ABSTRACT
Variability in toxicity and response to the same dose of medication may occur among cancer patients and contribute to the unpredictability of clinical outcomes. In addition to the potential importance of clinical factors in determining drug effects, inherited differences in drug metabolism are likely to have a profound effect on treatment outcomes. Pharmacogenetics, the study of the contribution of genetic variation to the interindividual differences, may allow for the individualization of therapy and improved prediction of pharmacodynamic events, including host toxicity and treatment efficacy. The taxanes paclitaxel and docetaxel have an important role in the treatment of early-stage breast cancer as well as metastatic disease. Although methotrexate has been widely used to treat many cancers, including leukemia, lymphomas, and breast cancer, as well as some autoimmune diseases, there has been limited research to evaluate the effects of genetic variability on treatment outcomes.
