Major Hull York Medical School study could save people with advanced cancer from unnecessary treatment for blood clots

New research challenges current thinking and shows the treatment of blood clots may not be needed for a large portion of cancer patients as they are not associated with serious symptoms or survival

A major new study co-published by Hull York Medical School researchers could save thousands of cancer sufferers from the stress of unnecessary medical treatment for blood clots.

The research, which has been published in prestigious medical journal The Lancet Haematology, challenges current thinking and shows the treatment of blood clots may not be needed for a large portion of cancer patients as they are not associated with serious symptoms or survival.

Professor Miriam Johnson, Professor of Palliative Medicine at Hull York Medical School and Director of the Wolfson Palliative Care Research Centre at Hull York Medical School and University of Hull, said:  “Our research has major implications for those cancer patients with far advanced disease who – while they may have blood clots in their legs, or be considered at risk of getting one – do not need to receive tablets or injections to treat or prevent one.

“It is our sincere hope that by driving improvements to healthcare practice we will be able to save patients the distress of unnecessary treatment at this stage of their lives."

The study, in The Lancet Haematology^1, has shown that around one-third of patients with advanced cancer*, admitted to specialist palliative care units (SPCU) had a blood clot in the main vein of the leg (femoral vein deep vein thrombosis, or DVT).

Despite current thinking, the clots did not appear to shorten life, or be associated with clinically significant symptoms.

People more likely to have a DVT on admission were those who had had a DVT in the past, or who had been bedbound at any point during the previous 3 months. However, very few without a DVT on admission developed a clot during their stay. 

The longitudinal multicentre study, led jointly by researchers at the Wolfson Palliative Care Research Centre, Hull York Medical School, University of Hull and Northern Ireland Hospice, Belfast in conjunction with co-investigators at the Marie Curie Palliative Research Centre, Cardiff University, is the first to demonstrate the true extent of the problem in people with advanced cancer and the impact on patient outcomes. DVT is the commonest preventable cause of hospital death and prevention of hospital acquired thrombosis is a major health service focus and patient safety issue.  People with cancer are at particular risk of DVTs and clinical guidelines recommend preventative medication for all with cancer if admitted to hospital unless there is a contraindication to anticoagulation or the patient is thought to be imminently dying. However, until now there have been no accurate figures for people with advanced disease admitted to SPCUs or information about the impact of DVTs on symptoms or survival.

The UK research group say these findings have significant implications for clinical practice worldwide, and challenge the current international recommendations for DVT prevention in people with advanced cancer, bringing into question whether these are appropriate for this group of patients.  Preventative treatment on admission may be unnecessary for many, thereby reducing the risk of distressing bleeds (a complication of anticoagulant treatment) in this group of patients.

The high prevalence but low three-week incidence of DVTs in people with advanced cancer admitted to SPCUs suggests that preventative treatment at this stage may be too late, say researchers.  Moreover, as the clots did not appear to shorten life, or cause clinically significant symptoms other than leg swelling, they question whether such intervention offers clinically meaningful benefit. 

Professor Johnson said: “By the time a patient is admitted to a specialist palliative care unit, one third already had a femoral vein DVT and of those who didn’t, very few developed a DVT during their stay. In this group of patients – with evidence of deterioration and in the last one to two months of life – giving daily injections for DVT prevention doesn’t really make sense.”

One of the chief investigators, Dr Clare White, Northern Ireland Hospice, Belfast, said:

“Patients approaching the end of their lives deserve the best care that can be provided, as often there is no second chance to get it right. This study should improve patient care through preventing patients like those in our study receiving clot prevention injections that are associated with minimal benefit and which might cause them harm.”

People with advanced cancer may experience a range of complex symptoms that require careful management and treatment.  The last thing they need, when the aim is to improve the quality of their end of life, is having treatments that could cause more harm than good, creating more distress to them and their families; a previous study showed that around one in 10 cancer patients receiving DVT prevention medication experienced clinically-relevant bleeding (from distressing nose bleeds to internal bleeding).  Professor Simon Noble, Marie Curie Palliative Care Research Centre, Cardiff University, and co-first author, said:

“This important research suggests we can no longer adopt a ‘one size fits all’ approach to DVT prevention in cancer patients. By recognising that clot prevention needs different approaches through the cancer journey, allows us to deliver a more personalised individual approach to care.”

People with advanced cancer admitted to SPCUs may be different to those with advanced cancer admitted to hospital – factors other than stage of cancer may have influenced the choice of admission. Therefore the results from this study do not inform treatment of people with advanced cancer admitted to hospitals, however, these data suggest that the hospital model of care may be inappropriate for those with advanced cancer admitted to a SPCU.  

The HIDDen* study, published in The Lancet Haematology, was funded by the National Institute of Health Research for Patient Benefit programme and supported by terminal illness charity Marie Curie.