A randomized phase III study evaluating dexamethasone-based mouthwash to prevent chemotherapy-induced stomatitis in patients with breast cancer

Stomatitis, which is a common side effect of chemotherapy, currently lacks a standardized approach for its prevention. Therefore, this multicenter, randomized, open-label, controlled phase III trial aims to assess the efficacy and safety of a dexamethasone-based mouthwash for preventing chemotherapy-induced stomatitis in patients with early breast cancer. We will randomly assign 230 patients with early breast cancer scheduled to receive chemotherapy in a 1:1 ratio to either the dexamethasone-based mouthwash group (10 ml, 0.1 mg/ml; swish for 2 min and spit 4 times daily for 8 weeks) or the mouthwash-with-tap-water group. The incidence of stomatitis, measured using electronic patient-reported outcomes, is the primary endpoint.