Pharmacogenetics of tamoxifen in breast cancer patients of African descent: Lack of data

Tamoxifen, a selective estrogen receptor modulator, is used to treat hormone receptor-positive breast cancer. Tamoxifen acts as a prodrug, with its primary therapeutic effect mediated by its principal metabolite, endoxifen. However, tamoxifen has complex pharmacokinetics involving several drug-metabolizing enzymes and transporters influencing its disposition. Genes encoding enzymes involved in tamoxifen disposition exhibit genetic polymorphisms which vary widely across world populations. This review highlights the lack of data on tamoxifen pharmacogenetics among African populations. Gaps in data are described in this study with the purpose that future research can address this dearth of research on the pharmacogenetics of tamoxifen among African breast cancer patients. Initiatives such as the African Pharmacogenomics Network (APN) are crucial in promoting comprehensive pharmacogenetics studies to pinpoint important variants in pharmacogenes that could be used to reduce toxicity and improve efficacy.