GoKawiilHigh smoking rates and polluted air mean lung cancer cases are rising fastest in places such as China. Africa could soon head in the same direction.
The number of smokers in Africa continues to grow despite a global decrease.Credit: Media Lens King/Alamy
China — a country where more than 40% of men smoke — has become the epicentre of the global lung cancer epidemic.
Historically, lung cancer has been predominantly a disease of rich industrialized nations. But the burden of disease in China is indicative of a global shift, with middle-income countries facing the greatest increase in cases as high rates of smoking combine with rapid population growth, urbanization and the associated air pollution.
The trend is most dramatic in upper-middle-income countries, as defined by the World Bank, including China, Brazil and Iran. Between 2003 and 2023, yearly deaths from tracheal, bronchus and lung cancers (lower respiratory tract cancers for which data is typically combined by health-tracking organizations because the causes are so similar) grew by almost two-thirds while populations grew by only about 16% in upper-middle-income countries (see ‘An unequal burden’). A similar pattern is evident in lower-middle income countries in Asia and Africa — particularly India and Nigeria. There, the number of tracheal, bronchus and lung cancer deaths more than doubled while populations increased by just over one-third.
Source: Institute of Health Metrics and Evaluation
The main driver is tobacco smoking, which contributes to 85% of lung cancer cases. “This is the next wave of the tobacco epidemic,” says Yannick Romero, who advises governments on lung cancer policy at the Union for International Cancer Control in Geneva, Switzerland.
China, the world’s second most populous country, has the highest number of smokers. In 2023, around 40% of the world’s two million lung cancer deaths occurred in China. “The influence of smoking is so strong,” says David Lam, a lung cancer specialist at the University of Hong Kong’s School of Clinical Medicine.
Smoking rates in China have begun to fall. In 2024, 23% of the country’s population smoked, down from 27% in 2018. But lung cancer cases will take decades to follow, owing to “the latency between the time you smoke and the time you have an onset of the cancer”, Romero says. Indeed, although global smoking rates have been falling since the 1980s, lung cancer death rates have continued to rise (see ‘The smoking disconnect’).
Source: Institute of Health Metrics and Evaluation
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