Risk factors for breast cancer associated with mammographic features in Singaporean chinese women.
BACKGROUND
Mammographic density has been found to be a strong risk factor for breast cancer and to be associated with age, body weight, parity, and menopausal status. Most studies to date have been carried out in Western populations. The purpose of the study described here was to determine in a cross-sectional study in a Singaporean Chinese population the demographic, menstrual, reproductive, and anthropometric factors that are associated with quantitative variations in age-adjusted percentage mammographic densities and to examine the association of these factors with the dense and nondense areas of the mammogram.


METHODS
We used mammograms and questionnaire data collected from subjects in the Singapore Breast Screening Project. Women ages 45 to 69 years participated and 84% of those screened were Chinese. Mammograms were digitized and percentage density was measured and analyzed in relation to the questionnaire data.


RESULTS
Percentage mammographic density was associated with several risk factors for breast cancer, most of them also associated, in opposite directions, with the dense and nondense components of the image. Percentage density was associated with age and weight (both negatively), height and age at first birth (both positively), and number of births and postmenopausal status (both negatively). Percentage density was weakly associated with a previous breast biopsy but was not associated with age at menarche or menopause, with use of hormones, or with a family history of breast cancer.


CONCLUSIONS
Percentage mammographic density in Singaporean Chinese women has similar associations with risk factors for breast cancer to those seen in Caucasians.
Heng
Derrick
D
Division of Epidemiology and Statistics, Ontario Cancer Institute, 610 University Avenue, Toronto, Ontario, Canada.
Gao
Fei
F
Jong
Roberta
R
Fishell
Eve
E
Yaffe
Martin
M
Martin
Lisa
L
Li
Tong
T
Stone
Jennifer
J
Sun
Limei
L
Hopper
John
J
Boyd
Norman F
NF
D000368:Aged; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000209:etiology*; D003430:Cross-Sectional Studies; D015914:Estrogen Replacement Therapy; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D016014:Linear Models; D008327:Mammography; D008593:Menopause; D008875:Middle Aged; D017584:Reproductive History; D012307:Risk Factors; D012846:Singapore; D011795:Surveys and Questionnaires