Anticoagulation is the therapy of choice after pulmonary embolism (PE). Whereas in the past heparin and other vitamin K antagonists (VKA) were mainly used, NOACs are now the most common. Uncertainty often prevails in tumor patients, who naturally carry a higher risk of thrombosis.
According to studies, NOACs are not inferior to classical VKA therapy with regard to the risk of recurrent thromboembolism. On the contrary, these novel drugs were even superior to VKA in the case of severe bleeding, i.e. significantly less severe bleeding events occurred among NOACs.
While the initial therapy after embolism can be anticoagulated with NOACs for three months, the question for the time afterward is what should happen after these first three months: continue therapy or stop?
There is also uncertainty as to the extent to which NOACs should be applied to tumor patients. However, meta-analyses of initial studies indicate that the drugs can also be used safely and effectively in cancer patients.
The US guidelines recommend anticoagulation of PE using NOACs before classical VKAs. Especially in the long-term treatment (> 6 months), NOACs seem to be perceived as more pleasant by the patients. However, NOACs do not completely prevent bleeding events compared to VKAs. Rather, it depends on the fact that bleeding as a serious side effect of anticoagulation is not so severe.
For Apixaban, previous studies had shown that it reduced the re-hospitalization rates of patients as well as the duration of hospitalizations. Apixaban was also associated with fewer recurrent venous thromboembolism (VTE) or related deaths (AMPLIFY-EXT study: 1.7 % Apixaban vs. 8.8 % placebo). However, at the same time, the risk of bleeding was slightly increased compared to placebo (AMPLIFY-EXT study: 2.7 % placebo vs. 3.2 % for 2.5 mg Apixaban vs. 4.3 % for 5 mg Apixaban).
Tumor patients with venous thromboembolism (VTE) pose a particular challenge. About 15% of these patients suffer VTE in the course of their medical history. Cancer patients also have about three times the risk of recurrence of VTE and twice the risk of bleeding compared to non-tumor patients.
Initial studies confirmed that NOACs also reduced the risk of recurrence of VTE in tumor patients. However, this risk reduction appears to be associated with a higher bleeding rate. A closer look at the studies, however, reveals that the bleeding events among NOACs were primarily observed in the gastrointestinal tract (GIT) of patients with GIT tumors.
In addition, there is too little data to rule out whether NOACs interact with cancer therapy or not. In the opinion of the experts, however, there is no sufficient statistical evidence to deprive patients of modern NOAC therapy due to their tumor treatment.
Transforming patient care in venous thromboembolism - The role of non-vitamin K antagonist oral anticoagulants. (Organizer: Bristol-Myers Squibb and Pfizer Alliance), 28.08.2018, ESC Munich.