Taking hormonal drugs for up to 15 years reduces the risk of breast cancers coming back, a landmark study suggests.
The trial, involving 1,918 patients, which had top billing at the world’s largest cancer conference, showed the risk was cut by a third.
Experts described it as a “big deal” that will change treatment for millions of women.
But they warned there were risks, including osteoporosis.
Globally, 1.7 million women are diagnosed with breast cancer around the world each year.