Steroid-Sparing De-escalation of Antiemetic Prophylaxis After Initial Control with a Four-Drug Regimen in Anthracycline/Cyclophosphamide Chemotherapy

Abstract Purpose The 2023 Japanese provide a weak recommendation for limiting dexamethasone administration to a single day in anthracycline/cyclophosphamide (AC) regimens. Since April 2022, our institution has been using a four-drug regimen, including olanzapine. To reduce steroid exposure, we implemented a steroid-sparing strategy from the second cycle onward in patients with adequate first-cycle control. This study aimed to evaluate the feasibility and clinical outcomes of this approach. Methods This single-center retrospective study included hospitalized patients with breast cancer who received AC regimens between April 2022 and April 2024. The endpoints included the complete response (CR) rate during the first cycle and incidence of nausea, vomiting, appetite loss, and other adverse events after dexamethasone omission. In patients with no or mild first-cycle nausea, de-escalation was proposed after explanation, and dexamethasone was reduced or omitted from the second cycle upon agreement. Results Forty patients were analyzed, and the first-cycle CR rate was 72.5%. Among the 13 patients who underwent steroid omission, the CR rate decreased from 69.2% to 46.2%. Nausea increased from 53.8% to 76.9% and vomiting from 0% to 23.1%. Most worsening events were low grade, and no severe complications were observed. Conclusion Early steroid omission was temporally associated with the deterioration of gastrointestinal symptoms in a substantial proportion of patients. These findings do not conclusively negate steroid-sparing strategies in AC regimens, but suggest that de-escalation should be cautiously implemented, with careful patient selection and attention to timing. Prospective studies are warranted to clarify the optimal candidates and refine the de-escalation approaches.