Blood clots often occur in people with lung cancer. Lung cancer can cause deep vein thrombosis (DVT), which is a type of clot that can break loose and travel to the lungs.
Cancer greatly increases the risk of developing various types of blood clots, including DVT and pulmonary embolism (PE).
Both DVT and PE are potentially deadly. DVT develops in a deep vein, usually in the legs. PE occurs when a blood clot such as DVT breaks free and travels to the lungs.
A recent study concluded that 3.7% of people with lung cancer develop PE. However, an estimated 29.4% to 63% of people with lung cancer have an unsuspecting pulmonary embolism (UPE). This means that a doctor identified a UPE in scans that they ordered for other purposes, not because they thought that the person may have PE.
In fact, doctors may mistake PE symptoms as symptoms of lung cancer or the side effects of lung cancer treatments, according to one study. This may be because the two conditions cause similar symptoms. As a result, a doctor may not initially suspect PE. They may later diagnose a UPE when scanning the lungs to assess treatment effectiveness.
The following sections outline everything a person needs to know about how blood clots relate to lung cancer.
All people with cancer are at risk of developing DVT and PE. Experts say that this may be because cancer tumors damage tissues involved in blood clotting.
Lung and pancreatic cancers are associated with the highest risk of blood clots. One recent study concluded that lung cancer is the most likely cancer to coexist with a blood clot in the lungs. It found that doctors most often diagnose blood clots in the lungs within 6 months of making a lung cancer diagnosis. People with stage 3 or 4 lung cancer have a higher risk of PE.
Some cancer treatments also increase the risk of clotting, including the following:
- vascular endothelial growth factor (VEGF) inhibitors, such as bevacizumab
- VEGF tyrosine kinase receptor inhibitors, such as sorafenib or sunitinib
- platinum, such as cisplatin
Some additional DVT risk factors include:
- having another condition that increases the risk of blood clots
- having a blood transfusion
- receiving some anemia treatments
- being over the age of 65 years
- sitting or lying down for a very long period of time
- being pregnant
- using birth control or other hormonal therapies
- having a family history of blood clots
- having overweight
- recently undergoing surgery
- having an infection
Having a blood clot that travels to the lungs, or PE, can be fatal and requires immediate medical attention.
Prompt medical attention gives a person a high likelihood of surviving. Treatment for PE typically involves reducing the size of the clot and preventing future clots from forming.
Doctors will usually inject and then prescribe oral blood thinners. These drugs will not break up an existing clot, but they usually help prevent new clots from forming.
In rare cases, blood thinners may not work. When this happens, a doctor may suggest surgery to remove the clot or to insert a device that prevents clots from traveling to the lungs.
DVT is a dangerous type of blood clot that usually forms in the legs, though it can occur in other areas of the body. All people with cancer are at risk of developing DVT. However, people with lung cancer are at a higher risk of developing both DVT and PE.
Some treatments for DVT include:
- anticoagulants or blood thinners
- inferior vena cava filter, which is a device inserted into the arteries to catch a clot before it reaches the lungs
- thrombectomy or embolectomy, which are surgical procedures to remove the clot from the legs or the lungs, respectively
Coughing up blood is one symptom of PE. Some other symptoms can include:
- pain in the chest
- shortness of breath that often comes on suddenly
- a rapid heartbeat
- loss of consciousness
Prompt medical attention and continued treatment help prevent death due to PE. Ongoing treatment can involve both lifestyle changes and medications such as blood thinners.
However, one recent study concluded that people with PE and lung cancer had a shorter survival time than those who only had lung cancer. In another study, researchers found that the average survival time was 8.9 months for people who had both conditions versus 22.5 months for those with lung cancer alone.
All situations are unique. People with lung cancer should talk with their doctor about their outlook following the development of PE.
Lung cancer and cancer treatments can increase a person’s risk of developing a blood clot in the legs, or DVT, that travels to the lungs, or PE. People with both lung cancer and PE have an overall shorter survival time, but prompt treatment can significantly help.