Recent research on tamoxifen has shown that up to 7-10% of women with breast cancer may not receive the full medical benefit from taking tamoxifen, because of their unique genetic make-up. These women have a special version of a gene called 2D6, which may reduce the effectiveness of tamoxifen and increase their chance of breast cancer recurrence

A simple and painless test for 2D6 genes is available from DNA Direct through this website.

FDA Recommends Relabeling Tamoxifen

On October 18, an FDA panel unanimously agreed that the 2D6 gene is a predictor of tamoxifen efficacy. They recommend relabeling tamoxifen to say that 2D6 poor metabolizers who take tamoxifen have a higher risk for breast cancer recurrence, and that testing is available.