This summary table contains detailed information about research studies. While viewing summary tables offers an informative glimpse at the science behind many breast cancer guidelines and recommendations, they should be viewed with some caution. There are a number of concepts you must understand to be able to successfully read and interpret research tables. To get some background information about understanding research tables, please see How to Read a Research Table.
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Introduction: Androgens are hormones, such as testosterone, that 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. Similar to higher blood estrogen levels, higher amounts of androgens in the blood may be linked to an increased risk of breast cancer in women.
Of the androgens that have been studied in relation to breast cancer risk, the most data are available for testosterone. In postmenopausal women, studies show that higher levels of blood testosterone are related to an increase in risk of breast cancer. And, there is some evidence that suggests higher levels of blood testosterone may also increase breast cancer risk in premenopausal women. However, at this time, results for premenopausal women are limited.
Most of the studies below excluded women who were taking postmenopausal hormones at the time of the blood collection. Certain types of postmenopausal hormones might mask the full effect that natural blood testosterone levels have on breast cancer risk. By looking only at women who do not take (or who have never taken) postmenopausal hormones, researchers may see more clearly how blood androgen levels affect breast cancer risk.
Find more information on the strengths and weaknesses of different types of studies.
See how this risk factor compares with other risk factors for breast cancer.
Study selection criteria: Available prospective nested case-control studies , case-control studies and pooled analyses with at least 100 breast cancer cases.
Table note: Odds ratios above 1 indicate increased risk. Odds ratios below 1 indicate decreased risk. Risks related to total testosterone levels are shown in this table. Although free testosterone may also be related to breast cancer risk, many studies have not measured free testosterone and data are limited at this time.
Study
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Study Population
(number of participants)
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Risk of Breast Cancer in Women with Higher Testosterone Levels
Compared to Women with Lower Testosterone Levels
Odds Ratio (95% CI)
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Premenopausal
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Postmenopausal
|
Nested case-control studies
|
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Cases
|
Controls
|
|
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EPIC [1,2]
|
677
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1,309
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|
1.85 (1.33–2.57)
|
|
370
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726
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1.73 (1.16-2.57)
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NYU Women’s Health Study [3]
|
297 |
563
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2.05 (1.19-3.53)
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Nurses Health Study [4]
|
312 |
628 |
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1.6 (1.0-2.4)
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Nurses Health Study II [5]
|
197 |
394
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2.0 (1.1-3.6)*
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Manjer et al. [6]
|
173 |
438 |
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1.87 (1.08-3.25)
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ORDET [7]
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165 |
672 |
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3.28 (1.93-5.55) |
| Case-control studies |
Wang et al. [8]
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367 |
367 |
1.41 (0.61-3.26)†
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2.83 (1.20-6.67)
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Yu et al. [9]
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300 |
300 |
2.01 (0.96-4.21)
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2.40 (1.11-5.21)
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Sturgeon et al. [10]
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169 |
195 |
1.12 (0.6-2.5)
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Pooled analyses
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Cases
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Controls
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The Endogenous Hormones and Breast Cancer Collaborative Group [11]
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663
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1,765
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2.22 (1.59-3.10)
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* For testosterone blood levels measured in the luteal phase of a woman’s menstrual cycle. Testosterone blood levels as measured in the early follicular stage, the risk was not significant, RR=1.8 (0.9-3.4).
† For testosterone blood levels measured in the luteal phase of a woman’s menstrual cycle. Testosterone blood levels as measured in the early follicular stage, the risk was also not significant, RR=0.45 (0.17-1.19).
References
- 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.
- 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.
- Missmer SA, Eliassen AH, Barbieri RL, Hankinson SE. Endogenous estrogen, androgen, and progesterone concentrations and breast cancer risk among postmenopausal women. J Natl Cancer Inst. 96(24):1856-65, 2004.
- Eliassen AH, Missmer SA, Tworoger SS, et al. Endogenous steroid hormone concentrations and risk of breast cancer among premenopausal women. J Natl Cancer Inst. 98(19):1406-15, 2006.
- 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.
- 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.
Updated 10/22/09
