Evaluation of the safety and effectiveness of direct oral anticoagulants and low molecular weight heparin in gastrointestinal cancer-associated venous thromboembolism

Comparative Efficacy of Oral Apixaban and Subcutaneous Low Molecular Weight Heparins in the Treatment of Cancer-Associated Thromboembolism: A Meta-Analysis

Cancer patients' risk of developing venous thromboembolism (VTE) is four to seven times higher than the general population. Cancer-associated VTE (CA-VTE), is a leading cause of morbidity and mortality in cancer patients. Low Molecular Weight Heparin (LMWH) has historically been the mainstay treatment of CA-VTE; however, complications such as bleeding and recurrent VTE make it challenging to manage these patients. Recent randomized controlled trials (RCTs) have proven that direct oral anticoagulants (DOACs) are as efficacious as LMWHs in treating CA-VTE. We conducted a systematic review and meta-analysis to ascertain the efficacy and safety of LMWH and Apixaban for the treatment of CA-VTE. A systematic review was conducted using Medline, Embase, and Scopus, databases for all cohort studies, case-control studies, and RCTs in English comparing cancer patients undergoing treatment with Apixaban or LMWH to treat CA-VTE from inception-May 2023. The Review Manager program, version 5.4.1, was used for statistical analysis and the Mantel-Haenszel fixed-effects models to calculate the risk ratio (RR) and 95% confidence intervals (CIs) and the inverse variance approach to get the weighted mean difference for the continuous outcomes. Q-test for heterogeneity was used to examine statistical heterogeneity and an I2 statistics value >50% was defined as significant heterogeneity. A total of four studies were included, and the total number of patients was 1,632 across all studies. The Apixaban group was associated with a statistically significant increase in minor bleeding (RR 1.57; 95% CI (1.12, 2.21); p=0.009; I2=0%), but not for major and total bleeding. The Apixaban group showed a statistically significant lower risk of recurrent VTE when compared to the LMWH group (RR: 0.61; 95% CI (0.41, 0.92); p=0.02; I2 = 7%), and there was no statistically significant difference in terms of mortality between the two groups (RR: 0.89; 95% CI (0.73, 1.09); I2=0). Our findings suggest that Apixaban may be a favorable anticoagulant option for managing cancer-associated thromboembolism, as it demonstrated a lower risk of recurrent VTE. The risk of bleeding with DOAC in gastrointestinal cancers warrants further investigation.

Comparative Efficacy of Direct Oral Anticoagulants and Low-Molecular-Weight Heparin in Cancer-Associated Thromboembolism: A Systematic Review and Meta-Analysis

Patients diagnosed with cancer often experience an abnormal occurrence of venous thromboembolism (VTE) and its related complications. In order to evaluate the safety and effectiveness of both treatment approaches, we conducted a comprehensive systematic review and meta-analysis within the realm of cancer-associated thromboembolism. A thorough search was conducted across PubMed, the Cochrane Library, and Embase databases to find studies comparing direct oral anticoagulants (DOACs) with low molecular weight heparins (LMWHs) for the treatment of VTE in patients with malignancy. The analyses utilized the random-effects model. This meta-analysis included 11 studies. The results showed that DOACs were associated with a significantly reduced risk of VTE recurrence (RR: 0.67; 95% CI: 0.55, 0.81, p<0.0001; I2: 0%) and deep vein thrombosis (DVT) (RR: 0.63; 95% CI: 0.46, 0.86, p<0.0001; I2: 0%) compared to LMWHs. However, there was no significant difference in the risk of pulmonary embolism (PE) (RR: 0.76; 95% CI: 0.54, 1.06, p=0.11; I2: 11%) between the two groups. The use of DOACs was also associated with a non-significant increase in the risk of major bleeding events (RR: 1.23; 95% CI: 0.85, 1.78, p: 0.26; I2: 49%), while clinically relevant non-major bleeding (CRNMB) was significantly higher with DOACs (RR: 1.92; 95% CI: 1.11, 3.30, p: 0.02; I2: 81%). Secondary outcomes, such as survival rates and fatal PE, did not show significant differences between the two treatment groups. Our analysis indicates that direct oral anticoagulants exhibit a substantial decrease in the occurrence of VTE recurrence, deep vein thrombosis, and pulmonary embolism when compared to low molecular weight heparin in cancer-associated thromboembolism. However, it should be noted that DOACs carry a higher risk of CRNMB. Based on these findings, DOACs are recommended as a superior therapeutic option for managing cancer-associated thromboembolism compared to LMWH.

Bleeding and thrombotic events in bevacizumab-treated patients with colorectal cancer on novel oral anticoagulants and antiplatelet medications

Background

Bevacizumab is a humanized monoclonal anti-VEGF antibody often given in combination with fluorouracil-based chemotherapy as therapy for metastatic colorectal cancer (mCRC). The bleeding and thrombotic event rates in the setting of concurrent novel oral anticoagulants with and without aspirin and bevacizumab treatment in patients with mCRC remain unclear.

Methods

462 patients with mCRC at Barnes-Jewish Hospital were identified between December 1, 2016 and December 1, 2021 and screened for concurrent treatment with bevacizumab and anticoagulant or antiplatelet therapy. Demographic and clinical information was extracted by electronic chart review.

Results

21 patients were identified who received bevacizumab and either apixaban or rivaroxaban for mCRC treatment. Aspirin was prescribed in some of these patients within three years of starting apixaban or rivaroxaban. Of the 13 patients without aspirin prescription, nine were given apixaban, and four were given rivaroxaban while on bevacizumab. Four out of nine of the patients who received apixaban had epistaxis, and only one case resulted in any treatment discontinuation. Three out of four of the patients who received rivaroxaban experienced bleeding, and one of these three patients discontinued bevacizumab. We also looked at eight patients who had received aspirin. Two out of seven patients who received apixaban/bevacizumab/aspirin experienced bleeding and discontinued a medication. The patient who received rivaroxaban/bevacizumab/aspirin experienced bleeding and discontinued bevacizumab. No patient experienced adverse thrombotic events.

Conclusions

Patients with mCRC treated with bevacizumab and apixaban with no history of aspirin use within three years have a relatively low risk of bleeding that warrants treatment discontinuation.

Direct oral anticoagulants versus low-molecular-weight heparins for the treatment of acute venous thromboembolism in patients with gastrointestinal cancer: a systematic review and meta-analysis

Background

The association between gastrointestinal (GI) cancer and a high incidence of venous thromboembolism (VTE) is well known. Previous randomized controlled studies demonstrated that direct oral anticoagulants (DOACs) effectively treat cancer-associated thrombosis (CAT). However, some DOACs appeared to increase the risk of bleeding, particularly in patients with GI malignancies. Therefore, the current systematic review and meta-analysis were conducted to evaluate the safety and efficacy of DOACs in GI cancer-associated thrombosis.

Methods

Two investigators individually reviewed all studies that compared DOACs and low-molecular-weight heparins (LMWHs) in GI cancer-associated thrombosis and were published in MEDLINE and EMBASE before February 2022. The effect estimates and 95% confidence intervals (CIs) from each eligible study were combined using the Mantel–Haenszel method.

Results

A total of 2226 patients were included in the meta-analysis. The rates of major bleeding in the DOAC and LMWH groups were not significantly different (relative risk [RR]: 1.31; 95% CI: 0.84–2.04; P = 0.23; I² = 41%). However, the rate of clinically relevant nonmajor bleeding (CRNMB) was significantly higher in the DOAC group (RR: 1.76; 95% CI: 1.24–2.52; P = 0.002; I² = 8%). The risks of recurrent VTE in the groups did not significantly differ (RR: 0.72; 95% CI: 0.49–1.04; P = 0.08; I² = 0%).

Conclusions

The current data suggest that treatment of GI cancer-associated thrombosis with DOACs significantly increases the risk of CRNMB. However, the risk of major bleeding was not significantly different. The efficacy of DOACs for preventing recurrent VTE in GI cancer was comparable to that of LMWHs.

Trial registration

INPLASY202180113.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00399-7.

Venous Thromboembolism In Cancer Patients: "From Evidence to Care"

This article seeks to review the current status of treatment and prevention of venous thromboembolic disease (VTE) in cancer patients after the addition of direct oral anticoagulants (DOAC) to the therapeutic arsenal available. The suitability of DOAC use in complex clinical situations, poorly represented in clinical trials, is controversial and difficult for care activity, making the recommendations in clinical practice guidelines the focus of special attention in this area. Recently, several randomized trials have compared low molecular weight heparin (LMWH) to DOAC for the management of CAT. Potential drug interactions with DOACs or the increased risk of bleeding in intraluminal tumors require special precautions, as do metastatic or primary brain disease and comorbid conditions, such as renal or liver failure, which are not suitably represented in pivotal studies. Furthermore, few data are available for situations involving elevated bleeding risk, with thrombocytopenia levels below the inclusion criterion of clinical trials, or recurrence during active anticoagulant therapy. Similarly, it is less clear that patients and physicians accept the presumption that oral DOAC administration is more convenient than subcutaneous LMWH, particularly when drug absorption may be compromised. The non-inclusion or under-representation of patients at higher risk for complications with anticoagulation in randomized clinical trials, makes their use complex in certain situations in health care. This paper provides a practical review of current clinical guideline recommendations regarding LMWH and/ or DOAC to treat and prevent CAT, as well as the most controversial clinical conditions for their use.

Factor Xa inhibitors versus low molecular weight heparin for the treatment of cancer associated venous thromboembolism; A meta-analysis of randomized controlled trials and non-randomized studies

INTRODUCTION

We compared the safety and efficacy of Xa-inhibitors to LMWH for treatment of venous thromboembolism in mixed and gastrointestinal cancer cohorts (CA-VTE).

METHODS

A systematic search identified RCTs and non-randomized studies (NRS) comparing Xa-inhibitors to LMWH for treating CA-VTE. Relative risks were computed. Certainty was assessed using the GRADE approach.

RESULTS

Xa-inhibitors reduced the risk of recurrent VTE (RR0.64;0.49-0.84) and NRS (RR0.74;0.60-0.92;Moderate-Low Certainty). There was no significant difference in recurrent PE in RCTs (RR0.72;0.50-1.02) and NRS (1.43;0.65-3.12;Low-Very Low Certainty). Xa-inhibitors increased the risk of overall bleeding events in RCTs (RR1.45;1.05-2.01) and NRS (RR1.72;1.42-2.08;Moderate-Low Certainty), and the risk of major bleeding events in NRS (RR1.56;1.17-2.07), but not in RCTs (RR1.33;0.94-1.89; Low-Very Low Certainty). Similar results were detected in gastrointestinal cancer patients.

CONCLUSION

Xa-inhibitors may reduce the risk of recurrent VTE, but not recurrent PE compared to LMWH. A higher overall bleeding risk, and a questionably higher major bleeding risk was found with Xa-inhibitor use.

Bleeding in Patients With Gastrointestinal Cancer Compared With Nongastrointestinal Cancer Treated With Apixaban, Rivaroxaban, or Enoxaparin for Acute Venous Thromboembolism

OBJECTIVE

To compare the bleeding risk in patients with gastrointestinal (GI) cancer with that in patients with non-GI cancer treated with anticoagulation for acute cancer-associated venous thromboembolism (Ca-VTE).

PATIENTS AND METHODS

Consecutive patients with Ca-VTE seen at the Mayo Thrombophilia Clinic between March 1, 2013, and April 20, 2020, were observed prospectively to assess major bleeding and clinically relevant nonmajor bleeding (CRNMB).

RESULTS

In the group of 1392 patients with Ca-VTE, 499 (35.8%) had GI cancer including 272 with luminal GI cancer (lower GI, 208; upper GI, 64), 176 with pancreatic cancer, and 51 with hepatobiliary cancer. The rate of major bleeding and CRNMB in patients with GI cancer was similar to that in 893 (64.2%) patients with non-GI cancer treated with apixaban, rivaroxaban, or enoxaparin. Apixaban had a higher rate of major bleeding in luminal GI cancer compared with the non-GI cancer group (15.59 vs 3.26 per 100 person-years; P=.004) and compared with enoxaparin in patients with luminal GI cancer (15.59 vs 3.17; P=.04). Apixaban had a lower rate of CRNMB compared with rivaroxaban in patients with GI cancer (3.83 vs 9.40 per 100 person-years; P=.03). Patients treated with rivaroxaban in the luminal GI cancer group had a major bleeding rate similar to that of patients with non-GI cancer (2.04 vs 4.91 per 100 person-years; P=.37).

CONCLUSION

Apixaban has a higher rate of major bleeding in patients with luminal GI cancer compared with patients with non-GI cancer and compared with enoxaparin in patients with luminal GI cancer. Rivaroxaban shows no increased risk of major bleeding in patients with GI cancer or luminal GI cancer compared with patients with non-GI cancer.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03504007.

Submassive Pulmonary Embolism: Current Perspectives and Future Directions

Submassive pulmonary embolism (PE) lies on a spectrum of disease severity between standard and high-risk disease. By definition, patients with submassive PE have a worse outcome than the majority of those with standard-risk PE, who are hemodynamically stable and lack imaging or laboratory features of cardiac dysfunction. Systemic thrombolytic therapy has been proven to reduce mortality in patients with high-risk disease; however, its use in submassive PE has not demonstrated a clear benefit, with haemodynamic improvements being offset by excess bleeding. Furthermore, meta-analyses have been confusing, with conflicting results on overall survival and net gain. As such, significant interest remains in optimising thrombolysis, with recent efforts in catheter-based delivery as well as upcoming studies on reduced systemic dosing. Recently, long-term cardiorespiratory limitations following submassive PE have been described, termed post-PE syndrome. Studies on the ability of thrombolytic therapy to prevent this condition also present conflicting evidence. In this review, we aim to clarify the current evidence with respect to submassive PE management, and also to highlight shortcomings in current definitions and prognostic factors. Additionally, we discuss novel therapies currently in preclinical and early clinical trials that may improve outcomes in patients with submassive PE.

The Net Clinical Benefit of Rivaroxaban Compared to Low-Molecular-Weight Heparin in the Treatment of Cancer-Associated Thrombosis: Systematic Review and Meta-Analysis

Cancer-associated thrombosis (CAT) carries significant morbidity and mortality. Low-molecular-weight heparin (LMWH) remains the standard of care, with recent systematic studies suggesting the efficacy and safety of rivaroxaban in the treatment of CAT. Uncertainty, however, remains regarding rivaroxaban efficacy and safety in real-world settings. We performed a systematic review and meta-analysis of studies comparing rivaroxaban to LMWH. We searched PubMed, MEDLINE, and EMBASE. The primary outcome was the net clinical benefit (NCB), while rates of major bleeding (MB), venous thromboembolism (VTE), clinically relevant nonmajor bleeding (CRNMB), and all-cause mortality events were secondary outcomes. Seventeen studies were included in the final analysis. Rivaroxaban had a better NCB (relative risk [RR] = 0.82; 95% CI = 0.75-0.89, Q = 10.51, I ² = 0%), less VTE events (RR = 0.73, 95% CI = 0.65-0.82, Q = 6.76, I ² = 0%), and lower all-cause mortality (RR = 0.72, 95% CI = 0.57-0.91, Q = 32.8, I ² = 79%) compared to LMWH. Additionally, comparable MB events (RR = 1.07, 95% CI = 0.85-1.33, Q = 16.9, I ² = 11%). However, CRNMB events were higher in the rivaroxaban group (RR = 2.02, 95% CI = 1.46-2.80, Q = 9.9, I ² = 19%). Additional analyses demonstrated consistency of results. Our review encompassing data from randomized and real-world data suggested rivaroxaban superiority compared to LMWH in terms of a better NCB, fewer VTE events, lower all-cause mortality, and comparable MB risk while carrying a higher risk of CRNMB. These findings support the use of rivaroxaban in the treatment of CAT. Additionally, it warrants a sizable randomized controlled study testing the superiority of rivaroxaban versus LMWH formulation and ascertaining bleeding outcomes according to cancer type and site.

Clinical controversies in the treatment of cancer-associated venous thromboembolism

Cancer-associated venous thromboembolism (VTE) is a common complication of malignancy. Patients with cancer exhibit risk factors for both recurrent VTE and major or minor bleeding. Direct oral anticoagulants (DOACs) are an attractive treatment option; however, there is a lack of consensus among national guidelines for choice between DOACs and LMWH, agent selection, dosing strategy, and duration of anticoagulation. Characteristics of the thrombotic event, the malignancy, the patient, and the anticoagulant must be considered. A systematic search of online databases was performed to identify literature on the management of cancer-associated VTE. Multiple controversies remain surrounding the optimal treatment of cancer-associated VTE.