New York: A study shows that breast cancer patients can benefit from having the cheap and widely-available female hormone progesterone added to their treatment.

Tumours fuelled by the female hormone oestrogen are treated with drugs like tamoxifen to block oestrogen receptors, which cause cancer cells to grow.

Women whose tumours have progesterone receptors as well are known to have a better outlook, but scientists for decades could not pinpoint why, said the study that appeared in the journal Nature.

Now, a team of scientists has revealed how the progesterone receptor ‘talks to’ the oestrogen receptor in breast cancer cells to change their behaviour, ultimately slowing down tumour growth.

“We have used cutting-edge technology to tease out the crucial role that progesterone receptors play in breast cancer – a mystery that has baffled scientists for many years,” said lead author Jason Carroll from at Cancer Research UK’s Cambridge Research Institute.

“This research helps explain why some breast cancer patients have a better outlook,” Carroll said.

“This study in the cells shows how a cheap, safe, and widely available drug could potentially improve treatment for around half of all breast cancer patients,” concluded Emma Smith, senior science communication officer at Cancer Research UK’s Cambridge Research Institute.