A new study from the University of Manchester has found that a drug already used for other health issues could help prevent breast cancer in women before menopause, especially those with a strong family history of the disease.
The drug, called ulipristal acetate, is currently available through the NHS and is used for other conditions. Now, researchers believe it could be repurposed to reduce breast cancer risk.
The research team at the Manchester Breast Centre discovered that blocking the hormone progesterone may help prevent breast cancer from developing. Progesterone is a natural hormone that plays a key role in the female body, but it can also cause certain breast cells to grow too much.
Some of these cells, called luminal progenitor cells, have the potential to turn into triple negative breast cancer, a fast-growing and aggressive form of breast cancer. This type is more common in younger women and Black women and is more likely to come back or spread in the first few years after treatment.
To test their idea, the researchers asked 24 women aged 34 to 44, all of whom had a family history of breast cancer, to take ulipristal acetate for 12 weeks between 2016 and 2019. The women had breast scans, blood tests, and biopsies before and after the treatment to check how their breast tissue changed.
The results were promising. MRI scans showed that the breast tissue became less dense after treatment. This is important because dense breast tissue is known to increase the risk of breast cancer. The treatment was especially helpful in women who started with higher breast density.
The researchers also noticed big changes in the structure of the breast tissue. Certain proteins, like collagen, which normally help support the tissue, were reduced after treatment. One protein called collagen 6 was significantly lower.
Since collagen affects how firm and stiff the breast tissue is, lowering it may make it harder for cancer to grow. These changes created a softer, less risky environment in the breast, making it less likely that cancer cells would develop.
Dr. Sacha Howell, the clinical lead of the study, said the research offers strong evidence that progesterone contributes to breast cancer in women at high risk. He explained that blocking progesterone’s effects with ulipristal acetate or similar drugs could become a new way to prevent breast cancer.
What makes this study special is that it combined medical scans and tissue studies, allowing scientists to understand how the drug works on both physical and cellular levels.
Dr. Bruno Simões, another lead researcher, said the drug changed the breast tissue in a way that reduced the number of cells that can start tumors. He added that women with high breast density might benefit the most from this type of preventive treatment.
Professor Rob Clarke also noted that this research was made possible by teamwork between scientists in Manchester, Cambridge, and Toronto. Together, they found biological markers that could help doctors figure out who will benefit most from the treatment.
Dr. Simon Vincent from Breast Cancer Now highlighted the urgent need for better ways to reduce the risk of breast cancer.
Right now, high-risk women often have to choose between surgery or long-term hormone therapy—both of which can greatly affect their quality of life. This study offers hope that a safer and more comfortable option may be possible in the future.
In summary, this study shows that ulipristal acetate may be able to prevent certain types of breast cancer in women who are at higher risk. The results are encouraging, but larger and longer-term studies are still needed. If confirmed, this could lead to a new way to protect women from breast cancer, using a drug that is already available.
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The study is published in Nature.
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