Impact of time since diagnosis and mortality rate on cancer-associated venous thromboembolism: the Scandinavian Thrombosis and Cancer (STAC) cohort

Risk of Venous Thromboembolism by Cancer Type: A Network Meta-Analysis

Patients with cancer have an increased risk of venous thromboembolism (VTE). Comparing tumor-specific VTE risk is complicated by factors such as surgery, disease stage, and chemotherapy. Network meta-analysis (NMA) using cancer types as network nodes enabled us to estimate VTE rates by leveraging comparisons across cancer types while adjusting for baseline VTE risk in individual studies. This study was conducted to estimate the risk of VTE by cancer type and factors influencing VTE risk. The Embase, MEDLINE, and Cochrane Library repositories were systematically searched to identify clinical trials and observational studies published from 2005 to 2022 that assessed the risk of primary cancer-related VTE among two or more distinct cancer types. Studies with similar cancer populations and study methods reporting VTE occurring within 1 year of diagnosis were included in the NMA. Relative VTE rates across cancer types were estimated with random-effects Bayesian NMAs. Absolute VTE rates were calculated from these estimates using the average VTE incidence in lung cancer (the most frequently reported type) as the "anchor." From 2,603 records reviewed, 30 studies were included in this NMA. The general network described 3,948,752 patients and 18 cancer types: 3.1% experienced VTE within 1 year of diagnosis, with cancer-specific rates ranging from 0.7 to 7.4%. Consistent with existing VTE risk prediction tools, pancreatic cancer was associated with higher-than-average VTE risk. Other cancer types with high VTE risk were brain and ovarian cancers. The relative rankings of VTE risk for certain cancers changed based on disease stage and/or receipt of chemotherapy or surgery.

Acute venous thromboembolism in patients with brain cancer: clinical course

Background

Patients with brain cancer have been excluded or were underrepresented in studies on the treatment of venous thromboembolism (VTE), mainly due to the fear of intracranial hemorrhage (ICH).

Objectives

The aim of this study was to provide data on the risk of ICH, recurrent VTE, and major bleeding in patients with active brain cancer.

Methods

This was a multicenter, international cohort study at participating sites of the Registro Informatizado Enfermedad Tromboembólica Registry. Patients included in this study were classified as having known active brain cancer, active nonbrain cancer, or without active cancer. ICH at 3 months was the primary study outcome.

Results

Overall, 98,377 patients with VTE were included: 616 with active brain cancer, 16,807 with active nonbrain cancer, and 80,954 without active cancer. At 3 months follow-up, ICH occurred in 2.8%, 0.3%, and 0.2% of the patients, respectively, and was fatal in 1.3%, 0.2%, and 0.1%, respectively. Both rates of major bleeding (3.7% vs 3.2% vs 1.5%, respectively) and recurrent VTE (3.9% vs 3.4% vs 1.1%, respectively) were higher in patients with brain or nonbrain cancer than in patients without cancer. Glioblastomas were associated with a numerically higher risk of ICH, fatal ICH, and recurrent VTE than other brain tumors.

Conclusion

In patients with VTE, active brain cancer was associated with a higher risk of ICH or fatal ICH than nonbrain or no active cancer. Further studies are needed to assess the value of different treatment approaches in patients with brain cancer and VTE.

Faktor Xa-hemmere til forebygging og behandling av venøs tromboembolisme ved kreft

Venous thromboembolism is a common complication of cancer. The prevalence varies according to cancer type and increases proportionally with the stage of cancer. In the past 15-20 years, low molecular weight heparin has been recommended as the first-line treatment. New international guidelines now allow for use of direct factor Xa inhibitors both as prophylaxis and treatment for venous thromboembolism. Prophylaxis should as a general rule only be initiated in patients with moderate to high risk. Bleeding risk assessment is important before starting anticoagulation. Both thrombosis and bleeding risk can change and should therefore be assessed on an ongoing basis. In this clinical review, use of anticoagulation therapy in cancer patients is discussed with particular emphasis on the use of direct factor Xa inhibitors.

ABO blood group type and risk of venous thromboembolism in patients with cancer

Venous thromboembolism (VTE) is common in patients with cancer. Although in the general population blood type non-O is associated with increased VTE risk, the impact of ABO blood type on risk of cancer-associated VTE has not been clarified. To determine the influence of ABO blood type on cancer-associated VTE risk, we conducted an analysis within the Vienna Cancer and Thrombosis Study, a prospective cohort study including patients with newly diagnosed or recurrent cancer observed for the primary outcome VTE. Restricted cubic spline analysis was performed and specific time-restricted subdistribution hazard ratios (SHR) were calculated to investigate the association between non-O blood type and VTE over time. One thousand, seven hundred and eight patients were included in the analysis (median follow-up time: 24 months; interquartile range: 10-24), and 151 patients developed VTE (8.8%). During the first 3 months of follow-up, there was no association between non-O blood type and VTE risk (SHR: 1.00; 95% confidence interval [CI]: 0.60-1.67). Thereafter, non-O blood type was associated with a higher VTE risk (SHR: 1.79; 95% CI: 1.12-2.85). Furthermore, non-O blood type was associated with increased VTE risk in patients with intermediate and low thrombotic risk tumor types (SHR: 1.73; 95% CI: 1.09-2.73) but not in very high-risk types (pancreatic, gastroesophageal, and brain cancer; SHR: 0.94; 95% CI: 0.55-1.61). This association was weakened after adjustment for factor VIII. Non-O blood type is a time-dependent predictor of VTE in patients with cancer. It is associated with increased VTE risk beyond 3 months of follow-up and in patients with intermediate- and low-risk tumor types.

Systemic coagulation is activated in patients with meningioma and glioblastoma

PURPOSE

Up to 30% of patients with glioblastoma (GBM) develop venous thromboembolism (VTE) over the course of the disease. Although not as high, the risk for VTE is also increased in patients with meningioma. Direct measurement of peak thrombin generation (TG) allows quantitative assessment of systemic coagulation activation in patients with GBM and meningioma. Our aim was to determine the extent of systemic coagulation activation induced by brain tumors, to measure the shift between pre- and post-operative peak TG in patients with GBM, and to assess the relationship between pre-surgical peak TG and pre-operative brain tumor volume on imaging.

METHODS

Pre- and post-surgical plasma samples were obtained from successive patients with GBM and once from patients with meningioma and healthy age- and sex-matched blood donor controls. TG was measured using the calibrated automated thrombogram (CAT) assay, and tumor volumes were measured in pre-surgical MRI scans.

RESULTS

Pre-surgical peak TG was higher in patients with GBM than in controls (288.6 ± 54.1 nM vs 187.1 ± 41.7 nM, respectively, P < 0.001), and, in the nine patients with GBM and paired data available, peak TG was significantly reduced after surgery (323 ± 38 nM vs 265 ± 52 nM, respectively, P = 0.007). Similarly, subjects with meningioma demonstrated higher peak TG compared to controls (242.2 ± 54.9 nM vs 177.7 ± 57.0 nM, respectively, P < 0.001). There was no association between peak TG and pre-operative tumor volume or overall survival.

CONCLUSION

Our results indicate that systemic coagulation activation occurs with both meningioma and GBM, but to a greater degree in the latter. Preoperative peak TG did not correlate with tumor volume, but removal of GBM caused a significant decrease in coagulation activation.

Cost-utility analysis of apixaban compared with usual care for primary thromboprophylaxis in ambulatory patients with cancer

Background:

Apixaban (2.5 mg) taken twice daily has been shown to substantially reduce the risk of venous thromboembolism (VTE) compared with placebo for the primary thromboprophylaxis of ambulatory patients with cancer who are starting chemotherapy and are at intermediate-to-high risk of VTE. We aimed to compare the health system costs and health benefits associated with primary thromboprophylaxis using apixaban with those associated with the current standard of care (where no primary thromboprophylaxis is given), from the perspective of Canada’s publicly funded health care system in this subpopulation of patients with cancer over a lifetime horizon.

Methods:

We performed a cost–utility analysis to estimate the incremental cost per quality-adjusted life-year (QALY) gained with primary thromboprophylaxis using apixaban. We obtained baseline event rates and the efficacy of apixaban from the Apixaban for the Prevention of Venous Thromboembolism in High-Risk Ambulatory Cancer Patients (AVERT) trial on apixaban prophylaxis. We estimated relative risk for bleeding, risk of complications associated with VTE treatment, mortality rates, costs and utilities from other published sources.

Results:

Over a lifetime horizon, apixaban resulted in lower costs to the health system (Can$7902.98 v. Can$14 875.82) and an improvement in QALYs (9.089 v. 9.006). The key driver of cost–effectiveness results was the relative risk of VTE as a result of apixaban. Results from the probabilistic analysis showed that at a willingness to pay of Can$50 000 per QALY, the strategy with the highest probability of being most cost-effective was apixaban, with a probability of 99.87%.

Interpretation:

We found that apixaban is a cost-saving option for the primary thromboprophylaxis of ambulatory patients with cancer who are starting chemotherapy and are at intermediate-to-high risk of VTE.

Association of smoking and cancer with the risk of venous thromboembolism: the Scandinavian Thrombosis and Cancer cohort

Smoking is a well-established risk factor for cancer, and cancer patients have a high risk of venous thromboembolism (VTE). Conflicting results have been reported on the association between smoking and risk of VTE, and the effect of smoking on VTE-risk in subjects with cancer is scarcely studied. We aimed to investigate the association between smoking and VTE in subjects with and without cancer in a large population-based cohort. The Scandinavian Thrombosis and Cancer (STAC) cohort included 144,952 participants followed from 1993-1997 to 2008-2012. Information on smoking habits was derived from self-administered questionnaires. Active cancer was defined as the first two years following the date of cancer diagnosis. Former smokers (n = 35,890) and those with missing information on smoking status (n = 3680) at baseline were excluded. During a mean follow up of 11 years, 10,181 participants were diagnosed with cancer, and 1611 developed incident VTE, of which 214 were cancer-related. Smoking was associated with a 50% increased risk of VTE (HR 1.49, 95% CI 1.12-1.98) in cancer patients, whereas no association was found in cancer-free subjects (HR 1.07, 95% CI 0.96-1.20). In cancer patients, the risk of VTE among smokers remained unchanged after adjustment for cancer site and metastasis. Stratified analyses showed that smoking was a risk factor for VTE among those with smoking-related and advanced cancers. In conclusion, smoking was associated with increased VTE risk in subjects with active cancer, but not in those without cancer. Our findings imply a biological interaction between cancer and smoking on the risk of VTE.

Prothrombotic genotypes and risk of venous thromboembolism in occult cancer

BACKGROUND

Studies have reported that the combination of some prothrombotic genotypes and overt cancer yields a synergistic effect on VTE risk. Whether individual prothrombotic genotypes or number of risk alleles in a genetic risk score (GRS) affect VTE risk in occult cancer have not been addressed. The aim of this study was to investigate the joint effect of five prothrombotic genotypes and occult cancer on VTE risk.

METHODS

Cases with incident VTE (n = 1566) and a subcohort (n = 14,537) were sampled from the Scandinavian Thrombosis and Cancer Cohort (1993-2012). Five single nucleotide polymorphisms previously reported in a GRS were genotyped: ABO (rs8176719), F5 (rs6025), F2 (rs1799963), FGG (rs2066865) and F11 (rs2036914). Hazard ratios (HRs) for VTE by individual SNPs and GRS were estimated according to non-cancer and occult cancer (one year preceding a cancer diagnosis) exposure.

RESULTS

Occult cancer occurred in 1817 subjects, and of these, 93 experienced a VTE. The VTE risk was 4-fold higher (HR 4.05, 95% CI 3.28-5.00) in subjects with occult cancer compared with those without cancer. Among subjects with occult cancer, those with VTE had a higher proportion of prothrombotic and advanced cancers than those without VTE. The VTE risk increased according to individual prothrombotic genotypes and GRS in cancer-free subjects, while no such effect was observed in subjects with occult cancer (HR for ≥4 versus ≤1 risk alleles in GRS: 1.14, 95% CI 0.61-2.11).

CONCLUSIONS

Five well-established prothrombotic genotypes, individually or combined, were not associated with increased risk of VTE in individuals with occult cancer.

Cancer and Thrombosis: New Treatments, New Challenges

The direct-acting oral anticoagulant (DOAC) has become an alternative to low-molecular-weight heparin (LMWH) for treatment and prophylaxis of venous thromboembolism (VTE) in cancer patients. The clinicians are, however, faced with difficult decisions regarding DOAC treatment: Which patients cannot use DOACs? Should incidental VTE be treated similar to symptomatic VTE? Is it safe to give DOACs to patients with gastrointestinal or urogenital cancers? How about drug–drug interactions? Should all cancer patients receive thromboprophylaxis? Is arterial thrombosis a problem? The current article reviews the available literature regarding these questions and aims to provide practical solutions based on data from the clinical trials and new guidelines.

Association of Venous Thromboembolism and Early Mortality in Patients with Newly Diagnosed Metastatic Non-Small Cell Lung Cancer

Purpose

To explore the relationship between venous thromboembolism (VTE) and early mortality (within six months) in Chinese patients with newly diagnosed metastatic non-small cell lung cancer (NSCLC) after entering the era of precision treatment.

Methods

A cohort of 706 consecutive subjects with newly diagnosed metastatic NSCLC were prospectively observed. Clinical and survival data were recorded over a six-month follow-up period. The predictive factors for the occurrence of VTE and the relationship with early mortality were evaluated through univariate and multivariate analyses.

Results

During the six-month follow-up period, VTE events occurred in 12.2% (86/706) of the enrolled patients. In the multivariate analyses for VTE, an age older than 70 years (vs < 70: sub-distribution hazard radio [SHR], 1.678; 95% confidence interval (CI), 1.073–2.600; P=0.022), an Eastern Cooperative Oncology Group performance status ≥2 (vs 0/1: SHR, 1.946; 95% CI, 1.277–2.970; P=0.002), and having an ALK rearrangement (vs non-rearrangement: SHR, 2.377; 95% CI, 1.186–4.760; P=0.015) were significantly associated with the occurrence of VTE. Within six months, 116 subjects (16.4%) died, and the occurrence of VTE (vs no VTE: adjusted HR: 1.863; 95% CI: 1.178–2.947, P=0.008) was remarkably associated with early mortality. Further analysis showed 98 patients (13.9%) with early mortality had EGFR/ALK wild-type genes, with a risk of early mortality 5.935-fold higher than that of patients with an EGFR mutation/ALK rearrangement. Finally, subgroup analyses showed that VTE occurrence was a significant factor for predicting early mortality in patients with EGFR/ALK wild-type genes (adjusted HR: 1.682; 95% CI: 1.023–2.768, P=0.041).

Conclusion

Patients with an EGFR mutation/ALK rearrangement had a significantly decreased risk of early mortality in the era of targeted therapy; however, VTE occurrence remained an important predictor for early mortality in metastatic NSCLC patients, especially in patients with EGFR/ALK wild-type genes.

Arterial Thromboembolism in Cancer Patients: A Danish Population-Based Cohort Study

Background

The relation between cancer and arterial thromboembolism (ATE) remains unclear.

Objectives

The purpose of this study was to evaluate ATE risk in cancer patients.

Methods

Danish registries were used to identify all cancer patients between 1997 and 2017, each matched to three cancer-free comparator individuals. ATE was defined as the composite of myocardial infarction, ischemic/unspecified stroke, and peripheral arterial occlusion. A competing risk approach was used to compute cumulative incidences and subdistribution hazard ratios (SHRs). Cause-specific hazard ratios (HRs) were calculated using Cox regression. Among cancer patients, mortality risk was estimated in Cox regression analysis by treating ATE as a time-varying exposure. Patients were followed for 12 months.

Results

The study included 458,462 cancer patients and 1,375,386 comparator individuals. In the 6-month period following cancer diagnosis/index date, the cumulative incidence for ATE was 1.50% (95% confidence interval [CI]: 1.47% to 1.54%) in cancer patients and 0.76% (95% CI: 0.75% to 0.77%) in comparator individuals (HR: 2.36; 95% CI: 2.28 to 2.44). Among cancer patients age <65 years, 65 to 75 years, and >75 years, this was 0.79% (95% CI: 0.74% to 0.83%), 1.61% (95% CI: 1.55% to 1.67%), and 2.30% (95% CI: 2.22% to 2.38%), respectively. Other predictors for ATE among cancer patients were prior ATE (SHR: 2.96; 95% CI: 2.77 to 3.17), distant metastasis (adjusted SHR: 1.21; 95% CI: 1.12 to 1.30), and chemotherapy (SHR: 1.47; 95% CI: 1.33 to 1.61). Among cancer patients, ATE was associated with an increased risk of mortality (HR: 3.28; 95% CI: 3.18 to 3.38).

Conclusions

Cancer patients are at increased risk of ATE. Clinicians should be aware of this risk, which is associated with mortality.

Venous thromboembolism in cancer patients: a population-based cohort study

The incidence of venous thromboembolism (VTE) in cancer patients may have changed in the past decade, possibly due to novel cancer therapies, improved survival, and high-resolution imaging. Danish medical registries were used to identify 499 092 patients with a first-time cancer diagnosis between 1997 and 2017, who were matched to 1 497 276 comparison individuals without cancer from the general population. We computed cumulative incidences of VTE 6 and 12 months after the diagnosis/index date. Hazard ratios (HRs) were calculated using Cox regression. Risk factors were examined by computing subdistribution hazard ratios (SHRs) in a competing-risk analysis. Cumulative incidence of VTE 12 months after the cancer diagnosis/index date was 2.3% (95% confidence interval [CI], 2.2% to 2.3%) in the cancer cohort and 0.35% (95% CI, 0.34% to 0.36%) in the comparison cohort (HR, 8.5; 95% CI, 8.2-8.8). Important risk factors for cancer patients were prior VTE (SHR, 7.6; 95% CI, 7.2-8.0), distant metastasis (SHR, 3.2; 95% CI, 2.9-3.4), and use of chemotherapy (SHR, 3.4; 95% CI, 3.1-3.7), protein kinase inhibitors (SHR, 4.1; 95% CI, 3.4-4.9), antiangiogenic therapy (SHR, 4.4; 95% CI, 3.8-5.2), and immunotherapy (SHR, 3.6; 2.8-4.6). Twelve-month incidence in the cancer cohort increased from 1.0% (95% CI, 0.9% to 1.2%) in 1997 to 3.4% (95% CI, 2.9% to 4.0%) in 2017, which was paralleled by improved 12-month survival and increased use of computed tomography scans, chemotherapy, and targeted therapies. In conclusion, the risk of VTE in cancer patients is increasing steadily and is ninefold higher than in the general population.

Epidemiology of Venous Thromboembolism After Second Cancer

Background

Venous thromboembolism (VTE) is a serious, yet preventable, complication in cancer. Some patients are diagnosed with a second cancer; however, little is known about the epidemiology of VTE in this population.

Methods

From Danish national healthcare registries, we studied all patients diagnosed with a first breast, prostate, lung, or colorectal cancer from 1995 to 2015. We estimated incidence rates (IRs) of VTE according to the timing of the diagnosis of a second cancer. We controlled for confounder variables in Poisson regression models.

Results

In total, 309,077 patients with a first breast, prostate, lung, or colorectal cancer were included in the study. A second cancer was diagnosed in 20,090 (6.5%) of these patients. In total, 11,908 VTEs were observed in the study period, 786 of these occurred after a diagnosis of second cancer. Second cancer types such as pancreas and stomach cancer were associated with fivefold higher IRs of VTE compared with second cancer types such as breast and prostate cancer. The IR of VTE was highest within the first 6 months after the second cancer was diagnosed (IR 40.5 per 1000 person-years, 95% CI 36.3–42.2) with no differences based on how long since the first cancer it was diagnosed.

Conclusion

The epidemiology of VTE after a second cancer is similar to the epidemiology of VTE after a first cancer with higher rates within the first months after aggressive second cancer types.

Impact of respiratory symptoms and oxygen saturation on the risk of incident venous thromboembolism-the Tromsø study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with risk of venous thromboembolism (VTE). It remains unknown whether individual respiratory symptoms and lowered oxygen saturation (SpO2), individually and in combination with COPD, affect the risk of VTE.

OBJECTIVES

To investigate whether measures of respiratory impairments including respiratory symptoms and SpO2, individually and combined with COPD, were associated with an increased risk of VTE.

METHODS

Spirometry, SpO2, and self-reported respiratory symptoms were collected in 8686 participants from the fifth (2001-2002) and sixth (2007-2008) surveys of the Tromsø Study. Incident VTE events were registered from the date of inclusion to December 31, 2016. Cox regression models with exposures and confounders as time-varying covariates (for repeated measurements) were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for VTE.

RESULTS

During a median follow-up of 9.1 years, 330 participants developed incident VTE. Subjects with SpO2 ≤ 96% (lowest 20th percentile) had a 1.5-fold higher risk of VTE (adjusted HR, 1.48; 95% CI, 1.13-1.93) compared with those with SpO2 ≥ 98%. Severe respiratory symptoms (dyspnea, cough, and phlegm) were associated with a 1.4- to 2.0-fold higher risk of VTE compared with no such symptoms. COPD, combined with respiratory symptoms or lowered SpO2, had an additive effect on the VTE risk.

CONCLUSIONS

Lowered SpO2 and severe respiratory symptoms were associated with increased VTE risk. COPD combined with respiratory impairments had an additive effect on VTE risk, and may suggest particular attention on VTE preventive strategies in COPD patients with respiratory impairments.

What's new in the prevention and treatment of cancer-associated thrombosis?

Venous thromboembolism (VTE) is a common complication in ambulatory cancer patients receiving chemotherapy. Current clinical guidelines recommend against the use of routine primary thromboprophylaxis in unselected ambulatory cancer patients. The Khorana score is a risk assessment tool derived and prospectively validated for the identification of cancer patients at high risk of thrombotic complications. Recently, 2 randomized, controlled trials have assessed the use of low-dose direct oral Xa inhibitors, apixaban and rivaroxaban, for the prevention of cancer-associated thrombosis in ambulatory patients at intermediate to high risk of VTE (Khorana score ≥2). Taken together, these trials have shown that low-dose direct oral Xa inhibitors reduce the risk of VTE in this patient population without a significant increase in major bleeding. These results should encourage clinicians to consider the use of primary thromboprophylaxis in ambulatory cancer patients at intermediate to high risk of VTE who do not have any apparent risk factors for bleeding. The direct oral Xa inhibitors have also been assessed in the acute management of cancer-associated thrombosis. Current evidence suggests that these drugs are a convenient, effective, and safe option for the management of acute VTE in many cancer patients. Low-molecular weight heparin, however, may continue to be the treatment of choice depending on the presence of bleeding risk factors, the type of cancer, drug-drug interactions, and patient preferences.

Definitions, adjudication, and reporting of pulmonary embolism-related death in clinical studies: A systematic review

BACKGROUND

Pulmonary embolism (PE)-related death is a component of the primary outcome in many venous thromboembolism (VTE) studies. The absence of a standardized definition for PE-related death hampers study outcome evaluation and between-study comparisons.

OBJECTIVES

To summarize definitions for PE-related death used in recent VTE studies and to assess the PE-related death rate.

PATIENTS/METHODS

A systematic literature search was conducted on 26 April 2018 from 1 January 2014 up to the search date in MEDLINE, Embase, and CENTRAL. Cohort studies and randomized trials in which PE-related death was included in the primary outcome were eligible. Screening of titles, abstracts, and full-text articles, and data extraction were independently performed in duplicate by two authors. Study outcomes included the definition for PE-related death, VTE case-fatality rate, and death due to PE rate. Descriptive statistics were used to analyze the data.

RESULTS

Of the 6807 identified citations, 83 studies were included of which 27% were randomized trials, 31% were prospective, and 42% retrospective cohort studies. Thirty-five studies (42%) had a central adjudication committee. Thirty-eight (46%) reported a definition for PE-related death of which the most frequently used components were "autopsy-confirmed PE" (50%), "objectively confirmed PE before death" (55%), and "unexplained death" (58%). Median VTE case-fatality rate was 1.8% (interquartile range, 0.0-13).

CONCLUSIONS

Only half of the included studies reported definitions for PE-related death, which were very heterogeneous. Case-fatality rate of VTE events varied widely across studies. Standardization of the definition and guidance on adjudication and reporting of PE-related death is needed.