Cancer-associated venous thromboembolism (VTE) is associated with high VTE recurrence and bleeding. We included all randomized clinical trials that evaluated the efficacy and safety of various anticoagulants in cancer-associated VTE. Trial-level data were extracted from 13 trials. Aggregate odds ratios (ORs) were calculated using direct and network meta-analysis. The primary outcome was VTE (pulmonary embolism and/or deep vein thrombosis) recurrence. Secondary outcomes were major bleeding and all-cause mortality. We identified 13 trials with 4869 patient-years of follow-up (6595 total patients; mean age 62.4 ± 12.2; 50.4 % female; 17.7 % hematological malignancies). The most common cancer type was colorectal and 48 % had metastatic cancer at baseline. Compared to vitamin-K-antagonists (VKAs), non-vitamin-K-antagonist-oral-anticoagulants (NOACs) were associated with significantly reduced VTE recurrence (OR, 0.58; 95 % CI, 0.40-0.83) and reduced major bleeding risks (OR, 0.56; 95 % CI, 0.35-0.91). However, no differences were observed in the subgroup analysis of patients with active cancer. Although NOACs were associated with reduced VTE recurrence compared with low-molecular-weight-heparin (LMWHs) (OR, 0.46; 95 % CI, 0.25- 0.85), there was a significant increased major bleeding in high-quality trials. LMWHs were associated with significantly reduced VTE recurrence compared with VKAs (OR, 0.52; 95 % CI, 0.39-0.71) and similar bleeding risks. Conclusions: Among patients with cancer-associated VTE, NOACs were associated with significantly reduced VTE recurrence and bleeding compared with VKAs, however, with similar outcomes in the active cancer population. NOACs were associated with reduced VTE recurrence but higher bleeding risks compared with LMWHs. LMWHs were associated with significantly reduced VTE recurrence and similar bleeding compared with VKAs.
PURPOSE: To provide updated recommendations about prophylaxis and treatment of venous thromboembolism (VTE) in patients with cancer.
METHODS: PubMed and the Cochrane Library were searched for randomized controlled trials (RCTs) and meta-analyses of RCTs published from August 1, 2014, through December 4, 2018. ASCO convened an Expert Panel to review the evidence and revise previous recommendations as needed.
RESULTS: The systematic review included 35 publications on VTE prophylaxis and treatment and 18 publications on VTE risk assessment. Two RCTs of direct oral anticoagulants (DOACs) for the treatment of VTE in patients with cancer reported that edoxaban and rivaroxaban are effective but are linked with a higher risk of bleeding compared with low-molecular-weight heparin (LMWH) in patients with GI and potentially genitourinary cancers. Two additional RCTs reported on DOACs for thromboprophylaxis in ambulatory patients with cancer at increased risk of VTE.
RECOMMENDATIONS: Changes to previous recommendations: Clinicians may offer thromboprophylaxis with apixaban, rivaroxaban, or LMWH to selected high-risk outpatients with cancer; rivaroxaban and edoxaban have been added as options for VTE treatment; patients with brain metastases are now addressed in the VTE treatment section; and the recommendation regarding long-term postoperative LMWH has been expanded. Re-affirmed recommendations: Most hospitalized patients with cancer and an acute medical condition require thromboprophylaxis throughout hospitalization. Thromboprophylaxis is not routinely recommended for all outpatients with cancer. Patients undergoing major cancer surgery should receive prophylaxis starting before surgery and continuing for at least 7 to 10 days. Patients with cancer should be periodically assessed for VTE risk, and oncology professionals should provide patient education about the signs and symptoms of VTE.Additional information is available at www.asco.org/supportive-care-guidelines.
Efficacy and safety of direct oral anticoagulants (DOACs) for preventing primary and recurrent venous thromboembolism (VTE) in patients with cancer remain unclear. In this study, we conducted a systematic review to summarize the most up-to-date evidence from randomized controlled trials (RCTs). Our primary outcomes included the benefit outcome (VTE) and safety outcome (major bleeding). A random-effects model was used to pool the relative risks (RRs) for data syntheses. The Grading of Recommendations Assessment, Development and Evaluation tool was used to evaluate the quality of the entire body of evidence across studies. We included 11 RCTs with a total of 3741 patients with cancer for analyses. The DOACs were significantly related with a reduced risk of VTE when compared with non-DOACs: RR = 0.77, 95% confidence interval [CI]: 0.61-0.99, P = .04. Nonsignificant trend towards a higher risk of major bleeding was found in DOACs: RR = 1.28 95% CI: 0.81-2.02, P = .29. The quality of the entire body of evidence was graded as moderate for risk of VTE, and low for risk of major bleeding. To summarize, DOACs were found to have a favorable effect on risk of VTE but a nonsignificant higher risk of major bleeding compared with non-DOACs in patients with cancer. The safety effect of DOACs in patients with cancer requires further evaluation in adequately powered and designed studies.
Venous thromboembolism (VTE) is highly prevalent in patients with cancer. Non-vitamin K antagonist oral anticoagulants (NOACs), directly targeting the enzymatic activity of thrombin or factor Xa, have been shown to be as effective as and safer than traditional anticoagulation for VTE prophylaxis in no-cancer patients. However, related studies that focused on the anticoagulation in cancer patients are lacked, and almost no net clinical benefit (NCB) analyses that quantified both VTE events and bleeding events have been addressed in this fragile population. Therefore, we aim to investigate this issue using a systematic review and NCB analysis. A comprehensive search of Medline, Embase, and Cochrane Library were performed for randomized controlled trials (RCTs) that reported the VTE events and major bleeding of NOACs and traditional anticoagulants in patients with or without cancer. Odds ratios (ORs) and 95% confidence intervals (CIs) of VTE and bleeding events were calculated using a random-effects model. The primacy outcome of narrow NCB was calculated by pooling ORs of VTE and major bleeding, with a weighting of 1.0. Similarly, the broad NCB was calculated by pooling ORs of VTE and clinically relevant bleeding. Heterogeneity was assessed through I2 test and Q statistic, and subgroup analyses were performed on the basis of different patients (VTE patients or acutely ill patients), comparators (vitamin-K antagonists or low-molecular-weight heparin), and follow-up duration (≤6 months or >6 months). Overall, 9 RCTs including 41,454 patients were enrolled, of which 2,902 (7%) were cancer patients, and 38,552 (93%) were no-cancer patients; 20,712 (50%) were administrated with NOACs and 20,742 (50%) were administrated with traditional anticoagulants. The use of NOACs had a superior NCB than traditional anticoagulation in both cancer patients (OR: 0.68, 95%CI: 0.50-0.85 for narrow NCB; OR: 0.76, 95%CI: 0.61-0.91 for broad NCB) and no-cancer patients (OR: 0.75, 95%CI: 0.54-0.96 for narrow NCB; OR: 0.85, 95%CI: 0.67-1.04 for broad NCB), with the estimates mainly from VTE patients receiving long-term warfarin treatment. In conclusion, NOACs may represent a better NCB property compared to traditional anticoagulants in cancer patients who need long-term anticoagulation treatment.
Cancer-associated venous thromboembolism (VTE) is associated with high VTE recurrence and bleeding. We included all randomized clinical trials that evaluated the efficacy and safety of various anticoagulants in cancer-associated VTE. Trial-level data were extracted from 13 trials. Aggregate odds ratios (ORs) were calculated using direct and network meta-analysis. The primary outcome was VTE (pulmonary embolism and/or deep vein thrombosis) recurrence. Secondary outcomes were major bleeding and all-cause mortality. We identified 13 trials with 4869 patient-years of follow-up (6595 total patients; mean age 62.4 ± 12.2; 50.4 % female; 17.7 % hematological malignancies). The most common cancer type was colorectal and 48 % had metastatic cancer at baseline. Compared to vitamin-K-antagonists (VKAs), non-vitamin-K-antagonist-oral-anticoagulants (NOACs) were associated with significantly reduced VTE recurrence (OR, 0.58; 95 % CI, 0.40-0.83) and reduced major bleeding risks (OR, 0.56; 95 % CI, 0.35-0.91). However, no differences were observed in the subgroup analysis of patients with active cancer. Although NOACs were associated with reduced VTE recurrence compared with low-molecular-weight-heparin (LMWHs) (OR, 0.46; 95 % CI, 0.25- 0.85), there was a significant increased major bleeding in high-quality trials. LMWHs were associated with significantly reduced VTE recurrence compared with VKAs (OR, 0.52; 95 % CI, 0.39-0.71) and similar bleeding risks. Conclusions: Among patients with cancer-associated VTE, NOACs were associated with significantly reduced VTE recurrence and bleeding compared with VKAs, however, with similar outcomes in the active cancer population. NOACs were associated with reduced VTE recurrence but higher bleeding risks compared with LMWHs. LMWHs were associated with significantly reduced VTE recurrence and similar bleeding compared with VKAs.
