Prophylaxis with oral zinc sulfate against radiation-induced oropharyngeal mucositis in patients with head and neck cancer: Protocol for a meta-analysis of randomized controlled trials

BACKGROUND: Oropharyngeal mucositis is considered to be an inevitable and the most troubling side effect of head and neck irradiation, which is caused by the direct toxic action of radiation on oral mucosa. Several randomized controlled trials (RCTs) have investigated the efficacy of zinc sulfate in prevention of radiation-induced oropharyngeal mucositis in patients with head and neck cancer. However, the definite conclusions have not been confirmed. The systematic review and meta-analysis will be performed to comprehensively evaluate whether zinc sulfate is effective in prevention of radiation-induced oropharyngeal mucositis in patients with head and neck cancer. METHODS: Relevant information will be identified by a comprehensive search of the following electronic databases: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and EBSCO from their inception to October 2018. Only RCTs which evaluated whether zinc sulfate is effective in prevention of radiation-induced oropharyngeal mucositis in patients with head and neck cancer will be eligible. Two independent investigators will be assigned to search literature, screen information, extract data, and appraise the risk of bias. The primary investigator will use Revman 5.3 software to perform all statistical analyses. We designed this systematic review and meta-analysis on June 5. 2018, and expect to complete the full-text on December 20, 2018. Results: This protocol has been registered with a unique identifier of CRD42018108533. We will submit this systematic review and meta-analysis to a peer-reviewed journal. Meanwhile, we also will dissemination the whole findings in topic-related conferences. Conclusion: As the first systematic review and metaanalysis, the present study will elucidate current evidence of the role of oral zinc for the prevention and treatment of radiation-induced oropharyngeal mucositis in the head and neck cancer.