An international team co-led by the University of British Columbia (UBC) in Canada and the Cancer Research Center in Salamanca, Spain, has found that cabergoline, a drug used to stop milk production, may reduce the risk of breast cancer after pregnancy. The study was published in Cancer Discovery.
The researchers analysed health records of more than 150,000 women in Spain and Norway: those who took the drug were around 70 per cent less likely to develop breast cancer in the following years. In mice with high-risk mutations, a single dose cut tumour incidence by about half. The drug appears to help the breast complete the natural “clean-up” that follows the end of breastfeeding.
The results still need to be confirmed in people. The team has secured funding for a multi-country clinical trial with women carrying a BRCA1 mutation, who will receive cabergoline or a placebo after weaning. Because the drug is already approved in Canada and Europe, its path to use could be faster.


