Intravenous iron versus oral iron or observation for gastrointestinal malignancies: a systematic review.

Background Anemia is a common condition in patients with gastrointestinal cancer. Current evidence for the use of intravenous compared with oral iron in this clinical setting is inconclusive. A systematic review was performed to assess evidence on the efficacy of intravenous iron versus oral/observation in gastrointestinal cancer patients in the preoperative and postoperative setting. Materials and methods We searched Medline and Embase from inception until December 2017 with no language restrictions. Outcomes included hemoglobin response, red blood cell transfusion, and adverse events. Screening, data abstraction, and risk of bias appraisal were performed by two independent reviewers. The risk of bias was assessed using the Cochrane tools for randomized and nonrandomized studies. Results A total of 10 studies (three randomized-controlled trials and seven nonrandomized studies) were included. Of the six preoperative studies, five reported that hemoglobin was significantly higher in the intravenous group compared with oral iron/observation. Among the four postoperative studies, three studies suggested that hemoglobin was significantly higher in the intravenous group compared with oral iron/observation. The overall risk of bias for all randomized-controlled trials was low. Quality assessments for nonrandomized studies found the risk of bias to be moderate for four studies and critical for three studies. Conclusion Despite the limitations of the current body of evidence, there is a likely benefit to the use of intravenous iron in this patient population. Further confirmatory research is needed to draw empirical conclusions.