title: Racial/ethnic differences in postmenopausal endogenous hormones: the multiethnic cohort study.
abstract: Postmenopausal women with increased estrogens and lowered sex hormone-binding globulin (SHBG) concentrations are at increased risk of breast cancer. In the Multiethnic Cohort Study, the highest incidence rates of postmenopausal breast cancer were observed among Native Hawaiians followed by Japanese Americans, Whites, African Americans, and Latinas. Ethnic differences in endogenous sex hormone profiles may contribute to some of the variation in breast cancer incidence. Plasma concentrations of androstenedione, testosterone, estrone (E(1)), estradiol (E(2)), and SHBG were measured in 739 postmenopausal women from the Multiethnic Cohort Study (240 African Americans, 81 Native Hawaiians, 96 Japanese Americans, 231 Latinas, and 91 Whites). After adjusting for age, known breast cancer risk factors and lifestyle factors, the mean levels of testosterone, estrogen, and SHBG varied across populations (Ps < or = 0.004). Across racial/ethnic groups, Native Hawaiians had the highest mean levels of androstenedione, testosterone, and estrogens and the lowest mean levels of SHBG. Compared with Whites, Native Hawaiians had higher androstenedione (+22%, P = 0.017), total testosterone (+26%, P = 0.013), bioavailable testosterone (+33%, P = 0.002), E(1) (> or =21%; P = 0.009), total E(2) (+26%, P = 0.001), bioavailable E(2) (+31%, P < 0.001), and lower SHBG (-12% P = 0.07) levels. Compared with Whites, Japanese Americans had higher E(2) (+15%, P = 0.036) and bioavailable E(2) (+18%, P = 0.024) levels. African Americans also had higher E(1) (+21%, P = 0.004), E(2) (+20%, P = 0.007), and bioavailable E(2) (+20%, P = 0.015) levels compared with Whites, whereas mean levels in Latinas were similar to those of Whites. Many of the differences in endogenous postmenopausal hormonal milieu across these five racial/ethnic groups are consistent with the known differences in breast cancer incidence across these populations.
authors.affiliation: Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA. vsetiawa@usc.edu
authors.forename: Veronica Wendy
authors.initials: VW
authors.lastname: Setiawan
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Haiman
authors.forename: Frank Z
authors.initials: FZ
authors.lastname: Stanczyk
authors.forename: Loïc
authors.initials: L
authors.lastname: Le Marchand
authors.forename: Brian E
authors.initials: BE
authors.lastname: Henderson
mesh_terms: D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D000728:Androgens / Q000097:blood; D000735:Androstenedione / Q000097:blood; D001213:Asian; D001943:Breast Neoplasms / Q000097:blood / Q000208:ethnology; D002140:California / Q000208:ethnology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004958:Estradiol / Q000097:blood; D004967:Estrogens / Q000097:blood*; D004970:Estrone / Q000097:blood; D005260:Female; D006254:Hawaii / Q000208:ethnology; D006630:Hispanic or Latino; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D015999:Multivariate Analysis; D017698:Postmenopause / Q000097:blood* / Q000208:ethnology*; D011446:Prospective Studies; D012307:Risk Factors; D018426:SEER Program; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D013739:Testosterone / Q000097:blood; D044465:White People
chemical_list: D000728:Androgens; D004967:Estrogens; D012738:Sex Hormone-Binding Globulin; D004970:Estrone; D013739:Testosterone; D000735:Androstenedione; D004958:Estradiol