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Dr. Marc Carrier

Primary Prevention of Cancer Associated Thrombosis


Matthew James, MSc Candidate, Translational Medicine and TMED Graduate Student Teaching Assistant

At the September 12 Medical Grand Rounds, the Department of Medicine was fortunate to host Dr. Marc Carrier, a senior clinician-scientist and world-renowned expert in thrombosis from the University of Ottawa. Dr. Carrier’s Grand Rounds presentation focused on the primary prevention of cancer associated venous thromboembolism and highlighted recent evidence from two important clinical trials.

Venous thromboembolism (VTE) refers to blood clots that form in the veins and includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). The incidence of rate of VTE in the general populations is 1 in 1000; however, Dr. Carrier reminded us that the incidence rate is four times greater in cancer patients, and that thromboembolism is the second leading cause of death for cancer patients. Previous evidence for preventative treatment with anticoagulants such as low molecular weight heparins suggested minimal benefit, and many of these treatments resulted in an increased risk of major bleeding.

Direct oral anticoagulants (DOACS) offer a potential for preventative treatment for cancer associated VTE, particularly in high risk patients. Two recent clinical trials (AVERT and CASSINI) examined the role of DOACS in patients who were at high risk for VTE. These trials showed that preventative treatment with DOACS resulted in a significantly lower rate of VTE compared to placebo, with no clinically relevant change in major bleeding events. Since the publication of these trials, the American Society of Clinical Oncology has updated their guidelines to indicate that preventative treatment with DOACS in cancer patients who are at high risk for VTE may be indicated.

Dr. Carrier prefaced his talk by stating that primary prevention for cancer associated VTE is controversial among clinicians. When the audience was polled, there was a fairly even split between those who support the use of DOACS for primary prevention and those who remain unconvinced or do not use DOACS for primary prevention. At our post rounds discussion, Dr. Carrier explained that when new data from clinical trials are published, there is a substantial lag period before this new information is disseminated amongst the medical community. The physicians who are familiar with the latest data from clinical trials are often the ones who form treatment guidelines and are the ones who can most readily implement them in their practice. Thus, in the case of cancer associated VTE, the thrombosis community may be more familiar with the research than physicians in other specialties. Dr. Carrier believes it is the responsibility of those who are familiar with new research to educate those around them. This is not limited to physicians, but should also include nurses, pharmacists and other allied health care professionals who often have more personal contact with patients.

Dr. Carrier also discussed clinical tools such as the Khorana Risk Score which can be used to determine which patients are at higher risk for cancer associated thrombosis. At the Ottawa Hospital, this instrument is integrated into the electronic medical records (EMR), and Dr. Carrier and his colleagues actively use it to assess their patients’ risk for VTE. This assessment tool is not used at every centre, and Dr. Carrier suggested that as more hospitals adopt EMR, integrating these tools may prompt clinicians to familiarize themselves with the research surrounding thrombosis prevention in cancer.

Despite the significant implications for patients, there is limited information in the lay press regarding thrombosis in cancer. This lack of information makes it difficult for patients to educate themselves on the nature of their condition, and thus, they may not know what questions to ask their health care providers regarding their risk for VTE and if preventative treatment is an option. Just as it is important to educate the health care community, Dr. Carrier believes it is extremely important to educate patients about the signs and symptoms of VTE. Patients are often educated about the warning signs of much less common cancer related illnesses, yet often do not know the warning signs of VTE despite. Taking 10 minutes to explain the risks and answer any questions may help reduce avoidable morbidity and mortality.

It was a pleasure to have Dr. Carrier at our first Medical Grand Rounds discussion. On behalf of the TMED graduate students, we thank him for his time and invaluable insight.

Comments

This event, although in its infancy is one of the many ways Dr. Carrier is hoping to educate patients and clinicians on Thrombosis. I spent time looking this up after our discussion and one of the tags on the main page was "DEDICATED TO FURTHERING EDUCATION & RESEARCH IN THROMBOTIC DISEASE" - which was one of the topics that Dr. Carrier emphasized during his talk and our discussion afterwards.

Name
Joseph Nashed

Name
Quentin Tsang

Tue, 09/17/2019 - 21:50

Dr. Carrier's address to Medical Grand Rounds was an example of "real-time" translational medicine happening right before our eyes. He brought forth novel research to a group of medical professionals and students and sought to provide insight and education to all regarding recent findings relating to VTE and cancer. This was extremely evident during his polling session of the audience during his lecture; who had changed their minds about DOACs (or anti-coagulants in general) in cancer patients? The room was split; a third that would consider using DOACs or anticoagulants, a third that began to start thinking about anticoagulants in cancer patients and a third that weren't convinced and were not going to change their minds. While it may seem disappointing that two-thirds of the audience did not put full faith in Dr. Carrier's findings, he was, in fact, able to convince a third of the room! That is the nature of translational medicine and knowledge translation: we will never be able to convince 100% of people, but if we're able to bring our findings to our colleagues and educate them (and hopefully inspire them) on new breakthroughs, we will be able to improve patient outcomes! To me, this was translational medicine happening in real-time.

I would like to thank Dr. Carrier for his time speaking with the Translational Medicine Graduate Cohort after rounds and inspiring thoughtful discussion.

Quentin Tsang, BScH - Kinesiology
MSc Translational Medicine '21 (Candidate)
Gastrointestinal Diseases Research Unit
Queen's University

Name
Quentin Tsang

Name
Thalia Hua

Tue, 09/17/2019 - 21:56

A big thank you to Dr. Carrier for speaking to us about cancer-associated thrombosis, as well as for opening our eyes to the obstacles associated with implementing new research into a clinical setting! We are hopeful that all health-care providers will be eager to apply new evidence-based findings into their practices, and Dr. Carrier emphasizes the importance of educating each other to move towards producing a comprehensive treatment plan suitable for the patient. Excellent summary Matthew!

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Thalia Hua

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Madison MacKinnon

Wed, 09/18/2019 - 10:21

I would like to extend a big thank you to Dr. Carrier for taking the time to discuss his research with the Translational Medicine students. He answered all of our questions enthusiastically, thoroughly and welcomed any sort of discussion on his research.
As a TMED student, something that really stood out to me was that despite the controversial nature of this topic, Dr. Carrier and his colleagues are still exploring the translational elements of this research. During the Grand Rounds presentation, he mentioned that during his research when his team identified patients with a high risk for cancer associated thrombosis, they gave those patients a sheet in the waiting room with information on the disease. This small step is invaluable in beginning the necessary education of cancer associated thrombosis that the public needs, and is an excellent example of clinicians performing knowledge translation of their work for the betterment of their patients.

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Madison MacKinnon

Thanks for raising this point Madison! As we discussed with Dr. Carrier, educating patients on the signs and symptoms of thrombosis is crucial to them seeking proper medical attention in a timely manner. Often people think of Translational Medicine as limited to direct bench-to-bedside research translation (such as a new drug). But it is often translation of knowledge and adopting practices (such as these patient education sheets) based on research that can yield the most meaningful benefits to patients. I'm sure that this is a theme that will continue to come up as we hear from more translational researchers from a variety of fields.

Name
Matthew James

That really stood out to me as well Madison! I found it really intriguing when Dr. Carrier told us about his experience interacting with people from all aspects of this field, from the patients to the doctors and researchers. Everyone was approaching the same issue from different backgrounds and connections to the problem, and they all wanted different information whenever he spoke with them. It was a great reminder that we all have a different perspective, and what is needed or works for one person doesn't necessarily work for everyone else!

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Marty VandenBroek

Name
Joseph Nashed

Wed, 09/18/2019 - 12:07

First I’d like to extend my thanks to Dr. Carrier for the wonderful presentation, and for his discussion with us afterwards

Dr. Carrier’s work highlights that Direct oral anticoagulants (DOACs) represent a potential preventative treatment in individuals at high risk for Venous thromboembolism (VTEs) - especially those with cancer. One of the topics that continually kept reappearing was how Dr. Carrier and his team could influence change in clinical practice with his colleagues in oncology. Despite his recent work, and changes in the American Society of Clinical Oncology recommending that DOACs are useful in preventing VTEs in cancer patients, many of Dr. Carriers colleagues and patients seem to remain slightly skeptical about including DOACs in a patient’s treatment. However, in our discussion afterwards, Dr. Carrier reiterated that educating patients and clinical practitioners is a process that involves time and patience. Convincing skeptics is not a new phenomenon in science, and one example that comes to mind is Dr. Barry Marshall’s work on H. Pylori, and convincing his colleagues that the bacteria induced ulcers. Dr. Carrier mentioned that he is hopeful that such education, time and patience can help clinicians and patients alike make the best informed decision in the treatment protocols for cancer patients at high risk of VTEs.

Once again I would like to thank Dr. Carrier for his time and wonderful presentation and discussion.

Name
Joseph Nashed

Name
Daniel Rivera

Tue, 09/24/2019 - 09:30

Thank you to Dr. Carrier for his presentations on the application of DOACs to treat VTE in cancer patients. As mentioned, there seems to be a split between the clinicians polled at the grand round - certainly interesting given that fairly compelling evidence was presented. Does raise the question, what will it take to convince clinicians further? More clear direction/information around DOAC use in clinical guidelines?

Dr. Carrier also raised a great point that day - what does this all mean to patients? VTE may not be on the top of a cancer patients mind, especially when pre-occupied with chemo + other treatments/symptoms associated with their primary concern, the cancer itself. However, it has been mentioned that cancer patients are at an increased risk for VTE. I'm interested to see how both patient and clinician interest in DOAC use for VTE takes off as more literature comes out and finds its way to those who create clinical guidelines.

Name
Daniel Rivera

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