Question: Am I at increased risk of developing deep vein thrombosis (DVT)?

Answer: Anna Jewell, Information Manager, Pancreatic Cancer UK

What is venous thrombosis?

Blood contains platelets and proteins which can act as clotting factors and sometimes form a kind of plug to stop bleeding when needed.

A venous thrombosis is a blood clot which forms inside a vein abnormally, blocking the vessel and reducing or preventing blood flow. It often occurs in deep veins, and this is known as a deep vein thrombosis (DVT). DVT is most common in the lower leg (calf), thigh or pelvis. A part or all of the blood clot may come free and travel to the lungs; this is called a pulmonary embolism. It is not common but it can be very serious.

Most clots can be successfully treated so it is important to report any symptoms to your health care team as soon as possible.

Risk of venous thrombosis in pancreatic cancer patients

The risk of venous thrombosis is increased in cancer patients and pancreatic cancer patients are at higher risk than patients with many other cancer types. Pancreatic cancer cells activate platelets in the blood and release substances that promote the formation of blood clots for example tissue factor and thrombin.

Patients with advanced or metastatic pancreatic cancer are particularly at risk. It is estimated that these patients have a 1 in 5 chance of developing a venous thrombosis.

Having major surgery, such as the Whipples operation for pancreatic cancer is a risk factor along with the reduced mobility which will occur during recovery from this surgery.  Reduced mobility is a risk factor because normally the movement of the legs helps to pump blood back to the heart.

Deep vein thrombosis most often occurs in the lower leg or calf.

Common symptoms of venous thrombosis (blood clots)

Bloods clots often do not cause any symptoms. However, there are a number of symptoms of blood clots that you can look out for. If you think you are experiencing these symptoms you should contact your health care team at the hospital or your GP urgently.

Symptoms of deep vein thrombosis (DVT)

• Pain, swelling or tenderness in one of your legs (or calf)
• Warm skin or redness of skin in the affected area
• Heavy ache in the affected area

Symptoms of pulmonary embolism (where clot has moved to lungs)

• Shortness of breath
• Pain in chest (especially on breathing in)
• Coughing up blood

How is a venous thrombosis diagnosed?

If a DVT is suspected you will usually undergo an ultrasound scan of the affected area and a D-dimer test (a blood test).

If a pulmonary embolism is suspected your hospital team will usually arrange a computed tomography pulmonary angiogram (CPTA) to look for the clot.

Reducing the risk of venous thrombosis

Risk assessment in hospital

National guidelines have been produced on reducing the risk of venous thrombosis in patients admitted to hospital. These guidelines state that all patients should be assessed on admission to hospital to identify people at increased risk of a venous thromboembolism (VTE). (NICE Reducing the risk of venous thromboembolism)

Patients are thought to be at increased risk of VTE if they have had reduced mobility for three days or more, or are expected to have on-going reduced mobility compared to their usual state and have one or more of the following risk factors:

• Active cancer or cancer treatment
• Over 60 years
• Critical care admission
• Dehydration
• Known thrombophilias
• Obesity
• Medical co-morbidities
• Personal history or first degree relative with history of VTE
• Use of hormone replacement therapy
• Use of oestrogen-containing contraceptive therapy
• Varicose veins with phlebitis.

Ways to reduce the risk

In hospital if you are identified as being at increased risk of developing a VTE a number of strategies will be used to help reduce your risk.

• You will be encouraged to get moving as soon as possible, particularly after surgery.
• You will be encouraged to keep well hydrated.
• You will be given anti-embolism stockings to wear
• Foot impulse devices or intermittent pneumatic compression devises may be used while you are inactive.
• You may be given a drug to reduce your risk of developing a clot. The drug most commonly used is low molecular weight heparin (LMWH).

When you are discharged from hospital you will be given information on the signs and symptoms of deep vein thrombosis and pulmonary embolism and how to seek help if you develop any symptoms.

Patients receiving chemotherapy or radiotherapy treatment for pancreatic cancer, do not routinely receive drugs to reduce the risk of clots. However, you should still be aware of the signs and symptoms of DVT and PE and have been given information on ways to reduce the risk of developing blood clots such as keeping mobile and keeping hydrated.

Treatment for venous thromboembolism (blood clot)

If a venous thromboembolism (blood clot) is found the standard treatment is to use anticoagulation drugs. These are drugs which thin the blood to prevent the clot getting bigger or further clots developing. The drug most often used in patients with active cancer and a confirmed DVT or PE is low molecular weight heparin (LMWH). The drug will usually be given for at least six months.

You should be given information on how to take the drug, how long for, the side effects and when to seek help. You should also be given an alert card for anticoagulants to carry with you.