This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Pinheiro, S. P. Articles by Hankinson, S. E. Search for Related Content PubMed PubMed Citation Articles by Pinheiro, S. P. Articles by Hankinson, S. E. Related Collections Epidemiology Epidemiology: Biomarkers

Racial Differences in Premenopausal Endogenous Hormones

¹ Department of Epidemiology, Harvard School of Public Health; ² Channing Laboratory, Department of Medicine, Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts; ³ Cancer Prevention Research Unit, Department of Oncology, Jewish General Hospital and McGill University, Montreal, Quebec, Canada; and ⁴ Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, Massachusetts

Requests for reprints: Simone P. Pinheiro, Channing Laboratory, Harvard Medical School and Brigham and Women's Hospital, 181 Longwood Avenue, Boston, MA 02115. E-mail: n2spp{at}channing.harvard.edu

Differences in breast cancer incidence across racial groups are well documented. African Americans have the highest rates of premenopausal breast cancer and Asians have lower breast cancer rates across all age groups. We hypothesized that levels of premenopausal endogenous hormones and growth factors, risk factors that have been predictive of breast cancer, would differ by race. Using a cross-sectional study design, we tested this hypothesis in the Nurses' Health Study II. We assayed estradiol, progesterone, prolactin, sex hormone binding globulin (SHBG), insulin-like growth factor-I (IGF-I), and IGFBP-3 in 111 African American and 111 Asian American women, matched to 111 Caucasian women on age, day of luteal phase, and day, time, and fasting status at blood collection. We analyzed the association between race and hormone levels using robust linear regression methods. In multivariate models, compared with Caucasians, African Americans had 18% higher levels of estradiol (P < 0.01), 17% higher free estradiol (P < 0.01), 11% lower SHBG (P = 0.05), 11% higher IGF-I (P < 0.01), 25% higher free IGF-I (P < 0.01), and 9% lower IGFBP-3 (P < 0.01) levels. In multivariate models, compared with Caucasian women, Asian Americans had 22% higher calculated free estradiol (P < 0.01), 31% lower SHBG (P < 0.01), and 25% higher free IGF-I (P < 0.01) levels. No racial differences were found in progesterone and prolactin levels. Our study showed hormone differences consistent with breast cancer risk between Caucasians and African Americans but inconsistent with breast cancer risk between Asian Americans and Caucasians. Further research is needed to explore differences across racial groups and the link between endogenous hormones and breast cancer risk.

This article has been cited by other articles:

				D. P. Rose, S. M. Haffner, and J. Baillargeon Adiposity, the Metabolic Syndrome, and Breast Cancer in African-American and White American Women Endocr. Rev., December 1, 2007; 28(7): 763 - 777. [Abstract] [Full Text] [PDF]

				M. R. Forman Changes in Dietary Fat and Fiber and Serum Hormone Concentrations: Nutritional Strategies for Breast Cancer Prevention over the Life Course J. Nutr., January 1, 2007; 137(1): 170S - 174S. [Abstract] [Full Text] [PDF]

				V. W. Setiawan, C. A. Haiman, F. Z. Stanczyk, L. Le Marchand, and B. E. Henderson Racial/Ethnic differences in postmenopausal endogenous hormones: the multiethnic cohort study. Cancer Epidemiol. Biomarkers Prev., October 1, 2006; 15(10): 1849 - 1855. [Abstract] [Full Text] [PDF]

				M.-J. Chen, W.-S. Yang, J.-H. Yang, C. K. Hsiao, Y.-S. Yang, and H.-N. Ho Low sex hormone-binding globulin is associated with low high-density lipoprotein cholesterol and metabolic syndrome in women with PCOS Hum. Reprod., September 1, 2006; 21(9): 2266 - 2271. [Abstract] [Full Text] [PDF]