Author: Sr Medical Oncologist, trained from Tata Memorial Hospital. Currently practising at Netaji Subash Chandra Bose Hospital, Kolkata.
As with all cancers, early detection of lung cancer improves treatment outcomes. However, it is often diagnosed at advanced stages due to lack of early symptoms.
Therefore, regular screening is crucial for individuals at high risk of developing lung cancer.
Lung Cancer Statistics
Lung cancer is one of the most common cancers globally, causing 2.09 million cases and 1.76 million deaths in 2018. It is the most common cancer in men and the third most common in women.
In India, lung cancer led to 67,795 new cases and 63,475 deaths in 2018.
Under the microscope, lung cancers are classified as:
- Small Cell Lung Cancer (SCLC): Aggressive, mostly in heavy smokers; accounts for 10–15% of cases.
- Non-Small Cell Lung Cancer (NSCLC): More common, accounts for 80–85% of all lung cancers.
Lung Cancer Risk and Its Screening
Smokers have a 15 to 30 times greater risk of developing and dying from lung cancer compared to non-smokers.
Other risk factors include:
- Second-hand smoke
- Occupational exposure to asbestos, arsenic
- Air pollution
- Family history of lung cancer
While lung cancer cannot be completely prevented, risk can be reduced through preventive measures, including screening.
Screening helps detect cancer early and reduce mortality.
Lung Cancer Screening Method
Screening is done using a low-dose computed tomography (LDCT) scan.
LDCT is a non-contrast, fast (under 25 seconds) scan using a multidetector CT scanner. Radiation exposure is less than one-third of a standard chest CT.
Clinical trials show LDCT screening reduces lung cancer mortality in high-risk individuals.
Should I Get Screened for Lung Cancer?
Screening is not for everyone—it's recommended only for high-risk individuals.
According to the American Cancer Society (ACS), annual screening is advised for individuals aged 55–74 years who are in good health and meet the following criteria:
- Have a smoking history of at least 30 pack-years (e.g., 1 pack/day for 30 years or 2 packs/day for 15 years)
- Are current smokers or have quit within the past 15 years
- Are ready to receive smoking cessation counselling (if currently smoking)
- Are aware of the potential benefits and risks of screening
Risks of Screening
- False-negative result: Test appears normal despite cancer being present—may delay treatment.
- False-positive result: Test suggests cancer when none exists—leads to anxiety and further testing.
- Overdiagnosis: Detection of slow-growing cancers that may never cause harm—can lead to unnecessary treatment.
- Radiation exposure: Repeated scans may slightly increase cancer risk.
Prevention of Lung Cancer
Lung cancer cannot be completely prevented, but avoiding risk factors can significantly reduce your risk.
Risk Factors That You Should Avoid
Smoking is the most preventable cause of lung cancer.
- Cigarette smoking and secondhand smoke: The best prevention is not smoking and avoiding secondhand smoke. Quitting smoking repairs lung tissue over time and lowers cancer risk.
- Workplace exposure: Limit exposure to asbestos, arsenic, and other carcinogens. Use protective gear if working in high-risk environments.
- Air pollution: Avoid outdoor activities in high-traffic or industrial areas. Stay indoors when pollution levels are high. Wear a mask if necessary.
Prevention Through Lifestyle
A healthy diet rich in fruits and vegetables, along with regular exercise, may help reduce lung cancer risk.
Studies suggest that diets high in fruits and vegetables offer protective benefits—even for smokers.