Relationships between circulating hormone levels, mammographic percent density and breast cancer risk factors in postmenopausal women.
BACKGROUND
Endogenous hormones and insulin-like growth factors (IGF) play a central role in breast cancer development. Mammographic density, an important breast cancer risk factor, has been associated with these biomarkers in premenopausal women. The aim of this study was to assess the relationships between circulating hormones, clinical features related to breast cancer risk and mammographic density in postmenopausal women.


METHODS
The study included 226 postmenopausal women participating in a clinical prevention trial. We performed baseline measurements of mammographic percent density and circulating levels of estradiol, sex-hormone binding globulin (SHBG), follicle stimulating hormone (FSH), prolactin, C-terminal cross-link telopeptide, IGF-I, and IGF binding protein-3.


RESULTS
Median age and time since last menses were 52 years and 15 months, respectively. Median body mass index was 24.1 kg/m(2). After adjusting for age and body mass index, estradiol was the only biomarker significantly correlated with mammographic density (r = 0.17; P = 0.04). Women with normal body mass index had higher mammographic density (P < 0.001), higher SHBG (P < 0.0001), higher FSH (P = 0.002) and lower estradiol levels (P = 0.01) than those who were overweight. Women who had previous biopsies for benign breast disease had a higher mammographic density (P = 0.006).


CONCLUSIONS
In these recently postmenopausal women, mammographic percent density is directly associated with circulating estradiol levels. Our results provide further support to the role of circulating hormones in breast cancer risk.
Johansson
Harriet
H
Division of Cancer Prevention and Genetics, European Institute of Oncology, Milan, Italy.
Gandini
Sara
S
Bonanni
Bernardo
B
Mariette
Frederique
F
Guerrieri-Gonzaga
Aliana
A
Serrano
Davide
D
Cassano
Enrico
E
Ramazzotto
Francesca
F
Baglietto
Laura
L
Sandri
Maria Teresa
MT
Decensi
Andrea
A
D015992:Body Mass Index; D001943:Breast Neoplasms / Q000097:blood* / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008327:Mammography; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D011388:Prolactin / Q000097:blood; D012307:Risk Factors; D012738:Sex Hormone-Binding Globulin / Q000032:analysis
D018972:Insulin-Like Growth Factor Binding Protein 3; D012738:Sex Hormone-Binding Globulin; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D011388:Prolactin; D005640:Follicle Stimulating Hormone