Clot Chronicles: Blood Clots and Cancer

Dr. Sam Goldhaber discusses the connection between blood clots and cancer, along with the recent results of the Hokusai VTE Cancer Trial.

This is Dr. Sam Goldhaber. I am president of NATF, and it is a pleasure to speak to you today with episode three of the NATF Clot Chronicles. Today we’re going to speak about a very special group of patients who have cancer, but they also have DVT or Pulmonary Embolism.

We know that cancer is a major predisposing factor for deep vein thrombosis and pulmonary embolism. We think the cancer cells release and secrete certain materials that predispose to blood clotting and treating cancer patients with venous thromboembolism can be very challenging. Their patients are often resistant to warfarin for treatment and typically guidelines say that patients with cancer plus DVT or cancer pulse pulmonary embolism should be treated with injections of low molecular weight heparin, such as enoxaparin, Lovenox, for at least three to six months without any oral anticoagulant.

Now, I can tell you in my practice my cancer patients with DVT or pulmonary embolism, after six months straight of injecting low molecular weight heparin into their bellies, they’re pretty black and blue, and they ask me, “Doc, what can we do as an alternative? Can we use of the new oral anticoagulants instead because we really don’t have any space left on our belly that’s not bruised and we’re sick and tired of injecting ourselves? It’s not doing anything to improve our quality of life. It’s enough to be fighting cancer but to have to face a daily injection can be a bit difficult.”

So, there’s been a lot of interest in studying the new oral anticoagulants. And, there’s one big study that’s just been published using a drug that was invented in Japan. The trial is called Hokusai after a very famous Japanese artist. Hokusai VTE, for venous thromboembolism, Cancer Trial. In this trial the novel anticoagulant, edoxaban, was compared with injections of low molecular weight heparin in patients with cancer. This treatment was continued for one year in patients with cancer who also had DVT or pulmonary embolism. Patients were randomized either to the edoxaban group or to the the low molecular weight heparin injection.
They were followed with an end point of seeing whether which treatment would be better for preventing a new blood clot and which treatment would be safer with fewer bleeding complications. The primary end point was a summation of major clotting events with major bleeding events.

The bottom line in Hokusai Cancer VTE trial is that it was a tie. It was a tie between the low molecular weight heparin injections once-a-day, and the once-a-day oral pill, edoxaban. It turned out that the patients who received the edoxaban had fewer new blood clots than the patients who received low molecular weight heparin, but the patients who took edoxaban had more major bleeding episodes particular upper gastro-intestinal tract bleeding and particularly in patients who had known stomach cancer.

So, the trial tells us that one approach is not superior to the other and it means the cancer patients with venous thromboembolism should really speak with their physicians and discuss the pros and cons of sticking with low molecular weight heparin or switching to edoxaban if these patients have cancer plus DVT or cancer pulmonary embolism.

Certainly, patients who have a stomach cancer should probably stick with low molecular weight heparin based on the results of this trial because there was extra bleeding with edoxaban. The patients who don’t have any GI tract cancer, I think it’s an open question about switching to edoxaban or sticking it out with low molecular weight heparin.

The trial tells us that one approach is not better than the other and the trial is important because it gives us another option and it’s a really patient-centered trial, where we have to take into account quality of life as well as efficacy and safety of the anticoagulant.

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

For more information, visit The New England Journal of Medicine for full trial information.