Impacts of Cytochrome P450 2D6 (CYP2D6) Genetic Polymorphism in Tamoxifen Therapy for Breast Cancer.

Tamoxifen (TMX) is the main drug used both in pre and postmenopausal women as adjuvant treatment for hormone receptor-positive breast cancer. An important barrier to the use of TMX is the development of drug resistance caused by molecular processes related to genetic and epigenetic mechanisms, such as the actions of cytochrome P450 2D6 () polymorphisms and of its metabolites. The present study aimed to review recent findings related to the impact of polymorphisms and how they can affect the results of TMX in breast cancer treatment.