BackgroundOral mucositis is a frequent and severe adverse event in patients undergoing chemoradiotherapy for head and neck cancers, especially grade 3 or 4 mucositis. Occurrence may result in drop-out from treatment, thereby reducing survival. We aimed to clarify the effectiveness and safety of rebamipide mouthwash for oral mucositis in patients with head and neck cancer receiving treatment.MethodsWe carried out a systematic review and meta-analysis of patients with head and neck cancer who were treated with rebamipide mouthwash. We searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL), and the World Health Organization (WHO) International Clinical Trial Registry Platform. The primary outcome was the incidence of severe oral mucositis, and secondary outcomes were time from treatment start to onset of oral mucositis, the response rate of radiotherapy, and any adverse events.ResultsWe included three studies comparing rebamipide versus placebo, all of which evaluating chemoradiotherapy induced oral mucositis. The chemotherapeutic agent was docetaxel in one study and cisplatin in the remaining two. Radiotherapy in each study consisted of 3D-conformal radiation therapy, intensity modulated radiation therapy and conventional radiation therapy, respectively. The calculated odds ratio was 0.29 [95% confidence interval (CI): 0.15 to 0.55], showing a positive association in the three studies between the incidence of grade 3–4 oral mucositis and chemotherapy for head and neck cancer. One study reported an onset of oral mucositis and the time to onset was 14.6 ± 6.4 days for the rebamipide group and 11.2 ± 4.4 days for placebo. One study reported a complete response of 8.3% for placebo and 16.7% for the rebamipide the group, and the partial response was 91.7 and 75.0%, respectively. Adverse events were reported in two studies to be 6.1 and 11.6% for placebo, and 19.4 and 26.0% in the rebamipide group, respectively.ConclusionsRebamipide mouthwash is effective in the prevention of severe mucositis and stomatitis. However, evaluation of adverse events in observational studies are needed.