Breast Density Research Appeal | Breast Cancer UK

Breast Density Research Appeal

We urgently need your help for us to meet our target.  

The aim of the research is to identify whether endocrine disrupting chemicals affect breast density, which can influence our breast cancer risk.

Read on to find out more about high breast density, why it's important for breast cancer risk, and how this research will help us to prevent breast cancer.

The significance of breast density

Women are 4-5 times more likely to get breast cancer if they have high breast density, compared to those with low breast density (1).  High breast density is the most significant breast cancer risk factor for women after ageing (2).

You can’t tell if you have dense breasts simply by looking at them or feeling them.  It is only something that can be determined via a breast X-ray (or mammogram).

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What determines high or low breast density?

Breast density is partly inherited, but is also influenced by the environment and changes over a women’s lifetime (3). Breast density increases in response to hormones such as oestrogen, although how this occurs at the cellular level is not fully understood. Post-menopausal women, who have less circulating oestrogen, have lower breast density.

What can cause high breast density?

Environmental factors that increase breast density include alcohol and diet (4), including consumption of sweet foods (5), and possibly air pollution (6) - although further studies are needed to confirm this. Use of certain synthetic hormones, including combined hormone replacement therapy (HRT), increases breast density and cessation of use lowers it (7, 8).

What might lower breast density?

Certain chemotherapeutic drugs used to prevent breast cancer such as tamoxifen (9), and stopping HRT use have been shown to reduce breast density. Surprisingly, it seems that a high Body Mass Index (BMI), usually an indication of being overweight, is generally associated with low breast density (11). However, it is important to remember that being overweight with high BMI is itself a risk factor for breast cancer.  

Where will the research be carried out?

The three year research project will be led by Professor Valerie Speirs from the University of Leeds and is jointly funded by Breast Cancer UK and Animal Free Research UK.  A PhD student, under the supervision of Professor Speirs, will investigate the effects of various oestrogen mimics on human breast tissue of different densities.

How are we studying breast cancer development using human-relevant animal free research?

The research uses human breast tissue and will use an innovative 3D in vitrohuman mammary gland model. Importantly, the research will not use any animals or animal-derived materials.  Breast Cancer UK fully supports the replacement of animal use in research and is pleased to be working Animal Free Research UK on this project.

Click here for Breast Cancer UK's Policy on Animal Expermentation

To help us reach our target and ensure this important research goes ahead please Donate today. 


1. Boyd et al. (2011). Mammographic density and breast cancer risk: current understanding and future prospects. Breast Cancer Research 13(6): 223.

2. Sherratt, M. J. et al (2016). Raised mammographic density: causative mechanisms and biological consequences. Breast Cancer Research 18: 45.

3. Huo, C. W. et al. (2014). Mammographic density a review on the current understanding of its association with breast cancer. Breast Cancer Research and Treatment 144: 479–502.

4. Voevodina, O. et al. (2013). Association of Mediterranean diet, dietary supplements and alcohol consumption with breast density among women in South Germany: a cross-sectional study. BMC Public Health 13: 203

5. Duchaine, C. S. et al. (2014). Consumption of sweet foods and mammographic breast density: a cross-sectional study. BMC Public Health. 26: 14: 554.

6. Yaghjyan, L. et al (2017). Association between air pollution and mammographic breast density in the Breast Cancer Surveillance Consortium. Breast Cancer Research 19: 36.

7. Greendale, G. A. et al (2003). Postmenopausal hormone therapy and change in mammographic density. Journal of the National Cancer Institute. 95(1):30-37.

8. Andersson, T. M.-L. et al. (2017). Breast Cancer: Results Using a Joint Longitudinal-Survival Modeling Approach. American Journal of Epidemiology Jun 13. doi: 10.1093/aje/kwx178. [Epub ahead of print].

9. Andersson, T. M.-L. et al. (2017). op cit

10. Huo, T. M.-L. et al. (2014). op cit

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