title: Cyclic endogenous estrogen and progesterone vary by mammographic density phenotypes in premenopausal women.
abstract: Estrogen and progesterone are key factors in the development of breast cancer, but it remains unclear whether these hormones are associated with mammographic density phenotypes in premenopausal women. We measured percent mammographic density, nondense area, and absolute mammographic density using computer-assisted breast density readings (Madena) from digitized mammograms taken on a scheduled day of the menstrual cycle (day 7-12) among 202 healthy, premenopausal women (Energy Balance and Breast cancer Aspects Study-I). Daily salivary concentrations of 17β-estradiol and progesterone throughout an entire menstrual cycle and fasting morning serum concentrations of hormones on 3 specific days of the menstrual cycle were assessed. Salivary and serum 17β-estradiol and progesterone were positively associated with percent mammographic density, we observed by 1 SD increase in overall salivary estradiol (β-value equal to 2.07, P=0.044), luteal salivary progesterone (β-value equal to 2.40, P=0.020). Women with above-median percent mammographic density had a 20% higher mean salivary 17β-estradiol level throughout the menstrual cycle. The odds ratio for having above-median percent mammographic density (>28.5%) per 1 SD increase in overall salivary 17β-estradiol was 1.66 (95% confidence interval 1.13-2.45). Women in the top tertile of the overall average daily 17β-estradiol concentrations had an odds ratio of 2.54 (confidence interval 1.05-6.16) of above-median percent mammographic density compared with women in the bottom tertile. Our finding of a relationship between estrogen, progesterone, and percent mammographic density and not with other mammographic density phenotypes in premenopausal women is biologically plausible, but needs to be replicated in larger studies.
authors.affiliation: aDepartment of Community Medicine, Faculty of Health Sciences, The Arctic University of Norway bDepartment of Oncology, Oslo University Hospital HF, Ullevål cDepartment of Microbiology and Infection Control, University Hospital North Norway, Tromsø dThe Norwegian Directorate of Health eCancer Registry of Norway, Oslo, Norway fFred Hutchinson Cancer Research Center, Seattle, Washington gDepartment of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA hDepartment of Environmental Health, Jagiellonian University Collegium Medicum, Krakow, Poland.
authors.forename: Anita
authors.initials: A
authors.lastname: Iversen
authors.forename: Hanne
authors.initials: H
authors.lastname: Frydenberg
authors.forename: Anne-Sofie
authors.initials: AS
authors.lastname: Furberg
authors.forename: Vidar G
authors.initials: VG
authors.lastname: Flote
authors.forename: Sissi Espetvedt
authors.initials: SE
authors.lastname: Finstad
authors.forename: Anne
authors.initials: A
authors.lastname: McTiernan
authors.forename: Giske
authors.initials: G
authors.lastname: Ursin
authors.forename: Tom
authors.initials: T
authors.lastname: Wilsgaard
authors.forename: Peter T
authors.initials: PT
authors.lastname: Ellison
authors.forename: Grazyna
authors.initials: G
authors.lastname: Jasienska
authors.forename: Inger
authors.initials: I
authors.lastname: Thune
mesh_terms: D000328:Adult; D001940:Breast / Q000002:abnormalities*; D000071060:Breast Density; D001943:Breast Neoplasms / Q000097:blood / Q000175:diagnosis*; D004967:Estrogens / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D042361:Mammary Glands, Human / Q000002:abnormalities; D008327:Mammography; D010641:Phenotype; D017697:Premenopause; D011374:Progesterone / Q000097:blood*; D012463:Saliva / Q000737:chemistry*
chemical_list: D004967:Estrogens; D011374:Progesterone