Objective:To investigate the disparities in breast cancer burden and changing epidemiological trends between China and the United States(US)from 1990 to 2021 and identify the key driving factors.Methods:The Global Burden of Disease database(1990-2021)was utilized to analyze breast cancer incidence,mortality,and disability adjusted life years(DALYs)in China and the US;we also assessed the as-sociations with risk factors(e.g.,obesity and smoking)through regression models and spatiotemporal analysis.Results:China's breast can-cer age-standardized incidence rate(ASIR)surged from 9.08/100,000 in 1990 to 19.36/100,000 in 2021,whereas the US ASIR declined from 44.37/100,000 to 37.49/100,000.Regarding the age-standardized mortality rate(ASMR),China saw a marginal reduction from 4.70/100,000 to 4.40/100,000,whereas the US experienced a significant decline from 13.03/100,000 to 9.28/100,000,narrowing the mortality gap from 2.8-fold to 2.1-fold.Key risk factors contributing to mortality and DALYs included smoking,exposure to secondhand smoke,low physical activity,high red meat and alcohol intake,elevated fasting blood glucose levels,and high body mass index.The rising cancer incidence in China is associated with the westernization of lifestyles and changes in fertility patterns,whereas the United States has achieved a dual de-cline in both incidence and mortality rates through widespread screening and control of hormone replacement therapy.Conclusions:Both the incidence and mortality rates of breast cancer in China rank among the highest globally,with incidence rates still increasing,indicating severe issues in prevention and control.In contrast,although the incidence rate in the US is higher than that in China,it shows a declining trend.To alleviate the growing burden of breast cancer,China must further enhance the intensity and coverage of breast cancer screening.

Objective:To investigate the disparities in breast cancer burden and changing epidemiological trends between China and the United States(US)from 1990 to 2021 and identify the key driving factors.Methods:The Global Burden of Disease database(1990-2021)was utilized to analyze breast cancer incidence,mortality,and disability adjusted life years(DALYs)in China and the US;we also assessed the as-sociations with risk factors(e.g.,obesity and smoking)through regression models and spatiotemporal analysis.Results:China's breast can-cer age-standardized incidence rate(ASIR)surged from 9.08/100,000 in 1990 to 19.36/100,000 in 2021,whereas the US ASIR declined from 44.37/100,000 to 37.49/100,000.Regarding the age-standardized mortality rate(ASMR),China saw a marginal reduction from 4.70/100,000 to 4.40/100,000,whereas the US experienced a significant decline from 13.03/100,000 to 9.28/100,000,narrowing the mortality gap from 2.8-fold to 2.1-fold.Key risk factors contributing to mortality and DALYs included smoking,exposure to secondhand smoke,low physical activity,high red meat and alcohol intake,elevated fasting blood glucose levels,and high body mass index.The rising cancer incidence in China is associated with the westernization of lifestyles and changes in fertility patterns,whereas the United States has achieved a dual de-cline in both incidence and mortality rates through widespread screening and control of hormone replacement therapy.Conclusions:Both the incidence and mortality rates of breast cancer in China rank among the highest globally,with incidence rates still increasing,indicating severe issues in prevention and control.In contrast,although the incidence rate in the US is higher than that in China,it shows a declining trend.To alleviate the growing burden of breast cancer,China must further enhance the intensity and coverage of breast cancer screening.

Objective To evaluate the risk factors and sonographic findings of pregnancies complicated by placenta increta or placenta percreta. Methods Totally, 2219 cases were retrospectively analyzed from 20 tertiary hospitals in China from January 2011 to December 2015. The data were collected based on the original case records. All cases were divided into two groups, the placenta increta (PI) group (79.1％, 1755/2219) and the placenta percreta (PP) group (20.9％, 464/2219), according to the degree of placental implantation. The risk factors and sonographic findings of placenta increta or percreta were analyzed by uni-factor and logistic regression statistic methods. Results The risk factors associated with the degree of placental implantation were age, gravida, previous abortion or miscarriage, previous cesarean sections, and placenta previa (all P<0.05), especially, previous cesarean sections (χ2=157.961) and placenta previa (χ2=91.759). Sonographic findings could be used to predict the degree of placental invasion especially the boundaries between placenta and uterine serosa, the boundary between placenta and myometrium, the disruption of the placental-uterine wall interface and loss of the normal retroplacental hypoechoic zone(all P<0.01). Conclusions Previous cesarean sections and placenta previa are the main independent risk factors associated with the degree of placenta implantation. Ultrasound could be used to make a prenatal suggestive diagnosis of placenta accreta spectrum disorders.