Lung cancer and heart health: understanding the two-way connection
Lung cancer and cardiovascular disease are more closely connected than many people realise.
Research over the past few years has made one thing clear: the relationship between lung cancer and heart health runs in both directions. People with existing heart disease have a higher chance of developing lung cancer, and people diagnosed with lung cancer have a higher chance of developing heart problems. Much of this comes down to risk factors the two conditions share, and to the effects of some treatments.
As lung cancer survival continues to improve, heart health is becoming a more visible part of long-term care.
Key points
The link between lung cancer and heart disease works both ways.
Smoking is the single biggest risk factor the two conditions share.
Some lung cancer treatments can affect the heart, which is why monitoring is becoming more common.
As more people live longer after diagnosis, long-term cardiac health is part of the wider conversation about care.
Is there a link between heart disease and lung cancer?
Yes, and recent evidence shows it works in both directions.
A large study using data from the UK Biobank, following more than 450,000 people, found that those with cardiovascular disease had around a 50% higher risk of developing non small cell lung cancer (NSCLC) compared with people without heart disease. Looking the other way, people who had been diagnosed with lung cancer were more than twice as likely to go on to develop cardiovascular disease.
A 2025 review in JACC: CardioOncology adds to this. Among all people living with cancer, those with lung cancer have the highest rate of existing heart disease at diagnosis, and the highest risk of cardiovascular events afterwards. In one large analysis, coronary artery disease was present in around one in five people in a lung cancer group.
This does not mean one condition directly causes the other. The same review and the UK Biobank study point to shared causes rather than a direct chain of cause and effect.
Why are lung cancer and heart disease connected?
Two main reasons explain most of the overlap.
Shared risk factors. Smoking is by far the most important. It is a leading cause of lung cancer and a major driver of heart disease, which is why the two so often appear together. Other shared factors include older age, high blood pressure, diabetes and obesity. Social and economic factors, such as income and access to care, also influence the risk of both.
Shared biology. Long-term inflammation and oxidative stress, a kind of cell-level wear and tear, play a part in both heart disease and cancer.
How can lung cancer treatment affect the heart?
Modern lung cancer treatment is effective, and for many people the benefits are substantial. Alongside those benefits, some treatments can place stress on the heart and blood vessels.
Radiotherapy to the chest can expose part of the heart to radiation, which over time can affect the heart muscle, valves and blood vessels.
Some chemotherapy can raise the risk of blood clots.
Certain targeted therapies can affect heart rhythm, blood pressure or cholesterol levels.
Immunotherapy is linked, in rare cases, to inflammation of the heart.
This is the focus of a growing field called cardio-oncology, which brings cancer and heart specialists together to assess risk, monitor for problems and prevent them where possible.
We looked at one part of this in more detail in our earlier article on heart health and lung cancer treatment, which covers new research on combining radiotherapy and immunotherapy.
Why heart health is now part of lung cancer care
Lung cancer treatment has improved a great deal. Five-year survival for non small cell lung cancer has risen, and for early-stage disease it can now reach as high as 80 per cent. More people are living longer after diagnosis, and many remain on treatment for years.
That progress changes the focus of follow-up care. Cardiac effects that take years to appear are now more likely to be seen, simply because more people are living long enough to experience them. British data cited in the JACC: CardioOncology review found that lung cancer survivors had nearly double the risk of heart failure beyond five years compared with people who had not had lung cancer.
The message is that good long-term care now needs to keep heart health in view alongside cancer outcomes.
What can help protect heart and lung health?
Several practical steps can support both, though decisions should always be made with a person’s own care team.
Stopping smoking. This lowers the risk of both lung cancer and heart disease, and stopping before surgery can reduce complications.
Asking about heart health at the start of treatment. The beginning of lung cancer treatment is a good moment to check blood pressure, cholesterol and other risk factors.
Monitoring during and after treatment where appropriate, particularly for people who have had radiotherapy to the chest or who already have heart disease.
Managing everyday risk factors, including blood pressure, cholesterol, blood sugar and physical activity.
There is also an opportunity built into lung cancer screening. The low-dose CT scans used to check for lung cancer can also reveal early signs of heart disease, such as calcium in the coronary arteries, which can prompt earlier action.
The bigger picture
The connection between lung cancer and heart health points towards more joined-up care. Treating the cancer remains the priority. At the same time, protecting the heart helps people live well during treatment and for longer afterwards.
Heart health is becoming part of the lung cancer conversation, and that is a sign of progress.
Sources
El-Rayes M, et al. Lung Cancer and Cardiovascular Disease: Common Pathophysiology and Treatment-Emergent Toxicity. JACC: CardioOncology, 2025. (Open access)
Zhang S, et al. Bidirectional Association Between Cardiovascular Disease and Lung Cancer in a Prospective Cohort Study. Journal of Thoracic Oncology, 2024.
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