A study to see how often people with advanced cancer have blood clots in their legs (HIDDen)

Cancer type:

All cancer types





This study looked at how often people who were in a hospice developed blood clots in their legs (deep vein thrombosis). This study was for people with an advanced cancer Open a glossary item.

This study was open for people to join between June 2016 and October 2017. These results were published in 2019. 

More about this trial

Up to 1 in 5 people (20%) with cancer develop a blood clot called a deep vein thrombosis (DVT). Left untreated a DVT could cause serious problems.
There are national recommendations to prevent DVTs in cancer patients when they go into hospital. But it wasn’t known if these recommendations were suitable for people in a hospice. 

Researchers didn’t know if trying to prevent or treating a DVT in someone who had advanced cancer improved any symptoms and changed their outlook (prognosis Open a glossary item). Or whether the side effects of treating the clot such as an increased risk of bleeding meant that treatment wasn’t appropriate.   

Researchers wanted to find out how many people with advanced cancer had a DVT when they went into a hospice. And how many developed a DVT while in the hospice.   

They hoped with this information: 

  • doctors and nurses working in hospices would know the best way to prevent and control symptoms of a DVT
  •  they would learn whether treating a DVT in someone with advanced cancer helped 

Summary of results

The team found that about a third of people with an advanced cancer who went into a hospice had a deep vein thrombosis (DVT). But this didn’t affect their outlook (prognosis). 

About this study
343 people joined the study. Researchers used an ultrasound Open a glossary item of the leg to look for a DVT in the femoral vein of the groin Open a glossary item. Everyone had an ultrasound when they joined and then once a week for up to 3 weeks. 

The researchers looked at how many of the 343 people had a DVT when they joined. They found that:

  • 92 people had a DVT
  • 181 people didn’t have a DVT
  • for 70 people they couldn’t use their scan results

The researchers looked at how many of the 343 people had scans done during the 3 week follow up period. They found that:

  • 290 people had more than one scan
  • for 53 people they didn’t have a scan result the team could use

The researchers then looked at how many people developed a DVT during the 3 week follow up period. 

4 people had no DVT when they joined the study but had a DVT on a follow up scan.

8 people had no usable scan results when they joined. So the team didn’t know if these people had a DVT then or not. But the follow up scan showed they had a DVT then. 

The researchers looked at whether there was any difference in the development of new or worse symptoms over the 3 week follow up period between the people who did have a DVT and the people who didn’t a DVT. They found no differences.

The team compared the average length of time people with a DVT on admission lived with people who didn’t. They found there wasn’t any difference between them. 

Predicting who might have a DVT 
The researchers looked at what factors might help predict who has a DVT. 

The team looked at the symptoms of a DVT people had when they went into the hospice. They included:

  • breathlessness
  • leg pain 
  • chest pain
  • coughing up blood 
  • lower leg swelling

They also looked at factors such as whether:

  • they’d had a previous DVT
  • they’d been bedbound in the past 12 weeks

They found that 3 factors might predict who has a DVT. They were:

  • a previous DVT
  • being bedbound for any reason in the past 12 weeks
  • lower leg swelling

Preventing a DVT
People who are less able to move around such as those who are bedbound are at a greater risk of developing a DVT.

For these people doctors can use medication and or special stockings for the legs to help prevent a DVT. 

The team looked at whether these measures made a difference. They found that for those people who are less able to move around these measures didn’t make much of a difference.  

The study team said about a third of the people admitted to a hospice with an advanced cancer had a blood clot called a deep vein thrombosis (DVT). And there was no connection between having a DVT and:

  • how long people lived 
  • whether people were on measures to prevent a DVT
  • symptoms apart from swelling of the leg

They state this is in keeping with DVTs being because of the advanced cancer rather than being a cause for an early death. And that there is no benefit from giving treatment to prevent DVT in people with advanced cancer who are needing a lot of help with care.

Where this information comes from    
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) 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.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Miriam Johnson

Supported by

NIHR Research for Patient Benefit (RfPB) Programme
University of Hull

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Wendy took part in a new trial studying the possible side effect of hearing loss

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"I was delighted to take part in a clinical trial as it has the potential to really help others in the future.”

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