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.
INTRODUCTION: Low-molecular-weight heparin (LMWH) and vitamin K antagonists (VKA) are current treatment options for cancer patients suffering from acute venous thromboembolism (VTE). The role of direct-acting oral anticoagulants (DOACs) for the treatment of VTE in cancer patients, particular in comparison with the current standard of care which is LMWH, remains unclear. In this network meta-analysis, we compared the relative efficacy and safety of LMWH, VKA, and DOAC for the treatment of cancer-associated VTE.
METHODS: A pre-specified search protocol identified 10 randomized controlled trials including 3242 cancer patients. Relative risks (RR) of recurrent VTE (efficacy) and major bleeding (safety) were analyzed using a random-effects meta-regression model.
RESULTS: LMWH emerged as significantly superior to VKA with respect to risk reduction of recurrent VTE (RR=0.60, 95%CI:0.45-0.79, p<0.001), and its safety was comparable to VKA (RR=1.08, 95%CI:0.70-1.66, p=0.74). For the DOAC vs. VKA efficacy and safety comparison, the relative risk estimates were in favor of DOAC, but had confidence intervals that still included equivalence (RR for recurrent VTE=0.65, 95%CI:0.38-1.09, p=0.10; RR for major bleeding=0.72, 95%CI:0.39-1.37, p=0.32). In the indirect network comparison between DOAC and LMWH, the results indicated comparable efficacy (RR=1.08, 95%CI:0.59-1.95, p=0.81), and a non-significant relative risk towards improved safety with DOAC (RR=0.67, 95%CI:0.31-1.46, p=0.31). The results prevailed after adjusting for different risk of recurrent VTE and major bleeding between LMWH vs. VKA and DOAC vs. VKA studies.
CONCLUSION: The efficacy and safety of LMWH and DOACs for the treatment of VTE in cancer patients may be comparable.
FUNDING: Austrian Science Fund (FWF-SFB-54).
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.
