Deaths from smoking-related cancers expected to increase in China over the next 20 years

Deaths from smoking-related cancers in China are expected to rise by almost 50% over the next two decades, finds research published online in the journal Tobacco Control.

Experience from other countries where peaks in smoking prevalence occurred in the mid-twentieth century has shown that peaks in smoking-related deaths generally occur several decades later.

For example, in the United States smoking prevalence peaked in 1955 among men and in 1965 among women, but the peak in lung cancer deaths came around four decades later - in the 1990s for men and the 2000s for women.

China's smoking epidemic started three to four decades later than in the United States, so the peak in deaths from lung cancer is yet to come, the researchers warn.

They used data from various sources, including the China Death Surveillance Database and surveys of smoking patterns in China, to model the likely course of smoking-related deaths over the next 20 years.

Between 2002 and 2018 smoking prevalence in China fell from 57.4% to 50.5% in men and from 2.6% to 2.1% in women. If smoking prevalence continues to fall at the same rates, by 2040, smoking prevalence will be 41.3% among men and 2.16% among women.

But when population ageing is factored in, the researchers estimate that deaths from smoking-related cancers will rise between 2020 and 2040 by 44% among men (from 337.2/100 000 to 485.6/100 000) and by nearly 53% among women (from 157.3/100 000 to 240.4/100 000).

Over 20 years, there would be 8.6 million excess deaths from smoking-related cancers in China, equal to 117.3 million years of life lost. Almost half (46%) of the life years lost would be from working age adults (54.1 million); 94% of these (110.3 million) would be lost in men.

The Healthy China initiative aims to improve the health of the Chinese population, which is the largest in the world. Its goal is to reduce the overall smoking rate to 20% by 2030.

If this goal was achieved, the smoking rate among men would fall to just over 26% by 2040, with around 1.4 million excess deaths averted, the researchers calculate.

"The observed rate of decrease in smoking prevalence is far from that required to meet the Healthy China 2030 goal," they write. "Even if this goal was achieved, the increasing trend in excess deaths would be reversed only slightly."

The researchers highlight several potential limitations to their study, which are likely to mean that the future smoking-related deaths are an underestimate.

And the lack of age-specific former smoking rates prevented the analysis from fully taking account of the impact of smoking among people who had quit, nor did it take into account smoking-related deaths due to causes other than cancer or those related to second-hand smoking.

The assumptions of smoking trends across age groups and cancer mortality rates were also based on limited data, with no increase in life expectancy over time included.

But they warn: "Unless widespread efforts to support smoking cessation are made by families, communities and society as a whole, the huge loss of life in the working-age population over the next 20 years will certainly add to the increasing difficulty in supporting China's ageing society and will be beyond the magnitude that any single existing intervention can prevent."

Given that around 22% of daily smokers began as children or adolescents, "Complete prevention of smoking uptake among adolescents is imperative for future generations to avoid the adverse outcomes of smoking-related diseases," they add.