New Delhi: Cases of lung cancer among individuals who have never smoked are increasing, with air pollution emerging as a potential driver, according to a study published in The Lancet Respiratory Medicine World Cancer Day.
The research, conducted by experts from the International Agency for Research on Cancer (IARC) under the World Health Organization, analysed data from the Global Cancer Observatory 2022 to estimate lung cancer cases worldwide across four subtypes: adenocarcinoma, squamous cell carcinoma, small-cell carcinoma, and large-cell carcinoma.
Findings indicate that adenocarcinoma—a cancer originating in glandular tissues that produce fluids like mucus and digestive enzymes—has become the most prevalent lung cancer subtype among both men and women. In 2022, adenocarcinoma accounted for 53-70 per cent of lung cancer cases among non-smokers globally.
Unlike other lung cancer subtypes, adenocarcinoma is weakly linked to cigarette smoking. “As smoking prevalence declines worldwide, the proportion of lung cancer cases in non-smokers is rising,” researchers noted.
Air pollution, a key risk factor
Freddie Bray, lead author of the study and head of the Cancer Surveillance Branch at IARC, highlighted shifting trends in lung cancer risks. “Changes in smoking patterns and rising exposure to air pollution are major contributors to the evolving landscape of lung cancer incidence,” he said.
Lung cancer remains the leading cause of cancer-related deaths globally. Among non-smokers, it ranks as the fifth leading cause of cancer-related mortality, predominantly occurring as adenocarcinoma, particularly among women and Asian populations.
In 2022, an estimated 908,630 new lung cancer cases were reported among women worldwide, with 541,971 (59.7%) classified as adenocarcinoma. Alarmingly, over 80,000 of these cases were linked to ambient particulate matter (PM) pollution.
Policy implications and future action
The study underscores the urgent need for targeted cancer prevention strategies. “Diverging trends between sexes offer crucial insights for policymakers to develop tobacco control and air pollution mitigation measures tailored to high-risk populations,” Bray added.
As of 2019, nearly all individuals worldwide reside in areas failing to meet the World Health Organization’s air quality standards, reinforcing the call for stronger environmental policies to curb air pollution and its associated health risks.
PTI
