Lung Cancer Prevention

Introduction

According to the World Health Organisation (WHO), lung cancer is the primary cause of cancer-related deaths globally, making it a major public health concern. Lung cancer was the cause of an estimated 1.8 million deaths in 2020. 

Although there is no sure way to prevent lung cancer, there are steps you can take to reduce your chance of developing it with the help of early detection, making lifestyle changes and reducing exposure to risk factors. This article outlines the various methods of lung cancer prevention, which includes stopping smoking, minimising exposure to environmental carcinogens (a substance capable of causing cancer) and maintaining a healthy diet.¹

Understanding lung cancer

Lung cancer occurs when abnormal cells in the lungs grow uncontrollably to form a tumour, causing a serious health risk that can lead to severe harm and even death. 

Some of the symptoms of lung cancer can include: 

• Persistent cough 
• Chest pain
• Difficulty breathing 

Seeking medical care early is crucial to minimise the potential health impacts. Treatments vary based on the individual's medical history and the stage of the disease. 

The two most common types of lung cancer are non-small cell carcinoma (NSCLC) and small cell carcinoma (SCLC). 

• NSCLC is more prevalent and tends to grow slowly
• SCLC is less common but often grows rapidly

Risk factors for lung cancer include: 

• Tobacco smoking 
• Alcohol consumption 
• Radon exposure 
• Air pollution
• Occupational exposures such as:
  • asbestos 
  • chromium compounds 
  • silica
  • diesel exhaust fumes

The risk of developing lung cancer is influenced by a combination of factors. Older age and a significant history of cigarette smoking are primary contributors to this risk. For individuals who do not smoke, exposure to secondhand smoke (also known as passive smoking), ionising radiation and occupational exposure to carcinogens linked to lung cancer risk such as asbestos are important risk factors.^2,3 

Additionally, environmental exposure to radon and high-dose radiation therapy, especially when administered to the chest or breast, is also associated with an increased risk of lung cancer. Smoking can interact with these risk factors, amplifying the overall risk significantly compared to the individual risks associated with each factor alone.^2,3

Prevention

Preventing lung cancer is possible, to a certain extent, by avoiding the mentioned risk factors. Various methods of cancer prevention are currently being researched, such as making changes to one's lifestyle or eating habits, steering clear of known carcinogens, and taking medications to treat precancerous conditions or to prevent the onset of cancer.⁴ It is entirely up to the individual whether or not they take the proactive approach when it comes to lung cancer prevention.

Stopping smoking

Cigarette, cigar, and pipe smoking are the most well-established risk factors for lung cancer. Hence, the best way to reduce your risk of developing lung cancer is not to smoke. 

Research has shown that individuals who stop smoking for more than 15 years experience a substantial 80% to 90% decrease in their risk of developing lung cancer compared to those who continue smoking. Even those who stop smoking later in life can significantly reduce their risk, while those who stop before middle age can avoid more than 90% of the risk associated with tobacco use. This highlights the importance of prioritising smoking cessation as a primary method of preventing lung cancer. 

Further studies have indicated that the risk of lung cancer continues to decrease the longer an individual abstains from smoking, with a 50% or greater reduction observed in the first decade of quitting. There have also been found to be beneficial effects of smoking cessation for both recent and distant former smokers in the 55 to 69 age group.^1,4

Avoid secondhand smoke

Exposure to secondhand smoke (also known as environmental tobacco smoke), can increase the risk of lung cancer in a dose-dependent manner, with the level of exposure directly affecting the relative risk. 

Researchers estimate that at least 17% of lung cancers in nonsmokers are due to exposure to high levels of secondhand smoke during childhood and adolescence. 

In 1964, the Surgeon General reported on the health risks of smoking and raised concerns about the dangers of environmental smoke exposure. Nonsmokers exposed to secondhand smoke have an increased rate of smoke-related problems, such as upper respiratory symptoms and eye irritation, and children are more likely to develop respiratory illnesses. This suggests that the carcinogenic effects of active tobacco smoking might also be present in those involuntarily exposed. 

Other studies have shown an increased risk of lung cancer in nonsmoking women married to men who smoke. A summary analysis of numerous studies found a 24% excess risk of lung cancer in nonsmokers who live with a smoker. Hence it is crucial that you avoid secondhand smoking to decrease your chances of developing lung cancer.^1,4

Lower exposure to workplace risk factors

Studies have shown that lung cancer risk increases with exposure to substances such as: 

• Asbestos 
• Arsenic 
• Chromium
• Nickel
• Beryllium
• Cadmium
• Tar
• Soot

This is particularly true in individuals who have never smoked. The risk of developing lung cancer is further heightened for those who are exposed to these substances and also smoke. Furthermore, living in areas with higher levels of air pollution has been linked to an increased risk of lung cancer.^1,4

The risk of developing lung cancer can be lowered by passing laws that protect workers from being exposed to the above mentioned cancer-causing substances. Additionally, laws preventing smoking in the workplace can reduce the risk of lung cancer caused by secondhand smoke.^1,4

Lower exposure to radon

Lowering radon levels may reduce the risk of lung cancer, especially among cigarette smokers. High levels of radon in homes can be decreased by preventing radon leakage, such as sealing the basement.^1,4

Radon is a colourless, odourless, and tasteless radioactive gas that naturally occurs due to the decay of uranium in rocks and soil. It slowly moves up through the ground and can seep into the air or water supply. Once inside a home, radon can enter through cracks in floors, walls, or the foundation, where its levels can accumulate over time.^1,4

Extensive research has shown a strong connection between high levels of radon gas in indoor spaces and an increased risk of lung cancer. This risk is particularly pronounced in smokers who are exposed to radon, as they face an even higher likelihood of developing lung cancer compared to non-smokers.

Shockingly, statistics reveal that approximately 26% of lung cancer deaths among non-smokers have been attributed to radon exposure. This underlines the urgency of testing for and mitigating radon levels in indoor environments to safeguard public health.^1,4

Diet

A healthy diet with plenty of fruits and vegetables may help lower the risk of lung cancer. 

There is some evidence to suggest that a diet rich in fruits and vegetables can offer protection against lung cancer for both smokers and non-smokers. However, it's important to note that the benefits of fruits and vegetables in reducing lung cancer risk are much smaller compared to the increased risk associated with smoking.^1,4

Physical activity

Some studies show that physically active people have a lower risk of developing lung cancer than people who are not. 

Physical activity is important in lung cancer prevention, treatment and rehabilitation post-intervention. Exercise influences lung function and prevents the risk of infections and respiratory diseases. However, since smokers tend to have different levels of physical activity to nonsmokers, it is hard to establish the influence of physical activity alone on the risk of developing lung cancer.^1,4,5

FAQ’s

When should I get screened for lung cancer?

• In the UK, targeted screening for lung cancer is recommended for individuals aged 55 to 74 if they are identified to be at high risk 
• Screening with low-dose computed tomography (CT) reduces lung cancer mortality

What are the symptoms of lung cancer?

There are no noticeable signs or symptoms during the early stages of lung cancer. However, as the condition progresses, certain symptoms may become noticeable. These can include:

• Recurring chest infections 
• Persistent cough lasting for more than three weeks 
• A chronic cough that worsens over time 
• Aches or pains when breathing or coughing 
• Coughing up blood 
• Persistent fatigue 
• Unexplained weight loss or loss of appetite
• Ongoing breathlessness

Can lung cancer be prevented with the help of medications?

At present, there are no medications which are approved to prevent lung cancer in individuals with no history of the disease. However, the potential of various drugs to treat precancerous conditions or reduce the risk of lung cancer development is still being researched.⁶

Summary

• Lung cancer is a leading cause of cancer-related deaths worldwide. The condition can be prevented through various methods
• Lifestyle changes, such as quitting smoking, can significantly reduce the chance of developing lung cancer, even for those who stop smoking later in life 
• Reducing the exposure to risk factors such as tobacco smoke, occupational hazards, radon and early detection are some other ways to prevent this disease 
• Decreasing the radon levels in homes, reducing exposure to workplace carcinogens and avoiding second-hand smoke are essential preventive measures 
• A healthy diet rich in fruits and vegetables and regular physical activity may also help reduce the risk of lung cancer 
• It is the responsibility of the individual to follow the above measures, highlighting the importance of proactive measures in lung cancer prevention