Could the Perioperative Use of Opioids Influence Cancer Outcomes After Surgery? A Scoping Review Protocol

Abstract BackgroundOpioids are commonly used for the treatment of cancer and non-cancer pain, and during and after general anesthesia. Because preclinical studies underlined a potential opioid-mediated immunosuppression, it was postulated that the perioperative administration of opioids could influence cancer outcomes after surgery. Nevertheless, clinical data have been extrapolated mainly from retrospective analyses. Thus, the precise link between perioperative opioids use and cancer recurrence/metastasis or cancer-related mortality/morbidity remains unresolved.Methods/designThis scoping review is planned following the Joanna Briggs Institute recommendations. The authors will conduct a literature review through the PRISMA statement using PubMed and EMBASE databases; the Grey literature will be explored using Google Scholar, Conference Proceedings Citation Index (via Web of Science) and Open Grey. The search strategy will be limited to articles published in the English language and to human studies. The database searches are planned from the inception to November 2020. Two reviewers will independently screen titles and abstracts, followed by a full-text screening of potentially relevant articles with standardized data extraction. Any disagreement for the inclusion between the two reviewers will be discussed with a third reviewer.DiscussionThe review aim to map the available literature focusing on a possible association between the perioperative opioids use and cancer outcomes in patients undergoing surgery. The proposed approach will allow to identify and analyze the knowledge gap in the field and, serving as a prerequisite for future research including systematic reviews and clinical studies.Scoping review registrationOpen Science Framework https://osf.io/ng57c/ DOI 10.17605/OSF.IO/NG57C