Tamoxifen drug can slash breast cancer deaths by half

Breast cancer patients who take the tamoxifen drug for 10 years instead of five halve their risk of dying from the disease, scientists claim.
Researcher said adding an extra five years of treatment cut the risk of dying by a further 25 per cent.
They said tamoxifen has transformed the treatment of breast cancer and is a key cause of the near 50 per cent fall in death rates in the last 30 years.
There are one million users of the drug worldwide. It works by preventing oestrogen being taken up by breast cells where it can be used to fuel cancer.

It is long since out of patent, and therefore inexpensive, and is used for treating oestrogen positive breast cancer, the most common sort, which accounts for three quarters of all cases, The Independent reported.
However, until recently it had been thought that five years of treatment with the drug was enough and longer treatment might carry extra risks.

Now a study of 7,000 women led by the University of Birmingham has confirmed that those who took tamoxifen for a decade had 23 per cent fewer recurrences of their cancer and a 25 per cent lower risk of dying than those who stopped treatment after five years.

The research follows a University of Oxford study of over 12,000 women which reached similar conclusions. Taken together the results from the two studies, and accumulating evidence worldwide, are likely to change medical practise.
"Doctors are now likely to recommend continuing tamoxifen for an extra five years and this will result in many fewer breast cancer recurrences and breast cancer deaths worldwide. Tamoxifen is cheap and widely available so this could have an immediate impact," lead researcher, Dr Daniel Rea, said.
However, tamoxifen has side effects causing some women to experience menopausal symptoms such as night sweats and hot flushes, the report said.

It also has rare but more serious effects increasing the risk of endometrial cancer blood clots and stroke.
In the latest study, researchers found an increase in endometrial cancer. But because it is often detected early when it can be successfully treated they estimated that for every endometrial cancer death caused by tamoxifen the drug would prevent 30 breast cancer deaths.