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The impact of breast cancer‐specific birth cohort effects among younger and older C hinese populations
Author(s) -
Sung Hyuna,
Rosenberg Philip S.,
Chen WanQing,
Hartman Mikael,
Lim Weiyen,
Chia Kee Seng,
WaiKong Mang Oscar,
TSE Lapah,
Anderson William F.,
Yang Xiaohong R.
Publication year - 2016
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.30095
Subject(s) - demography , medicine , cohort , incidence (geometry) , breast cancer , cohort study , cohort effect , cancer registry , population , gerontology , cancer , environmental health , physics , sociology , optics
Historically low breast cancer incidence rates among Asian women have risen worldwide; purportedly due to the adoption of a “Western” life style among younger generations ( i.e ., the more recent birth cohorts). However, no study has simultaneously compared birth cohort effects between both younger and older women in different Asian and Western populations. Using cancer registry data from rural and urban China, Singapore and the United States (1990–2008), we estimated age‐standardized incidence rates (ASR), annual percentage change (EAPC) in the ASR, net drifts, birth cohort specific incidence rates and cohort rate ratios (CRR). Younger (30–49 years, 1943–1977 birth cohorts) and older women (50–79 years; 1913–1957 birth cohorts) were assessed separately. CRRs among Chinese populations were estimated using birth cohort specific rates with US non‐Hispanic white women (NHW) serving as the reference population with an assigned CRR of 1.0. We observed higher EAPCs and net drifts among those Chinese populations with lower ASRs. Similarly, we observed the most rapidly increasing cohort‐specific incidence rates among those Chinese populations with the lowest baseline CRRs. Both trends were more significant among older than younger women. Average CRRs were 0.06–0.44 among older and 0.18–0.81 among younger women. Rapidly rising cohort specific rates have narrowed the historic disparity between Chinese and US NHW breast cancer populations particularly in regions with the lowest baseline rates and among older women. Future analytic studies are needed to investigate risk factors accounting for the rapid increase of breast cancer among older and younger women separately in Asian populations.