Despite the global decline in smoking rates, lung cancer remains a significant health concern, responsible for nearly 2 million deaths annually. Alarmingly, new studies indicate a rise in lung cancer cases among individuals who have never used tobacco.

A research team from various international institutions discovered that the increasing incidence of lung cancer in non-smokers may be linked to escalating pollution levels, particularly affecting East Asia, with China being the most severely impacted region.

The researchers emphasize the importance of understanding evolving patterns of lung cancer, stating, “Given that lung cancer is the most prevalent form of cancer globally, a thorough evaluation of these changes and their underlying causes is crucial,” as highlighted in their published findings.

Utilizing data from the Global Cancer Observatory (GLOBOCAN) survey of 2022 and additional cancer incidence records from 1988 to 2017, researchers identified adenocarcinoma as the most common type of lung cancer worldwide, accounting for approximately 45.6% of cases in men and 59.7% in women.

While adenocarcinoma originates in glandular tissue and can indeed be linked to smoking, it is not the prevalent lung cancer type among smokers. Instead, it is the most frequently diagnosed type among non-smokers.

By comparing their findings with previous research, the team uncovered a concerning trend: an increase in lung cancer cases among those who have never smoked. This trend, they argue, must be confronted, alongside ongoing campaigns encouraging smokers to quit and preventing youth from adopting the habit.

“As smoking rates continue to decline in many regions, the proportion of lung cancer cases among non-smokers has risen,” the researchers noted.

Furthermore, lung cancer in individuals who have never smoked is now estimated to be the fifth leading cause of cancer-related deaths globally, predominantly presenting as adenocarcinoma, most often affecting women and populations in Asia.

The research suggests that rising air pollution levels may play a significant role in the increased lung cancer rates among non-smokers. Several earlier studies have already linked adenocarcinoma to air pollution exposure.

East Asia, particularly China, continues to experience some of the world’s worst air quality, further compounding this health crisis.

As one risk factor for lung cancer diminishes, another — global pollution — continues to rise, challenging the notion that lifestyle choices are solely responsible for lung cancer occurrences.

Ongoing data collection and analysis are essential for providing scientists with deeper insights into the progression of lung cancer and strategies to combat this widespread disease.

“Our results offer valuable perspectives for developing and implementing tailored strategies aimed at reducing tobacco use and air pollution, particularly in populations with high lung cancer rates and developing risks,” the researchers concluded.

This groundbreaking research has been published in The Lancet Respiratory Medicine.