What you need to know about breastfeeding and breast cancer

6 August 2025
Charl Greeff

What you need to know about breastfeeding and breast cancer

Breast cancer is one of the most common cancers affecting women worldwide, with nearly one in eight women developing some form of the disease during their lifetime. For women who are breastfeeding or pumping, this period often makes them more aware of breast health due to the rapid and noticeable changes that occur in the body during lactation.

While many are aware of the benefits of breastfeeding for both mother and child, fewer know about its potential role in reducing the risk of breast cancer. To help clarify this connection, we explore some frequently asked questions with insights from medical professionals and foundations in the field of oncology.

Does breastfeeding reduce the risk of breast cancer?

Dr. Hoover explains that although many risk factors for breast cancer, such as age, genetics, and family history, are beyond a woman’s control, reproductive behaviours such as breastfeeding can make a meaningful difference.

“One very large study showed a 4.3% reduction in relative risk of breast cancer development for every 12 months a woman breastfeeds,” said Hoover. “Another large review demonstrated a 14% lower risk in women who had breastfed, compared to those who never breastfed.” (Garcia, 2024)

This may be due to hormonal changes. During breastfeeding, women often experience delayed return of their menstrual cycles, which results in reduced lifetime exposure to Oestrogen – a hormone associated with breast cancer development. (Garcia, 2024)

So how does breastfeeding help prevent cancer?

In addition to lowered Oestrogen levels, breastfeeding increases the turnover of breast tissue. This natural renewal process allows the body to shed and replace cells, including those that may have become damaged over time – another factor that can help reduce cancer risk.

Both factors altogether contribute to a lowered risk of developing breast cancer. (Collins, 2025)

Can I get breast cancer while breastfeeding?

It is possible to develop breast cancer at any stage of life, including while breastfeeding or pumping, however, there is no evidence to suggest that breastfeeding increases the risk of breast cancer during this time.

Because breastfeeding mothers are often more attuned to the changes occurring in their breasts, they may be more likely to notice early signs of concern. It’s normal for breasts to feel lumpy during this time due to milk production or blocked ducts. However, any lump that persists or does not reduce in size within about a week should be evaluated by a healthcare professional to rule out more serious conditions. (Garcia, 2024)

What are the benefits of breastfeeding and how long should you breastfeed to reduce your risk of breast cancer?

This blog post is for informational purposes only and should not be considered medical/financial advice. Please consult with a healthcare/financial professional for personalised guidance.

References

Collins, P. C. (2025). BREASTFEEDING AND CANCER. Retrieved from World Cancer Research Fund:
https://www.wcrf.org/preventing-cancer/topics/breastfeeding-and-cancer/

Garcia, S. (2024, August 02). 5 Things You Should Know About Breastfeeding and Breast Cancer. Retrieved from Moffit Cancer Center:
https://www.moffitt.org/endeavor/archive/5-things-you-should-know-about-breastfeeding-and-breast-cancer/

Sweet, J. (2025). Breastfeeding and Breast Cancer: Does Breastfeeding Lower Breast Cancer Risk? Retrieved from Breast Cancer Research Foundation:
https://www.bcrf.org/about-breast-cancer/breastfeeding-breast-cancer-risk/

World Cancer Research Fund. (2025). BREASTFEEDING AND CANCER. Retrieved from World Cancer Research Fund:
https://www.wcrf.org/preventing-cancer/topics/breastfeeding-and-cancer/