Project Summary

This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final.

What is the research about?

Each year, almost a million Americans have blood clots form in their veins. When blood clots form in the legs they are especially dangerous because the clot can move to the lungs and block the blood flow, keeping the body from getting oxygen. These clots can cause pain, hospitalization, and even death. People with cancer have a higher than normal risk for blood clots. Nearly 200,000 people with cancer experience blood clots each year.  

Several types of medicine can be used to treat blood clots. Medicines that have been in use for many years require the patient to inject the medicine every day or to have frequent blood tests. The FDA has recently approved new blood thinners that can be taken by mouth, do not have to be injected, and do not require regular blood tests. This study is comparing how well the new blood thinners and older, injectable blood thinners work for helping prevent and treat blood clots in cancer patients.

Who can this research help?

The study can help cancer patients and their doctors make an informed decision about the blood thinner they use to treat blood clots.

What is the research team doing?

Researchers are recruiting 820 patients who have a cancerous tumor and who have had a blood clot within the past month to participate in the study. Patients are assigned by chance to one of two groups. The first group receives one of the four new oral medicines to treat blood clots. Participants work with their doctors to choose which one is best for them. The second group receives one of the three injectable medicines to treat blood clots. Just like in the first group, participants and doctors decide which of the three is best for them. Patients in this group may also get warfarin, another medicine to treat blood clots. If a patient does not want to be assigned to a group by chance, that person can choose which group they want to be in. This option is available to 190 participants.

At the end of six months, the researchers are looking at how often patients have a new blood clot during treatment, how many times patients have experienced major bleeding, what patients report about their quality of life, and how hard it has been for patients to take the medicine. The research team is also looking to see whether patients have died from a blood clot, bleeding, or cancer.

Patients who have had cancer and blood clots are helping to design the study, inviting people to participate, and sharing the results.

Research methods at a glance

Design Element Description
Design Randomized controlled trial
Population Adults ages 21 and over who have been diagnosed with a cancerous tumor and who have had a blood clot within the past month
  • Direct oral anticoagulant (rivaroxaban, apixaban, edoxaban, dabigatran)
  • Usual care, low-molecular-weight heparin (dalteparin, enoxaparin, fondaparinux) with or without a transition to warfarin

Primary: cumulative venous thromboembolism recurrence reported by patients or clinicians

Secondary: cumulative rates of major bleeding, health-related quality of life reported by patients via the Optum SF-12v2 Health Survey questionnaire, burden of anticoagulation therapy reported by patients via the Anti-Clot Treatment Scale (ACTS) questionnaire, mortality reported by patients’ surrogates or clinicians

Timeframe 6-month follow-up for primary outcomes

Project Information

Deborah Schrag, MD, MPH
The Alliance for Clinical Trials in Oncology Foundation
Direct Oral Anticoagulants (DOACs) versus LMWH +/- Warfarin for VTE in Cancer: A Randomized Effectiveness Trial (CANVAS Trial)

Key Dates

September 2015
March 2022

Study Registration Information


Award Type
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: March 4, 2022