Individualized dosing strategies in breast cancer chemotherapy: Evidence for therapeutic drug monitoring-guided docetaxel treatment.

[BACKGROUND] Docetaxel is a first-line chemotherapy drug for breast cancer and is traditionally dosed based on body surface area (BSA). However, this method often leads to significant inter-patient variability and a high incidence of adverse drug reactions (ADRs). Therapeutic drug monitoring (TDM) offers a personalized dosing approach that may improve drug safety and efficacy. This study aimed to evaluate the clinical and pharmacoeconomic benefits of TDM-guided dosing compared to traditional BSA-based dosing in breast cancer patients receiving docetaxel-based chemotherapy.

[METHODS] A randomized controlled study was conducted at the Department of Breast Surgery, IPMCH, from October 2022 to July 2024. A total of 208 breast cancer patients were enrolled and randomly assigned to two groups: the BSA group (n = 104) and the TDM-guided pharmacokinetics (PK) group (n = 104). Adverse drug reactions-including hematological, gastrointestinal, skin, neurotoxic, and cardiotoxic events-were monitored and compared between groups. Liver function markers (ALT, AST, ALP) and pharmacoeconomic data (treatment-related costs) were also assessed. Statistical analyses included univariate and interaction models to evaluate the impact of dosing strategy on ADRs and costs.

[RESULTS] Patients in the TDM-guided PK group exhibited significantly lower levels of ALT, AST, and ALP, indicating reduced hepatic toxicity. Gastrointestinal ADRs-including nausea, diarrhea, and constipation-were less frequent and less severe in the PK group compared to the BSA group. Overall, the incidence and severity of ADRs were markedly reduced in the PK group. Pharmacoeconomic analysis demonstrated consistently lower treatment-related costs in the PK group. Both univariate and interaction analyses confirmed the clinical and economic benefits of TDM-guided dosing.

[CONCLUSION] TDM-guided docetaxel dosing significantly reduced ADRs and improved cost efficiency in breast cancer chemotherapy. These findings support the implementation of TDM as a superior strategy to traditional BSA-based dosing, with potential to enhance both patient safety and healthcare resource utilization.