Breast Cancer Wonder Drug Could Be Causing Secondary Tumours
Posted Aug 26 2009 10:47pm
New research released today has revealed worrying side effects developing from the supposed “gold standard” drug tamoxifen, used to treat breast cancer. The study shows that there is a serious risk of women developing a secondary type of tumour as a result of taking the drug.
Tamoxifen is commonly used for women after they have fought and survived breast cancer, to prevent new tumours forming by preventing the production of the sex-hormone oestrogen.
Approximately two thirds of breast cancers are hormone-sensitive - and it is for this reason that Tamoxifen can help stop tumours coming back for post-surgery women before they reach the menopause. However, this new research from the US, published in the Cancer Research journal, reveals this new and worrying risk that the drug presents. In fact taking Tamoxifen for over five years as much as quadrupled the risk of a non-hormone-sensitive tumour forming in the breast tissue.
Christopher Li, who headed up the team that carried out 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 gathered evidence on over 1,000 women who had been diagnosed with hormone-sensitive breast cancer. The results revealed that although taking Tamoxifen reduced the likeliness of a hormone-sensitive tumour re-appearing, it significantly increased the chance of a secondary oestrogen-negative forming.
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.”
There appeared to be no evidence of aggressive non-hormone-sensitive tumours appearing in women who had been taking Tamoxifen for less than five years.