A recent study has suggested that a drug commonly used as a ‘morning after pill’ in the NHS could potentially be repurposed to lower the risk of breast cancer in pre-menopausal women. Researchers from the Manchester Breast Centre, located at The University of Manchester, discovered that by inhibiting the effects of the hormone progesterone with ulipristal acetate, an existing NHS-approved drug, the likelihood of breast cancer development in women with a strong family history of the disease before menopause could be reduced.
Progesterone is known to facilitate the progression of breast cancer by stimulating the growth of specific breast cells that have the potential to transform into cancerous cells and by aiding healthy cells in transitioning into cancerous ones. The research indicates that blocking these progesterone effects could offer a novel approach to preventing breast cancer initiation.
Ulipristal acetate is primarily utilized as a key component in emergency contraceptive pills that work by delaying ovulation to prevent pregnancy. It is also currently employed in treating uterine fibroids, benign growths occurring in or around the womb.
The findings of the study, published in the journal Nature, demonstrate that the intake of ulipristal acetate effectively impedes the growth of breast cells that can evolve into cancer, specifically luminal progenitors. These cells serve as the starting point for triple negative breast cancer, a more aggressive form of the disease that is prevalent in younger and black women.
Previous studies have highlighted that the recurrence or spread of triple negative breast cancer within the initial years post-diagnosis is higher compared to other types of breast cancer. Over a 12-week period between 2016 and 2019, 24 women aged 34-44 with a family history of breast cancer participated in the trial involving ulipristal acetate. Throughout the trial, the participants underwent breast biopsies, blood tests, and detailed Magnetic Resonance Imaging (MRI) scans before and after the treatment.
The researchers assessed alterations in breast tissue to ascertain the potential protective effects of the drug against breast cancer development. The MRI scans revealed a reduction in breast tissue density following the treatment, which is crucial as higher breast density is associated with an increased risk of breast cancer. The team observed that the treatment was most effective in women with elevated breast density pre-treatment.
Moreover, significant changes in breast tissue were noted, including a notable decrease in the number and function of specific collagen proteins that typically support breast tissue. Overall, the breast tissue became less rigid, creating a less conducive environment for cancer growth and development.
One particular protein, collagen 6, exhibited the most significant decrease post-treatment. Based on these results, the researchers speculate that this protein may directly impact the behavior of luminal progenitor cells, which have the potential to give rise to breast cancer. These alterations suggest that the drug modifies breast tissue in a manner that hinders cancer cell proliferation, thereby diminishing the risk of breast cancer.
Dr. Sacha Howell, the clinical lead author and clinical senior lecturer at The University of Manchester, expressed gratitude to the study participants and emphasized the critical role of progesterone in breast cancer development among high-risk individuals. He highlighted the potential of ulipristal acetate and other anti-progestins as preventive treatments for women at elevated risk of breast cancer.
Additionally, Dr. Bruno Simões, the laboratory lead author and research fellow at The University of Manchester, noted the exciting implications of the study, suggesting that women with increased breast density, a well-known risk factor, may derive significant benefits from preventive treatment with an anti-progestin drug.
Dr. Simon Vincent, the chief scientific officer at Breast Cancer Now, which funded the research, highlighted the limited options currently available to women at high risk of breast cancer, underscoring the impact of surgery or long-term hormone therapy on their physical and emotional well-being.
Grace Burton, a 27-year-old from Bromley, Greater London, who underwent a preventative double mastectomy due to a high risk of breast cancer, shared her experience and optimism regarding the new research on preventative medication. She emphasized the hope it offers to women facing similar risks, envisioning a future where preventive measures could be less invasive and fear-inducing.
The study’s outcomes provide a promising path for larger trials to validate the potential of anti-progestins in diminishing the risk of breast cancer, offering hope for improved preventive strategies in high-risk populations.