Lung cancer among women non-smokers on the rise, says Lancet report: What are the triggers?

“This rising burden of lung cancer is an area of concern as the resultant loss of lives is largely preventable,” says Dr Pankaj Chaturvedi, Director, Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Mumbai.

What does the study say? 

Lung cancer remains the leading cause of cancer-related morbidity worldwide with approximately 2.5 million people diagnosed with it in 2022. Of the estimated 1.5 lakh new cases among men, 717,211 (45.6% of the male lung cancer burden) were adenocarcinoma. Among women, there were an estimated 908,630 new cases of lung cancer worldwide of which 541,971 (59.7% of the female lung cancer burden) were adenocarcinoma.

At the global level, an estimated 111,486 adenocarcinoma cases among men and 80,378 adenocarcinoma cases among women were attributable to ambient PM pollution. According to the study, adenocarcinoma accounted for 53%–70% of lung cancer cases among never-smokers worldwide, suggesting that the risk of lung cancer linked to air pollution is on the rise, especially in eastern Asia and China.

“There is accumulating evidence of a causal link between ambient PM pollution and an increased risk of adenocarcinoma. Changes in smoking patterns and exposure to air pollution are among the main determinants of the changing risk profile of lung cancer incidence by subtype that we see today,” says Dr Freddie Bray, lead author.

What triggers lung cancer in non-smoking women?

Studies have shown this could be because of specific gene variations that make them more susceptible to lung cancer, even without smoking. Fluctuations in female hormones, particularly during menopause, could increase risk. Of course, environmental pollution, be it exposure to radon gas in homes or outdoor exposure to PM 2.5 particles, can change the DNA of cells, changing how they divide, thereby causing cancer. In developing countries, chronic exposure to cooking fumes from burning wood or frying has been linked to an increased rate of lung cancers.

Tobacco still a key trigger

In an earlier study that explored the uniqueness of lung cancer in South East Asia (August 2024), Dr Chaturvedi along with other authors had found how 42 per cent of men and 14.2 per cent women currently either smoke or use smokeless tobacco. “The rising incidence of teenage smoking, especially in urban areas, is an area of concern. The tobacco industry has exploited every loophole in the regulatory framework to remain profitable. Lack of vendor licensing, low taxes, sale of loose cigarettes and tobacco farming are driving carcinogenic industries,” Dr Chaturvedi says.