Venous thromboembolism and cancer: a systematic review

Predictive modeling of lower extreme deep vein thrombosis following radical gastrectomy for gastric cancer: based on multiple machine learning methods

Postoperative venous thromboembolic events (VTEs), such as lower extremity deep vein thrombosis (DVT), are major risk factors for gastric cancer (GC) patients following radical gastrectomy. Accurately predicting and managing these risks is crucial for optimal patient care. This retrospective case‒control study involved 693 GC patients from our hospital who underwent radical gastrectomy. We collected plentiful and comprehensive clinical indicators including a total of 49 baseline, preoperative, surgical and pathological clinical data. Using univariate logistic regression, we identified potential risk factors, followed by feature selection through the Boruta algorithm. We then constructed the final predictive model using multivariate logistic regression and evaluated it using receiver operating characteristic (ROC) curve analysis, calibration plots, decision curve analysis, and other methods. Additionally, we applied various machine learning techniques, including decision trees and random forests, to assess our model's predictive strength. This retrospective case‒control study involved 693 GC patients from our hospital who underwent radical gastrectomy. We collected plentiful and comprehensive clinical indicators including a total of 49 baseline, preoperative, surgical and pathological clinical data. Using univariate logistic regression, we identified potential risk factors, followed by feature selection through the Boruta algorithm. We then constructed the final predictive model using multivariate logistic regression and evaluated it using receiver operating characteristic (ROC) curve analysis, calibration plots, decision curve analysis, and other methods. Additionally, we applied various machine learning techniques, including decision trees and random forests, to assess our model's predictive strength. Univariate logistic analysis revealed 14 risk factors associated with postoperative lower limb DVT. Based on the Boruta algorithm, six significant clinical factors were selected, namely, age, D-dimer (D-D) level, low-density lipoprotein, CA125, and calcium and chloride ion levels. A nomogram was developed using the outcomes from the multivariate logistic regression analysis. The predictive model showed high accuracy, with an area under the curve of 0.936 in the training set and 0.875 in the validation set. Various machine learning algorithms confirmed its strong predictive capacity. MR analysis revealed meaningful causal relationships between key clinical factors and DVT risk. Based on various machine learning methods, we developed an effective predictive diagnostic model for postoperative lower extremity DVT in GC patients. This model demonstrated excellent predictive value in both the training and validation sets. This novel model is a valuable tool for clinicians to use in identifying and managing thrombotic risks in this patient population.

A large-scale genome-wide cross-trait analysis for the effect of COVID-19 on female-specific cancers

Little is known regarding the long-term adverse effects of COVID-19 on female-specific cancers, nor the shared genetic influences underlying these conditions. We performed a comprehensive genome-wide cross-trait analysis to investigate the shared genetic architecture between COVID-19 (infection, hospitalization, and critical illness) with three female-specific cancers (breast cancer (BC), epithelial ovarian cancer (EOC), and endometrial cancer (EC)). We identified significant genome-wide genetic correlations with EC for both hospitalization (r g  = 0.19, p = 0.01) and critical illness (r g  = 0.29, p = 3.00 × 10-4). Mendelian randomization demonstrated no valid association of COVID-19 with any cancer of interest, except for suggestive associations of genetically predicted hospitalization (ORIVW = 1.09, p = 0.04) and critical illness (ORIVW = 1.06, p = 0.04) with EC risk, none withstanding multiple correction. Cross-trait meta-analysis identified 20 SNPs shared between COVID-19 with BC, 15 with EOC, and 5 with EC; and transcriptome-wide association studies revealed multiple shared genes. Findings support intrinsic links underlying these complex traits, highlighting shared mechanisms rather than causal associations.

Inpatient primary prophylaxis of cancer-associated thromboembolism (CAT)

PURPOSE

Cancer-associated thrombosis (CAT) increases morbidity and mortality in oncology patients. The risk of CAT is increased with hospitalization for acute medical illness. The goal of this review will be to examine the available evidence for (1) risk assessment and (2) primary thromboprophylaxis, (3) international published guideline recommendations, and (4) future directions to manage oncology patients admitted for an acute medical illness.

METHODS

A review was performed for each subject to gather information on the available evidence and recommendations available for oncology patients hospitalized for an acute medical illness.

RESULTS

Risk assessments for thrombosis are primarily developed and validated in the general population. There is not a risk assessment that has specifically been developed and validated in oncology patients hospitalized for an acute medical illness. Most evidence for thromboprophylaxis of oncology patients is from sub-group analysis of larger randomized-controlled trials in the general population. Evidence is conflicting and suggests an individualized approach evaluating the risk-benefit of thromboprophylaxis. The strength of recommendations of international guidelines is limited because of the available evidence. Guidelines usually recommend utilizing and/or offering thromboprophylaxis to oncology patients hospitalized for an acute medical illness barring contraindications. Future evidence needs to improve risk assessments and knowledge of the appropriate agent, dose, and duration of thromboprophylaxis if indicated.

CONCLUSION

Evidence for risk assessments and primary prophylaxis for oncology patients hospitalized for acute medical illness appears limited, with many research opportunities available to improve understanding on management of this patient population.

Increased activity of procoagulant factors in patients with small cell lung cancer

Small cell lung cancer (SCLC) patients have augmented risk of developing venous thromboembolism, but the mechanisms triggering this burden on the coagulation system remain to be understood. Recently, cell-derived microparticles carrying procoagulant phospholipids (PPL) and tissue factor (TF) in their membrane have attracted attention as possible contributors to the thrombogenic processes in cancers. The aims of this study were to assess the coagulation activity of platelet-poor plasma from 38 SCLC patients and to provide a detailed procoagulant profiling of small and large extracellular vesicles (EVs) isolated from these patients at the time of diagnosis, during and after treatment compared to 20 healthy controls. Hypercoagulability testing was performed by thrombin generation (TG), procoagulant phospholipid (PPL), TF activity, Protein C, FVIII activity and cell-free deoxyribonucleic acid (cfDNA), a surrogate measure for neutrophil extracellular traps (NETs). Our results revealed a coagulation activity that is significantly increased in the plasma of SCLC patients when compared to age-related healthy controls, but no substantial changes in coagulation activity during treatment and at follow-up. Although EVs in the patients revealed an increased PPL and TF activity compared with the controls, the TG profiles of EVs added to a standard plasma were similar for patients and controls. Finally, we found no differences in the coagulation profile of patients who developed VTE to those who did not, i.e. the tests could not predict VTE. In conclusion, we found that SCLC patients display an overall increased coagulation activity at time of diagnosis and during the disease, which may contribute to their higher risk of VTE.

Prognostic Value of Pretreatment D-Dimer Level in Small-Cell Lung Cancer: A Meta-Analysis

Purpose:

Pretreatment plasma d-dimer has been reported to be a potential prognostic indicator of lung cancer. To determine the prognostic significance of pretreatment d-dimer level in predicting clinical outcomes, such as the overall survival (OS) and progression-free survival (PFS), of patients with small cell lung cancer (SCLC).

Methods:

A systematic search in PubMed, Web of Science, EMBASE, Cochrane Library, CNKI, SinoMed, Wanfang and VIP databases was performed to identify available studies. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were applied to assess the association of pretreatment d-dimer level with prognosis of SCLC patients. All statistical analyses were conducted via the STATA 12.0 version software.

Results:

A total of 7 studies involving 964 patients were included in this meta-analysis and all patients were from China. The results showed that elevated pretreatment d-dimer level was significantly correlated with worse OS (HR = 1.90, 95% CI: 1.55-2.34, P < 0.001) and PFS (HR = 1.52, 95% CI: 1.24-1.85, P<0.001). Subgroup analyses based on the treatment, d-dimer cut-off, detection method and source of HR were also performed to further verify the prognostic value of pretreatment d-dimer level in SCLC.

Conclusions:

Pretreatment blood concentration of d-dimer may deserve as a reliable factor to predict prognosis of Chinese patients with SCLC. More well-designed prospective studies with large samples are still needed to verify our findings.

Expression variations and clinical significance of MMP-1, MMP-2 and inflammatory factors in serum of patients with deep venous thrombosis of lower extremity

Expression levels and clinical significance of matrix metalloproteinase-1 (MMP1), MMP-2 and inflammatory factors in the serum of patients with deep venous thrombosis (DVT) of lower extremity were investigated. Fifty untreated DVT patients were selected as the DVT group, and 50 patients undergoing health examination were enrolled as the normal control group. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of MMP-1, MMP-2, interleukin-6 (IL-6), IL-8 and tumor necrosis factor-α (TNF-α) in the serum. Western blotting was adopted to detect the expression levels of MMP-1 and MMP-2 proteins. Fluorescent reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was applied to examine the messenger ribonucleic acid (mRNA) expression levels. Moreover, the circumferences of the patients were measured. The difference between the circumference of affected extremity and unaffected extremity was calculated. Correlation analysis was conducted separately for the levels of serum MMP-1, MMP-2, IL-6, IL-8 and TNF-α of patients in the DVT group. In the DVT group, the levels of MMP-1, MMP-2, IL-6, IL-8, and TNF-α at 7 days after treatment were significantly lower than those before treatment (P<0.01). Compared with that before treatment, the circumference difference of the affected and unaffected extremities of the patients was reduced at 7 days after treatment (P<0.01). The levels of IL-6, IL-8 and TNF-α were positively correlated with the levels of MMP-1 and MMP-2, respectively in the DVT group (P<0.05 or P<0.01). MMP-1, MMP-2 and inflammatory factors play an important role in the occurrence and development of DVT, of which the levels of IL-6, IL-8 and TNF-α are positively correlated with the levels of MMP-1 and MMP-2, respectively. Therefore, monitoring the concentration of MMP-1, MMP-2 and inflammatory factors is of significant value for the diagnosis, progression and judgement of treatment effect of DVT in clinical practice.

Retrospective Evaluation of Thromboembolism Risk in Ovarian Cancer Patients Treated with Bevacizumab

Background

Bevacizumab is used in addition to standard, platinum-based chemotherapy to treat advanced-stage ovarian cancer patients. Thrombosis is a well-documented adverse effect of bevacizumab.

Objective

The aim of this study was to identify predictive parameters for thromboembolic events in ovarian cancer patients and to explain how bevacizumab increases the risk of these events.

Patients and Methods

Fifty-seven FIGO stage III ovarian cancer patients who underwent cytoreductive surgery and chemotherapy were identified and included in this retrospective study. Twenty-six patients were treated with carboplatin and paclitaxel (CP) only (control group), and 31 patients received CP with bevacizumab (study group). The two groups were compared with regard to thrombosis risk factors and laboratory parameters (total leukocytes, platelet count, hemoglobin, APTT, prothrombin time, INR, fibrinogen levels, D-dimer concentration) before treatment, after each course of chemotherapy, and during thromboembolic events.

Results

Only patients in the group receiving bevacizumab experienced venous thromboembolism (VTE) (p=0.03, χ² test). VTE occurred on average at the 13th cycle of chemotherapy. Patients who experienced VTE had increased BMI before chemotherapy as compared to patients with no thromboembolic event (27.2 vs. 23.3, p=0.005, Mann-Whitney test). D-dimer concentration before treatment was also elevated more in patients affected by VTE (3132.5) than in the non-VTE group (956.43) (p=0.0007, Mann-Whitney test). During the first four administrations of chemotherapy in patients with future VTE, there was a reduction in D-dimer concentration and an extension of APTT. A D-Dimer level higher than 485 ng/mL prior to first chemotherapy indicates for a risk of VTE with 94% sensitivity and 36% specificity.

Conclusions

An elevated D-dimer level and high BMI before chemotherapy are risk factors for VTE in ovarian cancer patients receiving bevacizumab. Bevacizumab possibly increases the risk for VTE.

Cancer patients' experiences of living with venous thromboembolism: A systematic review and qualitative thematic synthesis

BACKGROUND

Cancer-associated thrombosis is common. Recommended treatment is daily injected low-molecular-weight heparin for 6 months. Most studies focus on prophylaxis and treatment; few have explored the patients' experience.

AIMS

To identify and synthesise the available literature concerning patients' experience of cancer-associated thrombosis.

DESIGN

Systematic literature review and qualitative thematic synthesis.

DATA SOURCE

MEDLINE, Embase, CINAHL, PsycINFO (until 10/2016; limited to English) were searched. Eligible papers were qualitative studies of adult patients' experience of cancer-associated thrombosis. Two researchers screened titles/abstracts/papers against inclusion criteria with recourse to a third for disagreements. Critical Appraisal Skills Programme qualitative checklist tool was used for quality appraisal.

RESULTS

A total of 1397 articles were identified. Five qualitative studies (total n = 92; age range 32-84 years) met the inclusion criteria. Participants had various cancer types. Most had advanced disease and were receiving palliative care. Four major themes emerged from the data: knowledge deficit (patients and clinicians), effects of cancer-associated thrombosis (physical and psychological), effects of anticoagulation and coping strategies.

CONCLUSION

The cancer journey is difficult in itself, but thrombosis was an additional, frightening and unexpected burden. Although the association between cancer and thromboembolism is well-known, cancer patients are not routinely educated about the risk or warning symptoms/signs of thromboembolism which may otherwise be misattributed to the cancer by patient and clinician alike. This systematic review highlights the impact of cancer-associated thrombosis on the lives of cancer patients, and calls for education for patients and clinicians to be part of routine care and further work to address this patient priority.

High Rates of Thromboembolic Events in Patients with Germ Cell Cancer Undergoing Cisplatin-Based Polychemotherapy

BACKGROUND

We examined whether or not extended prophylaxis with low molecular weight heparin (LMWH) would significantly reduce thromboembolic event (TEE) rates in germ cell cancer patients undergoing cisplatin-based chemotherapy.

PATIENTS AND METHODS

LMWH prophylaxis was given from the first day of chemotherapy until 21 days after completing the last chemotherapy cycle to 45 out of 93 (48.4%) patients (extended), and to 48 out of 93 (51.6%) patients during their hospitalization only (limited) between January 2008 and December 2013. Patients were analyzed retrospectively for TEEs such as deep vein thrombosis (DVT), pulmonary embolism (PE), myocardial infarction (MI) or peripheral arterial thrombosis.

RESULTS

A total of 22/93 (23.7%) patients experienced 30 TEE during chemotherapy: 12 out of 30 (40%) deep vein thrombosis, 4 out of 30 (13.3%) MI, 10 out of 30 (33.3%) PE and 4 out of 30 peripheral arterial thrombosis (13.3%). TEE rates in both groups did not differ significantly (extended: 26.7 vs. limited: 20.8%).

CONCLUSIONS

The introduction of extended LMWH prophylaxis did not significantly reduce TEE rates in our patient cohort.

The Evaluation of Hydroxyethyl Starch (6% HES 130/0.4) Solution's Potential Preventive Effects on Coagulation Status in Women with Gynecologic Malignancies Using Rotation Thromboelastography

Objective: The aim of this study was to determine the effects of in vitro hemodilution with 6% hydroxyethyl starch (HES) 130/0.4 solution on the coagulation status of women with gynecologic malignancies by using rotation thromboelastogram (ROTEM®).

Materials and Methods: Twenty-two patients with gynecological tumors scheduled for anesthesia were enrolled. Blood samples were diluted by 20% with 6% HES (130/0.4) solution.

Results: In the INTEM assay, clotting time (CT) (p<0.01) and clot formation time (CFT) (p<0.001) were significantly increased and maximum maximum clot formation (MCF) (p< 0.001) was significantly decreased in HES hemodilution compared with the undiluted control samples. In the EXTEM assay, there was a similar significant increase in increase in CFT (p<0.01) and a decrease in maximum a decrease in MCF (p<0.01) in HES hemodilution when compared with control samples.

Conclusion: HES 130/0.4 solution causes significant hypocoagulable changes in the thromboelastographic profile of gynecologic cancer patients in vitro.

Autoimmune hemolytic anemia and venous thromboembolism: A systematic review and meta-analysis

OBJECTIVE

To investigate the risk of venous thromboembolism (VTE) among patients with autoimmune hemolytic anemia (AIHA).

METHODS

We conducted a systematic review and meta-analysis of observational studies that reported odds ratio, relative risk, hazard ratio or standardized incidence ratio comparing the risk of VTE in patients with AIHA versus participants without AIHA. Pooled risk ratio and 95% confidence intervals were calculated using a random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Out of 592 potentially relevant articles, four studies (three cohort studies and one cross-sectional study) met our inclusion criteria and were included in the data analysis. The pooled risk ratio of VTE in patients with AIHA was 2.63 (95% CI, 1.37-5.05). The statistical heterogeneity of this study was high with an I(2) of 97%.

CONCLUSIONS

Our study demonstrated a significantly increased risk of VTE among patients with AIHA.

The humanistic and economic burden of venous thromboembolism in cancer patients: a systematic review

The objective of this study was to present evidence on the epidemiology, health outcomes and economic burden of cancer-related venous thromboembolism (VTE). Medline, Cochrane Central Register of Controlled Trials, Econlit, Science Direct, JSTOR, Oxford Journals and Cambridge Journals were searched. The systematic literature search was limited to manuscripts published from January 2000 to December 2012. On the basis of the literature, cancer patients experience between two-fold and 20-fold higher risk of developing VTE than noncancer patients. They are more likely to experience a VTE event during the first 3-6 months after cancer diagnosis. In addition, an increased risk of VTE in patients with distant metastases and certain types of cancer (i.e. pancreatic or lung) was revealed. VTE was found to be a leading cause of mortality in cancer patients. The annual average total cost for cancer patients with VTE was found to be almost 50% higher than that of cancer patients without VTE. Inpatient care costs accounted for more than 60% of total cost. The existing evidence assessed in the present review demonstrated the significant health and economic consequences of cancer-related VTE, which make a strong case for the importance of its proper and efficient prevention and management.

Bevacizumab-Based Therapy for Patients with Brain Metastases from Non-Small-Cell Lung Cancer: Preliminary Results

BACKGROUND

Bevacizumab is a recombinant humanized monoclonal antibody that obstructs the vascular endothelial growth factor (VEGF) pathway. Despite its extensive employment in the treatment of primary tumors of the brain, experience of brain metastatic disease, a frequent complication in patients with lung cancer, is very limited. On the basis of the strong antiedemigenous effect and no risk of intracranial bleeding, we administered a bevacizumab-based chemotherapy to patients with non-small-cell lung cancer (NSCLC) and symptomatic metastatic brain lesions who were not suitable candidates for a specific local therapy.

METHODS

The patients received bevacizumab 7.5 mg/kg and cisplatin 75 mg/m(2) on day 1, and gemcitabine 1,250 mg/m(2) on days 1 and 8, every 21 days.

RESULTS

We studied 13 patients with clinical and radiological progressive brain metastases; the majority had a treatment-naïve disease. Bevacizumab-based chemotherapy was found to be well tolerated and effective: progression-free survival (PFS) was 9.1 months (range: 0.9-39.2+) and overall survival (OS) was 9.6 months (range 3-41.5+).

CONCLUSIONS

Bevacizumab-based therapy proved to be feasible and safe. The PFS and the OS data are very encouraging as well as the symptomatic benefit due to bevacizumab's high capacity to provide a long-lasting decrease of perilesional edema.

Effect of testing for cancer on cancer- and venous thromboembolism (VTE)-related mortality and morbidity in patients with unprovoked VTE

BACKGROUND

Venous thromboembolism (VTE) is a collective term for two conditions: deep vein thrombosis (DVT) and pulmonary embolism (PE). A proportion of patients with VTE have no underlying or immediately predisposing risk factors and the VTE is referred to as unprovoked. Unprovoked VTE can often be the first clinical manifestation of an underlying malignancy. This has raised the question of whether patients with an unprovoked VTE should be investigated for an underlying cancer. Treatment for VTE is different in cancer and non-cancer patients and a correct diagnosis would ensure that patients received the optimal treatment for VTE to prevent recurrence and further morbidity. Furthermore, an appropriate cancer diagnosis at an earlier, potentially curative stage could avoid the risk of cancer progression and thus lead to improvements in cancer-related mortality and morbidity.

OBJECTIVES

To determine whether testing for undiagnosed cancer in patients with a first episode of unprovoked VTE (DVT or PE) is effective in reducing cancer and VTE-related mortality and morbidity and to establish which tests for cancer are most useful.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched January 2015) and the Cochrane Register of Studies (CRS) (2014, Issue 12). Clinical trials databases were searched. The reference lists of relevant articles were also checked.

SELECTION CRITERIA

Randomised and quasi-randomised trials in which patients with an unprovoked VTE were allocated to receive specific tests for cancer or clinically indicated tests only were eligible for inclusion in this review. Primary outcomes included all-cause mortality, cancer-related mortality and VTE-related mortality.

DATA COLLECTION AND ANALYSIS

Selection of the studies, quality assessment and data extraction were completed independently by two review authors. Any disagreements were resolved by discussion.

MAIN RESULTS

Two studies with a combined total of 396 patients met the inclusion criteria for this review. Both studies assessed the effect of testing for cancer versus clinically indicated tests only in patients with an unprovoked VTE. The quality of the evidence was moderate because although the studies were judged to be at low or unclear risk of bias, there was concern that the studies were small as reflected in the wide confidence intervals (CIs). Pooled analysis showed that testing for cancer was consistent with either a benefit or no benefit on cancer-related mortality (odds ratio (OR) 0.49, 95% CI 0.15 to 1.67, P = 0.26). One study showed that, overall, malignancies were less advanced in patients belonging to the extensive screening group than in patients of the control group (64% versus 20%, P = 0.047) and that tested patients were diagnosed earlier than untested patients (mean 1 month versus 11.6 months to cancer diagnosis from the time of diagnosis of VTE). Standard deviations were not provided for time to diagnosis, so it was not possible to perform an independent statistical analysis on this association. Neither study measured all-cause mortality, VTE-related morbidity and mortality, side effects of anticoagulation, side effects of cancer tests or patient satisfaction.

AUTHORS' CONCLUSIONS

Testing for cancer in patients with idiopathic VTE leads to earlier diagnosis of cancer at an earlier stage of the disease. However, there is currently insufficient evidence to draw definitive conclusions concerning the effectiveness of testing for undiagnosed cancer in patients with a first episode of unprovoked VTE (DVT or PE) in reducing cancer and VTE-related morbidity and mortality. The results are imprecise and could be consistent with either harm or benefit. Further good-quality large-scale randomised controlled trials are required before firm conclusions can be made.

Antithrombotic Therapy in Patients With Thrombocytopenic Cancer

Background:

Guidelines are discordant concerning management of patients having thrombocytopenia with cancer-associated thrombosis (CAT).

Methods:

Hospitalized adults with CAT and platelets ≤50 × 109 cells/L were managed with dalteparin 100 units/kg subcutaneously once daily. Comparator patients with CAT and platelets >50 × 109 cells/L were managed with dalteparin 200 units/kg/d.

Results:

Outcomes of 35 patients with thrombocytopenia (mean platelet count 26 ± 8.3 × 109 cells/L) and 58 comparator patients (mean platelet count 155 ± 75 × 109 cells/L) were evaluated. In all, 2 (5.7%) patients in the thrombocytopenia group and 1 patient (1.9%) in the comparator group experienced new-onset venous thromboembolism (odds ratio 3.31, 95% confidence interval [CI] 0.29-37.90, P = .556). The incidence of bleeding in patients with thrombocytopenia (8.6%) was similar to that in comparator patients (9.4%; risk ratio 0.94, 95% CI 0.37-2.39, P = .607).

Conclusion:

In hospitalized patients having thrombocytopenia with CAT, reduced-dose low-molecular-weight heparin was generally efficacious.

Thromboprophylaxis in ambulatory lung cancer treatment

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, are common problems experienced by patients with lung cancer that can impact treatment plans, prognoses, and survival. Patients with lung cancer are at greatest risk for development of VTE in the ambulatory care treatment setting. Literature does exist on VTE management for medical and surgical oncology inpatients, as well as clinical guidelines for inpatient prophylaxis; however, published evidence is lacking on outpatient risk and thromboprophylaxis in medical oncology outpatients, particularly patients with lung cancer. Because patients with lung cancer treated in the ambulatory setting have established risks for VTE, they may benefit from thromboprophylaxis. Clinical guidelines for outpatient thromboprophylaxis direct the clinical practice for thromboprophylaxis in lung cancer treatment. The purpose of the current article is to explore the VTE risks associated with ambulatory lung cancer treatment and to review the recommended guidelines for thromboprophylaxis to guide clinical decision making for patients with lung cancer.

Tumour and microparticle tissue factor expression and cancer thrombosis

Cancer is frequently complicated by venous thromboembolic events (VTE), which pose a significant health burden due to the associated high morbidity and mortality rates, yet the exact details of the pathophysiological mechanisms underlying their development are yet to be fully elucidated. Tissue factor (TF), the primary initiator of coagulation, is often overexpressed in malignancy and as such is a prime candidate in predicting the hypercoagulable state. Further exploration of this potential role has identified increases in the number of TF-expressing microparticles (MP) in the circulation of cancer patients, in particular in those known to have high incidences of thromboembolic complications. The risk of VTE in cancer is found to be further elevated by chemotherapy. Chemotherapy may, in eliciting cancer cell apoptosis, result in an increase in release of circulating procoagulant MP. We discuss a potential role of elevated tumour TF expression and increased circulating TF-positive MP in predicting VTE risk.

[Thromboembolic events in malignant diseases]

There is a bidirectional connection between tumors and thrombosis. On one hand, thromboembolic events are more frequent in cases of malignancies, on the other hand, proliferation of tumor cells, progression of the malignant process and metastasis formation are facilitated by the activation of the hemostatic system. Thromboembolic events are associated with a worse prognosis in case of patients with malignant diseases. Thromboembolism is the second most frequent cause of death in patients with malignant tumors. Mortality is twice as high in patients with thromboembolism compared to those without it. The incidence of thromboembolism shows an increasing tendency. There has been a 28% increase among hospitalized cancer patients between 1995 and 2003. One reason is that the new anti-tumor agents have more pronounced prothrombotic activity than those of traditional chemotherapeutic drugs. Assessment of the thrombotic risk of cancer patients becomes more important. Several guidelines have been published concerning the prevention and treatment of thromboembolism in patients with malignancy. The risk of thrombosis is influenced not only by the type of malignancy but there are also large individual differences. Furthermore, the risk of thrombosis changes during the disease process in the same patient. Perioperative thromboprophylaxis is a very important issue considering oncologic surgery. Thromboprophylaxis of oncologic patients has a high significance in respect of morbidity and mortality. However, thromboprophylaxis may also cause serious complications thus the correct risk assessment of cancer patients is very important.

Venous thromboembolism in patients with cholangiocarcinoma: focus on risk factors and impact on survival

BACKGROUND

A high incidence of venous thromboembolism (VTE) has been observed in patients with cancer. However, few data are available on patients with cholangiocarcinoma.

OBJECTIVES

The aim of this study was to evaluate the clinical characteristics and risk factors of VTE and to investigate whether VTE would affect the survival of patients with cholangiocarcinoma.

METHODS

We retrospectively reviewed 273 patients who were diagnosed with cholangiocarcinoma from January 2004 to December 2008.

RESULTS

We observed 40 cases of VTE, among which 10 patients had VTE at diagnosis. There were 14 cases of pulmonary thromboembolism with or without deep vein thrombosis, 18 cases of portal vein thrombosis, four cases of inferior vena cava thrombosis, and four of hepatic vein thrombosis. We found that progression of stage, C-reactive protein, and chemotherapy were significantly associated with the occurrence of VTE (P=0.022, 0.006, and 0.014, respectively). The median survival in the VTE and non-VTE groups were 13.0 and 25.0 months, respectively (log-rank test, P=0.026). VTE was an unfavorable prognostic factor for cholangiocarcinoma (hazard ratio=1.626, P=0.042).

CONCLUSION

In our study, advanced stage, C-reactive protein, and treatment with chemotherapeutic agents were related to the occurrence of VTE in patients with cholangiocarcinoma. VTE was an independent unfavorable prognostic factor for survivors of cholangiocarcinoma.

Risk of venous thromboembolism in patients with cancer: a systematic review and meta-analysis

BACKGROUND

People with cancer are known to be at increased risk of venous thromboembolism (VTE), and this risk is believed to vary according to cancer type, stage of disease, and treatment modality. Our purpose was to summarise the existing literature to determine precisely and accurately the absolute risk of VTE in cancer patients, stratified by malignancy site and background risk of VTE.

METHODS AND FINDINGS

We searched the Medline and Embase databases from 1 January 1966 to 14 July 2011 to identify cohort studies comprising people diagnosed with one of eight specified cancer types or where participants were judged to be representative of all people with cancer. For each included study, the number of patients who developed clinically apparent VTE, and the total person-years of follow-up were extracted. Incidence rates of VTE were pooled across studies using the generic inverse variance method. In total, data from 38 individual studies were included. Among average-risk patients, the overall risk of VTE was estimated to be 13 per 1,000 person-years (95% CI, 7 to 23), with the highest risk among patients with cancers of the pancreas, brain, and lung. Among patients judged to be at high risk (due to metastatic disease or receipt of high-risk treatments), the risk of VTE was 68 per 1,000 person-years (95% CI, 48 to 96), with the highest risk among patients with brain cancer (200 per 1,000 person-years; 95% CI, 162 to 247). Our results need to be considered in light of high levels of heterogeneity, which exist due to differences in study population, outcome definition, and average duration of follow-up between studies.

CONCLUSIONS

VTE occurs in greater than 1% of cancer patients each year, but this varies widely by cancer type and time since diagnosis. The absolute VTE risks obtained from this review can aid in clinical decision-making about which people with cancer should receive anticoagulant prophylaxis and at what times.

Heparin impairs angiogenesis through inhibition of microRNA-10b

Heparin, which has been used as an anticoagulant drug for decades, inhibits angiogenesis, whereas thrombin promotes tumor-associated angiogenesis. However, the mechanisms underlying the regulation of angiogenesis by heparin and thrombin are not well understood. Here, we show that microRNA-10b (miR-10b) is down-regulated by heparin and up-regulated by thrombin in human microvascular endothelial cells (HMEC-1). Overexpression of miR-10b induces HMEC-1 cell migration, tube formation, and angiogenesis, and down-regulates homeobox D10 (HoxD10) expression via direct binding of miR-10b to the putative 3' UTR of HoxD10. In addition, HMEC-1 cell migration and tube formation are induced by HoxD10 knockdown, whereas angiogenesis is arrested when HoxD10 expression is increased after anti-miR-10b or heparin treatments. Furthermore, expression of miR-10b and its transcription factor Twist are up-regulated by thrombin, whereas HoxD10 expression is impaired by thrombin. Using quartz crystal microbalance analysis, we show that heparin binds to thrombin, thereby inhibiting thrombin-induced expression of Twist and miR-10b. However, the expression of miR-10b is not attenuated by heparin any more after thrombin expression is silenced by its siRNA. Interestingly, we find that heparin attenuates miR-10b expression and induces HoxD10 expression in vivo to inhibit angiogenesis and impair the growth of MDA-MB-231 tumor xenografts. These results provide insight into the molecular mechanism by which heparin and thrombin regulate angiogenesis.

Upper extremity deep venous thrombosis

Upper extremity deep venous thrombosis is a serious disease entity which, based on the pathogenesis and in view of the individual patient’s prognosis, must be divided into a primary and a secondary form. Primary upper extremity deep venous thrombosis is, when related to effort, a rather benign disease with excellent prognosis quoad vitam, carrying only a minor potential of developing disabling post-thrombotic syndrome. If primary upper extremity deep venous thrombosis occurs without any obvious cause, screening for underlying malignancy is recommended. Secondary upper extremity deep venous thrombosis typically occurs in older patients with severe comorbidities, mainly related to indwelling central venous catheters and cancer. As a consequence of the underlying diseases, prognosis of secondary upper extremity deep venous thrombosis is poor. Despite a lack of high-quality validation data, ultrasonography is regarded the first-line imaging technique, since it is a non-invasive method without exposure to radiation. In case of a non-diagnostic result of ultrasonography, other imaging modalities such as magnetic resonance imaging and computed tomography may be applied. Regardless of the etiology, the cornerstone of therapy is anticoagulant treatment with low molecular weight heparin or unfractionated heparin and vitamin K antagonists in order to prevent thrombus progression and pulmonary embolism. Owing to a lack of evidence, the optimal duration of anticoagulant treatment remains unclear. The additional benefit of compression therapy as well as of more aggressive therapeutic approaches such as thrombolysis, angioplasty and surgical decompression of the thoracic outlet needs to be investigated in randomized trials.