
“I think it’s really important that people keep signing up to these type of trials to push research forward.”
This study looked at how long people should be treated with heparin for blood clots caused by cancer. It was for people who had already had heparin to treat their blood clot for about 6 months. They also had cancer that had spread into surrounding tissue, or elsewhere in the body.
Blood clots (thrombosis) are more common in people who have cancer. Doctors know that cancer cells can release chemicals that make the blood thicker than usual, and so more likely to form a clot.
A blood clot in an arm or leg is called a deep vein thrombosis or DVT. It can cause redness, pain and swelling. If bits of the clot break off and are carried to the lungs, they can cause a blockage called a pulmonary embolism or PE. You may have a sudden cough, chest pain or breathlessness. The clots need treatment as some may be life threatening.
If you have a blood clot, you will have a drug to stop others forming, while the body reabsorbs the clot itself. At the moment, the for treating blood clots caused by cancer is low molecular weight heparin. It is currently
to be used for 6 months.
Some doctors prefer to use it for longer in people with cancer that has spread. This is because having cancer may continue to make the blood sticky and increase the risk further blood clots.
The study team planned to compare patients who continued heparin treatment for a further 6 months with people who stopped the heparin.
This was a feasibility study. Its aims were to
If the feasibility study was successful, the researchers planned to carry out a phase 3 trial. In this trial they would try to find out whether treatment with 1 year of heparin was better than 6 months for people with cancer.
The researchers found the planned phase 3 randomised trial was not feasible. This was because not enough people would agree to take part in this type of trial.
The researchers interviewed people who were willing to take part in a trial and those who weren’t. They also interviewed the people’s doctors.
From these interviews it seems that people did not want to take part because they had fixed views on what the length of treatment should be.
Patients
Doctors
Doctors appeared unwilling to recruit their patients on to the study because
The researchers felt the length of heparin treatment was still an important research question. But from their experience this would be difficult to look at in a trial setting.
There are other areas of research they think would be useful to look at. For example, comparing new anti-coagulants (blood thinning) drugs you take by mouth (orally) with low molecular weight heparin. And looking at the risk and treatment of blood clots for people with certain types of cancer, such as breast cancer.
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists () and published in a medical journal. The figures we quote above were provided by the trial team who did the research. We have not analysed the data ourselves.
Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.
Dr Simon Noble
Cancer Research UK
Cardiff University
NIHR Clinical Research Network: Cancer
NIHR Health Technology Assessment (HTA) programme
If you have questions about the trial please contact our cancer information nurses
Freephone 0808 800 4040
“I think it’s really important that people keep signing up to these type of trials to push research forward.”