To analyse the fractions and trends of cancer burden attributable to population ageing, adult population size, age-specific incidence and case fatality rate in China between 1990 and 2019.

We extracted data from the database of Global Disease Burden Study, including the number of cancer cases, deaths and corresponding population of 29 cancer types for Chinese adults aged 25 years and older from 1990 to 2019. Using the cancer deaths in 1990 as a reference, we employed a decomposition method to express cancer deaths as the product of four factors among men and women from 1991 to 2019. The fractions attributable to cancer deaths among total cancer deaths in that year were calculated and its time trends were assessed.

In 2019, we estimated that there were 2 690 000 cancer deaths among adults aged 25 and older in China. Of which, cancer deaths attributable to population ageing, adult population size, age-specific cancer incidence and case fatality rate were 740 000 (27.5% of total cancer deaths in 2019), 1 091 000 (40.6%), 198 000 (7.3%) and -728 000 (-27.1%), respectively. In 2019, lung cancer, stomach cancer, esophageal cancer, liver cancer and colorectal cancer ranked the top five cancers among population ageing attributable to cancer deaths. For 29 cancer types, the fractions of population ageing attributable to cancer deaths among total deaths of that cancer were ranged from 9.3% to 40.5%. The ageing attributable to cancer deaths and its fractions were increased rapidly since 1997, while those estimates were negative before 1997.

The population ageing process in China was one of the major contributors to the increase in cancer burden in recent years, which has caused more cancer deaths than that by age-specific cancer incidence. Accordingly, activities toward healthy ageing would be the key to cancer prevention and control.

Cancer burden; Ageing; Attributable fraction; Trend; China