Effects of reproductive and demographic changes on breast cancer incidence in China: a modeling analysis.
BACKGROUND
Breast cancer incidence is currently low in China. However, the distribution of reproductive and lifestyle risk factors for breast cancer among Chinese women is changing rapidly. We quantified the expected effect of changes in breast cancer risk factors on future rates of breast cancer in China.


METHODS
We first validated and calibrated the Rosner-Colditz log-incidence breast cancer model in Chinese women who participated in the Shanghai Women's Health Study cohort (N = 74,942). We then applied the calibrated model to a representative sample of Chinese women who were aged 35-49 years in 2001 using data from the Chinese National Family Planning and Reproductive Health Survey (NFPRHS, N = 17,078) to predict the age-specific and cumulative breast cancer incidence among all Chinese women of this age group. We evaluated the relative impact of changes in modifiable risk factors, including alcohol intake, parity, postmenopausal hormone use, and adult weight gain, on cumulative incidence of breast cancer.


RESULTS
Breast cancer incidence in China is expected to increase substantially from current rates, estimated at 10-60 cases per 100,000 women, to more than 100 new cases per 100,000 women aged 55-69 years by 2021. We predicted 2.5 million cases of breast cancer by 2021 among Chinese women who were 35-49 years old in 2001. Modest reductions in hormone and alcohol use, and weight maintenance could prevent 270,000 of these cases.


CONCLUSIONS
China is on the cusp of a breast cancer epidemic. Although some risk factors associated with economic development are largely unavoidable, the substantial predicted increase in new cases of breast cancer calls for urgent incorporation of this disease in future health care infrastructure planning.
Linos
Eleni
E
Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA. linos@stanford.edu
Spanos
Demetri
D
Rosner
Bernard A
BA
Linos
Katerina
K
Hesketh
Therese
T
Qu
Jian Ding
JD
Gao
Yu-Tang
YT
Zheng
Wei
W
Colditz
Graham A
GA
D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects / Q000639:trends; D001835:Body Weight; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology; D002681:China / Q000453:epidemiology; D015914:Estrogen Replacement Therapy / Q000009:adverse effects / Q000706:statistics & numerical data; D005193:Family Planning Services; D005260:Female; D006801:Humans; D015994:Incidence; D008019:Life Style; D008875:Middle Aged; D015233:Models, Statistical; D011157:Population Dynamics; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D043762:Reproductive Behavior; D012307:Risk Factors; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires