Prevention of oral mucositis in patients undergoing cancer chemotherapy using betamethasone mouthwash: A multicenter randomized controlled trial protocol

Background Oral mucositis is a frequent adverse effect of chemotherapy that significantly affects patients’ quality of life and treatment continuity. Despite its clinical relevance, effective preventive strategies remain limited. This study aims to compare the efficacy and safety of betamethasone mouthwash with those of sodium gualenate hydrate mouthwash for preventing chemotherapy-induced oral mucositis. Methods This Phase II, multicenter, open-label, randomized controlled trial aims to enroll 296 adult patients (≥18 years) undergoing chemotherapy for solid tumors (excluding head and neck and hematological cancers). Participants will be randomized 1:1 into two arms: a betamethasone mouthwash (intervention) group and a sodium gualenate hydrate mouthwash (control) group. The primary outcome is the prevention of Grade 1 oral mucositis, assessed using the Common Terminology Criteria for Adverse Events v3.0 and v5.0. Secondary outcomes include prevention of Grade 2–3 oral mucositis, the incidence of oral candidiasis, and chemotherapy completion rates. Data will be analyzed using Kaplan–Meier survival curves, log-rank tests, and Cox regression models. Expected Outcomes This study aims to establish betamethasone mouthwash as an effective preventive strategy for potentially enhancing the quality of life of patients with cancer. Trial registration This study was registered with the Japan Registry of Clinical Trials on September 20, 2024 (jRCTs071240060).