Lung cancer
Find out about the risk factors, signs and symptoms of lung cancer – and how screening and early assessment can support earlier diagnosis.
Overview
How common is lung cancer?
Lung cancer is the commonest cancer worldwide, with more than 2.5 million new cases a year and 1.8 million deaths each year. The incidence and mortality rates in men are double that of women but, incidence rates continue to rise in women and decrease in men.
Risks
Smoking
Smoking is the most important risk factor for lung cancer. Around 80-90% of lung cancers are linked to cigarette smoking. People who smoke are much more likely to develop lung cancer (15-30 times) than those who have never smoked. Your risk increases with the number of years and the amount you smoke.
Lifestyle factors
Other than smoking, there are no other lifestyle factors that have been shown to strongly influence lung cancer risk and avoiding tobacco exposure remains the most effective way to reduce your risk.
Family History
Having a close family history (parent/sibling/child) of lung cancer can increase your risk two-fold. Lung cancer is more common in White than in Black or Asian people.
Environmental factors
Lung cancer can also be influenced by environmental exposures. Radon gas, a naturally occurring radioactive gas, case cause lung cancer alongside other types of ionising radiation. Other risk factors include long-term exposure to air pollution and second-hand smoke, as well as certain workplace chemicals such as arsenic, diesel exhaust, and nickel.
Race/Ethnicity
Lung cancer affects people from all racial and ethnic backgrounds. Differences in risk are influenced by a combination of smoking patterns, environmental exposures, genetic factors and access to healthcare.
Black men have a higher risk of developing lung cancer even if they smoke fewer cigarettes. White men and women have a high overall incidence, although rates are declining as smoking rates fall. American Indian and Alaska Native populations also experience higher rates of lung cancer, reflecting higher rates of smoking in some regions.
Hispanic/Latino and Asian American populations have a lower incidence of lung cancer. However, lung cancer can still occur in people who have never smoked. In particular, Asian American women who have never smoked are disproportionately diagnosed with lung cancer due to mutations in the EGFR gene.
These differences highlight the importance of not assuming lung cancer risk is determined by smoking alone, and of seeking medical advice if symptoms arise, regardless of background or smoking history.
Symptoms
Lung cancer does not always cause symptoms in its early stages. When symptoms do appear, they can often be subtle at first and may be mistaken for other common respiratory conditions.
Any symptoms will vary depending on how far advanced the cancer is and its position within the chest.
The main symptoms include:
Appetite loss
Fatigue
Weight loss
A persistent cough or a change in a long-standing cough
Breathlessness or shortness of breath
Coughing up blood (phlegm with blood in it)
Aches or pains when breathing or coughing
Persistent chest infections that don’t respond to medical treatment
The following symptoms are less common and are usually associated with the more advanced stages of lung cancer. They include:
Difficulty when swallowing
A hoarse voice
Finger clubbing – changes to the shape of the fingers and fingernails
Swelling of the face and neck which may be due to obstruction of the venous drainage
Persistent pain in the chest and/or shoulder
Be Lung Aware
Are you showing any signs of these common symptoms of suspected x cancer?
Appetite loss
Fatigue
Weight loss
A persistent cough or a change in a long-standing cough
Breathlessness or shortness breath
Coughing up blood (phlegm with blood in it)
Aches or pains when breathing or coughing
Persistent chest infections that don't respond to medical treatment
Appetite loss
Fatigue
Weight loss
A persistent cough or a change in a long-standing cough
Breathlessness or shortness breath
Coughing up blood (phlegm with blood in it)
Aches or pains when breathing or coughing
Persistent chest infections that don't respond to medical treatment
Reduce risk
Stopping smoking
Avoiding industrial carcinogens
If you notice any symptoms that are new, persistent, or getting worse - particularly a cough that does not go away – it’s important to seek medical advice from your healthcare provider.
Getting tested
Screening
Low-dose lung CT screening from age 50 has been shown to be effective in people who smoke or have stopped in the last 15 years, and who have at least a 20 pack-year smoking history.
Screening is targeted to this group because it balances the benefits of early detection with potential downsides such as radiation exposure and the risk of detecting changes that may never cause harm. You should discuss the best screening options with your employer, health care provider, or insurer.
If you have symptoms
Any potential lung cancer symptoms would normally be investigated by lung CT scan, bronchoscopy and possible biopsy if any abnormality is found.
Advances in lung cancer screening and early detection
Lung cancer screening continues to evolve. Even with current screening programmes, many lung cancers are diagnosed outside existing criteria - including in younger people, lighter smokers, or people who have never smoked.
Research is ongoing into new approaches that may improve early detection. These include genetic risk assessment and simple blood-based tests that could help identify lung cancer risk, or detect cancer earlier, without the use of radiation.
In the future, combining imaging with blood-based markers may allow lung cancers to be identified sooner and more accurately across a wider range of people.
The overall aim is to improve early detection while reducing unnecessary tests and treatments.
Clinical insight informed by specialist advice from Professor Sam Janes, Consultant Pulmonologist and Professor of Medicine, University College London (UK).