AACR: Tamoxifen therapy and CYP2D6

April 30, 2010

Genetic differences in CYP2D6 and DT-1 were found to be significantly associated with shorter recurrence-free survival for those taking tamoxifen for breast cancer, according to study results presented at the 2010 American Association for Cancer Research (AACR) Annual Meeting.  CYP2D6 is a drug-metabolizing enzyme that has been suspected to influence clinical efficacy of tamoxifen.  DT-1, DT-2, and DT-3 are transporter proteins which are also involved in the drug metabolism process.  The investigators looked at 282 women with hormone receptor-positive invasive breast cancer who were receiving tamoxifen.  In these women, the researchers investigated the effects of polymorphisms (genetic differences) in CYP2D6 and single nucleotide polymorphisms (SNPs) of DT-1, DT2, and DT-3 on recurrence-free survival.