ACCIDENTAL CURES

MeDIcINeS discovered by accident. This week: Tamoxifen THIS drug is prescribed to about 13,000 women in the UK every year to treat the most common type of breast cancer. But it was originally developed as a potential contraceptive and was meant to work by suppressing ovulation, the release of an egg from the ovaries.

However, in the Sixties, scientists found it had the opposite effect — stimulating ovulation by blocking oestrogen receptors on cells in a part of the brain called the hypothalamus.

This meant it was useless as a contraceptive and was to be consigned to the bin when one researcher wondered if it could also block oestrogen receptors on cancer cells — ‘starving’ them to death.

In 1970, a trial began at the Christie Hospital in Manchester and tamoxifen soon emerged as a breakthrough in the treatment of oestrogen-positive breast cancer (tumours that thrive off the hormone oestrogen), which accounts for up to 80 per cent of cases.

It can also prevent the disease in high-risk patients.