, according to estimates of lung cancer incident cases, deaths, and their age-standardized rates.
The findings, based on recently released data from GLOBOCAN 2020 projected to the year 2050, suggest that the lung cancer epidemic will continue to unfold, according to Rajesh Sharma, PhD, et al., in a study published in the International Journal of Clinical Oncology. GLOBOCAN 2020 is an online database produced by the International Agency for Research on Cancer. It provides global cancer statistics from 185 countries for 36 cancer types.
The increase in lung cancer, the leading cancer worldwide in terms of deaths, is generally attributed to increases in cigarette smoking, Sharma et al. wrote. They point out that, while cigarette smoking is expected to have peaked in industrialized countries in the latter half of the twentieth century, the tobacco smoking epidemic is unfolding in regions of Asia and Africa with concomitant increases in lung cancer burden in several countries. Smoking is the most significant lung cancer risk factor, followed by air pollution (especially particulate matter, passive smoking, and occupational exposure to radon and asbestos).
The authors investigated bivariate associations between smoking prevalence and age-standardized rates of lung cancer, and projected lung cancer incident cases and deaths to 2050. They also looked at mortality-to-incidence, considered to be a proxy indicator of 5-year survival, and at human development index, a measure including life expectancy at birth, years of schooling, and standard of living. The results, they state, are expected to aid in policy formulation to combat the lung cancer burden at global, regional, and national levels.
Tobacco smoking prevalence was 21.9% worldwide in 2016, with tobacco smoking prevalence exceeding 25% in 57/149 countries. It was high in European countries with 5 of the top-10 countries among the 149 countries within Europe. Prevalence was greater than 10% in all European countries. Notably, 11/33 countries in Africa had a smoking prevalence less than 10%.
Analysis showed 2.21 million new lung cancer cases and 1.8 million deaths attributed to lung cancer worldwide in 2020, with males accounting for about two-thirds of the burden. The analysis projection for 2050 was for 3.8 million incident cases of lung cancer and 3.2 million lung cancer deaths globally. In 2050, lung cancer cases and deaths are projected to be more than 100,000 in 10/21 regions, led by Eastern Asia, projected to record 1.7 million incident cases and 1.5 million deaths.
The burden of lung cancer in regions of Asia and Africa is expected to increase at least twofold from 2020 to 2050, surpassing European regions that are expected to have the smallest increases. Also, while incident cases will remain much higher in Northern America than in Southeastern Asia and South-Central Asia, the number of lives lost is projected to be similar. The age-specific incidence and death rates rose with age such that the oldest age groups had the highest age-specific rates. With the human development index, mortality-to-incidence showed a negative correlation.
The authors wrote that worsening smoking and pollution levels in developing countries may push the future lung cancer burden much higher than these projections. Unless reversed, cases and death will grow unabated.
“Countering the burden of lung cancer also requires curtailment of other risk factors such as air pollution and exposure to carcinogens,” the authors wrote.
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. The authors stated that they have no conflicts of interest.