A study of tamoxifen, anastrozole and goserelin for women who have the BRCA 1 gene mutation (CIBRAC)

For women with the BRCA 1 gene change (mutation) removal of their breasts (mastectomy) is the current treatment used to reduce their risk of developing breast cancer.

We know that removing the ovaries can also reduce the risk of breast cancer for these women.

The ovaries produce the female hormone oestrogen. By removing the ovaries the level of oestrogen in the body is reduced. Researchers think this might be the reason why removing the ovaries reduces the risk of breast cancer. But they aren’t certain.

Levels of oestrogen can also be reduced by the drugs:

• tamoxifen
• anastrozole
• goserelin

Laboratory studies suggest that oestrogen can cause damage to the DNA in breast cells. This is a key early event in the development of breast cancer. So reducing the amount of damage to the breast cells could reduce the risk of breast cancer.

In this study women with the BRCA 1 gene change had tamoxifen, anastrozole and goserelin.

The aims of the study were to see:

• if women with the BRCA 1 gene change are willing to have these drugs
• what affect these drugs have on breast cells
• how the drugs affect quality of life for these women