Analysis of changing trends in female breast cancer mortality in China from 2013 to 2021

Objective: To explore the trend of mortality rates for female breast cancer in China and quantify the impact of demographic and non-demographic factors on the burden of breast cancer mortality.

Methods: Mortality data for female breast cancer from 2013 to 2021 were extracted from the Chinese Cause of Death Monitoring Dataset, and the 2000 Chinese population census data were used to standardize the mortality rates. The Joinpoint software was employed to analyze the mortality trends by calculating the Annual Percentage Change (APC) and Average Annual Percentage Change (AAPC). The population decomposition method was utilized to quantify the impact of changes in population age structure, population size, and non-demographic factors on the burden of breast cancer mortality.

Results: From 2013 to 2021, the crude mortality rate for female breast cancer in China showed an increasing trend, with an AAPC of 2.3% (95% CI: 1.7%-2.9%). The standardized mortality rate remained relatively stable, with an AAPC of -0.2% (95% CI: -1.6%-1.3%). However, Joinpoint trend analysis indicated that the standardized mortality rate had a turning point in 2017, with a rapid increase before this year (APC: 3.9%, 95% CI: 1.1%-6.9%), and a rapid decline after this year (APC: -4.1%, 95% CI: -6.8% to -1.4%). The growth speed of crude mortality rates in rural areas was higher than that in urban areas, with AAPCs of 3.0% (95% CI: 2.4%-3.5%) and 1.3% (95% CI: 0.4%-2.2%), respectively. The standardized mortality rate in rural areas remained relatively stable, with an AAPC of 0.6% (95% CI: -1.0%-2.2%), while in urban areas, it showed a decreasing trend, with an AAPC of -1.1% (95% CI: -2.2%-0.0%). In the eastern, central, and western regions, the crude mortality rates all showed an increasing trend, with AAPCs of 1.7% (95% CI: 0.7%-2.8%), 3.8% (95% CI: 2.5%-5.2%), and 2.2% (95% CI: 0.5%-4.0%), respectively, while the standardized mortality rates remained relatively stable, with AAPCs of -0.3% (95% CI: -1.7%-1.2%), 0.6% (95% CI: -1.2%-2.4%), and 0.0% (95% CI: -2.2%-2.2%), respectively. Compared with 2013, the number of deaths in 2021 increased by 42.8%, of which changes in population age structure accounted for 21.3%, the age structure changes of urban and rural residents contributed 22.8% and 19.2%, respectively, to the whole changes caused by population age structure, while those in the eastern, central, and western regions contributed 20.6%, 24.3%, and 15.9%, respectively.Demographically, the changes in population size accounted for 18.3%, and non-demographic factors only accounted for 3.2%.

Conclusions: From 2013 to 2021, the crude mortality rate for female breast cancer in China continued to rise, a trend mainly influenced by population age structure, with the fastest growth rates in crude mortality rates observed in rural areas and the central region. After adjusted for age structure, the standardized mortality rate for female breast cancer in China began to decline from 2017.