Patients' genotype could reduce effectiveness of tamoxifen

摘要

Flockhart's team focused on a tamoxifen metabolite, endoxifen, which is thoughttoblockoestrogenreceptorson breast cancer cells. The CYP2D6 enzyme converts endoxifen from another intermediate, N-desmethyltamoxifen (NDM). Researchers investigated the link between tamoxifen metabolism and CYP2D6 genotype in a prospective trial of 158 women undergoing tamoxifen treatment, who were grouped by phenotype on the basis of blood plasma concentrations of tamoxifen, endoxifen, and NDM. DNA samples were also tested for the presence of 33 different CYP2D6 alleles.