The rate of lung cancer among individuals who have never smoked is steadily increasing, with air pollution being highlighted as a significant contributing factor. The International Agency for Research on Cancer (IARC) has reported these findings based on research conducted in 2023.
According to IARC, lung cancer among non-smokers has become the fifth leading cause of cancer-related deaths worldwide. The study also revealed that lung cancer in non-smokers is primarily found as adenocarcinoma, a subtype of lung cancer, which is the most common among the four major types of lung cancer.
A recent IARC study published in Lancet Respiratory Medicine noted that in 2022, nearly 200,000 people were exposed to air pollution linked to adenocarcinoma. The research found that the association between air pollution and adenocarcinoma was especially high in East Asia, particularly in China.
Freddie Bray, head of cancer surveillance at IARC, emphasized the urgency of recognizing the shift in lung cancer risk factors. He called for more research to identify potential causes, like air pollution, if smoking is no longer the primary factor.
Globally, lung cancer is one of the most common cancers, with approximately 2.5 million cases diagnosed worldwide in 2022. Adenocarcinoma, squamous cell carcinoma, small cell carcinoma, and large cell carcinoma are the four primary subtypes of lung cancer. IARC reports that adenocarcinoma is now the leading subtype in both men and women.
In 2022, 45.6% of men and 59.7% of women diagnosed with lung cancer had adenocarcinoma. In 2020, the rates for men and women were 39% and 57.1%, respectively. IARC found that 70% of non-smokers diagnosed with lung cancer had adenocarcinoma.
Over the past 40 years, while the rate of lung cancer in men has decreased in many countries, the incidence in women continues to rise. Although the majority of lung cancer cases still affect men (about 16 million in 2022), the gap between men and women is narrowing, with nearly 9 million women diagnosed with lung cancer in 2022.
A 2023 report in The Guardian revealed that for the first time in the UK, more women than men were diagnosed with lung cancer. Experts have urged women to be as vigilant about lung cancer as they are about breast cancer, advising early detection and screening.
Cancer specialists stress the importance of being aware of lung cancer symptoms, just as women are encouraged to get checked if they feel any unusual changes in their breasts. Scientists are continuing to investigate other potential causes of lung cancer beyond smoking, as the trend of non-smokers developing the disease continues to grow.
