Thursday, August 27, 2009

Breast cancer drug Tamoxifen may have long-term risks

Another backflip in the official wisdom. People have been taking this stuff for decades

Thousands of women taking a “gold standard” drug to prevent the recurrence of breast cancer are at increased risk of another type of tumour developing, according to new research.

Tamoxifen, which is prescribed to most breast cancer survivors for several years after initial therapy, prevents new tumours by blocking the sex-hormone oestrogen. It can prevent the recurrence of cancer after surgery for pre-menopausal women with hormone-sensitive cancers — which account for about two thirds of breast cancers. But the US study, reported in the journal Cancer Research, shows Tamoxifen may raise the risk of developing other aggressive tumours. Researchers found that five or more years of Tamoxifen treatment quadrupled the chances of a non-hormone-sensitive breast tumour developing.

Christopher Li, who led the study at the Fred Hutchinson Cancer Research Centre in Seattle, said: “This is of concern, given the poorer prognosis of oestrogen-receptor negative tumours, which are also more difficult to treat.”

Dr Li’s team assessed Tamoxifen use among more than 1,000 women who had hormone-sensitive breast cancer diagnosed. Comparing those who received Tamoxifen with those who did not showed that the drug reduced the chances of oestrogen-positive breast cancer returning. However it also appeared to greatly increase the risk of an oestrogen-negative second tumour developing.

Alison Ross, senior science information officer at Cancer Research UK, said: “Women should be reassured that, based on extensive scientific evidence, the benefits of taking drugs such as Tamoxifen far outweigh any potential risks.”

The association was not seen in women who took Tamoxifen for less than five years.


Broken hearts mend with 'patch'

Very clever but probably pretty distant as a treatment. Showing the potential is important, however

A team of Israeli scientists has developed a potential way to fix the damage from heart attacks. A "patch" has been made from heart muscle that can be used to fix scarring left over from a heart attack. Writing in the journal PNAS, the scientists describe how the technique strengthened the hearts of rats that had suffered heart attacks. The "patch" was grown in abdominal tissue first, then transplanted to damaged areas of the heart.

This experiment is the first to show that such patches can actually improve the health of a heart after it has been damaged. The scientists measured an increase in the size of the muscle in damaged areas, and improved conduction of the electrical impulses needed for the heart to pump normally.

Heart attacks usually cause irreversible damage to heart muscle. If people survive, then the damaged muscle can cause another serious condition called heart failure.

It is hoped that the procedure may eventually lead to treatments in humans because of its "simplicity and safety", the authors - led by Tal Dvir from Ben-Gurion University of the Negev in Beer-Sheva - wrote in Proceedings of the National Academy of Sciences (PNAS). However, they added that "because most patients with heart attacks are old, and multiple surgery can pose a large risk to them, our strategy is not currently an option".

Ellen Mason, senior cardiac nurse at the British Heart Foundation (BHF), told BBC News: "In the last decade there has been significant research into injecting cells, including stem cells, into the heart to try and repair the damaged area. "This study was in animals, but may help scientists better understand how to repair damaged human hearts in the future." The technique is also being developed for livers and bladders.


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