القصرعينية
03-10-2004, 02:24 AM
What is tamoxifen?
Tamoxifen is an anti-oestrogen drug, designed to counteract the effects of oestrogen. It was developed over 30 years ago and is now used widely to treat breast cancer. It is also used to treat a variety of other conditions, including infertility.
How it works
The way in which tamoxifen works is quite complicated and not yet fully understood but its main function is as an anti-oestrogen drug. This means that it reduces or stops the action of the female hormone oestrogen.
Most breast cancers need supplies of the female hormone oestrogen to grow. Cancer cells have proteins called receptors on their surface that the *** hormones attach to. Cancers with oestrogen-receptors on the surface of their cells are called ‘oestrogenreceptor positive’ (ER-positive) and tamoxifen is most effective against these cancers.
Under normal circumstances when oestrogen comes into contact with the receptors it fits into them and activates the cancer cells to divide so that the tumour grows.
Tamoxifen imitates the action of oestrogen and fits into the receptor but does not activate the cells to divide. The tamoxifen remains in place and prevents oestrogen from reaching the cancer cells so that they either grow more slowly or stop growing altogether.
Tamoxifen can greatly reduce the chance of oestrogen-receptor positive cancers coming back after surgery. It can also be used to shrink large tumours down before surgery so that they can be removed.
Tamoxifen is an anti-oestrogen drug, designed to counteract the effects of oestrogen. It was developed over 30 years ago and is now used widely to treat breast cancer. It is also used to treat a variety of other conditions, including infertility.
How it works
The way in which tamoxifen works is quite complicated and not yet fully understood but its main function is as an anti-oestrogen drug. This means that it reduces or stops the action of the female hormone oestrogen.
Most breast cancers need supplies of the female hormone oestrogen to grow. Cancer cells have proteins called receptors on their surface that the *** hormones attach to. Cancers with oestrogen-receptors on the surface of their cells are called ‘oestrogenreceptor positive’ (ER-positive) and tamoxifen is most effective against these cancers.
Under normal circumstances when oestrogen comes into contact with the receptors it fits into them and activates the cancer cells to divide so that the tumour grows.
Tamoxifen imitates the action of oestrogen and fits into the receptor but does not activate the cells to divide. The tamoxifen remains in place and prevents oestrogen from reaching the cancer cells so that they either grow more slowly or stop growing altogether.
Tamoxifen can greatly reduce the chance of oestrogen-receptor positive cancers coming back after surgery. It can also be used to shrink large tumours down before surgery so that they can be removed.