Chinese Medical Journal investigates recent and future trends of lung cancer

Lung cancer is the most common type of cancer. According to the Global Cancer Observatory (GLOBOCAN), there were 2.2 million new cases of lung cancer and around 1.8 million deaths due to lung cancer worldwide in 2020. Notably, its incidence and mortality rates differ vastly between sexes, with higher rates observed among males than in females. These rates also vary across developed and developing countries. China, in particular, had the highest number of new cases, with 539,181 reported in 2020. Additionally, both incidence and mortality rates in China have been steadily rising from 1990 to 2019. This underscores lung cancer as a major global health challenge that requires urgent attention.

Against this backdrop, a team of researchers led by Dr. Lanwei Guo from the Department of Clinical Research Management at the Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital in China examined the global incidence and mortality of lung cancer in 2022. Their study was published on September 24, 2024 in the Chinese Medical Journal.

“Lung cancer is a serious burden worldwide. Despite female breast cancer being the most common cancer at present, lung cancer remains the leading cause of cancer death,” says Dr. Guo. To this end, researchers used the GLOBOCAN 2022 database to estimate lung cancer incidence and mortality rates across various countries by age, sex, and human development index (HDI). They also projected the number of new cases and deaths that China and the US will face by 2050.

Researchers noted that in 2022 there were around 2,480,675 new cases of lung cancer and 1,817,469 deaths due to lung cancer globally, showing a slight increase from 2020. Most of the cases were mainly attributed to smoking, which is the primary risk factor for lung cancer. As stated earlier, the incidence and mortality rates of lung cancer also differed across countries. Developed countries have lower rates, while underdeveloped countries have higher rates, owing to differences in tobacco control policies and healthcare systems.

In China, the age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) of males with lung cancer were around 1.7 and 2.7 times higher than those of females with lung cancer, respectively. This disparity could be due to factors like sex hormones, genes, and response to treatment. Studies also show that smoking rates were much higher among men than women. Even among non-smokers, men faced a higher risk of lung cancer than women. Dr. Guo further elaborates, “While continuing to strengthen tobacco control measures, we should also pay attention to other factors that exacerbate the burden of lung cancer, such as indoor and outdoor air pollution, smoke from heating and cooking, and secondhand smoke.”

Surprisingly, as the HDI increased, the ASIR and ASMR of lung cancer also increased. The ASIR and ASMR in countries with high HDIs were around 8.5 and 6.5 times higher than those in countries with low HDIs, respectively. This may be due to lower smoking rates, shorter lifespans, and limited healthcare access in low-HDI countries, such as Niger in Africa, which contribute to lower lung cancer incidence. In contrast, high-HDI countries like Hungary in Europe experience higher lung cancer rates due to factors such as higher smoking rates, longer lifespans, environmental pollution, and advanced medical screening systems.

From 2022 to 2050, both China and the US are expected to see high numbers of new lung cancer cases and deaths among males and females, with estimates being higher in China. This is largely due to China's high smoking rates and aging population, whereas the US benefits from better healthcare systems and stronger tobacco control measures. Highlighting the need for immediate action, Dr. Guo says, “China should take effective tobacco control measures, increase public health awareness, encourage early screening for high-risk groups, and develop and apply new treatment methods.”

The study highlights current epidemiological factors of lung cancer and provides a scientific basis for developing prevention and control strategies. Dr. Guo concludes, “To reduce the global burden of lung cancer, efforts should be made to promote the implementation of tertiary prevention measures for lung cancer, especially primary and secondary prevention measures; improve lung cancer screening strategies; and increase the effectiveness of lung cancer screening.”

Hopefully, these findings draw attention to the devastating impact of lung cancer and direct global efforts toward its prevention, early detection, and effective treatment.

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Reference

Titles of original papers: Global burden of lung cancer in 2022 and projected burden in 2050

Journal: Chinese Medical Journal

DOI:  10.1097/CM9.0000000000003268