Characteristics of adverse drug reactions resulting in modifications of antineoplastic therapy plan in patients with breast cancer at a comprehensive cancer center

IntroductionAdherence to standard antineoplastic treatment is associated with improved response in breast cancer patients. However, treatment modifications may be necessary for patients who experience significant adverse drug reactions (ADRs). Limited data exist on the characteristics of ADRs that require such modifications. We aimed to evaluate significant ADRs associated with antineoplastic agents in breast cancer patients.MethodsA retrospective observational study was conducted at King Hussein Cancer Center, included significant ADRs experienced by breast cancer patients between January 2018 and December 2020. We recorded patients' characteristics, medications involved, the type of ADRs, and the required treatment modifications, including dose reduction, treatment delay, or discontinuation. Descriptive analysis was performed to report the results.ResultsDuring the study period, 597 significant ADRs were reported in 351 patients, with a mean age of 53 years (11.8 SD). Additionally, 65.5% of patients presented with locally advanced disease. Docetaxel (44%) was the most common agent associated with ADRs. Hematologic and gastrointestinal ADRs were the most frequently reported, accounting for 38.0% and 18.0% of ADRs, respectively. Of the reported ADRs, 61.0%, 26.0%, 13.0% resulted in treatment dose reduction, delay and discontinuation of subsequent cycle, respectively.ConclusionIn this study evaluating a relatively large number of significant ADRs, docetaxel was the most common antineoplastic agent requiring treatment modifications. The most frequent modification was dose reduction. Future studies should be directed to identify measures that may reduce the incidence and severity of the ADRs.