First-Line Therapies for VTE Treatment and Secondary Prophylaxis in Patients With Cancer: A New Direction.

Objective: To review evidence behind anticoagulants in cancer-associated venous thromboembolism (VTE) with a focus on low-molecular-weight heparins (LMWH) and the role of direct oral anticoagulants (DOACs).

Data Sources: PubMed was searched using terms "venous thromboembolism," "cancer," and "anticoagulation." This search was restricted to clinical trials, meta-analyses, and subgroup analyses. Additional references were identified from reviewing literature citations.

Study Selection: English-language prospective and retrospective studies assessing the efficacy and safety of LMWH and DOACs in patients with cancer.

Data Analysis: Several trials were analyzed that compared anticoagulation therapies for prevention of recurrent VTE in patients with cancer. Many studies comparing LMWH and vitamin K antagonists (VKAs) found nonsignificant differences between therapies. A single study demonstrated that LMWHs are superior to VKAs. This evidence supporting LMWH for long-term VTE treatment in patients with cancer is based on comparison to VKA, but results are limited by methodological issues, and the benefit of LMWH may be driven by poor control. Subanalyses of DOAC trials suggest these are equally or more effective as VKA in cancer, but this conclusion is underpowered.

Conclusion: DOACs have the potential to bypass many challenges with traditional therapy. After analyzing the evidence available, we conclude that after careful consideration of risks and benefits, use of DOACs for VTE treatment are a reasonable option in patients with cancer.