Abdominal Blood Clots May Indicate Undiagnosed Cancer

When Mr. Smith is hospitalised with thrombosis (blood clots) in the liver, the thrombosis may not be the only problem. Researchers from Aarhus University and Aarhus University Hospital have just documented a link between certain types of thrombosis and cancer:

"It is well known that there can be a correlation between thrombosis in a leg or in the lungs and cancer. But our study shows that thrombosis around the liver can also be a sign of undetected cancer," says Kirstine Kobberøe Søgaard, PhD student at Aarhus University and medical doctor at Aarhus University Hospital.

She has carried out the study together with colleagues from the Department of Clinical Epidemiology, Aarhus University Hospital.

The study is the first to document a correlation between deep vein thrombosis in the abdominal region (known as splanchnic thrombosis) and cancer. The results of the survey were published on Thursday 18 June in the recognised American journal Blood. In the study, researchers have followed more than 1,000 Danish patients who were admitted to hospital with a deep vein thrombosis in the abdominal region between 1994-2011.

New knowledge about rare thrombosis
By combining data from the Danish Cancer Register and the patient register, the researchers could see that a total of 183 out of the 1,191 patients were subsequently diagnosed with cancer. The most common types of cancer were cancer of the liver, pancreas or cancers of the blood. More than half of the patients received a relatively quick cancer diagnosis following their hospital admission with a thrombosis.

"Patients who have had a deep vein thrombosis around or in the liver have incidences of cancer that are more than four times higher than expected. We can also see that more than half of the cancer diagnosis were made within three months after the thrombosis, where the risk was in fact 33 times higher than expected" says Kirstine Kobberøe Søgaard and continues:

“In addition, there were also a higher incidence of cancer in the blood more than a year after the thrombosis. So there is no doubt that there may be a correlation between cancer and this type of thrombosis in the stomach, though it is a relatively rare type."

The reason for the correlation may be that the cancer increases the tendency of the blood to congeal and that a growing tumour can press on a vein, making it more difficult for the blood to flow here, or that it grows into the blood vessel itself and thus provokes the formation of a thrombosis.

Worse outlook

The study also shows that the thrombosis patients who were subsequently diagnosed with cancer had poorer survival rates than other patients with the same types of cancer. The researchers cannot, however, say whether the increased mortality is due to the thrombosis itself, or whether other underlying factors relating to the patients are involved.

Kirstine Kobberøe Søgaard stresses that more studies are needed before it is possible to make any recommendations for changes to the diagnosis programme for these patients.

"To begin with, the new knowledge is naturally important for the doctors treating patients with these types of thrombosis, so that they can be aware of other symptoms of undetected cancer. With the knowledge we have now it may also be relevant to examine the advantages and disadvantages connected with any screening for these hidden cancers in the future," she says.

Facts

• The study comprised 1,191 patients with deep vein thrombosis during the period 1994-2011.
• 183 of these patients were subsequently diagnosed with cancer.

Contact

MD, PhD student Kirstine Kobberøe Søgaard
Aarhus University, Department of Clinical Medicine, Department of Clinical Epidemiology and
Aarhus University Hospital
Telephone: +45 8716 8257 / +45 2326 7267
kks@clin.au.dk

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