Hello, I’m Dr. Sam Goldhaber, President of NATF. Today on Clot Chronicles, I’m going to discuss the prevention of pulmonary embolism (PE) and deep vein thrombosis (DVT) in patients diagnosed with cancer. 

Certain cancers secrete substances that increase the body’s clottability. Patients with these particular types of cancer, such as pancreatic or stomach cancer, or certain types of lymphoma or brain tumors, are at very high risk of developing large PEs or DVTs. Furthermore, when these PEs or DVTs develop, they’re more resistant to standard anticoagulation compared with patients who do not have cancer. In addition, certain types of chemotherapy for cancer—for reasons we don’t understand—also predispose patients to PE and DVT. 

So, an ounce of prevention is worth a pound of cure, but until recently, we haven’t had any strong scientific evidence that prophylactic anticoagulation can reduce PE and DVT safely in patients with cancer or in patients receiving particular types of cancer chemotherapy. Recently, in the New England Journal of Medicine, two back-to-back trials were published about preventing PE and DVT in cancer patients. These trials randomized patients either to real rivaroxaban versus placebo or to real apixaban versus placebo. In each of the two studies, the direct oral anticoagulant (DOAC), rivaroxaban in one study and apixaban in the other study, markedly reduced the development of PE or DVT. 

Now, with anticoagulants, we have to keep in mind the bleeding complication rate. The major bleeding complication rate in each of the two studies was about 1%. Looking at the benefits versus the risks in these two studies, there was far more benefit than risk with rivaroxaban or apixaban. Now, this doesn’t hold for all cancers—only for cancers with a particular predilection for causing PE or DVT, and only for certain types of cancer chemotherapy. 

So, the bottom line is that if you have cancer or you have a relative or friend with cancer, you should encourage that individual to speak to the healthcare team—to the doctors and the others involved in the cancer care—to discuss whether it’s appropriate to prescribe one of these DOACs to reduce the risk of developing PE and DVT. 

This is Dr. Sam Goldhaber signing off for Clot Chronicles.