Associations of Breast Cancer Risk Factors with Premenopausal Sex Hormones in Women with Very Low Breast Cancer Risk.
Breast cancer incidence rates are low but rising in urban Mongolia. We collected reproductive and lifestyle factor information and measured anthropometrics and serum sex steroid concentrations among 314 premenopausal women living in Ulaanbaatar, Mongolia. Mean differences in hormone concentrations by these factors were calculated using age-adjusted quadratic regression splines. Estrone and estradiol in college-educated women were, respectively, 18.2% (p= 0.03) and 23.6% (p= 0.03) lower than in high-school-educated women. Progesterone concentrations appeared 55.8% lower (p= 0.10) in women residing in modern housing compared with women living in traditional housing (gers), although this finding was not statistically significant. Testosterone concentrations were positively associated with adiposity and central fat distribution % difference for highest vs. lowest quarter for body mass index (17.1% (p= 0.001)) and waist-to-height ratio (15.1% (p= 0.005)). Estrogens were higher in the follicular phase of women who breastfed each child for shorter durations. A distinct hormonal profile was associated with an urban lifestyle in premenopausal, Mongol women. In particular, heavier, more-educated women living in urban dwellings had higher testosterone and lower estrogen and progesterone levels. Higher breast cancer incidence in urban compared with rural women suggest that the hormonal profile associated with a more traditional lifestyle may be protective among Mongol women.
Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, USA. lh2746@columbia.edu.
Lauren C
LC
Houghton
Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA. gdavaasa@hsph.harvard.edu.
Davaasambuu
D
Ganmaa
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. rosenbep@exchange.nih.gov.
Philip S
PS
Rosenberg
Health Sciences University of Mongolia, Ulaanbaatar 210648, Mongolia. davaalham@yahoo.com.
Dambadarjaa
D
Davaalkham
Division of Reproductive Endocrinology and Infertility, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90033, USA. fstanczyk@att.net.
Frank Z
FZ
Stanczyk
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. hooverr@mail.nih.gov.
Robert N
RN
Hoover
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. troisir@mail.nih.gov.
Rebecca
R
Troisi
D000328:Adult; D001943:Breast Neoplasms / Q000097:blood* / Q000150:complications / Q000453:epidemiology*; D004522:Educational Status; D004967:Estrogens / Q000097:blood*; D005260:Female; D006801:Humans; D015994:Incidence; D008019:Life Style; D008875:Middle Aged; D008986:Mongolia / Q000453:epidemiology; D009765:Obesity / Q000097:blood / Q000150:complications / Q000453:epidemiology; D017697:Premenopause / Q000097:blood*; D011374:Progesterone / Q000097:blood*; D018570:Risk Assessment; D012307:Risk Factors; D013739:Testosterone / Q000097:blood*; D014505:Urban Population
D004967:Estrogens; D013739:Testosterone; D011374:Progesterone
Mongolia; breast cancer; estrogen; progesterone; sex steroids; testosterone; urban migration