Blood androgen levels and breast cancer risk
This summary table contains detailed information about research studies. Summary tables are a useful way to look at the science behind many breast cancer guidelines and recommendations. However, to get the most out of the tables, it’s important to understand some key concepts. Learn how to read a research table.
Introduction: Androgens (such as testosterone) are natural hormones. They are important in sexual development in both men and women.
In women, androgens are produced in small amounts by the ovaries and the adrenal glands. Higher levels of androgens in the blood may be linked to an increased risk of breast cancer in women.
Of the androgens, testosterone has been the most studied in relation to breast cancer risk.
Breast cancer risk after menopause
Studies show higher blood levels of testosterone may increase the risk of breast cancer in postmenopausal women.
Menopausal hormone therapy
Most of the studies below excluded women who were taking menopausal hormone therapy (MHT) at the time of the blood collection. MHT is also called postmenopausal hormone therapy and hormone replacement therapy (HRT).
Certain MHT may mask the full effect natural blood testosterone levels have on breast cancer risk. By looking only at women who don’t take (or who have never taken) MHT, researchers may see more clearly how blood androgen levels affect breast cancer risk.
Breast cancer risk before menopause
A pooled analysis of data from 5 studies found higher levels of blood testosterone increased breast cancer risk in premenopausal women .
Learn more about blood androgen levels and breast cancer risk.
Learn about the strengths and weaknesses of different types of studies.
See how this risk factor compares with other risk factors for breast cancer.
Table note: Odds ratios above 1 indicate increased risk. Odds ratios below 1 indicate decreased risk.
Risks related to total testosterone levels (unless noted) are shown in this table.
Risk of Breast Cancer in Women with Higher Testosterone Levels
Nested case-control studies
Nurses’ Health Study 
EPIC cohort [3-4]
Women’s Health Initiative Observational Study 
Estrogen receptor-positive cancers:
Estrogen receptor-negative cancers:
NYU Women’s Health Study [6-7]
Nurses’ Health Study II 
UK Collaborative Trial of Ovarian Cancer Screening 
Melbourne Collaborative Cohort Study 
Manjer et al. 
ORDET cohort [12-13]
Wang et al. 
Yu et al. 
Sturgeon et al. 
† Results are for blood levels of bioavailable testosterone.
‡ Results are for testosterone blood levels measured in the luteal phase of the menstrual cycle.
§ Results are for testosterone blood levels measured in the luteal phase of the menstrual cycle. For testosterone blood levels measured in the early follicular stage, findings were similar, RR=0.45 (0.17-1.19).
¶ Results are for highest vs. lowest blood testosterone levels. Results for a doubling of testosterone levels were statistically significant, RR=1.18 (1.03-1.35).
- Endogenous Hormones and Breast Cancer Collaborative Group. Sex hormones and risk of breast cancer in premenopausal women: a collaborative reanalysis of individual participant data from seven prospective studies. Lancet Oncol. 14(10):1009-19, 2013.
- Zhang X, Tworoger SS, Eliassen AH, Hankinson SE. Postmenopausal plasma sex hormone levels and breast cancer risk over 20 years of follow-up. Breast Cancer Res Treat. 137(3):883-92, 2013.
- Kaaks R, Rinaldi S, Key TJ, et al. Postmenopausal serum androgens, oestrogens and breast cancer risk: the European prospective investigation into cancer and nutrition. Endocr Relat Cancer. 12(4):1071-82, 2005.
- Kaaks R, Berrino F, Key T, et al. Serum sex steroids in premenopausal women and breast cancer risk within the European Prospective Investigation into Cancer and Nutrition (EPIC). J Natl Cancer Inst. 97(10):755-65, 2005.
- Farhat GN, Cummings SR, Chlebowski RT, et al. Sex hormone levels and risks of estrogen receptor-negative and estrogen receptor-positive breast cancers. J Natl Cancer Inst. 103(7):562-70, 2011.
- Zeleniuch-Jacquotte A, Shore RE, Koenig KL, et al. Postmenopausal levels of oestrogen, androgen, and SHBG and breast cancer: long-term results of a prospective study. Br J Cancer. 90(1):153-9, 2004.
- Zeleniuch-Jacquotte A, Afanasyeva Y, Kaaks R, et al. Premenopausal serum androgens and breast cancer risk: a nested case-control study. Breast Cancer Res. 14(1):R32, 2012.
- Fortner RT, Eliassen AH, Spiegelman D, Willett WC, Barbieri RL, Hankinson SE. Premenopausal endogenous steroid hormones and breast cancer risk: results from the Nurses’ Health Study II. Breast Cancer Res. 15(2):R19, 2013.
- Fourkala EO, Zaikin A, Burnell M, et al. Association of serum sex steroid receptor bioactivity and sex steroid hormones with breast cancer risk in postmenopausal women. Endocr Relat Cancer. 19(2):137-47, 2012.
- Baglietto L, Severi G, English DR, et al. Circulating steroid hormone levels and risk of breast cancer for postmenopausal women. Cancer Epidemiol Biomarkers Prev. 19(2):492-502, 2010.
- Manjer J, Johansson R, Berglund G, et al. Postmenopausal breast cancer risk in relation to sex steroid hormones, prolactin and SHBG (Sweden). Cancer Causes Control. 14(7):599-607, 2003.
- Sieri S, Krogh V, Bolelli G, et al. Sex hormone levels, breast cancer risk, and cancer receptor status in postmenopausal women: the ORDET cohort. Cancer Epidemiol Biomarkers Prev. 18(1):169-76, 2009.
- Schernhammer ES, Sperati F, Razavi P, et al. Endogenous sex steroids in premenopausal women and risk of breast cancer: the ORDET cohort. Breast Cancer Res. 15(3):R46, 2013.
- Wang B, Mi M, Wang J, et al. Does the increase of endogenous steroid hormone levels also affect breast cancer risk in Chinese women? A case-control study in Chongqing, China. Int J Cancer. 124(8):1892-9, 2009.
- Yu H, Shu XO, Shi R, et al. Plasma sex steroid hormones and breast cancer risk in Chinese women. Int J Cancer. 105(1):92-7, 2003.
- Sturgeon SR, Potischman N, Malone KE, et al. Serum levels of sex hormones and breast cancer risk in premenopausal women: a case-control study (USA). Cancer Causes Control. 15(1):45-53, 2004.
- Key T, Appleby P, Barnes I, Reeves G for the Endogenous Hormones and Breast Cancer Collaborative Group. Endogenous sex hormones and breast cancer in postmenopausal women: reanalysis of nine prospective studies. J Natl Cancer Inst. 94(8):606-16, 2002.