March 21, 2023

In this brief video, Dr. Jordan Schaefer discusses a new paradigm for VTE prophylaxis for the high thrombotic risk group of ambulatory medical oncology patients, which represent 15-20% of all patients with thrombosis. To access more resources on the practical management of VTE, visit

Hello i’m jordan schaefer i’m a hematologist at the university of michigan and today i’ll be talking about venous thromboembolism prophylaxis for ambulatory medical oncology patients so in some ways this represents a new paradigm in uh approach to uh venus pharmacologic venous thromboembolism prophylaxis for medical oncology patients while these patients

Represent a subset of patients traditionally offered risk adapted prophylaxis including hospitalized patients patients in the post-operative setting and patients with uh pregnancy or in the postpartum uh setting uh inventory medical oncology patients traditionally haven’t been offered pharmacologic venous thromboembolism prophylaxis this is a high thrombotic

Risk group though it is uh estimated that medical oncology patients represent 15 to 20 percent of all patients with thrombosis and depending on risk factors four to twenty percent of patients with uh cancer will experience a venous thromboembolism uh event with an annual incidence of about one percent uh per year this uh high thrombotic risk though has to be

Balanced against an increased risk of bleeding for example the patients being treated with chemotherapy may experience thrombocytopenia or have other bleeding risk factors when considering venous thromboembolism prophylaxis for patients with cancer there are multiple factors to consider this includes traditional risk factors such as thrombophilias obesity and

Smoking but also factors related to their uh to the malignancy itself for example the type of cancer with stomach and pancreatic cancers being especially high thrombotic risk the stage of disease with metastatic disease being higher thrombotic risk than localized disease certain cancer treatments have to be considered for example tamoxifen and breast cancer

Can be associated with an increased risk of venous and there can also be mechanical factors related to cancer for example compression from a tumor so uh important considering venous thromboembolism prophylaxis in this patient population is uh risk uh risk prediction and assessing uh this thrombotic risk the uh corona risk score is uh one of the most widely

Uh predictive prediction models with five readily available factors that are available from clinical and laboratory data including as you can see in the table here the site of the primary cancer the platelet value the hemoglobin value the leukocyte count and the body mass index and this has been uh well validated uh with uh scoring system uh to be associated

With uh thrombotic uh the percent of patients uh experiencing a thrombotic event with breakdowns of low intermediate and high with the high thrombotic risk group estimated to have a 6.7 to 12.9 percent uh risk of symptomatic venous thromboembolism so there’s been data to support pharmacologic prophylaxis in patients with cancer for many years including the data

From the trials listed here these trials studied low molecular weight heparins and did show some benefit to pharmacologic vte prophylaxis however the data from these trials was not widely adapted as the number needed to treat was high over 40 to 50. also there was a association with an increased risk of bleeding in unselected uh patients and there’s also the

Potential burden of placing patients on daily injection therapies for prophylaxis then came some pivotal clinical trials in 2019 was the publication of the avert trial that’s a randomized placebo-controlled uh double-blind uh clinical uh trial uh studying apixaban in over in 574 patients with new or recurrent uh cancer starting chemotherapy patients were

Followed for about 180 days and uh the uh this in instead of unselected oncology patients uh these were patients with a corona score uh greater than or equal to two so intermediate to high uh you know thrombotic risk based on that risk prediction uh store and uh the study showed that a pixaband was associated with a reduced risk of venous thromboembolism uh

But increased risk of bleeding for the patients on treatment the number needed to treat was about 16 with another number needed to harm of around 100. then also uh was the publication of the cassini trial which studied rivaroxaban in over a thousand uh patients also a double-blind randomized controlled trial with patients that were high who had solid tumors

Or lymphomas starting a new systemic regimen again patients were followed for approximately 180 days and had chronic scores greater than or equal to two and uh this study showed that during the intervention period there was a reduced uh incidence of uh reduced risk of being struggle embolism with an overall uh low risk of bleeding it did not significantly lower

The incidence of venous thromboembolism or death due to the during the 180 day uh trial period uh the number needed to treat though to prevent a venous thromboembolic event was 26 with the number needed to harm of around 101 for the patients on treatment so uh based on this data uh numerous uh guidelines have now incorporated uh considering uh pharmacologic uh

Venous thromboembolism prophylaxis with apixaban or rivaroxaban uh into uh their uh recommendations so this includes the national comprehensive cancer network the american society of clinical oncology the international society of thermoses and hemostasis and the american society of hematology also these documents in select settings allow for consideration of low

Molecular weight heparins and select patients apixaban and river oxidant are still off label uh for uh for this indication but again uh it’s something that’s been increasingly you know utilized in in clinical practice overall uh based on uh meta-analyses of of these data we see that um providing prophylaxis to uh high risk uh patient medical oncology patients

Is uh reduces the risk of being a stronghold embolism but this must be balanced about uh by the potential to increase the risk of bleeding and again numerous patient-specific factors to consider including you know patients with gastrointestinal tumors or potentially genital urinary tumors might have an increased risk of bleeding with the direct oral anticoagulants

And some you know patients have to be monitored for uh issues such as thrombocytopenia that could affect the decision to offer prophylaxis patients with mult certain types of cancers are handled differently including multiple myeloma and myoproliferative neoplasms so again this is limited to certain tumor types with a higher thrombotic risk and without a special

Increase especially increased risk of bleeding to consider uh prophylaxis uh drug interactions have to be uh especially considered often times these patients are on multiple medications and uh it need to do a detailed uh search to see if uh you know the directoral anticoagulant uh could interact with uh any any part of their cancer treatment or related medications

And ultimately you know uh because you’re balancing uh the potential you know benefits of reducing thrombotic outcomes against the potential harm of bleeding it’s important to engage patients in shared decision making when considering prophylaxis for this population so uh one uh you know basic uh approach uh when uh considering uh ambulatory medical oncology

Patients uh for prophylaxis uh first is uh you know to determine if these are you know patients with uh active cancer and and one of the tumor types that have been uh studied in in clinical trials uh calculating the corona score and you know for patients with a score under two there’s no uh data to support uh routine uh prophylaxis however for the patients with

The chronosphere greater than equal to two starting a systemic cancer therapy uh you know these patients can be looked at further for um you know considering pharmacologic prophylaxis and so you want to look at any contraindications to vte prophylaxis including active bleeding again thrombocytopenia coagulopathies uh spinal or neuraxial anesthesias or catheters

Recent surgeries uh patients with brain metastases those are the history of bleeding and again you know some patients with gastrointestinal cancers among other risk factors and for the patients without you know especially high bleeding risk you know look a little further you know are there any unavoidable uh drug interactions and if there’s not you know the

It’s reasonable to offer a prophylactic dose of uh apixaban or rivaroxaban for up to uh six months or longer as long as they’re in that higher thrombotic risk again engaging the patient in in shared decision making to talk about the the pros and cons of this approach but you know on a population uh basis uh the data do support a benefit so uh in conclusion you

Know patients uh with cancer are especially high thrombotic risk but you know again we’re balancing that competing risk of bleeding there’s uh increasing data to support risk adapted thromboprophylaxis often with a prophylactic dose of a directoral anticoagulant however you have to balance uh numerous uh factors and carefully consider this uh in in this patient

Population so uh thank you for your uh attention

Transcribed from video
Quick Tips for VTE Prophylaxis for Ambulatory Medical Oncology Patients By American College of Cardiology