Reproductive Health Supplies Coalition
By Laura Elvin
A new study has revealed a 'morning after pill' drug already approved for use in the NHS could be repurposed to prevent breast cancer in pre-menopausal women.
Researchers at the Manchester Breast Centre, based at The University of Manchester, found that blocking the effects of the hormone progesterone, using ulipristal acetate, a drug already used on the NHS, may reduce the risk of breast cancer developing in women before the menopause who have a strong family history of the disease.
Progesterone can drive breast cancer development because it promotes the growth of a type of breast cell that has the potential to turn into breast cancer, as well as making it easier for healthy cells to turn into cancerous ones.
Blocking these effects of progesterone could be a new way to stop breast cancer before it starts, according to the research, funded by charity Breast Cancer Now and supported by Prevent Breast Cancer.
Ulipristal acetate is primarily used as an active ingredient in an emergency contraceptive pill that works by delaying or preventing ovulation to avoid pregnancy.
Grace Burton underwent a preventative double mastectomy last year after finding out she was at high risk of breast cancer due to an inherited BRCA1 gene. (Courtesy of Breast Cancer Now via SWNS)
It is also currently used for the treatment of uterine fibroids - non-cancerous growths that develop in or around the womb.
The study, published today in the journal Nature, found that taking ulipristal acetate helped block the growth of breast cells that can turn into cancer, called luminal progenitors.
These cells are the starting point for triple-negative breast cancer, a more aggressive form of the disease that is more common in younger women and black women.
Previous research has shown that the risk of triple-negative breast cancer coming back or spreading in the first few years after diagnosis is higher than in other types of breast cancer.
Between 2016 and 2019, 24 women aged 34-44 with a family history of breast cancer took ulipristal acetate for a 12-week period. During the trial, they underwent breast biopsies, blood tests, and detailed Magnetic Resonance Imaging (MRI) scans before and after treatment.
The researchers were measuring changes in breast tissue to understand if the drug might have a protective effect against breast cancer development.
Dr. Sacha Howell, Dr. Rob Clarke and Dr. Bruno Simões. (Courtesy of Breast Cancer Now via SWNS)
MRI scans showed that the breast tissue became less dense with treatment, which is important because higher breast density is known to increase risk of breast cancer. The team found that the treatment worked best in women who had high breast density before treatment started.
Researchers also observed dramatic changes in breast tissue. They found that treatment significantly reduced the number and function of certain collagen proteins that normally help support breast tissue. Overall, the breast tissue became less stiff, making the environment less favourable for cancers to develop and grow.
One protein in particular – collagen 6 – showed the most noticeable decrease after treatment. Based on their findings, researchers now think that it may directly influence the behaviour of luminal progenitor cells, which can give rise to breast cancer.
All these changes suggest that the drug alters breast tissue in a way that makes it harder for cancer cells to develop and grow, therefore reducing the risk of breast cancer.
Clinical lead author, Dr. Sacha Howell, clinical senior lecturer at The University of Manchester, Director of Manchester Breast Centre and Consultant Oncologist at The Christie said: “We are profoundly grateful to the women who volunteered for this study.
"Our research, with them, provides evidence that progesterone plays a critical role in breast cancer development in high-risk individuals. By targeting its action, ulipristal acetate and other anti-progestins show promise as preventive treatments for women at increased risk.
“What makes this study particularly exciting is the combination of clinical imaging and biological analysis, which gives us a powerful tool to understand how prevention therapies work at both the tissue and molecular levels. These results lay important groundwork for larger trials to confirm the potential of anti-progestins in reducing breast cancer risk”.
Grace has a history of cancer in her family. (Courtesy of Breast Cancer Now via SWNS)
Laboratory lead author, Dr. Bruno Simões, research fellow at The University of Manchester and Principal Investigator at the Manchester Breast Centre added: "This study is particularly exciting because it suggests that women with increased breast density, a well-established risk factor, may benefit most from preventive treatment with an anti-progestin drug."
Dr. Simon Vincent, chief scientific officer at Breast Cancer Now, which funded the research, said currently women at high risk of breast cancer only have to risk-reducing treatments - surgery or long-term hormone therapy "both of which have a profound impact on their physical and emotional wellbeing".
Grace Burton, 27, from Bromley, Greater London, underwent a preventative double mastectomy last year after finding out she was at high risk of breast cancer due to an inherited BRCA1 gene change at the age of 21.
She said: "Breast cancer has had a huge impact on my family - both my mom and my aunt were diagnosed, and knowing I was at high risk was always in the back of my mind. Having later gone through preventative surgery myself, I know how heavy and difficult those decisions can feel.
"That’s why this new research into preventative medication is so exciting, it offers hope for other women who might one day have less invasive options to protect their health.
“For those of us with a strong family history, the possibility of preventing breast cancer before it starts is incredible. It gives me hope that future generations may not have to make the same tough choices and can grow up with more options and less fear around breast cancer.”
