@article{3150456,
    title = "Circulating sex hormones and breast cancer risk factors in
postmenopausal women: reanalysis of 13 studies",
    author = "Key, T. J. and Appleby, P. N. and Reeves, G. K. and Roddam, A. W. and and Helzlsouer, K. J. and Alberg, A. J. and Rollison, D. E. and Dorgan, J. and F. and Brinton, L. A. and Overvad, K. and Kaaks, R. and Trichopoulou, A. and and Clavel-Chapelon, F. and Panico, S. and Duell, E. J. and Peeters, P. and H. M. and Rinaldi, S. and Riboli, E. and Fentiman, I. S. and Dowsett, M. and and Manjer, J. and Lenner, P. and Hallmans, G. and Baglietto, L. and and English, D. R. and Giles, G. G. and Hopper, J. L. and Severi, G. and and Morris, H. A. and Koenig, K. and Zeleniuch-Jacquotte, A. and Arslan, A. and A. and Toniolo, P. and Shore, R. E. and Krogh, V. and Micheli, A. and and Berrino, F. and Muti, P. and Barrett-Connor, E. and Laughlin, G. A. and and Kabuto, M. and Akiba, S. and Stevens, R. G. and Neriishi, K. and Land, and C. E. and Cauley, J. A. and Lui, Li Yung and Cummings, Steven R. and and Gunter, M. J. and Rohan, T. E. and Strickler, H. D. and Endogenous and Hormones Breast Canc",
    journal = "British Journal of Cancer",
    year = "2011",
    volume = "105",
    number = "5",
    pages = "709-722",
    publisher = "Nature Publishing Group",
    issn = "0007-0920, 1532-1827",
    doi = "10.1038/bjc.2011.254",
    keywords = "breast cancer; hormones; oestrogens; androgens; sex hormone-binding
globulin",
    abstract = "BACKGROUND: Breast cancer risk for postmenopausal women is positively
associated with circulating concentrations of oestrogens and androgens,
but the determinants of these hormones are not well understood.
METHODS: Cross-sectional analyses of breast cancer risk factors and
circulating hormone concentrations in more than 6000 postmenopausal
women controls in 13 prospective studies.
RESULTS: Concentrations of all hormones were lower in older than younger
women, with the largest difference for dehydroepiandrosterone sulphate
(DHEAS), whereas sex hormone-binding globulin (SHBG) was higher in the
older women. Androgens were lower in women with bilateral ovariectomy
than in naturally postmenopausal women, with the largest difference for
free testosterone. All hormones were higher in obese than lean women,
with the largest difference for free oestradiol, whereas SHBG was lower
in obese women. Smokers of 15+ cigarettes per day had higher levels of
all hormones than non-smokers, with the largest difference for
testosterone. Drinkers of 20+ g alcohol per day had higher levels of all
hormones, but lower SHBG, than non-drinkers, with the largest difference
for DHEAS. Hormone concentrations were not strongly related to age at
menarche, parity, age at first full-term pregnancy or family history of
breast cancer.
CONCLUSION: Sex hormone concentrations were strongly associated with
several established or suspected risk factors for breast cancer, and may
mediate the effects of these factors on breast cancer risk. British
Journal of Cancer (2011) 105, 709-722. doi:10.1038/bjc.2011.254
www.bjcancer.com Published online 19 July 2011 (C) 2011 Cancer Research
UK"
}