AUTHOR=Luan Hang-Hang , Luo Li-Sha , Lu Zhi-Yan 

TITLE=Historical Trends in Incidence of Breast Cancer in Shanghai, Hong Kong and Los Angeles, 1973–2012: A Joinpoint and Age-Period-Cohort Analysis

JOURNAL=International Journal of Public Health

VOLUME=Volume 66 - 2021

YEAR=2021

URL=https://www.ssph-journal.org/journals/international-journal-of-public-health/articles/10.3389/ijph.2021.603810

DOI=10.3389/ijph.2021.603810

ISSN=1661-8564

ABSTRACT=Background: Breast cancer is the first leading cause of death among women. This study aimed to estimate the long-term trends and the age, period and cohort-related effects on breast cancer incidence in Shanghai, Hong Kong, compared with Los Angeles (LA), USA.
Methods: The incidence data of breast cancer were obtained from Cancer Incidence in Five Continents (CI5plus) database. The average annual percentage change (AAPC) was conducted by joinpoint regression analysis. The independent age, period and cohort effects on incidence were estimated by age-period-cohort (APC) analysis.
Results: The age-standardized incidence rates (ASIRs) in LA for both white and black populations were all higher than those in Shanghai and Hong Kong. During 1988-2012, the ASIRs significantly decreased in white women in LA (AAPC=0.6%, 95%CI: -0.9% to -0.4%) while increased in Shanghai (2.5%: 2.1% to 2.9%) and Hong Kong (2.2%: 2.0% to 2.5%). By APC analysis, the incidence risk of breast cancer increased with age in all four populations. The period effects decreased for all selected populations during 1988-2012, except slight increases during 1943-1962 in Shanghai and Hong Kong. The cohort effects decreased monotonically.
Conclusions: Although age and cohort effects were relatively strong, the period effect may be the key factor affecting trends of breast cancer incidence, which may be caused by increasing exposures to carcinogens and high-risk factors. Therefore, more effective measures should be carried out promptly to reduce the burden of breast cancer, especially among high-risk populations such as elder women who are exposure to risk factors of breast cancer.