls prothrombin expression by regulated RNA 3' end processing

Thrombin is a key protease involved in blood coagulation, complement activation, inflammation, angiogenesis, and tumor invasion. Although induced in many (patho-)physiological conditions, the underlying mechanisms controlling prothrombin expression remained enigmatic. We have now discovered that prothrombin expression is regulated by a posttranscriptional regulatory mechanism responding to stress and inflammation. This mechanism is triggered by external stimuli that activate p38 MAPK. In turn, p38 MAPK upmodulates canonical 3' end processing components and phosphorylates the RNA-binding proteins FBP2 and FBP3, which inhibit 3' end processing of mRNAs, such as prothrombin mRNA, that bear a defined upstream sequence element (USE) in their 3'UTRs. Upon phosphorylation, FBP2 and FBP3 dissociate from the USE, making it accessible to proteins that stimulate 3' end processing. We provide in vivo evidence suggesting the importance of this mechanism in inflammatory hypercoagulation and tumor invasion. Regulated 3' end processing thus emerges as a key mechanism of gene regulation with broad biological and medical implications.

Role of the tissue factor pathway in the biology of tumor initiating cells

Oncogenic transformation and aberrant cellular differentiation are regarded as key processes leading to malignancy. They produce heterogenous cellular populations including subsets of tumour initiating cells (TICs), also known as cancer stem cells (CSCs). Intracellular events involved in these changes profoundly impact the extracellular and systemic constituents of cancer progression, including those dependent on the vascular system. This includes angiogenesis, vasculogenesis, activation of the coagulation system and formation of CSC-related and premetastatic niches. Tissue factor (TF) is a unique cell-associated receptor for coagulation factor VIIa, initiator of blood coagulation, and mediator of cellular signalling, all of which influence vascular homeostasis. Our studies established a link between oncogenic events, angiogenesis and the elevated expression of TF in several types of cancer cells. The latter suggests that cancer coagulopathy and cellular events attributed to the coagulation system may have cancer-specific and genetic causes. Indeed, in human glioma cells, a transforming mutant of the epidermal growth factor receptor (EGFRvIII) triggers not only the expression of TF, but also of its ligand (factor VII) and protease activated receptors (PAR-1 and PAR-2). Consequently, tumour cells expressing EGFRvIII become hypersensitive to contact with blood borne proteases (VIIa, thrombin), which upregulate their production of angiogenic factors (VEGF and IL-8), and contribute to formation of the growth promoting microenvironment (niche). Moreover, TF overexpression accompanies features of cellular aggressiveness such as markers of CSCs (CD133), epithelial-to-mesenchymal transition (EMT) and expression of the angiogenic and prometastatic phenotype. Conversely, TF blocking antibodies inhibit tumour growth, angiogenesis, and especially tumour initiation upon injection of threshold numbers of tumourigenic cells. Likewise, TF depletion in the host compartment (e.g. in low-TF mice) perturbs tumour initiation. These observations suggest that both cancer cells and their adjacent host stroma contribute TF activity to the tumour microenvironment. We postulate that the TF pathway may play an important role in formation of the vascular niche for tumour initiating CSCs, through its procoagulant and signalling effects. Therapeutic blockade of these mechanisms could hamper tumour initiation processes, which are dependent on CSCs and participate in tumour onset, recurrence, drug resistance and metastasis.

Antithrombotic therapy and survival in patients with malignant disease

A broad range of studies suggest a two-way relationship between cancer and venous thromboembolism (VTE). Patients with cancer have consistently been shown to be at elevated risk for VTE; this risk is partly driven by an intrinsic hypercoagulable state elicited by the tumour itself. Conversely, thromboembolic events in patients without obvious risk factors are often the first clinical manifestation of an undiagnosed malignancy. The relationship between VTE and cancer is further supported by a number of trials and meta-analyses which, when taken together, strongly suggest that antithrombotic therapy can extend survival in patients with cancer by a mechanism that extends beyond its effect in preventing VTE. Moreover, accumulating evidence from in vitro and in vivo studies has shown that tumour growth, invasion, and metastasis are governed, in part, by elements of the coagulation system. On 22 May 2009, a group of health-care providers based in the United Kingdom met in London, England, to examine recent advances in cancer-associated thrombosis and its implications for UK clinical practice. As part of the discussion, attendees evaluated evidence for and against an effect of antithrombotic therapy on survival in cancer. This paper includes a summary of the data presented at the meeting and explores potential mechanisms by which antithrombotic agents might exert antitumour effects. The summary is followed by a consensus statement developed by the group.

Genetic Link Between Cancer and Thrombosis

From the beginning of their lives, cancer cells exert a procoagulant activity in their microenvironment, which can extend systemically and become clinically evident as Trousseau's syndrome, the well-known association between tumor and thrombosis. It is becoming clear that the genetic mechanisms responsible for neoplastic transformation (activation of oncogenes such as RAS or MET, and inactivation of tumor suppressor genes such as p53 or PTEN) directly induce the expression of genes controlling hemostasis. Activation of blood coagulation results in a selective advantage for cancer cells, as fibrin provides a scaffold for anchorage and invasion, and coagulation proteins induce receptor-mediated intracellular signals promoting invasive growth. Targeting the tumor procoagulant activity can fight not only a dangerous tumor adverse effect, but also the core mechanisms of cancer onset and progression.

Tissue factor in tumour progression

The linkage between activation of the coagulation system and cancer is well established, as is deregulation of tissue factor (TF) by cancer cells, their vascular stroma and cancer-associated inflammatory cells. TF is no longer perceived as an 'alternative' coagulation factor, but rather as a central trigger of the coagulation cascade and an important cell-associated signalling receptor activated by factor VIIa, and interacting with several other regulatory entities, most notably protease-activated receptors (PAR-1 and PAR-2). Preclinical studies revealed the role of oncogenic transformation and tumour micro-environment as TF regulators in cancer, along with the impact of this receptor on gene expression, tumour growth, metastasis, angiogenesis and, possibly, formation of the cancer stem cell niche. Increasing interest surrounds the shedding of TF-containing microvesicles from cancer cells, their entry into the circulation and their role in the intercellular transfer of TF activity, cancer coagulopathy and other processes. Recent data also suggest differential roles of cell autonomous versus global effects of TF in various settings. Questions are raised regarding the consequences of TF expression by tumour cells themselves and by their associated host stroma. Progress in these areas may soon begin to impact on clinical practice and, as such, raises several important questions. Can TF be exploited as a therapeutic target in cancer? Where and when may this be safe and beneficial? Is expression of TF in various disease settings useful as a biomarker of cancer progression or the associated hypercoagulability? What clinical questions related to TF are especially worthy of further exploration, at present and in the near future? Some of these developments and questions will be discussed in this chapter.

Quality of life after iatrogenic bile duct injury: a case control study

OBJECTIVE

To compare quality of life (QOL) of patients following iatrogenic bile duct injuries (BDI) to matched controls.

SUMMARY BACKGROUND DATA

BDI complicate approximately 0.3% of all cholecystectomy procedures. The literature regarding impact on quality of life is conflicted as assessment using clinical determinants alone is insufficient.

METHODS

The medical outcomes study short form 36 (SF-36), a sensitive tool for quantification of life quality outcome, was used. The study group of iatrogenic BDI was compared with an age- and sex-matched group who underwent uncomplicated cholecystectomy. Telephone questionnaire using the SF-36 quality of life tool was administered to both groups at a median postoperative time of 12 years 8 months (range, 2 months -20 years).

RESULTS

Seventy-eight patients were referred with BDI but due to mortality (n = 10) and unavailability (n = 6) 62 participated. The age- and sex-matched control cohort had undergone uncomplicated cholecystectomy (n = 62). Comparison between groups revealed that 7 of 8 variables examined were statistically similar to those of the control group (physical functioning, role physical, bodily pain, general health perceptions, vitality and social functioning, and mental health index). Mean role emotional scores were slightly worse in the BDI group (46 vs. 50) but the significance was borderline (P = 0.045). Subgroup analysis by method of intervention for BDI did not demonstrate significant differences.

CONCLUSION

Quality of life of surviving patients following BDI compares favorably to that after uncomplicated laparoscopic cholecystectomy.

The role of tumor-and host-related tissue factor pools in oncogene-driven tumor progression

Oncogenic events play an important role in cancer-related coagulopathy (Trousseau syndrome), angiogenesis and disease progression. This can, in part, be attributed to the up-regulation of tissue factor (TF) and release of TF-containing microvesicles into the pericellular milieu and the circulation. In addition, certain types of host cells (stromal cells, inflammatory cells, activated endothelium) may also express TF. At present, the relative contribution of host- vs tumor-related TF to tumor progression is not known. Our recent studies have indicated that the role of TF in tumor formation is complex and context-dependent. Genetic or pharmacological disruption of TF expression/activity in cancer cells leads to tumor growth inhibition in immunodeficient mice. This occurred even in the case of xenotransplants of human cancer cells, in which TF overexpression is driven by potent oncogenes (K-ras or EGFR). Interestingly, the expression of TF in vivo is not uniform and appears to be influenced by many factors, including the level of oncogenic transformation, tumor microenvironment, adhesion and the coexpression of markers of cancer stem cells (CSCs). Thus, minimally transformed, but tumorigenic embryonic stem (ES) cells were able to form malignant and angiogenic outgrowths in the absence of TF. However, these tumors were growth inhibited in hosts (mice) with dramatically reduced TF expression (low-TF mice). Depletion of host TF also resulted in changes affecting vascular patterning of some, but not all types of tumors. These observations suggest that TF may play different roles growth and angiogenesis of different tumors. Moreover, both tumor cell and host cell compartments may, in some circumstances, contribute to the functional TF pool. We postulate that activation of the coagulation system and TF signaling, may deliver growth-promoting stimuli (e.g. fibrin, thrombin, platelets) to dormant cancer stem cells (CSCs). Functionally, these influences may be tantamount to formation of a provisional (TF-dependent) cancer stem cell niche. As such these changes may contribute to the involvement of CSCs in tumor growth, angiogenesis and metastasis.

Atherosclerosis and vascular aging as modifiers of tumor progression, angiogenesis, and responsiveness to therapy

It is rarely considered that age-related common vascular co-morbidities may affect therapeutic outcomes of antiangiogenic therapy in cancer. Indeed, the accepted model of human disease consists of 4- to 8-week-old (young) tumor-bearing, but otherwise healthy, experimental mice, yet human cancers are diagnosed and treated in later decades of life when atherosclerosis and vascular diseases are highly prevalent. Here we present evidence that tumor growth and angiogenesis are profoundly altered in mice affected by natural aging and with genetically induced atherosclerosis (in ApoE(-/-) mice). Thus, transplantable tumors (Lewis lung carcinoma and B16F1) grew at higher rates in young (4 to 8 weeks old) ApoE(+/+) and ApoE(-/-) nonatherosclerotic syngeneic recipients than in their old (12 to 18 months old) or atherosclerotic (old/ApoE(-/-)) counterparts. These age-related changes were paralleled by reduced tumor vascularity, lower expression of tumor endothelial marker 1, increased acute tumor hypoxia, depletion of circulating CD45(-)/VEGFR(+) cells, and impaired endothelial sprouting ex vivo. Exposure of tumor-bearing mice to metronomic therapy with cyclophosphamide exerted antimitotic effects on tumors in young hosts, but this effect was reduced in atherosclerotic mice. Collectively, our results suggest that vascular aging and disease may affect tumor progression, angiogenesis, and responses to therapy.

Incidence of venous thromboembolism and the impact on survival in breast cancer patients

PURPOSE

The incidence of venous thromboembolism (VTE) and the risk factors associated with development of VTE have not been reported in a large population-based study of breast cancer patients.

PATIENTS AND METHODS

The California Cancer Registry was merged with the Patient Discharge Data Set, and the number of VTE events determined among patients diagnosed between 1993 and 1999.

RESULTS

Among 108,255 patients with breast cancer, the 2-year cumulative VTE incidence was 1.2%, with a rate of 1.2 and 0.6 events/100 patient-years during the first and second half-year, respectively. The 1-year incidence of VTE was significantly increased compared with the general population (standardized incidence ratio of VTE, 4.2; 95% CI, 3.9 to 4.4). In a multivariate model, significant predictors of developing VTE within 2 years were: age (hazard ratio [HR], 2.0 if > 75 years v < 45; 95% CI, 1.6 to 2.6), the number of chronic medical comorbidities (HR, 2.9 if 3 v 0; 95% CI, 2.4 to 3.5), and advancing cancer stage (HR, 6.3; 95% CI, 5.3 to 7.5 for metastatic v local disease). In multivariate models, VTE was a significant predictor of decreased 2-year survival (HR, 2.3; 95% CI, 2.1 to 2.6) and when stratified by initial cancer stage, the effect was highest in patients with localized (HR, 5.1; 95% CI, 3.6 to 7.1) or regional stage (HR, 3.5; 95% CI, 2.5 to 4.8) cancer compared with patients with metastatic disease (HR, 1.9; 95% CI, 1.5 to 2.4).

CONCLUSION

Approximately 1% of breast cancer patients developed VTE within 2 years, with the highest incidence in the first 6 months after diagnosis. Metastatic disease and comorbidities were the strongest predictors. The diagnosis of VTE was associated with a higher risk of death within 2 years.

Effect of non-anticoagulant N-desulfated heparin on expression of vascular endothelial growth factor, angiogenesis and metastasis of orthotopic implantation of human gastric carcinoma

AIM: To investigate the effect of N-desulfated heparin on tumor metastasis and angiogenesis, and expression of vascular endothelial growth factor (VEGF) of orthotopic implantation of human gastric carcinoma in male severe combined immune deficiency (SCID) mice.

METHODS: Human gastric cancer SGC-7901 cells were orthotopically implanted into the stomach of SCID mice. The mice were randomly divided into normal saline group and N-desulfated heparin group. One week after operation, the mice in N-desulfated heparin group received i.v. injections of N-desulfated heparin (Shanghai Institute of Cell Biology, Chinese Academy of Sciences, 10 mg/kg.d) twice weekly for 3 wk. The mice in normal saline group received i.v. injections of normal saline (100 μL) twice weekly for 3 wk. The mice were sacrificed six weeks after implantation. Tumor metastasis was evaluated histologically for metastasis under microscope. Intratumoral microvessel density (MVD) and VEGF expression were evaluated immuohistochemically. VEGF mRNA expression in gastric tissue of SCID mice was detected by real time PCR.

RESULTS: The tumor metastasis rate was 80% in normal saline group and 20% in N-desulfated heparin group (P < 0.05). MVD was 8.0 ± 3.1 in normal saline group and 4.3 ± 1.8 in N-desulfated heparin group (P < 0.05). VEGF positive immunostaining was found in cytoplasm of cancer cells. The rate of VEGF positive expression was higher in normal saline group than in N-desulfated heparin treated group (90% vs 20%, P < 0.05). VEGF mRNA expression was significantly inhibited by N-desulfated heparin and was higher in normal saline group than in N-desulfated heparin group (Ct value 19.51 ± 1.01 vs 22.55 ± 1.36, P < 0.05). N-desulfated heparin significantly inhibited the expression of VEGF mRNA in cancer cells. No bleeding occurred in N-desulfated heparin group.

CONCLUSION: N-desulfated heparin can inhibit metastasis of gastric cancer by suppressing tumor VEGF expression and tumor angiogenesis, but has no obvious anticoagulant activity.

Oncogenes, Trousseau Syndrome, and Cancer-Related Changes in the Coagulome of Mice and Humans

Cancer is often associated with venous thrombosis, a phenomenon that was first described by Trousseau in 1865 (Trousseau syndrome). Recent studies have begun to explain how oncogenic events may deregulate the hemostatic system. For instance, activated oncogenes (K-ras, EGFR, PML-RARalpha, and MET) or inactivated tumor suppressors (e.g., 53 or PTEN) may increase the risk of thrombosis by inducing the expression of tissue factor, a potent procoagulant molecule, and plasminogen activator inhibitor-1, a fibrinolysis inhibitor. In a more complex clinical reality, transforming genes may often act in concert with numerous epigenetic factors, including hypoxia, inflammation, anticancer therapy, contact between blood and metastatic cancer cells, and emission of procoagulant vesicles from tumors and their stroma into the circulation. To add to mechanistic insights gained from mouse models, which may not fully phenocopy human Trousseau syndrome, we suggest that valuable clues to progression and thrombosis risk may be obtained by monitoring multiple hemostatic variables in cancer patients ("coagulomics").

Invasive growth: a MET-driven genetic programme for cancer and stem cells

Metastasis follows the inappropriate activation of a genetic programme termed invasive growth, which is a physiological process that occurs during embryonic development and post-natal organ regeneration. Burgeoning evidence indicates that invasive growth is also executed by stem and progenitor cells, and is usurped by cancer stem cells. The MET proto-oncogene, which is expressed in both stem and cancer cells, is a key regulator of invasive growth. Recent findings indicate that the MET tyrosine-kinase receptor is a sensor of adverse microenvironmental conditions (such as hypoxia) and drives cell invasion and metastasis through the transcriptional activation of a set of genes that control blood coagulation.

The pathogenesis of venous thromboembolism in cancer: emerging links with tumour biology

Venous thromboembolism (VTE) is a frequent complication in individuals with cancer and is considered to be a cause of substantial mortality. Epidemiological studies identify malignancy as an independent VTE risk factor and show that cancer patients are at increased risk of both initial and recurrent VTE events. The risk due to cancer is compounded by the effects of chemotherapy and other treatments. The pathogenesis of cancer-associated VTE is complex involving multiple interactions between tumours and various components of haemostasis. The development of a systemic hypercoagulable state is considered a key pathogenetic feature and is attributed to tumour expression of tissue factor and other procoagulants, activation of vascular cells by tumour-derived cytokines and adhesive interactions between tumour cells and host cells. An increasing body of evidence indicates that the activation of haemostasis in malignant disease contributes to tumour growth and progression by stimulation of intracellular signalling pathways. The interaction of tissue factor, thrombin and other coagulation factors with protease activated receptor (PAR) proteins expressed by tumour cells and host vascular cells leads to the induction of genes related to the processes of angiogenesis, cell survival and cell adhesion and migration.

A Retrospective Study of Coagulation Abnormalities in Patients Receiving Concomitant Capecitabine and Warfarin

BACKGROUND

The extent and complications of the interaction between capecitabine and warfarin are not fully known.

PATIENTS AND METHODS

A retrospective study of 77 patients who received capecitabine was performed to analyze coagulation abnormalities with or without warfarin.

RESULTS

Twenty-one patients received warfarin with capecitabine. Twelve were on an average warfarin dosage of 19.4 mg per week (range, 7-35 mg) before capecitabine treatment, with a stable international normalized ratio (INR; range, 0.9-3.3). The dose of capecitabine ranged from 1.6 g/m2 to 2 g/m2 per day. Thirteen patients (11 on warfarin) had an INR > 3 (range, 3.23-11.5), resulting in a probability of an INR > 3 of 32% in the warfarin group versus 4% for those not on warfarin (P = 5.1 x 10(-14)) at 130 days. Six patients required a warfarin dose reduction (1-2.5 mg decrease). There were 7 episodes of bleeding (all gastrointestinal; 5 with warfarin). Seven patients who experienced bleeding had INRs ranging from 1.06 to 8 (average, 3.31) at the time bleeding occurred. Of the 7 bleeding episodes, 5 patients required transfusions, averaging 3.25 units of red blood cells and 2.4 units of fresh frozen plasma. The incidence of bleeding at 130 days of treatment with capecitabine was 18% with warfarin versus 2% without (P = 4 x 10(-13)). Bleeding episodes were not significantly different between patients with or without liver involvement (4 of 40 episodes vs. 3 of 37 episodes, respectively; P = 0.12). Patients with an INR > 3 were evenly distributed between those with or without liver involvement (6 of 40 patients vs. 7 of 37 patients, respectively). No INR increases persisted after discontinuation of capecitabine.

CONCLUSION

This study confirms a clinically significant interaction between warfarin and capecitabine-based chemotherapy akin to that already known for 5-fluorouracil. In addition to altered coagulation parameters, bleeding can be a complication. These events occurred in patients with and without liver metastases. We recommend weekly monitoring of coagulation parameters for all patients receiving concomitant warfarin and capecitabine, with an appropriate adjustment of warfarin dose. The nature and extent of this interaction requires further investigation.

Effect of N-desulfated heparin on angiogenesis and vascular endothelial growth factor expression in mice with severe combined immunodeficiency

AIM: To investigate the effect of N-desulfated heparin on tumor metastasis, angiogenesis, and expression of vascular endothelial growth factor (VEGF) after ortho-topic implantation of human gastric carcinoma in mice with severe combined immunodeficiency (SCID).

METHODS: The SCID mice metastasis model was established by in situ implantation of human gastric carcinoma tissue, then the mice were randomly divided into two groups: the normal saline group (treated with normal saline) and NNH group [treated with N-desulfat-ed heparin, 10 mg/(kg·d) iv, 2/wk, for 3 wk]. The mice were sacrificed 6 wk after the implantation. The tumor metastasis, intratumoral microvessel density (MVD), and VEGF expression were evaluated respectively..

RESULTS: The tumor metastasis rates were significan-tly different between normal saline and NNH group (80% vs 20%, P < 0.05). No side effect such as hemorrhage was observed in the mice. The MVD was 8.0 ± 3.1 in the normal saline group and 4.3 ± 1.8 in the NNH group, and there was significant difference between those 2 groups (P < 0.05). The positive rate of VEGF expressi-on was significantly higher in the normal saline group than that in the NNH group (90% vs 20%, P < 0.05).

CONCLUSION: N-desulfated heparin can inhibit the metastasis of gastric cancer through inhibiting the ex-pression of tumor VEGF and angiogenesis with no ob-vious side effect such as hemorrhage