Efficacy and safety of preoperative intravenous iron versus standard care in colorectal cancer patients with iron deficiency anemia: a systematic review and meta-analysis

Background: Anemia, particularly iron deficiency (ID) anemia, is common in colorectal cancer (CRC) patients, affecting up to 58% of individuals. This study aimed to compare the effectiveness and safety of preoperative intravenous iron (IVI) with standard care (no iron or oral iron) in CRC patients with ID anemia. Methods: A systematic search across multiple databases identified studies comparing IVI versus no iron or oral iron in CRC patients with ID anemia. Pooled data were analyzed for changes in hemoglobin (Hb) levels, need for red blood cell transfusions (RBCT), overall mean number of transfused RBC units, overall survival (OS), disease-free survival (DFS), and complications. Results: The authors analyzed data from 11 studies with 2024 patients and found that IVI significantly increased Hb levels at crucial time points: preoperative (MD=1.17, 95% CI [0.95-1.40], P<0.01), postoperative day one (MD=1.32, 95% CI [0.89-1.76], P<0.01), hospital discharge (MD=0.76, 95% CI [0.28-1.24], P=0.002), and 30 days postoperative (MD=1.57, 95% CI [1.27-1.87], P<0.01). IVI significantly decreased the overall need for RBCT, particularly in the postoperative period (RR=0.69, 95% CI [0.52-0.92], P=0.01). It also reduced the mean number of transfused RBC units, total complications, and wound dehiscence. However, there were no significant differences in total death, hospital stay, infections, paralytic ileus, OS, or DFS. Conclusion: Preoperative IVI significantly increased Hb levels at critical time points and markedly reduced the overall need for RBCT, complications, and wound dehiscence. To further validate these findings and ensure robust conclusions, more well-designed randomized controlled trials are warranted.