A drug already used after childbirth could cut breast cancer risk, study suggests
Scientists in Salamanca found that cabergoline halved tumours in high-risk mice and was linked to 70% lower breast cancer risk in younger women. A clinical trial will now put it to the test.
Cabergoline is a familiar drug: doctors prescribe it, when needed, to stop milk production after childbirth. A team at the Cancer Research Centre in Salamanca, Spain, thinks it may have a second use – lowering breast cancer risk in women who are more likely to develop it.
The study, published in Cancer Discovery and co-led by Jesús Pérez-Losada (CSIC) and Christopher Maxwell (University of British Columbia), brings together two lines of evidence. In mice carrying BRCA1 and TP53 mutations, a single dose at the end of breastfeeding roughly halved the share of animals that developed breast cancer.
The researchers then looked at the medical records of more than 150,000 women in Spain and Norway. Women under 50 who had taken cabergoline for medical reasons after a pregnancy had around 70% lower breast cancer risk.
Still early days
The authors urge caution: the human data are retrospective and show an association, not proof of cause, and mouse results don’t always translate to people. Cabergoline is not approved for cancer prevention, and the idea would never be to change breastfeeding plans – only to consider it afterwards. A clinical trial funded by the Gray Foundation, with women carrying BRCA1 mutations, will now test it against placebo.
