A PRISMA-guided systematic review of pharmacogenetic anticancer clinical trials registered on clinicaltrials.gov.

Pharmacogenetics plays an increasingly important role in oncology by supporting individualized therapeutic strategies based on patient genetic profiles. ClinicalTrials.gov provides a valuable platform for evaluating global trends in pharmacogenetic anticancer clinical trials. This systematic review aimed to evaluate pharmacogenetic-focused anticancer clinical trials registered on ClinicalTrials.gov and summarize trends in study design, cancer types, targeted biomarkers, therapeutic interventions, and geographic distribution. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-guided systematic review was conducted using ClinicalTrials.gov. Searches were performed between July 24 and July 26, 2025, using the terms "anticancer" AND "pharmacogenetics." Eligible studies included interventional and observational oncology trials containing a pharmacogenetic component. Data extracted included trial phase, study status, cancer type, pharmacogenetic targets, therapeutic interventions, sponsor type, and country of origin. A total of 12 trials met the inclusion criteria. Most studies were interventional (91.7%) and predominantly early-phase trials. Frequently investigated biomarkers included CYP450 enzymes, TPMT, UGT1A1, BRCA1/2, and Epidermal Growth Factor Receptor. Breast cancer, colorectal cancer, and non-small cell lung cancer were among the most commonly investigated malignancies. Most trials originated from the United States and Europe, while limited representation from low- and middle-income countries was observed. Increasing incorporation of multi-gene panels and biomarker-guided therapeutic strategies was identified. Pharmacogenetic approaches are increasingly being incorporated into anticancer clinical trials and may contribute to the advancement of precision oncology. However, broader global representation, larger late-phase trials, and more standardized biomarker integration remain necessary to support wider clinical implementation.