Lung Cancer: Trends, Causes, and Public Health Challenges

Context (IE): Lung cancer is the second-most common cancer among Indian men, making up 8.5% of all cancers, according to The Global Cancer Observatory’s India Factsheet 2022.

About Lung Cancer

Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer-related deaths.
It contributes to 10% of cancer deaths, with 81,000 cases and 75,000 deaths (2022).

India recorded 82000 new lung cancer cases in 2022.
India ranked 4^th in lung cancer incidence for men and 6^th for women in 2022. In north India, about 40% of lung cancer patients are non-smokers.
Mortality: Lung cancer caused about 9.2% of all cancer deaths in 2022.
Regional Hotspot: Aizawl, Mizoram, has the highest lung cancer rates in both genders (NCRP, ICMR).
Rising Incidence: Over 14 lakh cancer cases were reported in India in 2023.
Disease Burden: By 2025, cancers will cause 29.8 million DALYs in India.

Disability-Adjusted Life Years (DALYs) measure total years lost from illness, disability, or early death.

Non-smokers also face lung cancer risk from environmental, occupational, and genetic factors.
Second-hand Smoke: Passive tobacco exposure causes lung cancer among non-smokers.
Air Pollution: Ambient PM2.5 exposure increases lung cancer risk in adults.
Radon Exposure: Residential radon exposure elevates lung cancer risk among non-smokers.
Work Exposures: Diesel exhaust and asbestos cause occupational lung cancer in workers.
Genetic Drivers: EGFR-mutated lung adenocarcinoma is frequent among Indian non-smokers.

EGFR-mutated lung adenocarcinoma is a form of lung cancer caused by mutations in the epidermal growth factor receptor gene, which encodes a protein that regulates cell growth and division.

Resource constraints and a high TB burden lead to late-stage detection.
Over half of patients are diagnosed with distant metastasis (cancer that has spread from the original tumor to distant organs or distant lymph nodes).
Smoking (cigarettes, beedis, cigars, pipes) is the primary risk factor.
Second-hand smoke, air pollution, occupational hazards (asbestos, radon), hereditary cancer syndromes, and chronic lung diseases also pose risks, particularly to non-smokers.

Low-Dose Computed Tomography (LDCT) uses less radiation compared to standard CT scans to produce detailed images of the body’s internal structures. It is recommended for early screening in the US and Europe. It can reduce lung cancer mortality by 20% compared to Chest X-rays and by 24% compared to no screening.

National Screening Program: Implement a national lung cancer screening program like the National Lung Screening Trial in the USA.
Early detection will boost survival rates, with LDCT leading the way and research into blood and breath tests promising even better results, as seen in the UK Lung Cancer Screening Trial.
Increase awareness and preventive measures, including smoking cessation and addressing occupational exposures like the Canadian Lung Cancer Screening Study.
Invest in research for better diagnostic technologies and treatments tailored to the Indian population.