ABSTRACT
Venous thromboembolism (VTE) is a common complication among patients with cancer, associated with significant higher rate of mortality and morbidity. Low-molecular-weight heparin (LMWH) as a single therapeutic is considered as the standard of care for the treatment of acute cancer-associated thrombosis for many years, showing a significant 40% reduction of recurrent VTE (RR: 0.58; 95% CI, 0.43 - 0.77) without a significant increase of major bleeding complications compared to VKA (RR: 1.09; 95% CI 0.55 - 2.12). Based on results analysis studies only including patients with proximal DVT or PE the risk of recurrent VTE was similar in the DOAC and the LMWH (RR 0.68; 95% CI, 0.39 - 1.17) groups, without significantively increasing the risk of either major bleeding (RR = 1.32; 95% CI 0.7 - 2.47) or CRNMB (RR 1.6; 95% 0.99 - 2.6). Compared with LMWH, the risk of major bleeding and clinically relevant-non major bleeding was higher, although non-significantly, with DOACs than with LMWH, underlying that DOACs should be avoided in patients at high risk of bleeding. The higher risk of bleeding reported in DOACs-treated patients appears related to an excess of upper GI bleeding. In addition to GI cancer, other high-risk features associated with bleeding complications are an urothelial cancer, drug-drug interactions and use of anticancer drugs associated with GI toxicity. Overall, DOACs are an effective treatment option, and safe in most cancer patients with acute VTE. Nonetheless, DOACs should be used with caution in cancer patients at high risk for bleeding due to cancer site and stage per se or to cancer treatments.