Is a Dexamethasone-Sparing Strategy Capable of Preventing Acute and Delayed Emesis Caused by Combined Doxorubicin and Paclitaxel for Breast Cancer? Analysis of a Phase II Trial

Objective: The effectiveness of palonosetron without delayed dexamethasone dosing against emesis was investigated in patients scheduled to receive the corticosteroid-containing combination of doxorubicin and paclitaxel (AT) for 3 cycles. Methods: Chemo-naïve women with breast cancer receiving doxorubicin (60 mg/m2) and paclitaxel (200 mg/m2) were eligible. Patients received palonosetron 0.25 mg intravenously before chemotherapy, however, all patients also received a premedication consisting of prednisone (25 mg orally the evening before therapy) and hydrocortisone (250 mg intravenously just before paclitaxel). The primary end point was complete control (CC; no vomiting, no rescue anti-emetics, and no more than mild nausea) during the overall phase (days 1-5) following cycle 1. Results: Seventy-six patients were enrolled and evaluable (median age 50 years). Fifty-six patients (74%; 95% CI 62-83%) achieved overall CC. Acute (day 1) and delayed (days 2-5) CC rates were 78 and 74%, respectively. No vomiting rates for the acute, delayed and overall phases were 85, 85 and 83%, respectively. An exploratory analysis showed only a small decrease in the probability of achieving CC between cycle 1 (74%) and cycle 3 (66%). Conclusion: The dexamethasone-sparing strategy prevented emesis in more than 70% of breast cancer patients receiving their initial cycle of AT chemotherapy.