Hypercoagulable State in Patients with Advanced Gastrointestinal Cancer: Evidence for an Acquired Resistance to Activated Protein C

Acute Coronary Syndrome in Cancer Patients

Cardiologists are seeing an increasing number of oncology patients every day, and acute coronary syndrome (ACS) is one of the problems patients encounter during follow-up. Cardio-oncology is the care of patients with cancer and cardiovascular disease, whether overt or occult, already established or acquired during treatment. Cardiovascular complications can occur acutely during or shortly after treatment and persist as long-term effects for months to years after treatment. As a delayed effect of cancer treatment, cardiovascular damage can occur months to years after the initial treatment. Vasospasm, thrombosis, and radiation-induced cardiovascular diseases can all cause ACS. Careful surveillance of ACS symptoms and regular screening during follow-up of patients with malignancy are suggested. In this review, we summarize the ACS we usually encounter during a range of cancer treatments or post cancer survival by providing illustrative case examples.

Internal Jugular Vein Thrombosis as First Sign of Metastatic Lung Cancer

We describe a case of spontaneous internal jugular vein thrombosis occurring as the first sign of occult lung cancer. The peculiarity of the case was the unusual site of thrombosis and the lack of risk factors for DVT (only a moderated reduction of protein S without inherited thrombophilia) as well as the absence of clinical signs of cancer. This report shows once again the strong association between idiopathic venous thromboembolism and cancer. Hypercoagulation tests confirmed the association between cancer and thrombophilia. Reduction of protein S has been discovered recently in patients with lung cancer but further data are required to confirm this finding. Combined treatment (chemotherapy and radiotherapy) associated with oral anticoagulation therapy was started in our patient at the moment of diagnosis.

Increased coagulation activity and genetic polymorphisms in the F5, F10 and EPCR genes are associated with breast cancer: a case-control study

Background

The procoagulant state in cancer increases the thrombotic risk, but also supports tumor progression. To investigate the molecular mechanisms controlling cancer and hemostasis, we conducted a case-control study of genotypic and phenotypic variables of the tissue factor (TF) pathway of coagulation in breast cancer.

Methods

366 breast cancer patients and 307 controls were genotyped for SNPs (n = 41) in the F2, F3 (TF), F5, F7, F10, TFPI and EPCR genes, and assayed for plasma coagulation markers (thrombin generation, activated protein C (APC) resistance, D-dimer, antithrombin, protein C, protein S, and TF pathway inhibitor (TFPI)). Associations with breast cancer were evaluated using logistic regression to obtain odds ratios (ORs) and 95% confidence intervals (CIs), or the chi-square test.

Results

Four SNPs in F5 (rs12120605, rs6427202, rs9332542 and rs6427199), one in F10 (rs3093261), and one in EPCR (rs2069948) were associated with breast cancer. EPCR rs2069948 was associated with estrogen receptor (ER) and progesterone receptor (PR) positivity, while the SNPs in F5 appeared to follow hormone receptor negative and triple negative patients. The prothrombotic polymorphisms factor V Leiden (rs6025) and prothrombin G20210A (rs1799963) were not associated with breast cancer. High APC resistance was associated with breast cancer in both factor V Leiden non-carriers (OR 6.5, 95% CI 4.1-10.4) and carriers (OR 38.3, 95% CI 6.2-236.6). The thrombin parameters short lag times (OR 5.8, 95% CI 3.7-9.2), short times to peak thrombin (OR 7.1, 95% CI 4.4-11.3), and high thrombin peak (OR 6.1, 95% CI 3.9-9.5) predicted presence of breast cancer, and high D-dimer also associated with breast cancer (OR 2.0, 95% CI 1.3-3.3). Among the coagulation inhibitors, low levels of antithrombin associated with breast cancer (OR 5.7, 95% CI 3.6-9.0). The increased coagulability was not explained by the breast cancer associated SNPs, and was unaffected by ER, PR and triple negative status.

Conclusions

A procoagulant phenotype was found in the breast cancer patients. Novel associations with SNPs in F5, F10 and EPCR to breast cancer susceptibility were demonstrated, and the SNPs in F5 were confined to hormone receptor negative and triple negative patients. The study supports the importance of developing new therapeutic strategies targeting coagulation processes in cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-845) contains supplementary material, which is available to authorized users.

Activated protein C resistance as measured by residual factor V after Russell's viper venom and activated protein C treatment analyzed as a continuous variable in multiple myeloma and normal controls

Increased risk of venous thromboembolism (VTE) has been described in multiple myeloma patients, particularly when exposed to immunomodulatory drugs. Epidemiological studies have shown that monoclonal gammopathy of undetermined significance (MGUS) patients also have an increased risk of VTE compared with normal individuals. Acquired activated protein C resistance (APC-R) is an independent risk factor for VTE in hematologic malignancies. We reviewed the records of patients with multiple myeloma and MGUS for APC-R by PEFAKIT APC-R test and compared them to normal individuals. We excluded from the analysis patients with a documented factor V Leiden mutation. The PEFAKIT APC-R is a plasma-based functional prothrombin assay based on ratio of patient clotting time with and without APC. Thirty-three MGUS and 93 multiple myeloma patients were compared with 39 normal individuals. Baseline characteristics from the three groups were similar in terms of age, sex, and performance status. The median APC-R for multiple myeloma, MGUS, and controls were 1, 1.06, and 1.1, respectively. Multiple myeloma patients compared to normal individuals had significantly shorter APC-R (P=0.0012). No significant difference was observed between MGUS and normal individuals (P=0.17). After analyzing APC-R values and multiple coagulation parameters, a significant inverse correlation was found between APC-R and fibrinogen (P=0.0000001) and D-dimer (P=0.045) serum levels and a direct correlation with prothrombin time value (P=0.034). The Pefakit APC-R test measured as continuous variable shows a statistically significant decrease in patients with myeloma compared to normal individuals.

Arterial and venous thrombosis in cancer patients

The most frequent ultimate cause of death is myocardial arrest. In many cases this is due to myocardial hypoxia, generally arising from failure of the coronary macro- and microcirculation to deliver enough oxygenated red cells to the cardiomyocytes. The principle reason for this is occlusive thrombosis, either by isolated circulating thrombi, or by rupture of upstream plaque. However, an additionally serious pathology causing potentially fatal stress to the heart is extra-cardiac disease, such as pulmonary hypertension. A primary cause of the latter is pulmonary embolus, considered to be a venous thromboembolism. Whilst the thrombotic scenario has for decades been the dominating paradigm in cardiovascular disease, these issues have, until recently, been infrequently considered in cancer. However, there is now a developing view that cancer is also a thrombotic disease, and notably a disease predominantly of the venous circulation, manifesting as deep vein thrombosis and pulmonary embolism. Indeed, for many, a venous thromboembolism is one of the first symptoms of a developing cancer. Furthermore, many of the standard chemotherapies in cancer are prothrombotic. Accordingly, thromboprophylaxis in cancer with heparins or oral anticoagulation (such as Warfarin), especially in high risk groups (such as those who are immobile and on high dose chemotherapy), may be an important therapy. The objective of this communication is to summarise current views on the epidemiology and pathophysiology of arterial and venous thrombosis in cancer.

Expression of protein C (PC), protein S (PS) and thrombomodulin (TM) in human colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) is often complicated by thromboembolic episodes. It has been recognized that blood coagulation proteins play a role in cancer progression. An important inhibitory mechanism is provided by the protein C (PC) system consisting of PC, protein S (PS) and thrombomodulin (TM). Recently, novel biological activities have been ascribed to the PC system that do not relate to their hemostatic functions, eg. in angiogenesis, apoptosis and inflammation.

OBJECTIVES

The purpose of the study was to elucidate the solid phase interactions between CRC tissue and components of the PC system that may contribute to tumor progression.

MATERIAL AND METHODS

CRC tissues were obtained at surgical resection during treatment of 66 patients. Immunohistochemical studies were performed using polyclonal antibodies against PC, PS and TM. A semiquantitative analysis of the protein expression was also performed.

RESULTS

Weak expression of PC was observed in cancer cells of two-thirds of the specimens examined, while in 3/66 cases there was no staining for PC in cancer cells. One fourth of CRCs exhibited strong expression of PC. The presence of PS was demonstrated in 64/66 cases of CRC. However, its expression was irregular in terms of intensity of staining and percentage of cancer cells exhibiting protein expression. Weak expression of TM was demonstrated in two thirds of the cases examined, while a strong TM staining was revealed in one third of colon cancers.

CONCLUSION

Heterogeneous expression of the PC system components in CRC tissue may point to their biological activity modulating tumor growth.

Increased acquired activated protein C resistance in unselected patients with hematological malignancies

BACKGROUND

We have previously found that activation of coagulation in patients with various hematological malignancies was apparently not initiated by tissue factor (TF). Acquired activated protein C (APC) resistance may be another mechanism responsible for such hypercoagulation, and has been demonstrated in patients with solid tumors, but not in patients with hematological malignancy.

OBJECTIVE

To investigate acquired APC resistance in a hypercoagulable cohort of patients with hematological malignancies.

PATIENTS/METHODS

Blood samples from 93 patients with acute myeloid leukemia (AML), chronic lymphatic leukemia, multiple myeloma, or non-Hodgkin's lymphoma, were analyzed before start and after completion of cancer therapy. APC resistance was measured using calibrated automated thrombography. The APC sensitivity ratio (APC-SR) was calculated as the ratio of the endogenous thrombin potential (ETP) determined in plasma probed with either APC or buffer.

RESULTS

Untreated patients were found to have higher APC-SR than healthy controls, and patients with AML had higher APC-SR as compared to the other diagnoses, both findings being consistent with acquired APC resistance. The acquired APC resistance was partly ameliorated with cancer treatment. Decreased levels of protein S and TF pathway inhibitor were inversely correlated to APC resistance.

CONCLUSIONS

APC resistance may contribute to the hypercoagulable state in hematological malignancies.

Thrombophilia and risk of venous thrombosis in patients with cancer

Venous thrombosis is a common and severe complication in patients with cancer. We reviewed studies assessing whether a state of acquired or congenital thrombophilia influenced the risk of thrombosis in patients with cancer. The results are equivocal. However, the majority of studies were of limited size. The influence of thrombophilia in patients with cancer may be more difficult to demonstrate than in the general population, the risk of thrombosis due to cancer per se possibly outweighing the contribution of thrombophilic factors. Moreover, the results may depend on the genetic background of the population, the type of cancer, the type of thrombosis, and the chemotherapeutic treatment. Nevertheless, it appears that factor V Leiden or G20210A prothrombin gene mutation increases the risk of venous thromboembolism about 2- to 4-fold, compared with patients with cancer without either of these mutations. Similar results were observed for the occurrence of central venous catheter-associated thrombosis. Antiphospholipid antibodies and acquired resistance to activated protein C were frequently observed in patients with cancer and appeared to favor the occurrence of thrombosis. The role of hyperhomocysteinemia deserves further investigation. Since the clinical implications of these findings remain to be clarified, routine screening of cancer patients for thrombophilia cannot yet be recommended on the basis of these studies. Studies designed to assess the value of thromboprophylaxis in high-risk patients, including thrombophilic patients, with long-term central venous catheters may be valuable.

Activated Protein C Resistance and Factor V Leiden in Mexico

A common cause of hereditary thrombophilia is activated protein C resistance (APCR), and most cases result from factor V Leiden mutation. An APCR phenotype without association with factor V Leiden has been described. This transversal, observational, nonrandomized study evaluated these 2 phenomena in healthy indigenous and mestizo Mexican subjects (n = 4345), including 600 Mexican natives. No indigenous subjects had APCR, but 82 mestizo subjects did. After retesting, 50 subjects had a negative test. The remaining 32 subjects had factor V Leiden, giving a 0.85% prevalence of factor V Leiden in the mestizo Mexican population. Only 31% of APCR carriers had factor V Leiden. These results show a very low prevalence of APCR and factor V Leiden in Mexico. Except for factor V Leiden, there are no other mutations in the factor V gene responsible for the APCR phenotype. Acquired APCR is nearly twice as prevalent as the inherited variant.

Acquired resistance to activated protein C (aAPCR) in multiple myeloma is a transitory abnormality associated with an increased risk of venous thromboembolism

Acquired activated protein C resistance (aAPCR), not associated with factor V Leiden, has been described in cancer patients with an increased risk of venous thromboembolism (VTE). APCR was determined in 1178 myeloma patients using an activated partial thromboplastin time-based resistance assay in the presence of excess of factor V-deficient plasma; polymerase chain reaction amplification of genomic DNA was used to detect factor V Leiden mutation. A total of 109 patients were found to have abnormal APCR and one-third of them were carriers for the mutation. With a median follow-up of 40 months, the presence of aAPCR was associated with a significantly increased risk of thrombosis (P < or = 0.001). APCR was measured again after treatment in 31 patients with abnormal baseline values and had normalised in 30 of them. This study indicates that aAPCR is the most common single transitory baseline coagulation abnormality associated with VTE in myeloma patients.

Stroke Risk and Tamoxifen Therapy for Breast Cancer

BACKGROUND

Tamoxifen, which is used widely to treat, and increasingly to prevent, breast cancer, has been associated with increased risk of stroke. We assessed the impact of tamoxifen treatment for breast cancer on the risk of stroke, considering dose, duration, and recency of use of tamoxifen and known stroke risk factors.

METHODS

We conducted a nested case-control study of stroke after breast cancer among female Los Angeles County residents enrolled in a large health maintenance organization when diagnosed with breast cancer between January 1, 1980, and July 1, 2000. We obtained information on breast cancer treatment and stroke risk factors through medical record review and telephone interviews. The association (odds ratio [OR] and 95% confidence interval [CI]) between tamoxifen and stroke risk was determined by using a conditional logistic regression model, adjusting for menopausal status and history of hypertension and diabetes. All statistical tests were two-sided.

RESULTS

Of 11 045 women with breast cancer, 179 met stroke eligibility criteria and were individually matched to two stroke-free control subjects with breast cancer on age and year of breast cancer diagnosis. The mean age at breast cancer diagnosis was 66.6 years (standard deviation [SD] = 12.3 years), and the mean at-risk period (i.e., the time between breast cancer diagnosis and first stroke or comparable time period for control subjects) was 5.7 years (SD = 4.5 years). Tamoxifen use was not associated with risk of stroke, either overall (OR = 1.0, 95% CI = 0.6 to 1.6) or in subgroups defined by duration, dose, or recency of use. Chemotherapy, but not a specific chemotherapy regimen, was associated with an increased risk of stroke, regardless of tamoxifen use (no tamoxifen use, OR = 2.8, 95% CI = 1.3 to 6.3; tamoxifen use OR = 2.2, 95% CI = 1.2 to 4.1).

CONCLUSIONS

Tamoxifen use is not associated with increased stroke risk. Further exploration of possible increased stroke risk following chemotherapy treatment for breast cancer is needed.

Venous thromboembolism and malignancy

The association between venous thromboembolism (VTE) and malignancy was first recognized more than 135 years ago. Since then, a markedly increased incidence of VTE has been found in patients with malignant disease. Numerous clinical studies have demonstrated that malignancy or its treatment are major risk factors for VTE. Recent developments in moleculobiological studies have indicated that the high risk of VTE in malignancy is attributed to the hypercoagulable state caused by the disease and its treatments. Diagnostic approaches to clinically suspected VTE continue to evolve, making the diagnosis easier and more accurate. Recent advances in clinical studies have refined the management strategies for the prophylaxis and treatment of VTE in patients with or without cancer. In this paper, recent clinical studies will be reviewed, current understanding of the pathogenesis of thrombosis in malignancy described, and clinical implications discussed.

Markers of Coagulation and Angiogenesis in Cancer-Associated Venous Thromboembolism

Purpose: We sought to determine whether venous thromboembolism in cancer patients is associated with aberrant plasma levels of hemostatic and angiogenic factors.

Patients and Methods: Peripheral blood was collected before anticoagulant therapy from cancer patients with acute deep venous thrombosis (DVT; DVT + cancer group, n = 32), those without DVT (cancer control group, n = 36), and patients with acute DVT but no cancer (DVT control group, n = 58). Plasma assays of activation and inhibition of coagulation and fibrinolysis, as well as angiogenesis activation, were then performed.

Results: Median levels of thrombin-antithrombin complex, prothrombin fragments 1 + 2, and von Willebrand factor antigen were significantly greater in the DVT + cancer group than in the cancer control and DVT control groups (17.8 ng/mL v 4.6 ng/mL and 9.8 ng/mL, P = .0001 and P = .003, respectively; 3.65 nmol/L v 1.60 nmol/L and 2.71 nmol/L, P < .0001 and P = .011, respectively; and 4.04 U/mL v 2.26 U/mL and 2.06 U/mL, P < .0001, respectively). Median levels of tissue-type plasminogen activator were also significantly higher, while protein C activity was lower in the DVT + cancer group than in the DVT control group (14.6 ng/mL v 9.50 ng/mL, respectively, P = .0005; 0.89 U/mL v 1.11 U/mL, respectively, P = .0008).

Conclusion: These data not only support prior observations of coagulation activation in patients with malignancy, but also provide new evidence for enhanced coagulation activation in the setting of acute venous thromboembolism in cancer. Future prospective studies are warranted to determine whether these and other potential markers of hypercoagulability may help to identify cancer patients at highest risk for venous thromboembolism.

Cancer and the prothrombotic state

Thrombosis is a frequent complication of cancer, so it follows that the presence of a tumour confers a prothrombotic state. Indeed, in patients with cancer, each of the three components of Virchow's triad that predispose for thrombus formation have abnormalities, thus fulfilling the requirement for a prothrombotic or hypercoagulable state. The many signs and symptoms of the prothrombotic state in cancer range from asymptomatic basic abnormal coagulation tests to massive clinical thromboembolism, when the patient may be gravely ill. Many procoagulant factors, such as tissue factor and cancer procoagulant, are secreted by or are expressed at the cell surface of many tumours. Platelet turnover and activity are also increased. Damaged endothelium and abnormalities of blood flow in cancer also seem to play a part, as does abnormal tumour angiogenesis. Some studies have even suggested that these abnormalities may be related to long-term prognosis and treatment. We briefly describe the various clinical manifestations of thrombosis in cancer and discuss the evidence for the existence of a prothrombotic or hypercoagulable state associated with this disease. Further work is needed to examine the mechanisms leading to the prothrombotic state in cancer, the potential prognostic and treatment implications, and the possible value of quantifying indices of hypercoagulability in clinical practice.

Acquired activated protein C resistance is common in cancer patients and is associated with venous thromboembolism

PURPOSE

Cancer patients have an increased risk for venous thromboembolism. Because activated protein C resistance is a common risk factor for venous thromboembolism, we prospectively evaluated the activated protein C sensitivity ratio and factor V Leiden mutation in cancer patients with and without venous thromboembolism.

SUBJECTS AND METHODS

We studied 55 consecutive cancer patients with deep vein thrombosis, 58 cancer patients with no history of venous thromboembolism, 54 patients with venous thromboembolism without malignancy, and 56 healthy controls. The presence of factor V Leiden mutation was determined by polymerase chain reaction and allele specific restriction digestion. The activated protein C sensitivity ratio was expressed as the ratio of activated partial thromboplastin times measured in the presence and absence of activated protein C; a ratio <2.0 in patients who did not have factor V Leiden was considered to indicate acquired activated protein C resistance.

RESULTS

The prevalence of factor V Leiden mutation in cancer patients with thromboembolism (1 of 55, 2%) did not differ significantly from those in cancer patients without thromboembolism (4 of 58, 7%) or normal controls (2 of 56, 4%), but was significantly lower than that of patients with thromboembolism without cancer (18 of 54, 33%, P <0.001). The prevalence of acquired activated protein C resistance was significantly greater in cancer patients with thromboembolism (29 of 54, 54%, P = 0.001) compared with the other groups: 9 of 54 (17%) in cancer patients without thromboembolism, 7 of 36 (19%) in patients with thromboembolism without cancer, and none of the normal controls.

CONCLUSION

Although factor V Leiden is not a major risk factor for thrombosis in cancer patients, acquired activated protein C resistance is common and may contribute to the thrombotic tendency in these patients.

Changes of the coagulation and fibrinolysis system in malignancy: their possible impact on future diagnostic and therapeutic procedures

The interaction between malignant cell growth and the coagulation and fibrinolysis system has been a well known phenomenon for decades. During recent years, this area of research has received new attention. Experimental data suggest a role for the coagulation and fibrinolysis system in tumor development, progression and metastasis. Also, clinical research suggests that targeting the coagulation system or fibrinolysis system might influence the course of malignant disease beneficially. This paper reviews data on various hemostatic and fibrinolytic parameters in malignancy; the possible use of such parameters as risk markers in oncology patients; and possible targets of anti-neoplastic therapies using anticoagulant and/or antifibrinolytic strategies. Current evidence suggests that the tissue factor/factor VIIa pathway mediates the most abundant procoagulant stimulus in malignancy via the increase in thrombin generation. Tissue factor has been suggested to mediate pro-metastatic properties via coagulation-dependent and coagulation-independent pathways; tissue factor has also been implicated in tumor neo-angiogenesis. However, so far no model has been validated that would allow the use of tissue factor in its soluble or insoluble form as a marker for risk stratification in tumor patients. On the other hand, there is now good evidence that parts of the fibrinolytic system, such as urokinase-type plasminogen activator and its receptor ("uPAR"), can be used as strong predictors of outcome in several types of cancer, specifically breast cancer. Observation of various treatment options in patients with thromboembolic disease and cancer as well as attempts to use anticoagulants and/or therapies modulating the fibrinolytic system as anti-neoplastic treatment strategies have yielded exciting results. These data indicate that anticoagulant therapy, and specifically low molecular weight heparin therapy, is likely to have anti-neoplastic effects; and that their use in addition to chemotherapy will probably improve outcome of tumor treatment in certain types of cancer. However, the body of clinical data is still relatively small and the question whether or not we should routinely consider the coagulation and/or fibrinolysis system as therapeutic targets in cancer patients is yet to be answered.