[The spatio-temporal trend of female breast cancer incidence and mortality in Shandong Province from 2012 to 2023 and trend prediction].

We aimed to analyze the spatio-temporal trend of breast cancer incidence and mortality in Shandong Province from 2012 to 2023 and predict the development trend from 2024 to 2030. Data on the incidence and mortality of breast cancer in Shandong Province from 2012 to 2023 were obtained from the Shandong Cancer Registry. The incidence, age-specific incidence, mortality, and age-specific mortality in different years, as well as in urban and rural areas, were calculated, and the rates were standardized based on the age composition of the Chinese standard population in 2000. The average annual percent change (AAPC) rate was calculated using Joinpoint 4.8.0.1 software. The global and local spatial autocorrelation analysis were performed using GeoDa 1.12 software. The Bayesian age-period-cohort model was used to predict the trend of breast cancer incidence and mortality from 2024 to 2030. From 2012 to 2023, the breast cancer age-standardized incidence rate (ASIR) showed an increasing trend. The ASIR increased from 30.48/100 000 in 2012 to 39.94/100 000 in 2023 (AAPC=2.59%, <0.001). The ASIR of urban and rural females also showed an upward trend. Additionally, the ASIR in rural areas (AAPC=3.33%, <0.001) increased more than that in urban areas (AAPC=1.83%, =0.002). The incidence peak of breast cancer mainly concentrated in population aged 45-64 years, and with the increase of years, the incidence peak gradually moved forward. The age-standardized mortality rate (ASMR) showed a downward trend. The ASMR decreased from 6.89/100 000 in 2012 to 4.93/100 000 in 2023 (AAPC=-3.12%, <0.001). The ASMR of urban and rural females also showed a downward trend (urban: AAPC=-3.56%, =0.007; rural: AAPC=-2.72%, <0.001). The spatial analysis showed that from 2015 to 2023, the clustering areas of breast cancer incidence and mortality in Shandong had changed significantly. In 2015, the "High-high clusters" of ASIR mainly included Wendeng District in Weihai City, Dongying District, Kenli District, Lijin County, Guangrao County in Dongying City, Tianqiao District, Shizhong District in Jinan City; In 2023, the "High-high clusters" mainly included Jiaxiang County, Liangshan County, Jinxiang County, Wenshang County, Rencheng District in Jining City, Hedong District in Linyi City, Guangrao County in Dongying City. In 2015, the "High-high clusters" of ASMR only included Wenshang County in Jining City. In 2023, the "High-high clusters" mainly included Laizhou County in Yantai City, Junan County and Yishui County in Linyi City, Gaotang County in Liaocheng City, Dongping County and Ningyang County in Taian City. The Bayesian age-period-cohort model predicted that the ASIR trend of breast cancer in Shandong tended to be smooth (AAPC=0.33%, =0.001). However, the ASMR remained decreasing (AAPC=-4.68%, <0.001). The breast cancer incidence in Shandong showed an increasing trend, and it is expected to be smooth by 2030. However, the mortality showed a continuous downward trend. The incidence peak was mainly in the population aged 45-64 years, with obvious regional differences. Targeted prevention and control measures should be taken for high-risk groups and areas in Shandong Province.