Can I prevent breast cancer?
What does 'preventable' actually mean?
Can I prevent breast cancer?
Studies tell us that at least 30% of breast cancers are preventable through simple lifestyle changes, such as improved diet, drinking less alcohol, being active, managing your weight and reducing exposure to harmful chemicals.
We're here to show you how.
What does 'preventable' actually mean?
Scientists around the world have done hundreds of studies on breast cancer risk. But here’s the tricky part: not all studies measure risk in the same way or look at the same groups of people.
That makes it hard to pin down an exact number of cases that could be prevented. To solve this, researchers use a tool called the Population Attributable Fraction (PAF) a measure endorsed by the World Health Organisation (WHO). Think of it as a way of asking:
“If we could remove this risk factor, how much of the disease could we prevent in the whole population?”
In other words, the PAF tells us how big a role each risk factor plays in breast cancer. It combines the relative risk of the exposure with its prevalence in the population to quantify the disease burden attributable to that factor.
For example, a PAF of 64% for smoking and lung cancer means that 64% of lung cancer cases could be attributed to smoking.
Why 30%? Why not more?
We say 'at least 30%' to reflect what we can confidently say based on current evidence:
- It’s drawn from a wide range of international studies.
- It accounts for gaps (such as limited data on chemical exposures).
- It’s a conservative, science-backed minimum, meaning the true impact might be higher once we understand more.
Why it matters.
Knowing this empowers individuals, communities, and policymakers to act:
- You: Small changes - like improving diet, being more active, or limiting alcohol - can make a powerful difference.
- Society: If prevention becomes a shared goal, we can reduce the burden on people and the NHS.
- Policy: We call for stronger policies around product safety, healthy environments, and accessible prevention tools.
How have we estimated ‘at least 30%’?
At Breast Cancer UK, we have taken an estimate based on the population attributable fractions (as defined by The World Health Organisation – WHO) of diverse studies from around the world, as noted in the table below.
From the studies noted in the table below we estimate that at least 30% of breast cancer cases may be preventable. In our estimate, we have accounted for the limitation that many studies look at some risk factors and not others, as well as the fact that none of the studies incorporate an analysis of how chemical exposures may increase risk.
| Study Reference | Country | Estimated population attributable fraction (PAF) of potentially modifiable breast cancer risk factors | Modifiable Risk Factors that contribute to risk |
|---|---|---|---|
| Parkin 2011 | UK | 27% |
|
| Brown et al., 2018 | UK | 23% |
|
| Poirier et al., 2019 | Canada | 27% |
|
| Tamimi et al., 2016 | USA | 35% (post-menopausal breast cancers, nurses health study data) |
|
| Colditz & Bohlke, 2014 | USA | 19% premenopausal and 30% postmenopausal (taken as average from possible risk reduction figures noted in modifiable risk column) |
|
| Islami et al., 2018 | USA | 29% |
|
| Arthur et al., 2020 | UK |
22% premenopausal 31% postmenopausal |
|
| Turati et al., 2020 |
Italy and Switzerland
|
30% |
|
| Masala et al., 2017 | Italy | 30% postmenopausal |
|
| Lee et al., 2018 | Korea | 34% |
|
| van Gemert et al., 2015 |
Netherlands
|
26% postmenopausal |
|
| Catsburg et al., 2014 |
Canada |
31% |
|
Find out your risk: take the quiz
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Last review: Nov-25 | Next review: Jan-26.
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{1} Arthur, R. S., Wang, T., Xue, X., Kamensky, V., & Rohan, T. E. (2020). Genetic factors, adherence to healthy lifestyle behavior, and risk of invasive breast cancer among women in the UK biobank. Journal of the National Cancer Institute, 112(9), 893–901. https://doi.org/10.1093/jnci/djz241
{2} Brown, K. F., Rumgay, H., Dunlop, C., Ryan, M., Quartly, F., Cox, A., Deas, A., Elliss-Brookes, L., Gavin, A., Hounsome, L., Huws, D., Ormiston-Smith, N., Shelton, J., White, C., & Parkin, D. M. (2018). The fraction of cancer attributable to modifiable risk factors in England, Wales, Scotland, Northern Ireland, and the United Kingdom in 2015. British Journal of Cancer, 118(8), 1130–1141. https://doi.org/10.1038/s41416-018-0029-6
{3} Catsburg, C., Miller, A. B., & Rohan, T. E. (2014). Adherence to cancer prevention guidelines and risk of breast cancer. International Journal of Cancer, 135(10), 2444–2452. https://doi.org/10.1002/IJC.28887
{4} Colditz, G. A., & Bohlke, K. (2014). Priorities for the primary prevention of breast cancer. CA: A Cancer Journal for Clinicians, 64(3), 186–194. https://doi.org/10.3322/caac.21225
{5} Islami, F., Goding Sauer, A., Miller, K. D., Siegel, R. L., Fedewa, S. A., Jacobs, E. J., McCullough, M. L., Patel, A. V., Ma, J., Soerjomataram, I., Flanders, W. D., Brawley, O. W., Gapstur, S. M., & Jemal, A. (2018). Proportion and number of cancer cases and deaths attributable to potentially modifiable risk factors in the United States. CA: A Cancer Journal for Clinicians, 68(1), 31–54. https://doi.org/10.3322/CAAC.21440
{6} Kulhánová, I., Znaor, A., Shield, K. D., Arnold, M., Vignat, J., Charafeddine, M., Fadhil, I., Fouad, H., Al-Omari, A., Al-Zahrani, A. S., El-Basmy, A., Shamseddine, A., Bray, F., & Soerjomataram, I. (2020). Proportion of cancers attributable to major lifestyle and environmental risk factors in the Eastern Mediterranean region. International Journal of Cancer, 146(3), 646–656. https://doi.org/10.1002/ijc.32284
{7} Lee, J. E., Lee, S. A., Kim, T. H., Park, S., Choy, Y. S., Ju, Y. J., & Park, E. C. (2018). Projection of breast cancer burden due to reproductive/lifestyle changes in Korean Women (2013-2030) using an age-period-cohort model. Cancer Research and Treatment, 50(4), 1388–1395. https://doi.org/10.4143/crt.2017.162
{8} Masala, G., Bendinelli, B., Assedi, M., Occhini, D., Zanna, I., Sieri, S., Agnoli, C., Sacerdote, C., Ricceri, F., Mattiello, A., Panico, S., Tumino, R., Frasca, G., Saieva, C., & Palli, D. (2017). Up to one-third of breast cancer cases in post-menopausal Mediterranean women might be avoided by modifying lifestyle habits: the EPIC Italy study. Breast Cancer Research and Treatment, 161(2), 311–320. https://doi.org/10.1007/s10549-016-4047-x
{9} Parkin, D. M. (2011). The fraction of cancer attributable to lifestyle and environmental factors in the UK in 2010: Introduction. British Journal of Cancer, 105, S2–S5. https://doi.org/10.1038/bjc.2011.474
{10} Poirier, A. E., Ruan, Y., Volesky, K. D., King, W. D., O’Sullivan, D. E., Gogna, P., Walter, S. D., Villeneuve, P. J., Friedenreich, C. M., & Brenner, D. R. (2019). The current and future burden of cancer attributable to modifiable risk factors in Canada: Summary of results. Preventive Medicine, 122, 140–147. https://doi.org/10.1016/j.ypmed.2019.04.007
{11} Tamimi, R. M., Spiegelman, D., Smith-Warner, S. A., Wang, M., Pazaris, M., Willett, W. C., Eliassen, A. H., & Hunter, D. J. (2016). Population attributable risk of modifiable and nonmodifiable breast cancer risk factors in postmenopausal breast cancer. American Journal of Epidemiology, 184(12), 884–893. https://doi.org/10.1093/aje/kww145
{12} Turati, F., Dalmartello, M., Bravi, F., Serraino, D., Augustin, L., Giacosa, A., Negri, E., Levi, F., & Vecchia, C. La. (2020). Adherence to the world cancer research fund/american institute for cancer research recommendations and the risk of breast cancer. Nutrients, 12(3). https://doi.org/10.3390/nu12030607
{13} Van Gemert, W. A., Lanting, C. I., Goldbohm, R. A., van den Brandt, P. A., Grooters, H. G., Kampman, E., Kiemeney, L. A. L. M., van Leeuwen, F. E., Monninkhof, E. M., de Vries, E., Peeters, P. H., & Elias, S. G. (2015). The proportion of postmenopausal breast cancer cases in the Netherlands attributable to lifestyle-related risk factors. Breast Cancer Research and Treatment, 152(1), 155–162. https://doi.org/10.1007/s10549-015-3447-7
