This research, led by Dr. Freddie Bray and colleagues at the International Agency for Research on Cancer, sheds light on geographic variations and generational changes in lung cancer cases worldwide. 

The study analyzes data from the GLOBOCAN platform, which encompasses data from all population-based cancer registries worldwide.  

The study estimates that there were approximately 1.57 million new cases of lung cancer among men and 908,000 among women in 2022. Adenocarcinoma was the predominant subtype, accounting for 45.6% of male cases and 59.7% of female cases, indicating a shift from squamous cell carcinoma (SCC), which historically was the most common in many regions. This shift is believed to be influenced by changes in smoking patterns and exposure to environmental pollutants.  

Histologic type is also considered an important prognostic factor that is also changing trends in lung cancer survival, along with the advent of immunotherapy, as this recently published paper notes.   

An innovative aspect of the study was the evaluation of adenocarcinoma cases attributable to particulate matter (PM) air pollution. It was estimated that 114,486 cases in men and 80,378 in women were related to air pollution, with East Asia, especially China, being the most affected region. These findings highlight the increasing role of environmental factors in the epidemiology of lung cancer, which calls for urgent public health interventions.  

The methodology of the study is well suited to assess the impact of lung cancer on society and to evaluate trends in recent years.  

This research underscores the urgent need to develop tailored public health strategies to combat lung cancer. With tobacco control efforts showing effectiveness in reducing squamous cell carcinoma rates, attention must now turn to environmental policies targeting air pollution. In addition, continued monitoring of lung cancer trends in younger generations will be crucial to the formulation of effective prevention and treatment programs.

Lung cancer is the leading cause of cancer mortality worldwide. Tobacco use is estimated to be responsible for 85% of lung cancer deaths worldwide, so that most deaths from lung cancer could be avoided by effective prevention and control measures to prevent smoking initiation in adolescence and to encourage early cessation of tobacco use among smokers. In addition to the use of and exposure to environmental tobacco smoke, breathing in an environment polluted by small particles -such as those emitted by car combustion engines- increases the risk of developing lung cancer.   

The study published in The Lancet Respiratory Medicine analyzes data on the evolution of lung cancer incidence and its main subtypes (adenocarcinoma, squamous cell carcinoma, large cell carcinoma and small cell lung cancer) in 185 countries around the world. The results obtained show that the most frequent cancer subtype in almost all countries is adenocarcinoma, whose incidence shows a decreasing trend among men and an increasing trend among women, which the authors attribute to the changes that have been occurring in tobacco use worldwide since the 1970s.       

The downward trend in lung cancer incidence among smokers means that never-smokers tend to constitute an increasing proportion of all new lung cancer diagnoses. 

In addition, the results of the study indicate that lung cancer cases among non-smokers may be increasing especially in Asian countries such as China, where rapid economic growth has led to an increase in the emission of air-polluting microparticles. All this underscores the need to continue developing actions aimed at preventing lung cancer and other diseases by strengthening smoking control policies and also urban, industrial and mobility policies that prevent the quality of the air we breathe.

The article is of great importance because it shows the growth or decline according to lung cancer histology in a large number of countries (185). The data are of high quality and are rigorously validated with a highly contrasted methodology.   

The importance is that it confirms the change in the most frequent type of tumor in most countries: more cases of adenocarcinoma and less of squamous carcinoma, which may have repercussions on the type of treatment. This adenoid tumor is more peripheral and has a somewhat better prognosis. The greater growth in women is associated with the change in the type of tobacco and way of smoking.