Deep vein thrombosis in cancer: the scale of the problem and approaches to management

PDIA2 has a dual function in promoting androgen deprivation therapy induced venous thrombosis events and castrate resistant prostate cancer progression

Androgen deprivation therapy (ADT) is the first line of treatment for metastatic prostate cancer (PCa) that effectively delays the tumor progression. However, it also increases the risk of venous thrombosis event (VTE) in patients, a leading cause of mortality. How a pro-thrombotic cascade is induced by ADT remains poorly understood. Here, we report that protein disulfide isomerase A2 (PDIA2) is upregulated in PCa cells to promote VTE formation and enhance PCa cells resistant to ADT. Using various in vitro and in vivo models, we demonstrated a dual function of PDIA2 that enhances tumor-mediated pro-coagulation activity via tumor-derived extracellular vehicles (EVs). It also stimulates PCa cell proliferation, colony formation, and xenograft growth androgen-independently. Mechanistically, PDIA2 activates the tissue factor (TF) on EVs through its isomerase activity, which subsequently triggers a pro-thrombotic cascade in the blood. Additionally, TF-containing EVs can activate the Src kinase inside PCa cells to enhance the AR signaling ligand independently. Androgen deprivation does not alter PDIA2 expression in PCa cells but enhances PDIA2 translocation to the cell membrane and EVs via suppressing the clathrin-dependent endocytic process. Co-recruitment of AR and FOXA1 to the PDIA2 promoter is required for PDIA2 transcription under androgen-deprived conditions. Importantly, blocking PDIA2 isomerase activity suppresses the pro-coagulation activity of patient plasma, PCa cell, and xenograft samples as well as castrate-resistant PCa xenograft growth. These results demonstrate that PDIA2 promotes VTE and tumor progression via activating TF from tumor-derived EVs. They rationalize pharmacological inhibition of PDIA2 to suppress ADT-induced VTE and castrate-resistant tumor progression.

Apixaban for Extended Thromboprophylaxis After Oncologic Resection: Outcomes and Cost Analysis

BACKGROUND

Patients undergoing oncologic resection are at risk of developing venous thromboembolism (VTE), and this can lead to increased morbidity and hospital costs. Low-molecular weight heparin (LMWH) is recommended as extended thromboprophylaxis (ETP) in high-risk patients and has been shown to reduce rates of VTE.

METHODS

This is a retrospective review of consecutive patients undergoing resection for oncologic indications at a single institution from May 2016 to May 2019. This study evaluated the use of apixaban as ETP at discharge. The primary outcomes were deep vein thrombosis (DVT), pulmonary embolism (PE), or mesenteric/portal venous thromboembolism at 30, 60, and 90 days postoperatively.

RESULTS

A total of 600 patients were included; 449 patients received no ETP, and 151 patients received apixaban. PE occurred in 1.1, 1.6, and 2.3% of patients without ETP and 0, 0, and .7% of patients in the apixaban group (at 30, 60, and 90 days; P = .338, P = .201, and P = .306, respectively). DVT occurred in 1.8, 2.1, and 2.8% of patients without ETP and 0, 0, and 1.4% in the apixaban group (P = .211, P = .121, and P = .535, respectively). The total cost, including ETP and readmission for VTE, per patient was US $5.51 more in the apixaban group.

CONCLUSION

Apixaban therapy for ETP did not produce a statistically significant reduction in VTE events in our patients. Future studies should include more patients in a prospective multicenter trial.

Comparative Assessment of APTT Reagents for Evaluating Anticoagulant Sensitivity of Fucosylated Glycosaminoglycans (FGs) Derived from Sea Cucumbers

Fucosylated glycosaminoglycans (FGs) derived from sea cucumbers exhibit potent intrinsic Xase (iXase) inhibition, anticoagulation, and antithrombosis. Plasma activated partial thromboplastin time (APTT), a widely used screening test worldwide, is crucial for evaluating anticoagulant efficacy. However, the applicability of these commercially available APTT reagents for assessing anticoagulation of FGs remains unreported. In this study, we investigated the disparity between ellagic acid and colloidal silica APTT reagents in evaluating anticoagulation of dHG-5 and dHLFG-4, two depolymerized FGs, and elucidated the underlying rationale. The results demonstrated that dHG-5 and dHLFG-4 exhibited heightened sensitivity to the ellagic acid APTT reagent both in vitro and in vivo, and did not significantly affect the activation of APTT reagents for plasma. In addition, both ellagic acid and colloidal silica APTT reagents inhibited the anti-iXase of dHG-5 and dHLFG-4, and the inhibition of the ellagic acid APTT reagent was less pronounced compared to the colloidal silica APTT reagent. These findings suggest that the reduced impact of the ellagic acid APTT reagent on the anti-iXase activity of dHG-5 and dHLFG-4 is responsible for the increased sensitivity in plasma APTT analysis. This study offers valuable insights into the characteristics of two APTT reagents applied for assessing the anticoagulant activity of FG-related compounds.

Amputation of the Unsalvageable Leg in Vascular Patients with Cancer

OBJECTIVES

The aim of this study was to compare outcomes of major lower limb amputation (MLA) in patients with and without cancer and with cancer patients receiving palliation over amputation for their unsalvageable limb.

METHODS

Cancer patients who underwent a major amputation or palliation between 2013 and 2018 were included. Comparison groups were cancer-MLA (active/managed cancers), non-cancer MLA (historic cancer or no cancer history) and cancer-palliation at presentation with unsalvageable limbs. Prospectively collected data was retrospectively analysed for outcomes including survival, postoperative complications, length of stay, suitability for rehabilitation and discharge destination.

RESULTS

262 (cancer and non-cancer) patients underwent MLA and 18 patients with cancer received palliation. Of those amputated, 26 (9.9%) had active or managed cancer, of which 12 were diagnosed in the 6 months before MLA. Cancer-MLA patients presented with more acute ischaemia compared to non-cancer patients. Median survival was significantly different between the cancer-MLA (14.1 [9.5 - 29.5, 95% CI] months), non-cancer MLA (57.7 [45 - 73.6, 95% CI] months) and cancer-palliation (.6 [.4 - 2.3, 95% CI] months) groups, P < .001. A significantly higher proportion of cancer-MLA patients (10/26, 38.5%) were deemed unsuitable for rehabilitation in post-operative assessment compared to non-cancer MLA (21/236, 8.9%) patients, P < .001. There was a variation in destinations of discharge, with a greater proportion of cancer-MLA patients (4/26, 15.4%) going to a nursing home compared to non-cancer MLA (10/236, 4.2%) patients, P = .016.

CONCLUSION

Cancer is prevalent among vascular amputees, with a large proportion being occult diagnoses. Cancer is associated with poorer outcomes following amputation, but survival remains significantly better compared to palliation in cancer patients presenting with unsalvageable limbs.

Predictors of Symptomatic Venous Thromboembolism in Patients with Soft Tissue Sarcoma in the Lower Extremity

Orthopedic surgery and soft-tissue sarcoma (STS) both independently increase the risk of developing symptomatic venous thromboembolic events (SVTE), but there are no established risk factors or guidelines for how to prophylactically treat patients with STS undergoing surgery. The objectives of this study were to (1) identify the prevalence of SVTE in patients undergoing STS surgery, (2) identify risk factors for SVTE, and (3) determine the risk of wound complications associated with VTE prophylaxis. This retrospective study was conducted in a tertiary level, academic hospital. A total of 642 patients were treated for soft-tissue sarcoma in the lower extremity with follow up for at least 90 days for the development of SVTE such as deep venous thrombosis and pulmonary embolism. Multivariate logistic regression was used to identify predictors for these events by controlling for patient characteristics, surgical characteristics, and treatment variables, with significance held at p < 0.05. Twenty eight patients (4.36%) were diagnosed with SVTE. Multivariate analysis found six significant predictors ordered based on standardized coefficients: pre-operative (PTT) partial thromboplastin time (p < 0.001), post-operative PTT (p = 0.010), post-op chemotherapy (p = 0.013), metastasis at diagnosis (p = 0.025), additional surgery for metastasis or local recurrence (p = 0.004), and tumor size larger than 10 cm (p < 0.001). The risk of wound complications (p = 0.04) and infection (p = 0.017) increased significantly in patients who received chemical prophylaxis. Our study identifies risk factors for patients at increased risk of developing VTE. Further prospective research is necessary to identify which protocols would be beneficial in preventing SVTE in high-risk patients with a low profile of wound complications.

Incidence of venous thromboembolism and hemorrhage in Chinese patients after pulmonary lobectomy: mechanical prophylaxis or mechanical prophylaxis combined with pharmacological prophylaxis: a randomized controlled trial

Background

Venous thromboembolism (VTE) and postoperative bleeding are important complications of lung resection surgery. We investigated the preventive effect of mechanical prophylaxis versus pharmacological prophylaxis after lobectomy, and evaluated the effect of both on the incidence of hemorrhagic events.

Methods

A prospective study of 424 lobectomies with moderate to high risk of VTE (Caprini risk score <5) in a single center was performed from April 2020 to March 2021. Patients were 1:1 randomly allocated to mechanical prophylaxis or to the low-molecular-weight heparin (LMWH)-combination-prophylaxis. The incidence of postoperative thrombotic and bleeding events and relevant factors of the two groups were analyzed.

Results

A total of 410 participants, with 202 and 208 in the mechanical prophylaxis and LMWH-combination-prophylaxis groups respectively, were selected for analysis. Both groups had similar baseline and clinical characteristics. There were no cases of VTE or major bleeding during the study, but the incidence rate of minor bleeding in the LMWH-combination-prophylaxis group was significantly higher than mechanical prophylaxis group [odds ratio (OR) 0.035, 95% confidence interval (CI): 0.011–0.113].

Conclusions

A case-by-case risk assessment of VTE and hemorrhage remains necessary to determine the most appropriate method of thrombosis prophylaxis for patients undergoing pulmonary surgery. Mechanical prophylaxis may be preferable for lung cancer patients with moderate to high risk of VTE (Caprini risk score <5) undergoing lobectomy.

Trial Registration

Chinese Clinical Trial Registry ChiCTR2100051073.

Cumulative incidence of venous thromboembolism in patients with advanced cancer in prospective observational study

Venous thromboembolism (VTE) is frequently observed in patients with advanced cancer. The objective of this prospective observational study was to estimate, based on intensive screening, using computed tomography, lower‐extremity ultrasonography, and D‐dimer testing, the prevalence of VTE in patients with advanced cancer.

Patients with metastatic or locally advanced cancer without anticoagulant therapy, who were planning to receive chemotherapy during 4 weeks, were eligible. Evaluations of VTE were performed at pretreatment, 12 weeks, and 24 weeks after the start of chemotherapy. Primary endpoint was cumulative incidence of VTE for 24 weeks. Secondary endpoints included incidence of VTE (pretreatment, 12 weeks, and 24 weeks after the start of chemotherapy), VTE according to primary cancer site, symptomatic VTE, pulmonary thromboembolism (PE), and treatment of VTE.

We enrolled 860 patients with a median age of 68 years, including 34% female and 71% lung cancer. Cumulative incidence of VTE for 24 weeks was 22.6% (95% confidence interval: 19.8%–25.5%) (194 of 860 patients). Incidence of VTE was 11.3% pretreatment, 16.8% 12 weeks, and 14.1% 24 weeks. Symptomatic VTE was observed in 4.0% and PE in 1.0% of patients. By multivariate analysis, sex, D‐dimer level, and platelet count were independent risk factors of VTE for 24 weeks.

This large prospective observational study showed that cumulative incidence of VTE was high in advanced cancer patients, mainly lung cancer. Although most patients showed asymptomatic VTE, intensive screening of VTE may be considered in advanced cancer patients, especially in women with high level of D‐dimer and decreased platelet count (UMIN000015243).

Prognostic Significance of Incidental Deep Vein Thrombosis in Patients with Cancer Presenting with Incidental Pulmonary Embolism

In symptomatic acute pulmonary embolism (PE), the presence of deep vein thrombosis (DVT) is a risk factor for 30- and 90-day mortality. In patients with cancer and incidental PE, the prognostic effect of concomitant incidental DVT is unknown. In this retrospective study, we examined the effect of incidental DVT on all-cause mortality in such patients. Adjusted Cox multivariate regression analysis was used for relevant covariates. From January 2010 to March 2018, we included 200 patients (mean age, 65.3 ± 12.4 years) who were followed up for 12.5 months (interquartile range 7.4-19.4 months). Of these patients, 62% had metastases, 31% had concomitant incidental DVT, and 40.1% (n = 81) died during follow-up. All-cause mortality did not increase in patients with DVT (hazard ratio [HR] 1.01, 95% confidence interval [CI] 0.43-2.75, p = 0.855). On multivariate analysis, weight (adjusted HR 0.96, 95% CI 0.92-0.99, p = 0.032), and metastasis (adjusted HR 10.26, 95% CI 2.35-44.9, p = 0.002) were predictors of all-cause mortality. In conclusion, low weight and presence of metastases were associated with all-cause mortality, while presence of concomitant DVT was unrelated to poorer survival.

Latest advances in preventing thromboembolic disease in the ambulatory oncology patient

Venous thromboembolism (VTE) is often cited as a major cause of death and morbidity in cancer patients. Even a non-lethal VTE causes distress and is commonly perceived by patients as a set-back in the cancer journey and a threat to the cancer treatment. It is also known that the risk of VTE varies between cancers (cancer-related risk factors), between patients (patient-related risk factors), and also within the cancer journey of a single patient. Risk can increase during treatments like surgery and chemotherapy and decline during remission. Neither the low molecular weight heparins nor the vitamin K analogues have gained an established role in thromboprevention guidance other than in 'the high risk' patient, who remains a rather ambiguous entity. The recently published randomised studies of rivaroxaban and apixaban in moderate- to high-risk thrombosis patients, assigned by the Khorana Risk Score, has seen the inclusion of direct oral anticoagulants (DOACs) in recent guidelines (e.g. the American Society of Clinical Oncology 2019 guidelines) for this indication. The ease of administration and the demonstrated greater patient adherence to oral agents has heightened the expectation that a practice-changing thromboprevention study in cancer patients should be realizable. However, key unmet needs that pose familiar challenges remain and as yet do not have satisfactory solutions. Anticoagulants carry risks of bleeding that are higher in the cancer population. There is therefore the challenge of sufficient risk reduction of VTE from the intervention balanced against the number of patients that may be harmed from bleeding. There is also the challenge of penetrating the risk threshold beyond which oncologists would deem thromboprevention a clinically meaningful praxis. Thus, identifying the high-risk groups of patients or targeting the length or timing of the thromboprevention to when the risks are highest are major questions that remain the subject of ongoing research. Notably all this is taking place against a backdrop of changing therapeutics for many cancers (e.g. targeted agents, checkpoint inhibitors and combinations) and their assorted impact on VTE incidence. In this review, past data for the ambulatory cancer patient are summarised, the latest evidence for the direct oral anticoagulants apixaban and rivaroxaban are analysed and the challenges of identifying the high-risk patients that have the greater chance of benefiting from thromboprophylaxis are discussed.

Could Preoperative Unintended Weight Loss Predispose to Postoperative Thrombosis in Patients Undergoing Colorectal Cancer Surgery? An Analysis of the NSQIP Data

Objective: A significant portion of colorectal cancer patients lose weight preoperatively. Here we examine the influence of pre-operative significant weight loss on venous thromboembolism (VTE) risk and determine whether pre-operative BMI and albumin could influence VTE outcomes in patients who have lost significant weight prior to surgery.Methods: We conducted a retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) and identified 103,455 colorectal cancer patients undergoing major surgery from 2008 to 2012. Patients were assigned to one of two groups based on whether they lost significant weight preoperatively or not. Simple and stepwise multiple logistic regressions were used to evaluate the association between pre-operative unintended weight loss and 30-days postoperative outcomes. The association between weight loss and postoperative thrombosis was further assessed across several strata.Results: The overall prevalence of pre-operative significant weight loss was 6.8%. Significant weight loss prior to surgery was significantly and independently associated with a higher risk of VTE (adjusted OR 1.23, 95% CI 1.06-1.44), mortality (adjusted OR 1.55, 95% CI 1.35-1.78), composite morbidity (adjusted OR 1.52, 95% CI 1.42-1.62), bleeding (adjusted OR 1.78, 95% CI 1.67-1.91) and return to operation room (adjusted OR 1.29, 95% CI 1.16-1.42). The effect of pre-operative significant weight loss on thromboembolic outcome was evident across patients with a BMI <18.5 kg/m², 18.5 < BMI < 24.99 and BMI >40kg/m².Conclusions: Significant weight loss and BMI both need to be measured preoperatively to stratify patients who are at a higher risk of VTE.

Breast Cancer: Lifestyle, the Human Gut Microbiota/Microbiome, and Survivorship

Patients with a current diagnosis of breast cancer are enjoying dramatic cure rates and survivorship secondary to an increase in awareness, earlier detection, and more effective therapies. Although strategies such as Breast Cancer Awareness Month in October focus on early detection, lifestyle changes are seldom discussed other than dietary concerns and physical activity. Lifestyle modifications centered on diet and exercise have been demonstrated to affect overall disease-free survival in breast cancer. Since the early 2000s, the role of the human gut microbiota and its relation to breast cancer has become a major area of interest in the scientific and medical community. We live and survive owing to the symbiotic relationship with the microorganisms within us: the human microbiota. Scientific advances have identified a subset of the gut microbiota: the estrobolome, those bacteria that have the genetic capability to metabolize estrogen, which plays a key role in most breast cancers. Recent research provides evidence that the gut microbiome plays a substantial role in estrogen regulation. Gut microbiota diversity appears to be an essential component of overall health, including breast health. Future research attention should include a more extensive focus on the role of the human gut microbiota in breast cancer.

Treatment of venous thromboembolism with tinzaparin in oncological patients

Venous thromboembolism (VTE) is a major cause of morbidity and mortality in patients with cancer. For over a decade, the gold standard of treatment and secondary prevention of cancer-associated thrombosis (CAT) has been represented by low-molecular-weight heparins (LMWHs), which are currently recommended as the first-line treatment for CAT. Among the LMWHs that were more extensively tested in patients with CAT, tinzaparin is a LMWH produced by the enzymatic degradation of porcine-derived unfractionated heparin. The efficacy of tinzaparin in this setting is supported by well-grounded evidence. However, there is a need to discuss the positioning of tinzaparin in the continuously evolving treatment scenario of VTE therapy in cancer patients. In this paper, which was developed by a group of clinicians with wide experience in the treatment of VTE in cancer patients, we discuss the current therapeutic options and the role of tinzaparin for the treatment of CAT.

Clinical practice guidelines for prophylaxis of venous thomboembolism in cancer patients

Symptomatic venous thromboembolism (VTE) occurs 4-7 times more frequently in cancer patients as compared to non-cancer patients. A significant number of risk factors, which can be subcategorised as patient-, cancer- or treatment-related, have been shown to influence the risk of VTE during malignancy and further incorporated in risk-assessment models. Safe and efficient thromboprophylaxis regimens allow substantial decreased in VTE rates, since VTE is most often a largely preventable disease, but thromboprophylaxis remains underused in cancer compared to non-cancer patients. If thromboprophylaxis is warranted in cancer patients undergoing surgery or hospitalised for acute medical illness or with a lower mobility in the absence of contraindications to anticoagulants, its benefit remains controversial in outpatients and may be limited to locally advanced or metastatic pancreatic or lung cancer treated with chemotherapy. The International Initiative on Thrombosis and Cancer-CME free mobile app (ios and android), based on the International Clinical Practice Guidelines (CPG), facilitates their implementation and dissemination of knowledge worldwide so as to improve VTE treatment and prophylaxis in cancer patients.

Locoregional recurrence of breast cancer presenting as upper limb venous thromboembolism

Locoregional recurrence of breast cancer is a major concern for both patient and oncologist. Presentation as venous thromboembolism (VTE) carries risk of delayed diagnosis and has a poor prognosis. Here we describe, for the first time in the literature, a delayed diagnosis of local recurrence of infiltrative inflammatory breast cancer presenting as extensive deep venous thrombosis of the upper arm veins. This case demonstrates the need for a high level of vigilance for recurrence of malignancy in patients with no concurrent risk factors for VTE and atypical clinical progression in order to reach a timely diagnosis.

Targeting of C-type lectin-like receptor 2 or P2Y12 for the prevention of platelet activation by immunotherapeutic CpG oligodeoxynucleotides

Essentials CpG oligodeoxynucleotide (ODN) immuotherapeutics cause undesired platelet activating effects. It is crucial to understand the mechanisms of these effects to identify protective strategies. CpG ODN-induced platelet activation depends on C-type lectin-like receptor 2 (CLEC-2) and P2Y12. Targeting CLEC-2 or P2Y12 fully prevents CpG ODN-induced platelet activation and thrombosis.

SUMMARY

Background Synthetic phosphorothioate-modified CpG oligodeoxynucleotides (ODNs) show potent immunostimulatory properties that are widely exploited in clinical trials of anticancer treatment. Unexpectedly, a recent study indicated that CpG ODNs activate human platelets via the immunoreceptor tyrosine-based activation motif (ITAM)-coupled receptor glycoprotein VI. Objective To further analyze the mechanisms of CpG ODN-induced platelet activation and identify potential inhibitory strategies. Methods In vitro analyses were performed on human and mouse platelets, and on cell lines expressing platelet ITAM receptors. CpG ODN platelet-activating effects were evaluated in a mouse model of thrombosis. Results We demonstrated platelet uptake of CpG ODNs, resulting in platelet activation and aggregation. C-type lectin-like receptor 2 (CLEC-2) expressed in DT40 cells bound CpG ODNs. CpG ODN uptake did not occur in CLEC-2-deficient mouse platelets. Inhibition of human CLEC-2 with a blocking antibody inhibited CpG ODN-induced platelet aggregation. CpG ODNs caused CLEC-2 dimerization, and provoked its internalization. They induced dense granule release before the onset of aggregation. Accordingly, pretreating platelets with apyrase, or inhibiting P2Y12 with cangrelor or clopidogrel, prevented CpG ODN platelet-activating effect. In vivo, intravenously injected CpG ODN interacted with platelets adhered to mouse injured endothelium, and promoted thrombus growth, which was inhibited by CLEC-2 deficiency or by clopidogrel. Conclusions CLEC-2 and P2Y12 are required for CpG ODN-induced platelet activation and thrombosis, and might be targeted to prevent adverse events in patients at risk.

Pharmacology of Heparin and Related Drugs

Heparin has been recognized as a valuable anticoagulant and antithrombotic for several decades and is still widely used in clinical practice for a variety of indications. The anticoagulant activity of heparin is mainly attributable to the action of a specific pentasaccharide sequence that acts in concert with antithrombin, a plasma coagulation factor inhibitor. This observation has led to the development of synthetic heparin mimetics for clinical use. However, it is increasingly recognized that heparin has many other pharmacological properties, including but not limited to antiviral, anti-inflammatory, and antimetastatic actions. Many of these activities are independent of its anticoagulant activity, although the mechanisms of these other activities are currently less well defined. Nonetheless, heparin is being exploited for clinical uses beyond anticoagulation and developed for a wide range of clinical disorders. This article provides a "state of the art" review of our current understanding of the pharmacology of heparin and related drugs and an overview of the status of development of such drugs.

Venous thromboembolism prevention during asparaginase-based therapy for acute lymphoblastic leukemia

BACKGROUND

Venous thromboembolism (vte) is a recognized complication in patients treated with asparaginase-containing chemotherapy regimens; the optimal preventive strategy is unclear. We assessed the safety and efficacy of prophylaxis using low-dose low molecular weight heparin in adult patients with acute lymphoblastic leukemia in complete remission treated with an asparaginase-based post-remission chemotherapy regimen.

METHODS

As part of the intensification phase of the Dana-Farber Cancer Institute 91-01 regimen, asparaginase was administered weekly to 41 consecutive patients for 21-30 weeks; these patients also received prophylaxis with enoxaparin 40 mg daily (60 mg for patients ≥80 kg). Outcomes were assessed against outcomes in a comparable cohort of 99 patients who received the same chemotherapy regimen without anticoagulation prophylaxis.

RESULTS

The overall rate of symptomatic venous thrombosis was not significantly different in the prophylaxis and non-prophylaxis cohorts (18.92% and 21.74% respectively). Among patients receiving prophylaxis, vte occurred in higher proportion in those who weighed at least 80 kg (42.86% vs. 4.35%, p = 0.0070). No major bleeding complications occurred in the prophylaxis group (minor bleeding: 8.1%).

CONCLUSIONS

Prophylaxis with low-dose enoxaparin during the intensification phase was safe, but was not associated with a lower overall proportion of vte.

The Role of Inferior Vena Cava Filters in Cancer Patients

Cancer induces a hypercoagulable state and renders patients susceptible to venous thromboembolism. While anticoagulation remains the mainstay of treatment, many of these patients require placement of an inferior vena cava (IVC) filter, often due to a contraindication to or failure of anticoagulation. In this article, the available data on IVC filter usage in cancer patients will be reviewed.

Unprovoked venous thromboembolism and subsequent cancer risk: a population-based cohort study

ESSENTIALS: A relationship between unprovoked venous thromboembolism (VTE) and cancer risk was investigated. We collected 27,751 VTE patients and compared them with 110,409 frequency-matched people without VTE. This cohort study showed significantly higher risks of overall and site-specific cancers in the VTE group. There is an increased risk in the first 6 months after VTE, and VTE can be an indicator of occult cancer.

SUMMARY

BACKGROUND

We investigated the relationship between unprovoked venous thromboembolism (VTE) and subsequent cancer risk in Taiwan, focusing on both short-term and long-term cancer development.

METHODS

For the case group, we obtained data on 27,751 patients diagnosed with unprovoked VTE between 1 January 1998, and 31 December 2008. For the comparison group, four people without unprovoked VTE were frequency-matched with each unprovoked VTE patient according to age, sex, and index year. Cox proportional hazards regression models were employed to determine the effects of unprovoked VTE on cancer risk.

RESULTS

Overall cancer risk was significantly higher in the unprovoked VTE group than in the comparison group (adjusted hazard ratio = 2.26, 95% confidence interval = 2.16-2.37). The increased risk was observed in both men and women in various age groups. The patients in the unprovoked VTE group showed a significantly increased risk of cancer at all site-specific cancer sites. Analyses stratified according to follow-up duration revealed that significant differences were more evident between the two groups over a follow-up duration of < 0.5 years than over a follow-up duration of ≥ 3 years. Furthermore, the 1-year mortality risk of cancer patients with unprovoked VTE was significantly higher than that for cancer patients in the non-VTE group.

CONCLUSION

The results of this study show that unprovoked VTE is associated with a consistently high risk of subsequent cancer diagnosis. This is particularly true in the first 6 months after VTE. It suggests that unprovoked VTE can be an indicator of occult malignancy.

Venous thromboembolism in cancer patients: risk assessment, prevention and management

Thrombosis and thromboembolic events contribute to significant morbidity in cancer patients. Venous thrombosis embolism (which includes deep vein thrombosis and pulmonary embolism) accounts for a large percentage of thromboembolic events. Appropriate identification of cancer patients at high risk for venous thromboembolism and management of thromboembolic event is crucial in improving the quality of care for cancer patients. However, thromboembolism in cancer patients is a complex problem and the management has to be tailored to each individual. The focus of this review is to understand the complex pathology, physiology and risk factors that drive the process of venous thrombosis and embolism in cancer patients and the current guidelines in management.

Preoperative Chemoprophylaxis is Safe in Major Oncology Operations and Effective at Preventing Venous Thromboembolism

BACKGROUND

We prospectively evaluated the safety and efficacy of adding preoperative chemoprophylaxis to our institution's operative venous thromboembolism (VTE) prophylaxis policy as part of a physician-led quality improvement initiative.

STUDY DESIGN

Patients undergoing major cancer surgery between August 2013 and January 2014 were screened according to service-specific eligibility criteria and targeted to receive preoperative VTE chemoprophylaxis. Bleeding, transfusion, and VTE rates were compared with rates of historical controls who had not received preoperative chemoprophylaxis.

RESULTS

The 2,058 eligible patients who underwent operation between August 2013 and January 2014 (post-intervention) were compared with a cohort of 4,960 patients operated on between January 2012 and June 2013, who did not receive preoperative VTE chemoprophylaxis (pre-intervention). In total, 71% of patients in the post-intervention group were screened for eligibility; 82% received preoperative anticoagulation. When compared with the pre-intervention group, the post-intervention group had significantly lower transfusion rates (pre- vs post-intervention, 17% vs 14%; difference 3.5%, 95% CI 1.7% to 5%, p = 0.0003) without significant difference in major bleeding (difference 0.3%, 95% CI -0.1% to 0.7%, p = 0.2). Rates of deep venous thrombosis (1.3% vs 0.2%; difference 1.1%, 95% CI 0.7% to 1.4%, p < 0.0001) and pulmonary embolus (1.0% vs 0.4%; difference 0.6%, 95% CI 0.2% to 1%, p = 0.017) were significantly lower in the post-intervention group.

CONCLUSIONS

In patients undergoing major cancer surgery, institution of a single dose of preoperative chemoprophylaxis, as part of a physician-led quality improvement initiative, did not increase bleeding or blood transfusions and was associated with a significant decrease in VTE rates.

Diagnosis and therapy in cancer-associated thromboembolism – what about guideline recommendations?

Oncogenic transformation is closely linked to coagulation activation and cancer-associated venous thromboembolism (VTE) is a common problem. Guidelines recommend thromboprophylaxis with a low molecular weight heparin for hospitalized cancer patients. However, thromboprophylaxis is not customarily advised for ambulatory cancer patients. Cancer patients with VTE are usually treated with a low molecular weight heparin for 3–6 months. Vitamin K antagonists have a higher bleeding risk and there are not sufficient data to recommend any of the new oral anticoagulants. All physicians taking care of cancer patients should be aware of the current guideline recommendations. Oncology professionals should educate patients about the signs of VTE.

Low molecular heparin for cancer-associated venous thromboembolism – still the “CATCH of the day“?

In December 2014 the CATCH study was presented at the annual meeting of the American Society of Hematology. CATCH is a randomized controlled trial comparing the low molecular weight heparin tinzaparin with warfarin for 6 months extended treatment (=secondary prophylaxis) of cancer-associated venous thromboembolism (VTE). 6.9 % of patients in the tanzaparin arm experienced recurrent symptomatic and asymptomatic VTE compared with 10 % in the warfarin arm, this difference was statistically not significant. The difference became significant when only symptomatic VTEs were compared. There was no difference in the incidence of major bleeding events, but significantly fewer patients experienced clinically relevant non-major bleeding with tinzaparin than warfarin. The CATCH study is so far the largest study on extended treatment of cancer-associated VTE. It supports the guideline recommendation that low molecular weight heparins should be preferred to vitamin K antagonists for anticoagulation of cancer-associated VTE.

Carbohydrate antigens as potential biomarkers for the malignancy in patients with idiopathic deep venous thrombosis: a retrospective cohort study

A variety of biomarkers have been identified in recent prospective and retrospective reports as being potentially predictive of venous thromboembolis (VTE), particularly idiopathic deep venous thrombosis (IDVT). This study identified a serum tumor biomarker for early screening of IDVT. A total of 128 IDVT patients (54 females and 74 males; average age: 50.9±17.4 years) were included. Carcinoembryonic antigen (CEA), ferritin, β2-microglobulin, cancer antigen (CA) 125, CA 15-3, CA 19-9, squamous cell carcinoma antigen (SCC), alpha-fetoprotein (AFP), prostate specific antigen (PSA), free PSA (f-PSA), and beta-human chorionic gonadotropin (β-HCG) in patients with IDVT were detected. Malignancies were histo- or cytopathologically confirmed. Of the 128 IDVT patients, 16 (12.5%) were found to have malignancies. Serum CEA, CA 125, CA 15-3, and CA 19-9 were found to be helpful for detecting malignancies in IDVT patients. Our study revealed a positive association between these markers and tumors in IDVT patients. On the other hand, SCC and AFP were not sensitive enough to be markers for detecting tumors in patients with IDVT. No significant differences were found in positive rates of ferritin and β2-microglobulin between tumor and non-tumor groups, and no significant difference exists in serum levels of ferritin and β2-microglobulin between the two groups. Carbohydrate antigens, CA 15-3 in particular, may be useful for differential diagnosis and prediction of malignancies in patients with IDVT.

Implementing thrombosis guidelines in cancer patients: a review

Venous thromboembolism is a frequent and serious complication in patients with cancer. It is an independent prognostic factor of death in cancer patients and the second leading cause of death, but physicians often underestimate its importance, as well as the need for adequate prevention and treatment. Management of venous thromboembolism in patients with cancer requires the coordinated efforts of a wide range of clinicians, highlighting the importance of a multidisciplinary approach. However, a lack of consensus among various national and international clinical practice guidelines has contributed to knowledge and practice gaps among practitioners, and inconsistent approaches to venous thromboembolism. The 2013 international guidelines for thrombosis in cancer have sought to address these gaps by critically re-evaluating the evidence coming from clinical trials and synthesizing a number of guidelines documents. An individualized approach to prophylaxis is recommended for all patients.

Venous thromboembolism prophylaxis

Venous thromboembolism (VTE) can occur after major general surgery. Pulmonary embolism is recognized as the most common identifiable cause of death in hospitalized patients in the United States. The risk of deep venous thrombosis (DVT) and pulmonary embolism (PE) is higher in colorectal surgical procedures compared with general surgical procedures. The incidence of venous thromboembolism in this population is estimated to be 0.2 to 0.3%. Prevention of VTE is considered a patient-safety measure in most mandated quality initiatives. The measures for prevention of VTE include mechanical methods (graduated compression stockings and intermittent pneumatic compression devices) and pharmacologic agents. A combination of mechanical and pharmacologic methods produces the best results. Patients undergoing surgery should be stratified according to their risk of VTE based on patient risk factors, disease-related risk factors, and procedure-related risk factors. The type of prophylaxis should be commensurate with the risk of VTE based on the composite risk profile.

Acute limb ischemia in cancer patients: aggressive treatment is justified

BACKGROUND

The outcome of cancer patients with acute limb ischemia (ALI) is not well defined. The purpose of this study is to report our experience treating patients with active malignancy who developed ALI and compare their outcome with non-cancer patients.

METHODS

A retrospective review of patients treated for ALI between 2009 and 2012 with ALI. We identified those patients who suffered from ALI and compared the outcome of those with active malignancy to those without malignancy.

RESULTS

Of 147 patients treated for ALI (122 lower extremity, 25 upper extremity), 24 (16%) were cancer patients. Mean follow-up was 9.8 months for the malignancy group and 13.4 months for the control. Perioperative mortality rates were similar among cancer and non-cancer patients (20% vs. 16%, respectively, NS). Freedom from major amputation at 30 months was similar (95% vs. 89%, NS). Long-term survival rates of cancer patients were significantly lower compared to non-cancer patients (45% vs. 77% respectively, P<0.05).

CONCLUSIONS

Treatment of ALI among cancer patients can be achieved with perioperative mortality and limb salvage rates comparable to non-cancer patients. Aggressive treatment is justified when treating cancer patients with ALI.

Venous thromboembolism prophylaxis

Venous thromboembolism (VTE) can occur after major general surgery. Pulmonary embolism is recognized as the most common identifiable cause of death in hospitalized patients in the United States. The risk of deep venous thrombosis (DVT) and pulmonary embolism (PE) is higher in colorectal surgical procedures compared with general surgical procedures. The incidence of venous thromboembolism in this population is estimated to be 0.2 to 0.3%. Prevention of VTE is considered a patient-safety measure in most mandated quality initiatives. The measures for prevention of VTE include mechanical methods (graduated compression stockings and intermittent pneumatic compression devices) and pharmacologic agents. A combination of mechanical and pharmacologic methods produces the best results. Patients undergoing surgery should be stratified according to their risk of VTE based on patient risk factors, disease-related risk factors, and procedure-related risk factors. The type of prophylaxis should be commensurate with the risk of VTE based on the composite risk profile.

Prevention and treatment of venous thromboembolism in patients with cancer

BACKGROUND

Many patients who experience a venous thromboembolic event have cancer, and thrombosis is much more prevalent in patients with cancer than in those without it. Thrombosis is the second most common cause of death in cancer patients and cancer is associated with a high rate of recurrence of venous thromboembolism (VTE), bleeding, requirement for long-term anticoagulation and poorer quality of life.

METHODS

A literature review was conducted to identify guidelines and evidence pertaining to anticoagulation prophylaxis and treatment for patients with cancer, with the goal of identifying opportunities for pharmacists to advocate for and become more involved in the care of this population.

RESULTS

Many clinical trials and several guidelines providing guidance to clinicians in the treatment and prevention of VTE in patients with cancer were identified. Current clinical evidence and guidelines suggest that cancer patients receiving care in hospital with no contraindications should receive VTE prophylaxis with unfractionated heparin (UFH), a low-molecular-weight heparin (LMWH) or fondaparinux. Patients who require surgery for their cancer should receive prophylaxis with UFH, LMWH or fondaparinux. Cancer patients who have experienced a VTE event should receive prolonged anticoagulant therapy with LMWH (at least 3 months to 6 months). No routine prophylaxis is required for the majority of ambulatory patients with cancer who have not experienced a VTE event. Most publicly funded drug plans in Canada have developed criteria for funding of LMWH therapy for patients with cancer.

CONCLUSIONS

Evidence suggests that LMWH for 3 to 6 months is the preferred strategy for most cancer patients who have experienced a thromboembolic event and for hospital inpatients, but this is often not implemented in practice. Concerns about adherence with injectable therapy should not prevent use of these agents. Pharmacists should assess cancer patients for their risk of VTE and should advocate for optimal VTE pharmacotherapy as appropriate. If LMWH is the preferred agent, on the basis of the evidence, the pharmacist should educate the patients appropriately and work with the prescriber to ensure best care.

Risk factors for post-operative venous thromboembolism in patients with a malignancy of the lower limb

It is important to be able to identify patients with an increased risk of venous thromboembolism (VTE) in order to minimise the risk of an event. We investigated the incidence and risk factors for post-operative VTE in 168 consecutive patients with a malignancy of the lower limb. The period of study included ten months before and 12 months after the introduction of chemical thromboprophylaxis. All data about the potential risk factors were identified and classified into three groups (patient-, surgery- and tumour-related). The outcome measure was a thromboembolic event within 90 days of surgery. Of the 168 patients, eight (4.8%) had a confirmed symptomatic deep-vein thrombosis and one (0.6%) a fatal pulmonary embolism. Of the 28 variables tested, age > 60 years, higher American Society of Anesthesiologists grade and metastatic tumour were independent risk factors for VTE. The overall rate of symptomatic VTE was not significantly different between patients who received chemical thromboprophylaxis and those who did not. Knowledge of these risk factors may be of value in improving the surgical outcome of patients with a malignancy of the lower limb.

Adjuvant therapy in breast cancer and venous thromboembolism

Breast cancer patients are considered to be at relatively low risk of developing a TEE. The highest incidence of VTE events occurs in metastatic breast cancer patients likely due to extension of disease, immobility for pathologic bone fractures, cancer cachexia and venous compression by the tumour mass. Although thrombosis is less common in patients with early stage cancer compared to those with more advanced disease, it does occur and is clinically challenging. The adjuvant setting is of particular interest in order to assess the specific thrombogenic potential of systemic chemotherapy, because of the low tumor burden with only microscopic tumor foci at the time of treatment administration. This review summarizes risk factors, incidence and strategies to avoid VTE in breast cancer patients receiving adjuvant therapy.

Regional lymph node metastases are a strong risk factor for venous thromboembolism: results from the Vienna Cancer and Thrombosis Study

Advanced cancer is a risk factor for venous thromboembolism. However, lymph node metastases are usually not considered an established risk factor. In the framework of the prospective, observational Vienna Cancer and Thrombosis Study we investigated the association between local (N0), regional (N1-3), and distant (M1) cancer stages and the occurrence of venous thromboembolism. Furthermore, we were specifically interested in the relationship between stage and biomarkers that have been reported to be associated with venous thromboembolism. We followed 832 patients with solid tumors for a median of 527 days. The study end-point was symptomatic venous thromboembolism. At study inclusion, 241 patients had local, 138 regional, and 453 distant stage cancer. The cumulative probability of venous thromboembolism after 6 months in patients with local, regional and distant stage cancer was 2.1%, 6.5% and 6.0%, respectively (P=0.002). Compared to patients with local stage disease, patients with regional and distant stage disease had a significantly higher risk of venous thromboembolism in multivariable Cox-regression analysis including age, newly diagnosed cancer (versus progression of disease), surgery, radiotherapy, and chemotherapy (regional: HR=3.7, 95% CI: 1.5-9.6; distant: HR=5.4, 95% CI: 2.3-12.9). Furthermore, patients with regional or distant stage disease had significantly higher levels of D-dimer, factor VIII, and platelets, and lower hemoglobin levels than those with local stage disease. These results demonstrate an increased risk of venous thromboembolism in patients with regional disease. Elevated levels of predictive biomarkers in patients with regional disease underpin the results and are in line with the activation of the hemostatic system in the early phase of metastatic dissemination.

Incidence of venous thromboembolism among chemotherapy-treated patients with lung cancer and its association with mortality: a retrospective database study

Cancer patients, especially those with lung cancer and undergoing chemotherapy, have an elevated risk for venous thromboembolism (VTE). This study assessed incidence, timing, and risk factors for VTE (specifically receipt of chemotherapy), along with the association between VTE and survival among lung cancer patients receiving chemotherapy. Using Florida Medicaid administrative claims data (2000-2008), patients with any diagnosis of primary lung cancer were selected. Patients with recent prior VTE and those enrolled in Medicare or an HMO were excluded. Crude rates of VTE per 100 person years were estimated, and Cox proportional hazards models were developed to assess risk factors for VTE in the lung cancer population, and the association between VTE and survival among patients undergoing chemotherapy. Of 15,749 lung cancer patients, 7,052 (2,242 receiving chemotherapy and 4,810 not receiving chemotherapy) met cohort selection criteria. The incidence of VTE was 10.8 per 100 person-years (PYs) in the chemotherapy cohort and 6.8 per 100 PYs in the non-chemotherapy cohort. Among patients on chemotherapy developing VTE, median time to occurrence was 109 days, with 61 and 82 % of patients experiencing an event within six and 12 months, respectively. In multivariate analyses, the adjusted risk of VTE was 30 % higher among patients undergoing chemotherapy. Comorbidity and the presence of a central venous catheter also were significantly associated with a greater risk of developing VTE. Moreover, patients in the chemotherapy cohort who developed VTE had a significantly faster time-to-death (adjusted hazard ratio [HR] = 1.97; 95 % CI 1.69-2.29).VTE was common among lung cancer patients, especially among patients receiving chemotherapy, with the majority of VTE events occurring within 6 months of initiation of chemotherapy. The presence of a VTE event was significantly associated with an increased risk of mortality.

Incidence and predictors of venous thromboembolism (VTE) among ambulatory high-risk cancer patients undergoing chemotherapy in the United States

BACKGROUND

Recent studies suggest that thromboprophylaxis is beneficial in preventing venous thromboembolism (VTE) in cancer outpatients, but this is not widely adopted because of incomplete understanding of the contemporary incidence of VTE and concerns about bleeding. Therefore, the authors examined the incidence and predictors of VTE in ambulatory patients with bladder, colorectal, lung, ovary, pancreas, or gastric cancers.

METHODS

Data were extracted from a large health care claims database of commercially insured patients in the United States between 2004 and 2009. Demographic and clinical characteristics of the cancer cohort (N = 17,284) and an age/sex-matched, noncancer control cohort were evaluated. VTE incidence was recorded during a 3-month to 12-month follow-up period after the initiation of chemotherapy. Multivariate analyses were conducted to identify independent predictors of VTE and bleeding.

RESULTS

The mean age of the study population was 64 years, and 51% of patients were women. VTE occurred in 12.6% of the cancer cohort (n = 2170) over 12 months after the initiation of chemotherapy versus 1.4% of controls (n = 237; P < .0001); incidence ranged by cancer type from 19.2% (pancreatic cancer) to 8.2% (bladder cancer). Predictors of VTE included type of cancer, comorbidities (Charlson Comorbidity Index score or obesity), and commonly used specific antineoplastic or supportive care agents (cisplatin, bevacizumab, and erythropoietin).

CONCLUSIONS

This large, contemporary, real-world analysis confirmed high rates of VTE in select patients with solid tumors and suggested that the incidence of VTE is high in the real-world setting. Awareness of the benefits of targeted thromboprophylaxis may result in a clinically significant reduction in the burden of VTE in this population.

Venous thromboembolism is a relevant and underestimated adverse event in cancer patients treated in phase I studies

BACKGROUND

To investigate, retrospectively, the role of tumour histotype and antiangiogenic drugs for venous thromboembolism (VTE) development in advanced cancer patients treated in phase I studies.

METHODS

Patients enrolled and treated in phase I studies conducted by SENDO (Southern Europe New Drugs Organisation) were considered.

RESULTS

Data of 1415 patients were included in the analysis: 526 (37.2%) patients were males, median age was 57.3 years (range: 13-85). Fifty-six (3.96%) patients developed a VTE. At multivariate analysis gynaecologic (hazard ratio (HR): 2.8, 95% confidence interval (CI): 1.29-6.23, P=0.009) and gastrointestinal tumours (HR: 3.23, 95% CI: 1.18-8.87, P=0.023) as well as combination regimens of cytotoxic and antiangiogenic agents (HR: 2.6, 95% CI: 1.11-6.30, P=0.028), white blood cell >11,000 μl(-1) (HR: 2.59, 95% CI: 1.10-6.09, P=0.028) and haemoglobin<10 g dl(-1) (HR: 3.1, 95% CI: 1.07-8.94, P=0.037) were statistically correlated with VTE development. Venous thromboembolism was the fourth most common cause of drug discontinuation. The median time from first drug administration to discontinuation was 1.4 for VTE and 2.3 months for the other adverse events (P=0.02).

CONCLUSION

Venous thromboembolism is a relatively common complication among patients treated in the context of phase I studies, and may lead to early drug discontinuation. A greater risk of developing VTE is associated with the diagnosis of gynaecologic and gastrointestinal tumours and the combined use of chemotherapy and antiangiogenic drugs.

Venous Thromboembolism in Cancer Patients Undergoing Major Abdominal Surgery: Prevention and Management

Cancer is an important risk factor for venous thrombosis. Venous thromboembolism is one of the most common complications of cancer and the second leading cause of death in these patients. Recent research has given insight into mechanism and various risk factors in cancer patients which predispose to thromboembolism. The purpose of this review is to summarize the current knowledge on the prophylaxis, diagnosis, and management of venous thromboembolism in these patients.