
We helped shape how tamoxifen is used
Bringing a new drug to patients is a long and winding road. But the journey doesn’t stop once a drug is approved for use – researchers continue to study and refine how best to give it to patients.
The latest in our High Impact Science series is the story of tamoxifen, a discovery in 1966 that has gone on to save the lives of millions of women with breast cancer.
The background
Around 8 in every 10 breast cancers diagnosed in the UK are classified as ‘oestrogen receptor-positive’ (or ER positive for short). The cancer cells in ER-positive tumours contain large quantities of a protein called the oestrogen receptor. This means the tumours grow in response to the female hormone, oestrogen, which circulates in a woman’s bloodstream.
Being dependent on oestrogen gives ER-positive cancers an Achilles heel: it makes them sensitive to drugs like tamoxifen, which block oestrogen from affecting cancer cells.
Tamoxifen works like a broken key in a lock – it sticks to the oestrogen receptor, preventing the normal ‘key’ (oestrogen) from fitting anymore, thereby stopping the tumour in its tracks. Its precision targeting of ER-positive breast cancer cells in this way mean it is, in effect, a ‘targeted treatment’.
Since its approval in the UK in 1972, tamoxifen’s effectiveness and affordability have earned it a place on a global stage – it appears on the World Health Organisation’s list of essential drugs for the treatment of breast cancer in both developing and developed countries. So, how was this widely used, remarkable drug discovered?





